WO2025228342A1 - Communication method and apparatus - Google Patents

Abstract

The present application relates to the technical field of communications, and discloses a communication method and apparatus. In the present application, for handover of a second node connected to a first node in a high-mobility network system, handover information is used to instruct the first node to hand over a first functional unit of the first node and a second functional unit of the first node from the second node to a third node, or conditional handover information is used to instruct the first node to carry out conditional handover on the first functional unit of the first node and the second functional unit of the first node, thereby realizing access handover under the high-mobility network system, and thus being conducive to reducing signaling overhead and resource overhead, shortening mobility interruption time, improving handover efficiency, and realizing efficient mobility management. For reselection of a second node where a first node in a connected state of a high-mobility network system camps, by means of node camping reselection information, the first node is assisted in reselecting the second node, thereby realizing node camping reselection under the high-mobility network system.

Description

Communication methods and devices

This application claims priority to Chinese Patent Application No. 202410537790.0, filed on April 29, 2024, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference.

Technical Field

This application relates to the field of communication technology, and in particular to a communication method and apparatus.

Background Technology

Currently, mobility management in terrestrial network (TN) systems includes cell handover in connected mode, cell reselection in idle/inactive mode, registration updates, and tracking area updates. In TN systems, cell handover or cell reselection is typically required due to the movement of terminal devices, while nodes providing access functions (such as network equipment) are generally considered to be stationary or infrequently moving. For example, the movement of network equipment is not considered during cell handover and cell reselection.

However, for mobility management in frequent mobility network systems, the nodes providing access functions in these systems are characterized by frequent movement. When frequent mobility network systems directly reuse mobility management from the TN system, this may lead to problems such as large signaling overhead and mobility interruption latency, resulting in handover/reselection failures and very inefficient mobility management. Therefore, how to perform efficient mobility management in frequent mobility network systems requires further research.

Summary of the Invention

This application provides a communication method and apparatus to achieve efficient mobility management in a frequently moving network system.

In a first aspect, a communication method according to this application includes: a first node receiving switching information from a second node, the switching information being used to instruct a first functional unit and a second functional unit of the first node to switch from the second node to a third node; and the first node switching the first functional unit and the second functional unit of the first node from the second node to the third node according to the switching information.

The first node is used to provide backhaul access function, the second and third nodes are used to provide core network connection function, the first functional unit of the first node is used to provide backhaul function, and the second functional unit of the first node is used to provide access function.

As can be seen, in a frequently moving network system, the second node informs the first node via handover information to switch the first functional unit and the second functional unit of the first node from the second node to the third node. In this way, by switching the first and second functional units of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed using the same handover procedure. This helps to reduce signaling overhead, reduce resource consumption, shorten mobility interruption latency, and improve handover efficiency, thus achieving efficient mobility management.

In some possible examples, the handover information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information; the first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure backhaul radio link control; the fifth information is used to configure the F1 application protocol; and the sixth information is used to configure the second functional unit of the first node.

It is evident that the second node will inform the first node of at least one of the following information: the backhaul adaptation protocol address reserved by the third node for the first functional unit of the first node and the second functional unit of the first node, the transmission path from the second node to the third node, the resources on the transmission path, the backhaul radio link control configuration, the F1 application protocol configuration, or the configuration of the second functional unit of the first node, so that the first node can perform access switching based on this information and ensure successful access switching.

In some possible examples, the sixth piece of information includes at least one of the following: a list of physical cell identifiers, resource configuration information, tracking area identifier configuration information, or tracking area code configuration information.

As can be seen, the second node will inform the first node of at least one of the physical cell identifier list, resources, tracking area identifier or tracking area code configured by the third node, thereby ensuring that the first node's access handover is successful.

In some possible examples, if the first functional unit and the second functional unit of the first node switch from the second node to the third node, then the terminal device or sub-node served by the first node switches from the second node to the fourth node, whereby the fourth node is used to provide core network connectivity or to provide backhaul access functionality.

It can be seen that when the access switching of the terminal device or sub-node served by the first node is involved, if the terminal device or sub-node served by the first node does not move with the first node, and the first functional unit and the second functional unit of the first node switch from the second node to the third node, then the second node can trigger the terminal device or sub-node served by the first node to switch from the second node to the fourth node.

In some possible examples, before receiving handover information from the second node, the first node sends capability indication information to the second node. The capability indication information is used to indicate whether the first node supports or does not support the access handover of the first node's first functional unit and/or the first node's second functional unit.

As can be seen, before the second node determines whether an access handover to the first node is necessary, the first node can report or broadcast its node capabilities to the second node. These capabilities indicate whether the first node supports access handover for its first functional unit and/or second functional unit. Specifically, the first node may support access handover for both the first and second functional units simultaneously, or it may support only the first functional unit, or only the second functional unit, or it may not support either. Thus, the second node will only determine whether an access handover to the first node is necessary if the first node supports access handover for both the first and/or second functional units.

Secondly, a communication method according to this application includes: a second node sending handover information to a first node, the handover information being used to instruct the first functional unit and the second functional unit of the first node to switch from the second node to a third node. The first node is used to provide backhaul access functionality, the second and third nodes are used to provide core network connectivity functionality, the first functional unit of the first node is used to provide backhaul functionality, and the second functional unit of the first node is used to provide access functionality.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node informs the first node via handover information to switch the first functional unit and the second functional unit of the first node from the second node to the third node. In this way, by switching the first and second functional units of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed using the same handover procedure. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thus achieving efficient mobility management.

In some possible examples, before sending the handover information to the first node, the second node sends a handover request information to the third node, which requests that the first functional unit and the second functional unit of the first node be switched from the second node to the third node; the second node receives a handover response information from the third node, which indicates that the first functional unit and the second functional unit of the first node are permitted to switch from the second node to the third node.

As can be seen, since the second node provides access services to the first node, it can determine whether an access handover to the first node is necessary. For example, the second node can make a handover decision based on measurement reports reported by the first node. When the second node decides that the first functional unit and the second functional unit of the first node need to be switched from the second node to the third node, the second node can request the third node to switch the first functional unit and the second functional unit of the first node from the second node to the third node through a handover request message, so that the third node can perform handover admission control.

After receiving the handover request information, the third node will perform handover admission control to decide whether to allow the first functional unit and the second functional unit of the first node to switch from the second node to the third node, and inform the second node through the handover response information to allow the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

In some possible examples, before sending the handover information to the first node, the second node receives capability indication information from the first node, which is used to indicate whether the first node supports or does not support the first functional unit and/or the second functional unit of the first node for access handover.

As can be seen, before the second node determines whether an access handover to the first node is necessary, the first node can report or broadcast its node capabilities to the second node. These capabilities indicate whether the first node supports access handover for its first functional unit and/or second functional unit. Specifically, the first node may support access handover for both the first and second functional units simultaneously, or it may support only the first functional unit, or only the second functional unit, or it may not support either. Thus, the second node will only determine whether an access handover to the first node is necessary if the first node supports access handover for both the first and/or second functional units.

In some possible examples, the switching request information includes first identification information and second identification information; the first identification information is used to indicate the identifier of the first functional unit of the first node, and the second identification information is used to indicate the identifier of the second functional unit of the first node.

As can be seen, the first identification information and the second identification information are used to indicate the first functional unit and the second functional unit of the first node, so that the third node can confirm that the switching request is for the first functional unit and the second functional unit of the first node.

In some possible examples, the handover request information may further include at least one of the following: third identification information, first context information, fourth identification information, or second context information; the third identification information is used to indicate the identifier of the terminal device served by the first node; the first context information is used to indicate the context of the terminal device served by the first node; the fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node; the second context information is used to indicate the context of the child node served by the first node.

As can be seen, if a terminal device served by the first node requests to switch from the second node to the third node, the switch request information includes third identification information and/or first context information. Thus, the third identification information and/or first context information are used to inform the third node of the terminal device's request to switch from the second node to the third node, enabling the third node to perform relevant access control.

If a child node served by the first node requests to switch from the second node to the third node, the switch request information includes fourth identification information and/or second context information. In this way, the fourth identification information and/or second context information inform the third node of the child node's request to switch from the second node to the third node, so that the third node can perform the relevant admission control.

In some possible examples, the handover response information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information; the first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure backhaul radio link control; the fifth information is used to configure the F1 application protocol; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, in order to ensure that the first functional unit and the second functional unit of the first node switch from the second node to the third node during the handover admission control in the third node, the third node needs to reserve at least one of the following information for the first functional unit and the second functional unit of the first node to perform the access handover: backhaul adaptation protocol address, transmission path from the second node to the third node, resources on the transmission path, backhaul radio link control configuration, F1 application protocol configuration, or configuration of the second functional unit of the first node. This information is used by the first node to perform the access handover and ensure that the access handover is successful.

In some possible examples, the sixth piece of information includes at least one of the following: a list of physical cell identifiers, resource configuration information, tracking area identifier configuration information, or tracking area code configuration information.

It is evident that the third node needs to configure at least one of the following for the second functional unit of the first node during the handover admission control process: physical cell identifier list, resources, tracking area identifier, or tracking area code, in order to ensure that the first node can successfully perform the access handover.

Thirdly, a communication method according to this application includes: a third node receiving a handover request message from a second node, the handover request message being used to request the first functional unit and the second functional unit of the first node to be switched from the second node to the third node; the third node sending a handover response message to the second node, the handover response message being used to indicate permission for the first functional unit and the second functional unit of the first node to be switched from the second node to the third node.

As can be seen, for the first node, second node, and third node in a frequently moving network system, the second node in this embodiment can determine whether an access handover to the first node is required. When the second node decides that the first functional unit and the second functional unit of the first node need to be switched from the second node to the third node, the second node requests the third node to switch the first functional unit and the second functional unit of the first node from the second node to the third node through a handover request message, so that the third node can perform handover admission control.

In this way, by switching from the second node to the third node through the first functional unit and the second functional unit of the first node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed together using the same handover process. This helps to reduce signaling overhead, reduce resource overhead, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

Fourthly, a communication method according to this application includes: a first node receiving condition switching information from a second node, the condition switching information being used to configure a first functional unit of the first node and a second functional unit of the first node to perform condition switching.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node to perform conditional handover of its first and second functional units through conditional handover information. In this way, by performing conditional handover of the first and second functional units of the first node, the conditional handover of the first and second functional units of the first node is executed together using the same handover process. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

In some possible examples, the conditional handover information includes at least one of the following: handover condition information, first information, second information, third information, fourth information, fifth information, or sixth information; the handover condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node, and the third node is used to provide core network connectivity functions; the first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure backhaul radio link control; the fifth information is used to configure the F1 application protocol; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, the second node will inform the first node of at least one of the following information: the switching conditions configured by the third node, the backhaul adaptation protocol address required for the access switching of the first functional unit and the second functional unit of the first node, the transmission path from the second node to the third node, the resources on the transmission path, the backhaul radio link control configuration, the F1 application protocol configuration, or the configuration of the second functional unit of the first node, so that the first node can perform access switching based on this information and ensure successful access switching.

In some possible examples, the conditions indicated by the switching condition information include: the distance between the reference position of the second node is greater than a first distance threshold, and/or the distance between the reference position of the third node is less than a second distance threshold; and/or, the backhaul radio link control validity time of at least one relay node on the transmission path to the second node is less than a validity time threshold.

As can be seen, if the switching condition information indicates that the distance between the first node and the reference position of the third node is less than the second distance threshold, then after the first node obtains the switching condition information, the first node can determine whether the distance between its own position and the reference position of the third node is less than the second distance threshold, in order to determine whether the conditions indicated by the switching condition information are met. When the conditions are met, the first node can execute the switching of its first functional unit and second functional unit from the second node to the third node.

If the handover condition information indicates that at least one relay node on the transmission path to the second node has a BH-RLC validity period less than a validity period threshold, then after the first node obtains the handover condition information, the first node can determine whether there is a relay node on the transmission path from the first node to the second node whose BH-RLC validity period is less than the validity period threshold, in order to determine whether the conditions indicated by the handover condition information are met. When the conditions are met, the first node can execute the handover of its first functional unit and second functional unit from the second node to the third node.

In some possible examples, after receiving a conditional switching command from the second node, the method further includes: if the conditions indicated by the switching condition information are met, the first node switches the first functional unit and the second functional unit of the first node from the second node to the third node.

In some possible examples, before receiving condition switching information from the second node, the method further includes: the first node sending capability indication information to the second node, the capability indication information being used to indicate whether the first node supports or does not support condition switching of the first node's first functional unit and/or the first node's second functional unit.

As can be seen, before the second node determines whether a conditional switch is needed for the first node, the first node can report or broadcast its node capabilities to the second node. These capabilities indicate whether the first node supports conditional switching of its first functional unit and/or second functional unit. Specifically, the first node may support conditional switching of both the first and second functional units simultaneously, or it may support only the first functional unit, or only the second functional unit, or it may not support either. Thus, the second node will only determine whether a conditional switch is needed for the first node if the first node supports conditional switching of both the first and/or second functional units.

Fifthly, a communication method according to this application includes: a second node sending condition switching information to a first node, the condition switching information being used to configure a first functional unit of the first node and a second functional unit of the first node to perform condition switching.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node to perform conditional handover of its first and second functional units through conditional handover information. In this way, by performing conditional handover of the first and second functional units of the first node, the conditional handover of the first and second functional units of the first node is executed together using the same handover process. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

In some possible examples, before sending condition switching information to the first node, the method further includes: the second node sending condition switching request information to the third node, the condition switching request information being used to request the first functional unit and the second functional unit of the first node to perform condition switching; the second node receiving condition switching response information from the third node, the condition switching response information being used to instruct permission for the first functional unit and the second functional unit of the first node to perform condition switching.

As can be seen, since the second node provides access services to the first node, it can determine whether a conditional handover of the first node is necessary. For example, the second node can make a conditional handover decision based on measurement reports reported by the first node. When the second node decides that a conditional handover of the first node is necessary, it can request the third node to perform a conditional handover between the first node's first functional unit and its second functional unit via a conditional handover request message, so that the third node can execute conditional handover access control.

After receiving the conditional switching request information, the third node will perform conditional switching admission control to decide whether to allow the first functional unit and the second functional unit of the first node to perform conditional switching, and inform the second node to allow the first functional unit and the second functional unit of the first node to perform conditional switching through conditional switching response information.

In some possible examples, before sending condition switching information to the first node, the method further includes: the second node receiving capability indication information from the first node, the capability indication information being used to indicate whether the first node supports or does not support condition switching of the first node's first functional unit and/or the first node's second functional unit.

As can be seen, before the second node determines whether a conditional switch is needed for the first node, the first node can report or broadcast its node capabilities to the second node. These capabilities indicate whether the first node supports conditional switching of its first functional unit and/or second functional unit. Specifically, the first node may support conditional switching of both the first and second functional units simultaneously, or it may support only the first functional unit, or only the second functional unit, or it may not support either. Thus, the second node will only determine whether a conditional switch is needed for the first node if the first node supports conditional switching of both the first and/or second functional units.

In some possible examples, the condition switching request information includes first identification information and second identification information; the first identification information is used to indicate the identifier of the first functional unit of the first node, and the second identification information is used to indicate the identifier of the second functional unit of the first node.

As can be seen, the first identification information and the second identification information are used to indicate the first functional unit and the second functional unit of the first node, so that the third node can confirm that the condition switching request is made for the first functional unit and the second functional unit of the first node.

In some possible examples, the condition switching request information may further include at least one of the following: third identification information, first context information, fourth identification information, or second context information; the third identification information is used to indicate the identifier of the terminal device served by the first node; the first context information is used to indicate the context of the terminal device served by the first node; the fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node; the second context information is used to indicate the context of the child node served by the first node.

As can be seen, if the terminal device served by the first node needs to configure conditional switching, the conditional switching request information includes third identification information and/or first context information. In this way, the third identification information and/or first context information are used to inform the third node of the conditional switching configuration of the terminal device.

If a child node served by the first node needs to be configured with condition switching, the condition switching request information includes fourth identification information and/or second context information. In this way, the fourth identification information and/or second context information are used to inform the third node about configuring condition switching for that child node.

In some possible examples, the conditional handover response information includes at least one of the following: handover condition information, first information, second information, third information, fourth information, fifth information, or sixth information; the handover condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node; the first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure backhaul radio link control; the fifth information is used to configure the F1 application protocol; or, the sixth information is used to configure the second functional unit of the first node.

As can be seen, in the conditional handover admission control performed by the third node, in order to ensure that the first functional unit and the second functional unit of the first node switch from the second node to the third node through conditional handover, the third node needs to configure at least one of the following information: the conditions that the first functional unit and the second functional unit of the first node need to meet when switching from the second node to the third node; the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to perform access handover; the transmission path from the second node to the third node; the resources on the transmission path; the backhaul radio link control configuration; the F1 application protocol configuration; or the configuration of the second functional unit of the first node. This information is used by the first node to perform conditional handover and ensure that the conditional handover is successful.

In some possible examples, the conditions indicated by the switching condition information include: the distance between the reference position of the second node is greater than a first distance threshold, and/or the distance between the reference position of the third node is less than a second distance threshold; or, the backhaul radio link control validity time of at least one relay node on the transmission path to the second node is less than a validity time threshold.

As can be seen, if the switching condition information indicates that the distance between the first node and the reference position of the third node is less than the second distance threshold, then after the first node obtains the switching condition information, the first node can determine whether the distance between its own position and the reference position of the third node is less than the second distance threshold, in order to determine whether the conditions indicated by the switching condition information are met. When the conditions are met, the first node can execute the switching of its first functional unit and second functional unit from the second node to the third node.

If the handover condition information indicates that at least one relay node on the transmission path to the second node has a BH-RLC validity period less than a validity period threshold, then after the first node obtains the handover condition information, the first node can determine whether there is a relay node on the transmission path from the first node to the second node whose BH-RLC validity period is less than the validity period threshold, in order to determine whether the conditions indicated by the handover condition information are met. When the conditions are met, the first node can execute the handover of its first functional unit and second functional unit from the second node to the third node.

A sixth aspect is a communication method according to this application, comprising: a third node receiving condition switching request information from a second node, the condition switching request information being used to request a first functional unit of a first node and a second functional unit of the first node to perform condition switching; the third node sending condition switching response information to the second node, the condition switching response information being used to instruct permission for the first functional unit of the first node and the second functional unit of the first node to perform condition switching.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment can determine whether a conditional handover of the first node is necessary. When the second node decides that a conditional handover of the first node's first and second functional units is required, the second node requests the third node to perform the conditional handover of the first node's first and second functional units through a conditional handover request message, so that the third node can execute conditional handover admission control. In this way, by performing a conditional handover of the first node's first and second functional units, the conditional handover of the first node's first and second functional units can be executed together using the same handover process, thereby reducing signaling overhead, reducing resource overhead, shortening mobility interruption time, and improving handover efficiency, achieving efficient mobility management.

A seventh aspect is a communication method according to this application, comprising: a first node receiving node reselection information, wherein the node reselection information is used to indicate at least one of the following: type information, coverage information, path information, or validity information; the type information is used to indicate the type of a second node, wherein the second node is used to provide core network connection functions; the coverage information is used to indicate the service coverage of the second node; the path information is used to indicate the transmission path of the second node; and the validity information is used to indicate the validity time of the F1 interface of the second node.

As can be seen, for the first node and the second node in a frequent mobility network system, when the first node camps on the second node, this embodiment assists the first node in reselecting the second node through node camp reselection information, thereby realizing node camp reselection in a frequent mobility network system and achieving efficient mobility management.

In some possible examples, after receiving the node residency reselection information, the method further includes: the first node sending the node residency reselection information to the child nodes or terminal devices served by the first node.

As can be seen, the child nodes or terminal devices served by the first node can reselect the second node based on the node reselection information.

In some possible examples, after receiving node relocation information, the method further includes: the first node determining a third node based on the node relocation information, the third node being used to provide core network connectivity functions.

As can be seen, when the first node resides on the second node, the first node determines the third node based on the node residency reselection information, and thus chooses to reside on the third node, thereby realizing node residency reselection.

In some possible examples, the coverage information includes the reference location and distance threshold of the second node, and/or the service validity time information and service validity time threshold of the second node; the coverage range of the second node is the range where the distance between the second node and its reference location is less than the distance threshold; or, the coverage information includes at least one of the following: satellite ephemeris information of the second node, service validity time information and service validity time threshold of the second node, coverage area information of the second node, or reference location information of the core network anchor point associated with the second node.

In some possible examples, the path information includes at least one of the following: first hop count information, second hop count information, first delay information, second delay information, first distance information, or second distance information; the first hop count information is used to indicate the number of hops on the transmission path from the node served by the second node to the second node; the second hop count information is used to indicate the number of hops on the transmission path from the terminal device served by the second node to the second node; the first delay information is used to indicate the transmission delay from the node served by the second node to the second node; the second delay information is used to indicate the transmission delay from the terminal device served by the second node to the second node; the first distance information is used to indicate the distance from the node served by the second node to the second node; the second distance information is used to indicate the distance from the terminal device served by the second node to the second node.

In some possible examples, valid information includes a valid time period or a timer; the valid time period is the valid time period of the F1 interface between the second node and the nodes served by the second node; the runtime of the timer is the valid duration of the F1 interface between the second node and the nodes served by the second node.

Eighthly, a communication method according to this application includes: a second node sending node reselection information, wherein the node reselection information is used to indicate at least one of the following: type information, coverage information, path information, or validity information; the type information is used to indicate the type of the second node, which is used to provide core network connection functions; the coverage information is used to indicate the service coverage of the second node; the path information is used to indicate the transmission path of the second node; and the validity information is used to indicate the validity period of the F1 interface of the second node.

As can be seen, for the first node, the second node, and the terminal device in a frequent mobility network system, when the first node camps on the second node, this embodiment assists the first node or the terminal device in reselecting the second node through node camping reselection information, thereby realizing node camping reselection in a frequent mobility network system and achieving efficient mobility management.

A ninth aspect is a communication method according to this application, comprising: a terminal device receiving node reselection information, wherein the node reselection information is used to indicate at least one of the following: type information, coverage information, path information, or validity information; the type information is used to indicate the type of a second node, the second node being used to provide core network connection functions; the coverage information is used to indicate the service coverage of the second node; the path information is used to indicate the transmission path of the second node; and the validity information is used to indicate the validity time of the F1 interface of the second node.

As can be seen, for the second node and terminal device in a frequent mobility network system, when the terminal device camps on the second node, this embodiment assists the terminal device in reselecting the second node through node camping reselection information, thereby realizing node camping reselection in a frequent mobility network system and achieving efficient mobility management.

In some possible examples, after receiving node relocation information, the method further includes: the terminal device determining a third node based on the node relocation information, or updating the packet data aggregation layer co-processor configuration information of the first node or the second node based on the node relocation information.

As can be seen, if the first node can continue to provide access services to the terminal device, the terminal device only needs to update the first node's packet data aggregation layer protocol layer configuration information according to the node relocation information, without needing to update the configuration information of other related layers.

The tenth aspect is a communication device according to this application, comprising a processing unit, which is configured to perform the steps in the methods designed in the first, fourth, or seventh aspects described above, or the processing unit is configured to perform the steps in the methods designed in the second, fifth, or eighth aspects described above, or the processing unit is configured to perform the steps in the methods designed in the third or sixth aspects described above, and the processing unit is configured to perform the steps in the methods designed in the ninth aspect described above.

Eleventhly, a communication device according to this application includes a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps in the methods designed in the first, fourth, or seventh aspects, or the processor executes the computer program or instructions to implement the steps in the methods designed in the second, fifth, or eighth aspects, or the processor executes the computer program or instructions to implement the steps in the methods designed in the third or sixth aspects.

Optionally, the communication device can be a node or a chip.

The twelfth aspect is a terminal device according to this application, including a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps in the method designed in the ninth aspect above.

Thirteenth aspect, a chip according to this application, includes a processor, wherein the processor performs the steps of the method designed in any one of the first to ninth aspects described above.

Optionally, the chip also includes a communication interface through which the processor executes the sending and/or receiving steps in the method designed in any one of the first to ninth aspects described above.

The fourteenth aspect is a chip module according to this application, including a chip, the chip including a processor, wherein the processor performs the steps of the method designed in any one of the first to ninth aspects described above.

Optionally, the chip module further includes a transceiver component, through which the processor performs the transmission step and/or reception step in any of the first to ninth aspects described above.

The fifteenth aspect is a computer-readable storage medium of this application, wherein it stores a computer program or instructions that, when executed, implement the steps of the method designed in any one of the first to ninth aspects described above. For example, the computer program or instructions are executed by a processor.

The sixteenth aspect is a computer program product of this application, comprising a computer program or instructions, wherein when the computer program or instructions are executed, the steps in the method designed in any one of the first to ninth aspects described above are performed. For example, the computer program or instructions are executed by a processor.

Attached Figure Description

Figure 1 is a schematic diagram of the architecture of a frequent mobility network system according to an embodiment of this application;

Figure 2 is a schematic diagram of the transparent transmission architecture of an NTN system according to an embodiment of this application;

Figure 3 is a schematic diagram of the regeneration architecture of an NTN system according to an embodiment of this application;

Figure 4 is a schematic diagram of the architecture of an NTN system according to an embodiment of this application;

Figure 5 is a schematic diagram of the architecture of another NTN system according to an embodiment of this application;

Figure 6 is a schematic diagram of the architecture of an IAB according to an embodiment of this application;

Figure 7 is a schematic diagram of the architecture of TN IAB mobility management according to an embodiment of this application;

Figure 8 is a schematic diagram of the mobility management architecture of another TN IAB according to an embodiment of this application;

Figures 9 to 12 are schematic diagrams of the architecture of another frequent mobility network system according to an embodiment of this application;

Figure 13 is a flowchart illustrating an access handover method in a frequent mobility network system according to an embodiment of this application;

Figure 14 is a flowchart illustrating another access handover method in a frequent mobile network system according to an embodiment of this application;

Figure 15 is a schematic diagram of the mobility management architecture of a frequent mobility network system according to an embodiment of this application;

Figure 16 is a flowchart illustrating an access handover method in a frequent mobile network system based on conditional handover according to an embodiment of this application.

Figure 17 is a flowchart illustrating another access handover method in a frequent mobile network system based on conditional handover according to an embodiment of this application.

Figures 18 to 20 are schematic flowcharts of a node relocation method in a frequent mobility network system according to an embodiment of this application;

Figures 21 to 24 are functional unit block diagrams of a communication device according to an embodiment of this application;

Figure 25 is a schematic diagram of the structure of a node according to an embodiment of this application;

Figure 26 is a schematic diagram of the structure of a terminal device according to an embodiment of this application.

Detailed Implementation

It should be understood that the terms "first," "second," etc., used in the embodiments of this application are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, software, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may also include steps or units not listed, or may also include other steps or units inherent to these processes, methods, products, or devices.

The term "embodiment" as used in the embodiments of this application means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

In the embodiments of this application, "at least one" or "at least one item" refers to one or more, and "multiple" refers to two or more.

In this application's embodiments, "and/or" describes the association relationship between related objects, indicating that three relationships can exist. For example, A and/or B can represent the following three cases: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character "/" indicates that the preceding and following related objects have an "or" relationship.

In the embodiments of this application, "at least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent the following seven cases: a, b, c, a and b, a and c, b and c, a, b, and c. Each of a, b, and c can be an element or a set containing one or more elements.

In the embodiments of this application, the terms "of," "corresponding (relevant)," "corresponding," "associated (related)," and "mapped" may sometimes be used interchangeably. It should be noted that when no distinction is emphasized, the concepts or meanings expressed are consistent.

In the embodiments of this application, "network" can be expressed as the same concept as "system," and a communication system is a communication network.

In this application, "connection" refers to various connection methods, such as direct connection or indirect connection, to achieve communication between devices, and is not specifically limited thereto.

The frequent mobility network system of this embodiment will be described in detail below.

A TN system refers to a communication network system composed of nodes and infrastructure located on the ground. These nodes may include terminal equipment and/or nodes that provide access functions. Typically, the locations of nodes providing access functions in a TN system are fixed or do not change frequently. For example, a node providing access functions in a TN system can be a network device, and the location of network devices is usually fixed.

However, unlike the TN system, this embodiment considers a frequently moving network system. A frequently moving network can be understood as a network in which the locations of nodes providing access functions move frequently.

For example, frequently moving network systems can include non-terrestrial networks (NTN) systems or converged TN and NTN network systems. In these systems, the nodes providing access functionality can be satellites, whose locations are frequently changing.

It should be noted that a frequent mobility network system may include terminal devices and nodes for providing access functionality. The nodes for providing access functionality can provide access to the terminal devices. For example, as shown in Figure 1, node 120 provides access services to terminal device 110. Furthermore, in a frequent mobility network system, the terminal device may move along with the nodes for providing access functionality, or it may not move with the nodes for providing access functionality.

In a frequently moving network system, the nodes used to provide access functionality may include type I nodes and/or type II nodes.

The first type of node can be used to provide backhaul access functionality and may include a first functional unit and a second functional unit. The first functional unit can be used to provide backhaul functionality, and the second functional unit can be used to provide access functionality.

For example, taking Integrated Access and Backhaul (IAB) as an example, the first type of node can be an IAB node (IAB-node). An IAB-node can provide both access and backhaul functions and may include an IAB-node-Mobile-Termination (IAB-node-MT) and an IAB-node-Distributed Unit (IAB-node-DU). The IAB-node-MT can act as a terminal device, providing backhaul functionality. The IAB-node-DU can act as a pole-mounted cell on the access side, providing coverage gaps and providing access to terminal devices or sub-IAB-node-MTs (or lower-level IAB-node-MTs). In this case, the first functional unit can be an IAB-node-MT, and the second functional unit can be an IAB-node-DU.

The second type of node can be used to provide core network connectivity and access functions, and may include a third functional unit and a fourth functional unit. The third functional unit can provide core network connectivity and access functions, and can provide access services to the second functional unit and/or the fourth functional unit. The fourth functional unit can provide access functions, and can provide access services to terminal devices and/or the first functional unit.

For example, taking IAB as an example, the second type of node can be an IAB host (IAB-donor). An IAB-donor can be viewed as a network device supporting additional IAB functions, capable of connecting to the core network via non-IAB methods. It can include an IAB host aggregation unit (IAB-donor-central unit, IAB-donor-CU) and an IAB host distribution unit (IAB-donor-DU). The IAB-donor-CU can provide access services to IAB-donor-DU and IAB-node-DU; the IAB-donor-DU can provide access services to terminal devices or IAB-node-MT. In this case, the third functional unit can be an IAB-donor-CU, and the fourth functional unit can be an IAB-donor-DU.

The following embodiment will provide a detailed description of the terminal device mentioned above.

A terminal device can be a device with transceiver capabilities, and can also be called a terminal, user equipment (UE), remote terminal equipment (relay UE), relay equipment (relay UE), access terminal equipment, user unit, user station, mobile station, mobile station, remote station, mobile device, user terminal equipment, smart terminal equipment, wireless communication equipment, user agent, or user device. It should be noted that a relay device is a terminal device capable of providing relay forwarding services to other terminal devices (including remote terminal devices).

For example, terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminal devices in industrial control, wireless terminal devices in autonomous driving, wireless terminal devices in remote medical care, wireless terminal devices in smart grids, wireless terminal devices in transportation safety, wireless terminal devices in smart cities, or wireless terminal devices in smart homes, etc.

For example, a terminal device can be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, in-vehicle device, wearable device, terminal device in next-generation communication systems (such as NR communication systems, 6G communication systems), or terminal device in a future public land mobile network (PLMN), etc., without specific limitations.

Furthermore, terminal devices can be deployed on land, including indoors or outdoors, handheld, wearable, or vehicle-mounted; on water (such as ships); or in the air (such as airplanes, balloons, and satellites). Terminal devices may include devices with wireless communication capabilities, such as chip systems, chips, or chip modules. For example, the chip system may include chips, and may also include other discrete devices. Terminal devices can be chips, chip modules, devices, units, etc., without specific limitations.

The following embodiment provides a detailed description of the network devices mentioned above. A network device can be a device with transceiver capabilities. In a TN system, the network device may include access network devices and/or core network (CN) devices. In an NTN system, the network device may include at least one of a satellite, access network device, NTN gateway, and core network device. These will be described separately below.

Access network equipment can be a radio access network (RAN). The RAN can consist of multiple 5G-RAN nodes, implementing radio physical layer functions, resource scheduling and radio resource management, radio access control, and mobility management functions.

For example, access network equipment can be a base station (BTS) in a Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) system, a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, an evolved Node B (eNB or eNodeB) in an LTE communication system, a next-generation evolved Node B (ng-eNB) in an NR communication system, a next-generation Node B (gNB or gNodeB) in an NR communication system, a master node (MN) in a dual connectivity architecture, a secondary node (SN) in a dual connectivity architecture, a transmission receiving point (TRP), etc., without specific restrictions.

Access network equipment functions as CUs and DUs. One CU can control one or more DUs. CUs and DUs are physically connected via optical fiber, and logically share a specially defined F1 interface for communication between them.

A CU (Controller Unit) refers to a logical node that hosts protocol layers with low latency sensitivity. These low-latency-sensitivity protocol layers include the Radio Resource Control (RRC) layer, Packet Data Convergence Protocol (PDCP) layer, and Service Data Adaptation Protocol (SDAP) layer of the access network equipment. The RRC layer is primarily responsible for RAN-related control plane procedures. The PDCP layer is primarily responsible for IP header compression, encryption, and integrity protection. The SDAP layer is a newly added protocol layer in the gNodeB's user plane protocol stack, primarily responsible for adding QoS Flow Identifiers (QFIs) to data packets and mapping QoS flows to data radio bearers (DRBs).

A DU (Dedicated Unit) refers to a logical node that hosts high-latency-sensitive protocol layers. A DU is controlled by a CU (Control Unit), and one DU supports one or more cells; a cell can only belong to one DU. The high-latency-sensitive protocol layers include the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and the Physical (PHY) layer. The RLC layer is primarily responsible for data segmentation and reassembly. The MAC layer is primarily responsible for logical channel multiplexing, Hybrid Automatic Repeat Request (HARQ) retransmission, and scheduling-related functions. The Physical layer is primarily responsible for encoding, decoding, modulation, demodulation, and multi-antenna mapping.

Core network equipment may include network elements that provide various functions. The term "network element" can also be referred to as an entity, device, apparatus, or module, etc., without specific limitations. Furthermore, for ease of description and explanation, the term "network element" is omitted in some descriptions. For example, a network exposure function (NEF) network element is abbreviated as NEF. In this case, "NEF" should be understood as either a NEF network element or a NEF entity. The following omits further explanation of similar or identical cases.

For example, core network equipment may include a mobility management entity (MME), a broadcast multicast service center (BMSC), or corresponding functional entities in the 5G system, such as core network control plane (CP) or user plan (UP) network functions. The core network control plane can also be understood as the core network control plane function (CPF) entity.

The following embodiment will provide a detailed description of the satellite, NTN gateway, and NTN system mentioned above.

A satellite can be a spacecraft that transmits signals using a transparent payload (or bent pipe payload) or a regenerative payload; that is, a transparent satellite or a regenerative satellite.

It should be noted that satellites can be classified according to their orbital altitude into geostationary orbit (GEO) satellites, medium earth orbit (MEO) satellites, low earth orbit (LEO) satellites, and high elliptical orbit (HEO) satellites, etc.

An NTN gateway, which can be a ground-based earth station or gateway, provides sufficient radio frequency (RF) power and RF sensitivity to enable connections between ground devices (such as network equipment) and satellites. A non-terrestrial network gateway is a node in the transport network layer (TNL).

Depending on the type of payload, NTN systems have two common architectures: pass-through architecture and regenerative architecture. These will be explained below.

In a transparent transmission architecture, the signal only undergoes frequency conversion and amplification on the satellite; the satellite is transparent to the signal, as if it doesn't exist. For example, taking the gNB as the access network device, the transparent transmission architecture of the NTN system is shown in Figure 2. In Figure 2, the terminal device, NTN gateway, and gNB are located on the Earth's surface, while the satellite is in Earth orbit. The satellite, NTN gateway, and gNB constitute the radio access network (NG-RAN). The NG-RAN connects to the 5G core network through the NG interface, and the 5G core network connects to the data network through the N6 interface. The satellite and NTN gateway can be considered as remote radio units, and they can communicate with each other through the NR Uu interface.

In a regenerative architecture, the satellite operates in regenerative mode and possesses some or all of the functions of a base station. For example, taking the access network equipment as a gNB, the regenerative architecture of the NTN system is shown in Figure 3. In Figure 3(a), the terminal equipment is located on the Earth's surface, and the satellite possesses all the functions of the gNB. The satellite and gNB together form the NG-RAN. The NG-RAN connects to the 5G core network via the NG Uu interface, and the 5G core network connects to the data network via the N6 interface. The gNB and the terminal equipment can communicate via the NR Uu interface.

In Figure 3(b), the terminal device is located on the Earth's surface, and the satellite has gNB-DU functionality. The satellite, gNB-DU, and gNB-CU together form the NG-RAN. The NG-RAN connects to the 5G core network via the NG Uu interface, and the 5G core network connects to the data network via the N6 interface. The gNB and the terminal device can communicate via the NR Uu interface.

In addition, based on the operating mode of the payload (such as beam), NTN systems can generally be divided into eye-fixed (earth-fixed or quasi-earth fixed) and non-eye-moving (earth-moving) NTN systems.

In a non-staring system, the satellite beam coverage area moves along with the satellite over a period of time, as shown in Figure 4(a). In Figure 4(a), the satellite beam coverage area moves along with the satellite over the period from time T1 to time T3.

In a staring system, the satellite dynamically adjusts its beam pointing over a period of time to ensure that the beam approximately covers the same area of the ground, as shown in Figure 4(b). In Figure 4(b), the satellite beam coverage area is the same during the period when the satellite moves from time T1 to time T3.

In an NTN system, the service area of a satellite network is divided into multiple smaller geographical regions, each called a beam position. Beam positions can be represented in different shapes to indicate the coverage area of a satellite beam.

In the NTN system, the movement of LEO satellites can cause problems such as group handover (e.g. for connected terminal devices) or group reselection (e.g. for idle or inactive terminal devices) in a certain area (wavelength).

Taking group handover with the terminal device being a UE as an example. At time T1, as shown in Figure 5(a), for satellite 510, there are multiple beams in area 530 (i.e., beams 5301, 5302, 5303, 5304, 5305, and 5306); for satellite 520, there are multiple beams in area 540, and beam 5401 contains a UE cluster, namely UE-G1 (UE-G1 contains multiple UEs). At time T1, UE-G1 is served by one or more beams of satellite 520.

Satellites 510 and 520 are constantly moving over time. From time T1 to time T2, assuming the UEs within UE-G1 do not move (as shown in Figure 5(b)), the movement of satellite 520 causes it to cease providing service to UE-G1. Instead, one or more beams of satellite 510 provide service to UE-G1. This process of UE-G1 switching from satellite 520 to satellite 510 can be called group handover.

Because satellites move at relatively high speeds, approximately 7.5 km/s, group handovers occur only once every few seconds to tens of seconds. In other words, group handovers are commonplace in hopping-beam LEO satellite networks.

The following embodiment will provide a detailed explanation of the IAB mentioned above.

The purpose of the IAB (Infrastructure Access Block) is to support wireless backhaul and relay links, enabling flexible and very dense cell deployments without proportionally encrypting the wired transmission network. Typical deployment scenarios include supporting outdoor small cell deployments, indoor small cell deployments, and even mobile relays (e.g., on buses or trains). The functional architecture of the IAB is as follows:

An IAB-node provides access and backhaul capabilities and can consist of an IAB-node-MT and an IAB-node-DU. The IAB-node-MT acts as a terminal device, providing backhaul functionality. The IAB-node-DU acts as an access-side pole cell, providing coverage coverage and offering access services to terminal devices or sub-IAB-node-MTs.

An IAB-donor can be viewed as a network device that supports additional IAB functions (such as a gNodeB). It can connect to the core network through non-IAB connections and includes IAB-donor-DU and IAB-donor-CU. Among them, IAB-donor-CU can provide access services for IAB-donor-DU and IAB-node-DU; IAB-donor-DU can provide access services for terminal devices or IAB-node-MT.

It should be noted that when an IAB-node provides access services to a terminal device (or when an IAB-node-DU provides access services to a terminal device), the terminal device is referred to as "the terminal device connected to the IAB-node", "the terminal device served by the IAB-node", or "the terminal device associated with the IAB-node".

When an IAB-donor provides access services to an IAB-node (or when an IAB-donor-CU provides access services to an IAB-node-DU), the IAB-node is referred to as "the IAB-node to which the IAB-donor is connected", or "the IAB-node served by the IAB-donor", or "the IAB-node associated with the IAB-donor"; the IAB-donor is referred to as "the IAB-donor to which the IAB-node is connected", or "the IAB-donor associated with the IAB-node".

When an IAB-donor provides access services to a terminal device (or when an IAB-donor-DU provides access services to a terminal device), the terminal device is referred to as "the terminal device connected to the IAB-donor", "the terminal device served by the IAB-donor", or "the terminal device associated with the IAB-donor"; the IAB-donor can be referred to as "the IAB-donor connected to the terminal device" or "the IAB-donor associated with the terminal device".

When the first IAB-node provides access services to the second IAB-node (the first IAB-node-DU provides access services to the second IAB-node-MT), the second IAB-node is referred to as "the child IAB-node or lower-level IAB-node connected to the first IAB-node," or "the child IAB-node or lower-level IAB-node served by the first IAB-node," or "the child IAB-node or lower-level IAB-node associated with the first IAB-node." Simultaneously, the first IAB-node is referred to as "the parent IAB-node or superior IAB-node of the second IAB-node," or "the IAB-node connected to the second IAB-node."

When an IAB-node provides access services to a terminal device (or when an IAB-node-DU provides access services to a terminal device), the terminal device is referred to as "the terminal device connected to the IAB-node", "the terminal device served by the IAB-node", or "the terminal device associated with the IAB-node"; the IAB-node is referred to as "the IAB-node connected to the terminal device" or "the IAB-node associated with the terminal device".

For example, taking a base station as gNodeB and a terminal device as UE as an example, as shown in Figure 6. In Figure 6, gNodeB 620, IAB-donor 630, IAB-node 650 and IAB-node 670 constitute NR-RAN.

The gNodeB 620 connects to the 5G core network (5G CN) 610 via the NG interface. The IAB-donor 630 includes IAB-donor-CU 6301 and IAB-donor-DU 6302. IAB-donor-CU 6301 connects to IAB-donor-DU 6302 via the F1 interface, IAB-donor-CU 6301 connects to the gNodeB 620 via the Xn-C interface, and IAB-donor-CU 6301 connects to the 5G CN 610 via the NG interface; IAB-donor-DU 6302 connects to the UE 640 via the NR Uu interface.

The IAB-node 650 includes IAB-node-MT 6501 and IAB-node-DU 6502. IAB-node-MT 6501 is connected to IAB-donor-DU 6302 via the NR Uu interface. IAB-node-DU 6502 is connected to IAB-donor-CU 6301 via the F1 interface. IAB-node-DU 6502 is connected to UE 660 via the NR Uu interface.

IAB-node 670 includes IAB-node-MT 6701 and IAB-node-DU 6702. IAB-node-MT 6701 is connected to IAB-node-DU 6702 via the NR Uu interface, and IAB-node-DU 6702 is connected to IAB-donor-CU 6301 via the F1 interface. IAB-node 670 can be considered a child or lower-level IAB-node of IAB-node 650, and IAB-node 650 can be considered a parent or upper-level IAB-node of IAB-node 670.

Additionally, an IAB whose location can be moved can be called a "mobile IAB (mIAB)". The functional architecture of a mIAB is as follows:

A mIAB-node can contain mIAB-node-MT and mIAB-node-DU. mIAB-node-MT can be an IAB-node-MT whose location can be moved, and mIAB-node-DU can be an IAB-node-DU whose location can be moved.

A mIAB-donor can include mIAB-donor-MT and mIAB-donor-DU. Among them, mIAB-donor-MT can be an IAB-donor-MT whose position can be moved, and mIAB-donor-DU can be an IAB-donor-DU whose position can be moved.

The following embodiment provides a detailed description of TNIAB's mobility management.

It should be noted that TN IAB can refer to an IAB located on the ground or a ground/land-based IAB. Specifically, a TN IAB-node can be an IAB-node located in a ground/land-based network or an IAB-node belonging to the TN system; a TN IAB-donor can be an IAB-donor located in a ground/land-based network or an IAB-donor belonging to the TN system; a TN mIAB-node can be a mIAB-node located in a ground/land-based network or a mIAB-node belonging to the TN system; and a TN mIAB-donor can be a mIAB-donor located in a ground/land-based network or an IAB-node belonging to the TN system.

NTN IAB-nodes can be IAB-nodes located in non-terrestrial/non-land network networks, or IAB-nodes belonging to the NTN system; NTN IAB-donors can be IAB-donors located in non-terrestrial/non-land network networks, or IAB-donors belonging to the NTN system; NTN mIAB-nodes can be mIAB-nodes located in non-terrestrial/non-land network networks, or mIAB-nodes belonging to the NTN system; NTN mIAB-donors can be mIAB-donors located in non-terrestrial/non-land network networks, or IAB-nodes belonging to the NTN system. In TN IAB mobility management, the mobility of TN mIAB-nodes includes the following scenarios:

In the first scenario, as the TN mIAB-node moves, the TN IAB-donor-CU connected to the TN mIAB-node-MT needs to be switched, while the TN IAB-donor-CU connected to the TN mIAB-node-DU does not need to be switched; that is, the TN mIAB-node-DU still needs to maintain its connection with the original TN IAB-donor-CU. However, because the TN IAB-donor-CU connected to the TN mIAB-node-MT is switched, the transmission path from the TN mIAB-node-DU to that TN IAB-donor-CU will change. Furthermore, since mIAB scenarios typically involve the switching of at least one UE served by the mIAB, but in existing networks, UEs and TN mIAB-nodes usually move together (e.g., a group of UEs served by a vehicle-mounted mIAB), meaning the relative positional relationship between the UE and the TN mIAB-node remains unchanged, RACH-less handover can usually be considered to further reduce handover overhead.

For example, taking the UE as the terminal device, as shown in Figure 7. In Figure 7(a), TN mIAB-node 740 includes TN mIAB-node-MT 7401 and TN mIAB-node-DU 7402. TN mIAB-node-MT 7401 is connected to TN IAB-donor-CU 7201 via TN IAB-donor-DU 7202, and TN mIAB-node-DU 7402 is connected to TN IAB-donor-CU 7101 and UE 750 respectively. The transmission path from TN mIAB-node-DU 7402 to TN IAB-donor-CU 7101 requires passing through TN IAB-donor-DU 7202. Then, UE 750 moves along with TN mIAB-node 740.

In Figure 7(b), TN miAB-node-MT 7401 switches from TN IAB-donor-CU 7201 to TN IAB-donor-CU 7301, and TN miAB-node-MT 7401 is connected to TN IAB-donor-CU 7301 via TN IAB-donor-DU 7302. TN miAB-node-DU 7402 continues to maintain its connection with TN IAB-donor-CU 7101. The transmission path from TN miAB-node-DU 7402 to TN IAB-donor-CU 7101 requires traversing TN IAB-donor-DU 7302.

In the second scenario, as the TN mIAB-node moves, the TN IAB-donor-CU connected to the TN mIAB-node-DU needs to be switched, while the TN IAB-donor-CU connected to the TN mIAB-node-MT does not need to be switched; that is, the TN mIAB-node-MT continues to maintain its connection with the original TN IAB-donor-CU. For the TN mIAB-node-DU switch, the TN mIAB-node needs to support simultaneous service of multiple logical TN mIAB-node-DU functions to minimize the mobility interruption time caused by the switch. Furthermore, since mIAB scenarios are usually accompanied by UE switchover, but in existing networks, the UE and TN mIAB-node typically move together, meaning their relative positions remain unchanged, RACH-less handover can often be considered to further reduce handover overhead.

For example, as shown in Figure 8. In Figure 8(a), TN mIAB-node 840 includes TN mIAB-node-MT 8401 and TN mIAB-node-DU 8402. TN mIAB-node-MT 8401 is connected to TN IAB-donor-CU 8201 via TN IAB-donor-DU 8202, and TN mIAB-node-DU 8402 is connected to TN IAB-donor-CU 8101 and UE 850 respectively. The transmission path from TN mIAB-node-DU 8402 to TN IAB-donor-CU 8101 requires passing through TN IAB-donor-DU 8202. Then, UE 850 moves along with TN mIAB-node 840.

In Figure 8(b), TN miAB-node-DU 8402 switches from TN IAB-donor-CU 8201 to TN IAB-donor-CU 8301. TN miAB-node-DU 8403 connects TN IAB-donor-CU 8301 and UE 850, while TN miAB-node-MT 8401 maintains its connection with TN IAB-donor-CU 8101. The transmission path from TN miAB-node-DU 8403 to TN IAB-donor-CU 8301 requires traversing TN IAB-donor-DU 8302.

The following embodiment provides a detailed description of mobility management in a frequently moving network system.

Currently, mobility management in the TN system includes cell handover in connected mode, cell reselection in idle/inactive mode, registration update, and tracking area update. Taking cell handover in terrestrial networks as an example, the cell handover process mainly includes steps such as cell handover measurement, measurement result reporting, handover decision, and handover execution.

For example, in cell handover measurement, the source base station sends measurement configurations for multiple cells (including the serving cell and neighboring cells) to the terminal device. The terminal device can then measure the cell signal quality (such as Reference Signal Receiving Power (RSRP) and/or Reference Signal Receiving Quality (RSRQ)) based on these configurations. In measurement result reporting, the terminal device can report the measurement results to the source base station, either periodically or via event-triggered reporting. During handover decision-making, the source base station can select suitable neighboring cells based on the reported results and exchange information related to cell handover context, admission control, and reserved resources. During handover execution, the terminal device receives handover-related control information from the source base station and completes the access procedure at the target base station.

In mobility management under a TN system, cell handover or cell reselection is usually required due to the movement of terminal devices, while nodes providing access functions are typically considered to be stationary or move infrequently. For example, cell handover and cell reselection do not require consideration of network device movement.

However, for mobility management in frequent mobility network systems, the nodes providing access functions in these systems are prone to frequent movement. Directly reusing mobility management from the TN system can lead to significant signaling overhead and mobility interruption latency, resulting in handover/reselection failures and highly inefficient mobility management. Therefore, this embodiment discusses how to perform efficient mobility management in frequent mobility network systems.

Based on the above description, the mobile network system of this embodiment includes terminal equipment, a first type of node, a second type of node, and a core network. The first type of node and the second type of node will be further described in detail below.

Type I nodes can provide access services to terminal devices and/or their sub-Type I nodes. Type I nodes can exist in the following ways: 1) Type I nodes can be mobile, meaning their location can be moved, for example, a type I node is a mIAB-node; 2) Type I nodes may not be mobile, meaning their location is fixed, for example, a non-mIAB-node, an IAB-node, or a stationary/fixed IAB-node; 3) Type I nodes can support NTN, meaning they are located outside the ground (air) or the second node belongs to the NTN system, for example, a type I node is an NTN IAB-node or an NTN mIAB-node; 4) Type I nodes can support TN, meaning they are located on the ground or the second node belongs to the TN system, for example, a type I node is a TN IAB-node or a TN mIAB-node.

Type II nodes can connect to the core network and provide access services to Type I nodes and/or terminal equipment. Type II nodes can exist in the following ways: 1) Type II nodes can support mobility, for example, a Type II node is a mIAB-donor; 2) Type II nodes may not support mobility, for example, a non-mIAB-donor, an IAB-node, or a stationary/fixed IAB-donor; 3) Type II nodes can support NTN, for example, a Type II node is an NTN IAB-donor or an NTN mIAB-donor; 4) Type II nodes can support TN, for example, a Type II node is a TN IAB-donor or a TN mIAB-donor.

Based on this, mobility management in this frequent mobility network system can include the switching of a second type of node connected to a first type of node in the connected state, and the reselection of a second type of node where a first type of node resides in the idle/inactive state.

The following examples, using NTN IAB systems or converged NTN IAB and TN IAB systems as examples, illustrate four scenarios for mobility management in frequent mobility network systems. It should be noted that in NTN IAB systems or converged NTN IAB and TN IAB systems, the first type of node can include NTN IAB-nodes and/or TN IAB-nodes, and the second type of node can include NTN IAB-donor or TN IAB-donor.

In "Scenario 1," the frequent mobility network system includes a TN IAB-donor, an NTN IAB-node, a UE, and a core network. The core network is located on the ground; the TN IAB-donor connects to the core network and provides access services to the NTN IAB-node and/or the UE; the NTN IAB-node can provide access services to its sub-NTN IAB-nodes and/or the UE. Mobility management in "Scenario 1" under the frequent mobility network system includes handover of the TN IAB-donor connected to the NTN IAB-node in connected mode and reselection of the TN IAB-donor where the NTN IAB-node resides in idle/inactive mode.

Taking the handover of the TN IAB-donor connected to the NTN IAB-node in connected state as an example, as shown in Figure 9. In Figure 9, the frequent mobility network system includes core network 910, TN IAB-donor 920, TN IAB-donor 930, NTN IAB-node 940, NTN IAB-node 950, NTN IAB-node 960, UE 970, UE 980 and UE 990. The core network 910 is located on the ground; TN IAB-donor 920 connects to core network 910 and provides access services to NTN IAB-node 950; TN IAB-donor 930 connects to core network 910 and provides access services to NTN IAB-node 940 and UE 970; NTN IAB-node 940 provides access services to NTN IAB-node 950; and NTN IAB-node 950 provides access services to NTN IAB-node 960, UE 980, and UE 990. With the movement of NTN IAB-node 950, it needs to switch from TN IAB-donor 920 to TN IAB-donor 930.

In "Scenario 2," the frequent mobility network system includes an NTN IAB-donor, an NTN IAB-node, a UE, an NTN gateway, and a core network. The core network is located on the ground; the NTN gateway connects the core network and the NTN IAB-donor; the NTN IAB-donor provides access services to the NTN IAB-node and/or the UE; and the NTN IAB-node provides access services to its sub-NTN IAB-nodes and/or the UE. Mobility management in "Scenario 2" under the frequent mobility network system includes handover of the NTN IAB-donor connected to the NTN IAB-node in connected mode and reselection of the NTN IAB-donor where the NTN IAB-node resides in idle/inactive mode.

Taking the handover of the NTN IAB-donor connected to the NTN IAB-node in connected state as an example, as shown in Figure 10. In Figure 10, the frequent mobility network system includes core network 1010, NTN gateway 1020, NTN IAB-donor 1030, NTN IAB-donor 1040, NTN IAB-node 1050, NTN IAB-node 1060, UE 1070, and UE 1080. Among them, core network 1010 is located on the ground; NTN gateway 1020 connects core network 1010 and NTN IAB-donor 1030; NTN IAB-donor 1030 provides access services to NTN IAB-node 1050; NTN IAB-node 1050 provides access services to NTN IAB-node 1060, UE 1070, and UE 1080. With the relocation of NTN IAB-node 1050, NTN IAB-node 1050 needs to be switched from NTN IAB-donor 1030 to NTN IAB-donor 1040.

In "Scenario 3," the frequent mobility network system includes an NTN IAB-donor, a TN IAB-donor, an NTN IAB-node, a UE, an NTN gateway, and a core network. The core network is located on the ground; the NTN gateway can connect to the core network and the NTN IAB-donor; the NTN IAB-donor can provide access services to the NTN IAB-node and/or the UE; the TN IAB-donor can connect to the core network and can provide access services to the NTN IAB-node and/or the UE; the NTN IAB-node can provide access services to its sub-NTN IAB-node and/or the UE. Mobility management in the frequent mobility network system of "Scenario 3" includes the handover of the NTN IAB-donor or TN IAB-donor to which the NTN IAB-node is connected in the connected state, and the reselection of the NTN IAB-donor or TN IAB-donor to which the NTN IAB-node resides in the idle/inactive state.

Taking the handover of the TN IAB-donor connected to the NTN IAB-node in connected state as an example, as shown in Figure 11. In Figure 11, the frequent mobility network system includes core network 1110, NTN gateway 1120, TN IAB-donor 1130, NTN IAB-donor 1140, NTN IAB-node 1150, NTN IAB-node 1160, UE 1170, and UE 1180. Among them, core network 1110 is located on the ground; NTN gateway 1120 connects core network 1110 and NTN IAB-donor 1140; TN IAB-donor 1130 provides access services to NTN IAB-node 1150; NTN IAB-node 1150 provides access services to NTN IAB-node 1160, UE 1170, and UE 1180. With the relocation of NTN IAB-node 1150, NTN IAB-node 1150 needs to be switched from TN IAB-donor 1130 to NTN IAB-donor 1140.

In "Scenario 4," the frequent mobility network system includes an NTN IAB-donor, a TN IAB-donor, an NTN IAB-node, a TN IAB-node, a UE, and a core network. The core network is located in the air; the NTN IAB-donor can connect to the core network and provide access services to the NTN IAB-node and/or the UE; the TN IAB-donor can connect to the core network and provide access services to the NTN IAB-node and/or the UE; and the NTN IAB-node can provide access services to its sub-TN IAB-node and/or the UE. Mobility management in the frequent mobility network system of "Scenario 4" includes the handover of the NTN IAB-donor to which the NTN IAB-node is connected in the connected state, and the reselection of the NTN IAB-donor to which the NTN IAB-node resides in the idle/inactive state.

Taking the handover of the NTN IAB-donor connected to the NTN IAB-node in connected state as an example, as shown in Figure 12. In Figure 12, the frequent mobility network system includes core network 1210, NTN IAB-donor 1220, NTN IAB-donor 1230, NTN IAB-node 1240, TN IAB-node 1250, UE 1260, UE 1270, and UE 1280. Among them, core network 1210 is located on a satellite; NTN IAB-donor 1220 provides access services to NTN IAB-node 1240; NTN IAB-node 1240 provides access services to TN IAB-node 1250, UE 1270, and UE 1280; and TN IAB-node 1250 provides access services to UE 1260. With the relocation of NTN IAB-node 1240, NTN IAB-node 1240 needs to be switched from NTN IAB-donor 1220 to NTN IAB-donor 1230.

Based on the above description, this embodiment will now explain the handover of the second type of node connected to the first type of node in the connected state in a frequently moving network system.

It should be noted that, since the first type of node includes a first functional unit and a second functional unit, and the first functional unit and the second functional unit are connected to the second type of node, the switching of the second type of node connected to the first type of node includes the switching of the second type of node connected to the first functional unit and/or the switching of the second type of node connected to the second functional unit.

For example, taking IAB-node-MT as the first functional unit, IAB-node-DU as the second functional unit, and IAB-donor as the second type of node, the switching of the IAB-donor connected to the IAB-node includes the switching of the IAB-donor connected to IAB-node-MT and/or the switching of the IAB-donor connected to IAB-node-DU. The IAB-donor connected to IAB-node-MT and the IAB-donor connected to IAB-node-DU can be the same or different. For example, as shown in Figure 7 or Figure 8.

For ease of description, in the following embodiment, "the switching of the second type of node connected to the first type of node" can be abbreviated as "the access switching of the first type of node", "the switching of the second type of node connected to the first functional unit" can be abbreviated as "the access switching of the first functional unit", and "the switching of the second type of node connected to the second functional unit" can be abbreviated as "the access switching of the second functional unit".

Because the access handover process for Type I nodes requires the execution of a handover procedure, which includes steps such as cell handover measurement, measurement result reporting, handover decision, and handover execution, and each step incurs signaling overhead, resource overhead, and time consumption, when the access handover of the first functional unit and the access handover of the second functional unit each execute their own handover procedure, this leads to problems such as high signaling overhead, high resource overhead, and long time consumption. The long time consumption also results in prolonged mobility interruption. Furthermore, since Type I nodes may move frequently in a frequently mobile network system, the first and second functional units may frequently perform access handovers, and executing their own handover procedures will also lead to low handover efficiency.

Based on this, for the access switching process of the first type of node, this embodiment considers that the first functional unit and the second functional unit of the first type of node are connected to the same second type of node, and the first functional unit and the second functional unit of the first type of node need to switch to the same second type of node.

For example, taking the first functional unit as IAB-node-MT, the second functional unit as IAB-node-DU, and the second type of node as IAB-donor, in the connected state, IAB-node-MT and IAB-node-DU of the IAB-node are simultaneously connected to the first IAB-donor, and IAB-node-MT and IAB-node-DU need to switch to the second IAB-donor.

As can be seen, since the first functional unit and the second functional unit are connected to the same second type node, and the first functional unit and the second functional unit need to switch to the same second type node, the access handover of the first functional unit and the access handover of the second functional unit can be performed together using the same handover process. This helps to reduce signaling overhead, reduce resource overhead, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

The following embodiment uses an example where a first type of node includes a first node, a second type of node includes a second node and a third node, and the first and second functional units of the first node need to switch from the second node to the third node. This example will specifically illustrate the switching process executed for the access switching of the first functional unit and the access switching of the second functional unit. Based on the above description, the first node, the second node, and the third node will be further explained below.

The first node can be used to provide backhaul access functionality, providing access services to child nodes and/or terminal devices. The first node can be in the following states: 1) The first node can support mobility, for example, the first node is a mIAB-node; 2) The first node may not support mobility, for example, the first node is a non-mIAB-node, an IAB-node, or a stationary/fixed IAB-node; 3) The first node can support NTN, for example, the first node is an NTN IAB-node or an NTN mIAB-node; 4) The first node can support TN, for example, the first node is a TN IAB-node or a TN mIAB-node.

The second node can connect to the core network and provide access services to the first type of nodes and/or terminal equipment. The second node can be in the following situations: 1) The second node can support mobility, for example, the second node is a mIAB-donor; 2) The second node may not support mobility, for example, it can be a non-mIAB-donor, an IAB-donor, or a stationary/fixed IAB-donor; 3) The second node can support NTN, for example, the second node is an NTN IAB-donor or an NTN mIAB-donor; 4) The second node can support TN, for example, the second node is a TN IAB-donor or a TN mIAB-donor.

The third node can connect to the core network and provide access services to Type 1 nodes and/or terminal equipment. The third node can exist in the following ways: 1) The third node can support mobility, for example, the third node is a mIAB-donor; 2) The third node may not support mobility, for example, it can be a non-mIAB-donor, an IAB-donor, or a stationary/fixed IAB-donor; 3) The third node can support NTN, for example, the third node is an NTN IAB-donor or an NTN mIAB-donor; 4) The third node can support TN, for example, the third node is a TN IAB-donor or a TN mIAB-donor.

As shown in Figure 13, Figure 13 is a flowchart illustrating an access handover method in a frequent mobility network system according to an embodiment of this application. Figure 13 includes the following steps:

S1301. The second node sends a handover request to the third node.

Correspondingly, the third node receives the handover request information.

The switching request information can be used to request the switching of the first functional unit and the second functional unit of the first node from the second node to the third node.

As can be seen, since the second node provides access services to the first node, it can determine whether an access handover to the first node is necessary. For example, the second node can make a handover decision based on measurement reports reported by the first node. When the second node decides that the first functional unit and the second functional unit of the first node need to be switched from the second node to the third node, the second node can request the third node to switch the first functional unit and the second functional unit of the first node from the second node to the third node through a handover request message, so that the third node can perform handover admission control.

Optionally, the switching request information includes first identification information and second identification information. The first identification information is used to indicate the identifier of the first functional unit of the first node, and the second identification information is used to indicate the identifier of the second functional unit of the first node.

In this way, the first identification information and the second identification information are used to indicate the first functional unit and the second functional unit of the first node, so that the third node can confirm that the switching request is for the first functional unit and the second functional unit of the first node.

Optionally, the switching request information may also include at least one of the following: third identification information, first context information, fourth identification information, or second context information.

The third identification information is used to indicate the identifier of the terminal device served by the first node, the first context information is used to indicate the context of the terminal device served by the first node, the fourth identification information is used to indicate the identifier of the first functional unit of the sub-node served by the first node and the identifier of the second functional unit of the sub-node served by the first node, and the second context information is used to indicate the context of the sub-node served by the first node.

It should be noted that if a terminal device served by the first node requests to switch from the second node to the third node, the switch request information includes third identification information and/or first context information. In this way, the third identification information and/or first context information inform the third node of the terminal device's request to switch from the second node to the third node, so that the third node can perform the relevant access control.

If a child node served by the first node requests to switch from the second node to the third node, the switch request information includes fourth identification information and/or second context information. In this way, the fourth identification information and/or second context information inform the third node of the child node's request to switch from the second node to the third node, so that the third node can perform the relevant admission control.

S1302. The third node sends a handover response message.

Correspondingly, the second node receives the handover response information.

The switching response information is used to indicate that the first functional unit and the second functional unit of the first node are permitted to switch from the second node to the third node.

It should be noted that after the third node receives the handover request information, the third node will perform handover admission control to decide whether to allow the first functional unit and the second functional unit of the first node to switch from the second node to the third node, and inform the second node through the handover response information to allow the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

Optionally, the switching response information may include at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information.

The first information is used to configure the backhaul adaptation protocol (BAP) address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure the backhaul radio link control (BH-RLC); the fifth information is used to configure the F1 application protocol (F1-AP); and the sixth information is used to configure the second functional unit of the first node.

As can be seen, in order to ensure that the first functional unit and the second functional unit of the first node switch from the second node to the third node, the third node needs to reserve at least one of the following information for the first functional unit and the second functional unit of the first node to perform access handover: BAP address, transmission path from the second node to the third node, resources on the transmission path, BH-RLC configuration, F1-AP configuration, or configuration of the second functional unit of the first node. This information is used by the first node to perform access handover and ensure successful access handover.

Optionally, the sixth piece of information includes at least one of the following: a list of Physical Cell Identifiers (PCIs), resource configuration information, Tracking Area Identifier (TAI) configuration information, or Tracking Area Code (TAC) configuration information.

It is evident that the third node needs to configure at least one of the following for the second functional unit of the first node during the handover admission control process: PCI list, resources, TAI, or TAC, in order to ensure that the first node can successfully perform the access handover.

Optionally, the handover response information may also include random access information required for the handover of the terminal equipment and/or sub-nodes served by the first node. For example, random access information may include a cell-specific radio network temporary identifier (C-RNTI), a preamble, a random access channel occurrence (RO), and random access time-frequency resources.

As can be seen, if a terminal device and/or sub-node served by the first node requests to switch from the second node to the third node, the third node needs to configure the random access information required for the terminal device and/or sub-node to perform the handover during the handover admission control process, so that the terminal device and/or sub-node can perform random access based on the random access information to complete the access handover.

S1303. The second node sends a handover message to the first node.

Correspondingly, the first node receives the switching information.

The switching information is used to instruct the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

It should be noted that after the second node learns that the third node has permitted the first node to perform an access handover, the second node can inform the first node through the handover information that an access handover needs to be performed, and begin to switch the first functional unit and the second functional unit of the first node from the second node to the third node.

Optionally, the switching information may include at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information.

The first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, the second node will inform the first node of at least one of the following information: the BAP address reserved by the third node for the first functional unit of the first node and the second functional unit of the first node for access switching, the transmission path from the second node to the third node, the resources on the transmission path, the BH-RLC configuration, the F1-AP configuration, or the configuration of the second functional unit of the first node, so that the first node can perform access switching based on this information and ensure successful access switching.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

As can be seen, the second node will inform the first node of at least one of the PCI list, resources, TAI or TAC configured by the third node, thereby ensuring that the first node's access handover is successful.

Optionally, the handover information is carried by RRC signaling (such as an RRC reconfiguration request message). In this way, the second node informs the first access node to perform an access handover via RRC signaling.

S1304. The first node switches its first functional unit and second functional unit from the second node to the third node according to the switching information.

It should be noted that during the access handover process, the first node needs to complete uplink and downlink synchronization with the third node.

The following example illustrates a possible complete process for access handover in a frequently mobile network system, based on the handover process shown in Figure 13 above.

As shown in Figure 14, Figure 14 is a flowchart illustrating another access handover method in a frequently mobile network system provided in this embodiment.

Figure 14 includes the following steps:

S1401. The second node sends measurement configuration information to the first node.

Correspondingly, the first node receives the measurement configuration information.

It should be noted that the second node can send measurement configuration information corresponding to multiple second-type nodes (including the third node) to the first node. This measurement configuration information can be used to configure Layer 1 (L1) and/or Layer 3 (L3) measurements, and may include measurement frequency points, synchronization signal block measurement timing configuration (SMTC), measurement reporting trigger conditions (e.g., periodic, non-periodic, event-triggered), and measurement objects (e.g., location, signal quality). Furthermore, the measurement configuration information can be carried by RRC signaling. Then, the first node can measure signal quality (e.g., RSRP and/or RSRQ) according to the measurement configuration information to obtain signal quality results. The measurement signal can be a downlink synchronization signal SSB (e.g., cell defining SSB, CD-SSB) or a channel state information reference signal (CSI-RS), etc.

S1402. The first node sends a measurement report to the second node.

Correspondingly, the second node receives the measurement report.

It should be noted that the first node can report measurement results to the second node. The measurement report may include the first node's location-related information (such as its Global Navigation Satellite System (GNSS) position or position ID, satellite ephemeris, etc.) and signal quality results. Furthermore, the reporting method can be periodic reporting or event-triggered reporting. In event-triggered reporting, the reporting condition can be that the second node's signal quality is less than a first preset threshold and/or the third node's signal quality is greater than a second preset threshold.

S1403. The second node determines the switching decision corresponding to the first node based on the measurement report.

It should be noted that the second node determines the switching decision for the first functional unit and the second functional unit of the first node to switch from the second node to the third node based on the measurement report.

S1404. The second node sends a handover request to the third node.

Correspondingly, the third node receives the handover request information.

The switching request information can be used to request the switching of the first functional unit and the second functional unit of the first node from the second node to the third node.

It should be noted that after the second node makes a switching decision, the second node can request the third node to switch the first functional unit and the second functional unit of the first node from the second node to the third node.

Optionally, the switching request information includes first identification information and second identification information. The first identification information is used to indicate the identifier of the first functional unit of the first node, and the second identification information is used to indicate the identifier of the second functional unit of the first node.

In this way, the first identification information and the second identification information are used to indicate the first functional unit and the second functional unit of the first node, so that the third node can confirm that the switching request is for the first functional unit and the second functional unit of the first node.

Optionally, the handover request information may further include at least one of the following: third identification information, first context information, fourth identification information, or second context information. Wherein, the third identification information is used to indicate the identifier of the terminal device served by the first node, the first context information is used to indicate the context of the terminal device served by the first node, the fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node, and the second context information is used to indicate the context of the child node served by the first node.

It should be noted that if a terminal device served by the first node requests to switch from the second node to the third node, the switch request information includes third identification information and/or first context information. In this way, the third identification information and/or first context information are used to inform the third node of the terminal device's request to switch from the second node to the third node.

If a child node served by the first node requests to switch from the second node to the third node, the switch request information includes fourth identification information and/or second context information. In this way, the fourth identification information and/or second context information are used to inform the third node of the child node's request to switch from the second node to the third node.

S1405. The third node sends a handover response message.

Correspondingly, the second node receives the handover response information.

The switching response information is used to indicate that the first functional unit and the second functional unit of the first node are permitted to switch from the second node to the third node.

It should be noted that after the third node receives the handover request information, the third node will perform handover admission control to determine whether the first functional unit and the second functional unit of the first node are allowed to switch from the second node to the third node, and inform the second node through the handover response information.

Optionally, the handover response information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information; the first information is used to configure the BAP required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, in order to ensure that the first functional unit and the second functional unit of the first node switch from the second node to the third node during the handover admission control process at the third node, the third node needs to reserve one of the following information for the first functional unit and the second functional unit of the first node to perform the access handover: BAP address, transmission path from the second node to the third node, resources on the transmission path, BH-RLC configuration, F1-AP configuration, or configuration of the second functional unit of the first node. This information is used by the first node to perform the access handover and ensure that the access handover is successful.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

It is evident that the third node needs to configure at least one of the following for the second functional unit of the first node during the handover admission control process: PCI list, resources, TAI, or TAC, in order to ensure that the first node can successfully access the handover.

Optionally, the handover response information may also include random access information required for the handover of the terminal devices and/or sub-nodes served by the first node. For example, random access information may include C-RNTI, preamble, RO, and random access time-frequency resources.

As can be seen, if a terminal device and/or sub-node served by the first node requests to switch from the second node to the third node, the third node needs to configure the random access information required for the terminal device and/or sub-node to perform the handover during the handover admission control process, so that the terminal device and/or sub-node can perform random access based on the random access information to complete the access handover.

S1406. The second node sends a handover message to the first node.

Correspondingly, the first node receives the switching information.

The switching information is used to instruct the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

It should be noted that after the second node learns that the third node has permitted the first node to perform an access handover, the second node can inform the first node through the handover information that an access handover needs to be performed, and begin to switch the first functional unit and the second functional unit of the first node from the second node to the third node.

Optionally, the switching information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information; the first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, the second node will inform the first node of one of the following information: the BAP address reserved by the third node for the first functional unit of the first node and the second functional unit of the first node for access switching; the transmission path from the second node to the third node; the resources on the transmission path; the BH-RLC configuration; the F1-AP configuration; or the configuration of the second functional unit of the first node. This information will enable the first node to perform access switching and ensure successful access switching.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

As can be seen, the second node will inform the first node of at least one of the PCI list, resources, TAI or TAC configured by the third node, thereby ensuring that the first node's access handover is successful.

Optionally, the handover information is carried by RRC signaling (such as an RRC reconfiguration request message). In this way, the second node informs the first access node to perform an access handover via RRC signaling.

S1407. The first node switches its first functional unit and second functional unit from the second node to the third node according to the switching information.

It should be noted that during the access handover process, the first node needs to complete uplink and downlink synchronization with the third node.

S1408. The second node sends context information to the third node.

Correspondingly, the third node receives the context information.

The context information includes the context information of the first node.

Optionally, the context information may also include the context information of the terminal devices and/or child nodes served by the first node.

S1409. The third node sends user data to the second node.

Correspondingly, the second node receives user data. This user data can be the same as the user data from the first node.

S1410. The first node sends a handover completion message to the third node.

Correspondingly, the third node receives the handover completion information.

The switching completion information indicates that the first functional unit and the second functional unit of the first node have completed the switching from the second node to the third node.

S1411. The third node sends a handover success response message to the second node.

Correspondingly, the second node receives a successful handover response message.

The successful switchover response information indicates that the first functional unit and the second functional unit of the first node have completed the switchover from the second node to the third node.

S1412. The second node sends a path switching request to the core network equipment.

The path switching request information is used to request a path switching.

It should be noted that core network equipment may include AMF and/or UPF.

S1413. The core network equipment executes a path switching decision based on the path switching request information.

In this way, user data is transmitted from the core network equipment to the third node via a new path.

S1414. The core network equipment sends path switching response information to the third node.

Correspondingly, the third node receives the path switching response information.

The path switching response information is used to indicate that the path switching is complete.

S1415. The third node sends a context release message to the second node.

Correspondingly, the second node receives the context release information.

The context release information is used to instruct the second node to release the context information of the first node.

The following example illustrates the access switching of the terminal devices or sub-nodes served by the first node.

In some possible examples, based on Figure 13 or Figure 14 above, when it involves the access handover of terminal devices or sub-nodes served by the first node, if the terminal devices or sub-nodes served by the first node do not move with the first node, and the first functional unit and the second functional unit of the first node switch from the second node to the third node, then the second node can trigger the terminal devices or sub-nodes served by the first node to switch from the second node to the fourth node. The fourth node is different from the third node, and the fourth node is used to provide core network connectivity or to provide backhaul access. For example, the fourth node is an IAB-node or an IAB-donor.

In addition, the access handover method for the terminal devices or sub-nodes served by the first node can be the traditional L3 handover, L1/L2 triggered mobility (LTM) handover, conditional handover (CHO) or a combination of the above methods, which will not be elaborated further.

For example, taking the UE as the terminal device, as shown in Figure 15. In Figure 15(a), mIAB-node 1540 includes mIAB-node-MT 1541 and mIAB-node-DU 1542. mIAB-node-MT 1541 is connected to IAB-donor-CU 1511 through IAB-donor-DU 1512, and mIAB-node-DU 1542 is connected to IAB-donor-CU 1511 and UE 1560 respectively. IAB-node 1550 includes IAB-node-MT 1551 and IAB-node-DU 1552. IAB-node-MT 1551 is connected to IAB-donor-DU 1532, IAB-node-DU 1552 is connected to IAB-donor-CU 1531, and IAB-donor-CU 1531 is connected to IAB-donor-DU 1532.

In Figure 15(b), as miAB-node 1540 moves, since UE 1560 does not move with miAB-node 1540, IAB-donor-CU 1511 will trigger UE 1560 to switch from IAB-donor-CU 1511 to IAB-donor-CU 1531, or IAB-donor-CU 1511 will trigger UE 1560 to switch from miAB-node 1540 to IAB-node 1550, and UE 1560 will connect to IAB-node-DU 1552. Additionally, miAB-node-MT 1541 and miAB-node-DU 1542 will switch from IAB-donor-CU 1511 to IAB-donor-CU 1521. The mIAB-node-MT 1541 connects to the IAB-donor-DU 1522, and the mIAB-node-DU 1542 connects to the IAB-donor-CU 1521.

The following example illustrates the reporting of node capabilities of the first node.

In some possible examples, before the second node determines whether an access handover to the first node is necessary, the first node may report or broadcast its node capabilities to the second node. These capabilities may indicate whether the first node supports access handover for its first functional unit and/or second functional unit. Specifically, the first node may support access handover for both the first and second functional units simultaneously, or it may support only the first functional unit, or only the second functional unit, or it may not support either. Thus, the second node will only determine whether an access handover to the first node is necessary if the first node supports access handover for both the first and/or second functional units.

For example, in Figure 13, before S1301, the first node sends capability indication information to the second node; correspondingly, the second node receives the capability indication information. The capability indication information is used to indicate whether the first node supports or does not support access switching for the first functional unit and/or the second functional unit of the first node.

Optionally, if the capability indication information takes a first value, the capability indication information is used to indicate that the first node supports the access handover between the first functional unit and the second functional unit; if the capability indication information takes a second value, the capability indication information is used to indicate that the first node supports the access handover between the first functional unit; if the capability indication information takes a third value, the capability indication information is used to indicate that the first node supports the access handover between the second functional unit; if the capability indication information takes a fourth value, the capability indication information is used to indicate that the first node does not support the access handover between the first functional unit and the second functional unit.

Taking a capability indication information consisting of 2 bits as an example, if the value of the 2 bits is 00, it indicates that the first node supports the access switching between the first functional unit and the second functional unit; if the value of the 2 bits is 01, it indicates that the first node supports the access switching between the first functional unit; if the value of the 2 bits is 10, it indicates that the first node supports the access switching between the second functional unit; if the value of the 2 bits is 11, it indicates that the first node does not support the access switching between the first functional unit and the second functional unit.

In some possible examples, capability indication information can be associated with time and/or location information. Specifically, the time information associated with the capability indication information can indicate the effective time of the capability indication information; the location information associated with the capability indication information can indicate the effective area of the capability indication information. That is, the content indicated by the capability indication information is only effective within the effective time period and within the effective area of the capability indication information.

For example, if the capability indication information takes the first value and the effective time of the capability indication information is [t1, t2] (where t1 represents the start time and t2 represents the end time), then within the time [t1, t2], the first node supports the first functional unit and the second functional unit to switch access.

For example, if the capability indication information is the fourth value and the effective area is the first area (where the first area can refer to the area where the distance from the reference position is less than the distance threshold), then within the first area, the first node does not support the access switching between the first functional unit and the second functional unit.

As shown in Figure 16, Figure 16 is a flowchart illustrating an access handover method in a frequent mobile network system based on conditional handover, according to an embodiment of this application. Figure 16 includes the following steps:

S1601. The second node sends a condition switching request to the third node.

Correspondingly, the third node receives the condition switching request information.

Among them, the condition switching request information can be used to request a conditional switch between the first functional unit and the second functional unit of the first node.

As can be seen, since the second node provides access services to the first node, it can determine whether a conditional handover of the first node is necessary. For example, the second node can make a conditional handover decision based on measurement reports reported by the first node. When the second node decides that a conditional handover of the first node is necessary, it can request the third node to perform a conditional handover between the first node's first functional unit and its second functional unit via a conditional handover request message, so that the third node can execute conditional handover access control.

Optionally, the condition switching request information includes first identification information and second identification information. The first identification information is used to indicate the identifier of the first functional unit of the first node, and the second identification information is used to indicate the identifier of the second functional unit of the first node.

In this way, the first identification information and the second identification information are used to indicate the first functional unit and the second functional unit of the first node, so that the third node can confirm that the condition switching request is made for the first functional unit and the second functional unit of the first node.

Optionally, the condition switching request information may further include at least one of the following: third identification information, first context information, fourth identification information, or second context information. Wherein, the third identification information is used to indicate the identifier of the terminal device served by the first node, the first context information is used to indicate the context of the terminal device served by the first node, the fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node, and the second context information is used to indicate the context of the child node served by the first node.

It should be noted that if the terminal device served by the first node needs to configure conditional switching, the conditional switching request information includes third identification information and/or first context information. In this way, the third identification information and/or first context information are used to inform the third node about configuring conditional switching for the terminal device.

If a child node served by the first node needs to be configured with condition switching, the condition switching request information includes fourth identification information and/or second context information. In this way, the fourth identification information and/or second context information are used to inform the third node about configuring condition switching for that child node.

S1602. The third node sends a condition switching response message.

Correspondingly, the second node receives the condition switching response information.

Among them, the condition switching response information is used to instruct the first functional unit and the second functional unit of the first node to perform condition switching.

It should be noted that after the third node receives the conditional switching request information, the third node will perform conditional switching admission control to decide whether to allow the first functional unit and the second functional unit of the first node to perform conditional switching, and inform the second node to allow the first functional unit and the second functional unit of the first node to perform conditional switching through conditional switching response information.

Optionally, the condition switching response information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information.

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node; the first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, in the conditional handover admission control performed by the third node, in order to ensure that the first functional unit and the second functional unit of the first node switch from the second node to the third node through conditional handover, the third node needs to configure at least one of the following information: the conditions that the first functional unit and the second functional unit of the first node need to meet when switching from the second node to the third node; the BAP address required for the first functional unit and the second functional unit of the first node to perform access handover; the transmission path from the second node to the third node; the resources on the transmission path; the BH-RLC configuration; the F1-AP configuration; or the configuration of the second functional unit of the first node. This information is used by the first node to perform conditional handover and ensure that the conditional handover is successful.

Optionally, the conditions indicated by the switching condition information include: the distance between the reference position of the second node is greater than a first distance threshold, and/or the distance between the reference position of the third node is less than a second distance threshold; or, the BH-RLC validity time of at least one relay node on the transmission path to the second node is less than a validity time threshold.

It should be noted that the reference location of the second node can represent its geographical location. The second node can have one or more reference locations. When the second node is located on the ground/land (e.g., TN IAB-donor), its reference location is determined based on the location deployment of the frequent mobility network system, and this reference location is fixed. Similarly, the reference location of the third node can represent its geographical location. The third node can have one or more reference locations. When the third node is located on the ground/land (e.g., TN IAB-donor), its reference location is determined based on the location deployment of the frequent mobility network system, and this reference location is fixed.

Furthermore, if the switching condition information indicates that the distance between the first node and the reference position of the second node is greater than a first distance threshold, then after the first node obtains the switching condition information, the first node can determine whether the distance between its own position and the reference position of the second node is greater than the first distance threshold, in order to determine whether the conditions indicated by the switching condition information are met. When the conditions are met, the first node can execute the switching of its first functional unit and its second functional unit from the second node to the third node.

If the switching condition information indicates that the distance between the first node and the reference position of the third node is less than a second distance threshold, then after the first node obtains the switching condition information, the first node can determine whether the distance between its own position and the reference position of the third node is less than the second distance threshold, in order to determine whether the conditions indicated by the switching condition information are met. When the conditions are met, the first node can switch its first functional unit and second functional unit from the second node to the third node.

If the handover condition information indicates that at least one relay node on the transmission path to the second node has a BH-RLC validity period less than a validity period threshold, then after the first node obtains the handover condition information, the first node can determine whether there is a relay node on the transmission path from the first node to the second node whose BH-RLC validity period is less than the validity period threshold, in order to determine whether the conditions indicated by the handover condition information are met. When the conditions are met, the first node can execute the handover of its first functional unit and second functional unit from the second node to the third node.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

It is evident that the third node needs to configure at least one of the following for the second functional unit of the first node in the condition switching admission control process: PCI list, resources, TAI or TAC, in order to ensure that the first node can successfully perform condition switching.

Optionally, the conditional handover response information may also include random access information required for the handover of the terminal equipment and/or sub-nodes served by the first node. For example, random access information may include C-RNTI, preamble, RO, and random access time-frequency resources.

It is evident that if the terminal device and/or sub-node served by the first node need to be configured for conditional handover, the third node needs to configure the random access information required for the terminal device and/or sub-node to perform conditional handover in the conditional handover admission control process, so that the terminal device and/or sub-node can perform random access based on the random access information to complete the conditional handover.

S1603. The second node sends condition switching information to the first node.

Correspondingly, the first node receives the condition switching information.

Among them, the condition switching information is used to configure the first functional unit and the second functional unit of the first node to switch conditions.

It should be noted that after the second node learns that the third node has permitted the first node to perform a conditional switch, the second node can inform the first node of the need to perform the conditional switch via conditional switch information. Additionally, after receiving the conditional switch information, the first node may send an RRC reconfiguration completion message to the third node.

Optionally, the condition switching information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information.

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node; the first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, the second node will inform the first node of at least one of the following information: the switching conditions configured by the third node, the BAP address reserved for the first functional unit and the second functional unit of the first node to perform access switching, the transmission path from the second node to the third node, the resources on the transmission path, the BH-RLC configuration, the F1-AP configuration, or the second functional unit configuration of the first node, so that the first node can perform access switching based on this information and ensure successful access switching.

Optionally, the conditions indicated by the switching condition information include: the distance between the reference position of the second node is greater than a first distance threshold, and/or the distance between the reference position of the third node is less than a second distance threshold; or, the BH-RLC validity time of at least one relay node on the transmission path to the second node is less than a validity time threshold.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

As can be seen, the second node will inform the first node of at least one of the PCI list, resources, TAI or TAC configured by the third node, thereby ensuring that the first node's access handover is successful.

Optionally, the conditional handover information can be carried by RRC signaling (such as an RRC reconfiguration request message). In this way, the second node informs the first access node to perform a conditional handover via RRC signaling.

S1604. The first node performs condition switching between the first functional unit and the second functional unit of the first node according to the condition switching information.

It should be noted that the first node will determine whether the conditions indicated by the switching condition information are met. If the conditions indicated by the switching condition information are met, the condition switching will be performed, switching the first functional unit and the second functional unit of the first node from the second node to the third node.

The following example illustrates a possible complete process for access handover in a frequent mobile network system based on conditional handover, based on the handover process shown in Figure 17 above.

As shown in Figure 17, Figure 17 is a flowchart illustrating another access handover method for a frequent mobile network system based on conditional handover provided in this embodiment. Figure 17 includes the following steps:

S1701. The second node sends measurement configuration information to the first node.

Correspondingly, the first node receives the measurement configuration information.

It should be noted that the second node can send measurement configuration information corresponding to multiple second-type nodes (including the third node) to the first node. This measurement configuration information can be used to configure L1 and/or L3 measurements, and may include measurement frequency points, synchronization signal block measurement timing configuration (SMTC), measurement reporting trigger conditions (e.g., periodic, non-periodic, event-triggered), and measurement objects (e.g., location, signal quality). Furthermore, the measurement configuration information can be carried by RRC signaling. The first node can then measure signal quality (e.g., RSRP and/or RSRQ) according to the measurement configuration information to obtain signal quality results. The measured signal can be an SSB (e.g., CD-SSB or CSI-RS).

S1702. The first node sends a measurement report to the second node.

Correspondingly, the second node receives the measurement report.

It should be noted that the first node can report measurement results to the second node. The measurement report may include location-related information of the first node (such as GNSS position or wavelet ID, satellite ephemeris, etc.) and signal quality results. Furthermore, the reporting method can be periodic reporting or event-triggered reporting. In event-triggered reporting, the reporting condition can be that the signal quality of the second node is less than a first preset threshold and/or the signal quality of the third node is greater than a second preset threshold.

S1703. The second node determines the condition switching decision corresponding to the first node based on the measurement report.

It should be noted that the second node determines the conditional switching between the first functional unit and the second functional unit of the first node based on the measurement report.

S1704. The second node sends a condition switching request to the third node.

Correspondingly, the third node receives the condition switching request information.

Among them, the condition switching request information can be used to request a conditional switch between the first functional unit and the second functional unit of the first node.

As can be seen, since the second node provides access services to the first node, it can determine whether a conditional handover of the first node is necessary. For example, the second node can make a conditional handover decision based on measurement reports reported by the first node. When the second node decides that a conditional handover of the first node is necessary, it can request the third node to perform a conditional handover between the first node's first functional unit and its second functional unit via a conditional handover request message, so that the third node can execute conditional handover access control.

Optionally, the condition switching request information includes first identification information and second identification information. The first identification information is used to indicate the identifier of the first functional unit of the first node, and the second identification information is used to indicate the identifier of the second functional unit of the first node.

In this way, the first identification information and the second identification information are used to indicate the first functional unit and the second functional unit of the first node, so that the third node can confirm that the condition switching request is made for the first functional unit and the second functional unit of the first node.

Optionally, the condition switching request information may further include at least one of the following: third identification information, first context information, fourth identification information, or second context information. Wherein, the third identification information is used to indicate the identifier of the terminal device served by the first node, the first context information is used to indicate the context of the terminal device served by the first node, the fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node, and the second context information is used to indicate the context of the child node served by the first node.

It should be noted that if the terminal device served by the first node needs to configure conditional switching, the conditional switching request information includes third identification information and/or first context information. In this way, the third identification information and/or first context information are used to inform the third node of the terminal device's conditional switching configuration information. If a child node served by the first node needs to configure conditional switching, the conditional switching request information includes fourth identification information and/or second context information. In this way, the fourth identification information and/or second context information are used to inform the third node of the child node's conditional switching configuration information.

S1705. The third node sends a condition switching response message.

Correspondingly, the second node receives the condition switching response information.

Among them, the condition switching response information is used to instruct the first functional unit and the second functional unit of the first node to perform condition switching.

It should be noted that after the third node receives the conditional switching request information, the third node will perform conditional switching admission control to decide whether to allow the first functional unit and the second functional unit of the first node to perform conditional switching, and inform the second node to allow the first functional unit and the second functional unit of the first node to perform conditional switching through conditional switching response information.

Optionally, the condition switching response information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information.

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node; the first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, in the conditional handover admission control performed by the third node, in order to ensure that the first functional unit and the second functional unit of the first node switch from the second node to the third node through conditional handover, the third node needs to configure at least one of the following information: the conditions that the first functional unit and the second functional unit of the first node need to meet when switching from the second node to the third node; the BAP address required for the first functional unit and the second functional unit of the first node to perform access handover; the transmission path from the second node to the third node; the resources on the transmission path; the BH-RLC configuration; the F1-AP configuration; or the configuration of the second functional unit of the first node. This information is used by the first node to perform conditional handover and ensure that the conditional handover is successful.

Optionally, the conditions indicated by the switching condition information include: the distance between the reference position of the second node is greater than a first distance threshold, and/or the distance between the reference position of the third node is less than a second distance threshold; or, the BH-RLC validity time of at least one relay node on the transmission path to the second node is less than a validity time threshold.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

It is evident that the third node needs to configure at least one of the following for the second functional unit of the first node in the condition switching admission control process: PCI list, resources, TAI or TAC, in order to ensure that the first node can successfully perform condition switching.

Optionally, the handover response information may also include random access information required for the handover of the terminal devices and/or sub-nodes served by the first node. For example, random access information may include C-RNTI, preamble, RO, and random access time-frequency resources.

It is evident that if the terminal device and/or sub-node served by the first node need to be configured for conditional handover, the third node needs to configure the random access information required for the terminal device and/or sub-node to perform conditional handover in the conditional handover admission control process, so that the terminal device and/or sub-node can perform random access based on the random access information to complete the conditional handover.

S1706. The second node sends condition switching information to the first node.

Correspondingly, the first node receives the condition switching information.

Among them, the condition switching information is used to configure the first functional unit and the second functional unit of the first node to switch conditions.

It should be noted that after the second node learns that the third node has permitted the first node to perform a conditional switch, the second node can inform the first node of the need to perform the conditional switch via conditional switch information. Additionally, after receiving the conditional switch information, the first node may send an RRC reconfiguration completion message to the third node.

Optionally, the condition switching information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information.

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node; the first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node; the second information is used to configure the transmission path from the second node to the third node; the third information is used to configure the resources on the transmission path from the second node to the third node; the fourth information is used to configure BH-RLC; the fifth information is used to configure F1-AP; and the sixth information is used to configure the second functional unit of the first node.

As can be seen, the second node will inform the first node of at least one of the following information: the switching conditions configured by the third node, the BAP address reserved for the first functional unit and the second functional unit of the first node to perform access switching, the transmission path from the second node to the third node, the resources on the transmission path, the BH-RLC configuration, the F1-AP configuration, or the second functional unit configuration of the first node, so that the first node can perform access switching based on this information and ensure successful access switching.

Optionally, the conditions indicated by the switching condition information include: the distance between the reference position of the second node is greater than a first distance threshold, and/or the distance between the reference position of the third node is less than a second distance threshold; or, the BH-RLC validity time of at least one relay node on the transmission path to the second node is less than a validity time threshold.

Optionally, the sixth piece of information includes at least one of the following: PCI list, resource configuration information, TAI configuration information, or TAC configuration information.

As can be seen, the second node will inform the first node of at least one of the PCI list, resources, TAI or TAC configured by the third node, thereby ensuring that the first node's access handover is successful.

Optionally, the conditional handover information can be carried by RRC signaling (such as an RRC reconfiguration request message). In this way, the second node informs the first access node to perform a conditional handover via RRC signaling.

S1707. The first node performs condition switching between the first functional unit and the second functional unit of the first node according to the condition switching information.

It should be noted that the first node will determine whether the conditions indicated by the switching condition information are met. If the conditions indicated by the switching condition information are met, the condition switching will be performed, switching the first functional unit and the second functional unit of the first node from the second node to the third node.

S1708. The second node sends context information and user data to the third node.

Correspondingly, the third node receives context information and user data.

The context information includes the context information of the first node, and the user data can be the user data of the first node.

Optionally, the context information may also include the context information of the terminal devices and/or child nodes served by the first node.

It should be noted that the execution order of steps S1707 and S1708 can be dynamically interchanged.

S1709. The first node determines and performs uplink and downlink synchronization with the third node.

S1710. The first node sends a handover completion message to the third node.

Correspondingly, the third node receives the handover completion information.

The switching completion information indicates that the first functional unit and the second functional unit of the first node have completed the switching from the second node to the third node.

S1711. The third node sends a handover success response message to the second node.

Correspondingly, the second node receives a handover success response message.

The successful switchover response information indicates that the first functional unit and the second functional unit of the first node have completed the switchover from the second node to the third node.

S1712. The second node sends a path switching request to the core network equipment.

The path switching request information is used to request a path switching.

It should be noted that core network equipment may include AMF and/or UPF.

S1713. The core network equipment executes path switching decisions based on the path switching request information.

In this way, user data is transmitted from the core network equipment to the third node via a new path.

S1714. The core network equipment sends path switching response information to the third node.

Correspondingly, the third node receives the path switching response information.

The path switching response information is used to indicate that the path switching is complete.

S1715. The third node sends a context release message to the second node.

Correspondingly, the second node receives the context release information.

The context release information is used to instruct the second node to release the context information of the first node.

The following provides examples illustrating the access switching of terminal devices or sub-nodes served by the first node, as well as the reporting of the first node's node capabilities.

In some possible examples, based on Figure 16 or Figure 17 above, when it involves the access handover of terminal devices or sub-nodes served by the first node, if the terminal devices or sub-nodes served by the first node do not move with the first node, and the first functional unit and the second functional unit of the first node switch from the second node to the third node, then the second node can trigger the terminal devices or sub-nodes served by the first node to switch from the second node to the fourth node. The fourth node is different from the third node, and the fourth node is used to provide core network connectivity or to provide backhaul access. For example, the fourth node is an IAB-node or an IAB-donor. Furthermore, the access handover method for terminal devices or sub-nodes served by the first node can adopt traditional L3 handover, LTM handover, conditional handover (CHO), or a combination of the above methods, which will not be elaborated further.

In some possible examples, before the second node determines whether a conditional switch is needed for the first node, the first node may report or broadcast its node capabilities to the second node. These capabilities may indicate whether the first node supports conditional switching of its first functional unit and/or second functional unit. Specifically, the first node may support conditional switching of both the first and second functional units simultaneously, or it may support only the first functional unit, or only the second functional unit, or it may not support either. Thus, the second node will only determine whether a conditional switch is needed for the first node if the first node supports conditional switching of both the first and/or second functional units.

For example, in Figure 16, before S1601, the first node sends capability indication information to the second node; correspondingly, the second node receives the capability indication information. The capability indication information is used to instruct the first node to support or not support conditional switching of its first functional unit and/or its second functional unit.

Optionally, if the capability indication information takes a first value, the capability indication information is used to indicate that the first node supports conditional switching between the first functional unit and the second functional unit; if the capability indication information takes a second value, the capability indication information is used to indicate that the first node supports conditional switching between the first functional unit; if the capability indication information takes a third value, the capability indication information is used to indicate that the first node supports conditional switching between the second functional unit; if the capability indication information takes a fourth value, the capability indication information is used to indicate that the first node does not support conditional switching between the first functional unit and the second functional unit.

Taking a capability indication information of 2 bits as an example, if the value of the 2 bits is 00, it indicates that the first node supports conditional switching between the first functional unit and the second functional unit; if the value of the 2 bits is 01, it indicates that the first node supports conditional switching between the first functional unit; if the value of the 2 bits is 10, it indicates that the first node supports conditional switching between the second functional unit; if the value of the 2 bits is 11, it indicates that the first node does not support conditional switching between the first functional unit and the second functional unit.

In some possible examples, capability indication information can be associated with time and/or location information. Specifically, the time information associated with the capability indication information can indicate the effective time of the capability indication information; the location information associated with the capability indication information can indicate the effective area of the capability indication information. That is, the content indicated by the capability indication information is only effective within the effective time period and within the effective area of the capability indication information.

For example, if the capability indication information takes the first value and the effective time of the capability indication information is [t1, t2] (where t1 represents the start time and t2 represents the end time), then within the time [t1, t2], the first node supports conditional switching between the first functional unit and the second functional unit.

For example, if the capability indication information is the fourth value and the effective area is the first area (where the first area can refer to the area where the distance from the reference position is less than the distance threshold), then within the first area, the first node does not support conditional switching between the first functional unit and the second functional unit.

Based on the above description, this embodiment will now explain the reselection of the second type of node where the first type of node resides in the idle/inactive state in a frequently moving network system.

For ease of description, this embodiment will use the example of a first type of node including a first node and a second type of node including a second node and a third node to specifically explain the reselection of the second node where the first node resides. In this embodiment, "reselection of the second node where the first node resides" can be simply referred to as "reselection of the node resides of the first node".

It is worth noting that the first node can be used to provide backhaul access functionality; the second node can be used to provide core network connectivity functionality and can provide access services to the first node; the third node can be used to provide core network connectivity functionality. For example, the first node is an IAB-node, the second node is the first IAB-donor, and the third node is the second IAB-donor.

Furthermore, the first node can support movement, and the second and third nodes can support movement or no movement. For example, the first node is a mIAB-node, the second node is the first mIAB-donor, and the third node is the second mIAB-donor. The first node can support NTN, for example, the first node is an NTN IAB-node. The second and third nodes can support either NTN or TN, for example, the second node is the first NTN IAB-donor or the first TN IAB-donor, and the third node is the second NTN IAB-donor or the second TN IAB-donor.

As shown in Figure 18, Figure 18 is a flowchart illustrating a node relocation method in a frequently moving network system according to an embodiment of this application.

Figure 18 includes the following steps:

S1801. The second node sends node reselection information to the first node.

Correspondingly, the second node receives node relocation information and performs node relocation relocation for the second node based on the node relocation information.

The node residency reselection information is used to indicate at least one of the following: type information, coverage information, path information, or valid information.

As can be seen, the second node assists the first node in reselecting the second node by using node reselection information, thereby realizing node reselection in a frequent mobility network system and achieving efficient mobility management.

The following provides a detailed explanation of type information, coverage information, path information, and valid information.

Type information can be used to indicate the type of the second node. The type of the second node can include one of the following: the second node supports TN, the second node supports NTN, the second node supports mobile, or the second node does not support mobile.

As can be seen, the second node can tell the first node its type through type information, so that the first node can reselect the second node based on the type information.

It should be noted that the second node supports TN, which means the second node is located on the ground/land or belongs to the TN system, such as a TN IAB-donor or a TN miIAB-donor. The second node supports NTN, which means the second node is located off-ground (in the air) or belongs to the NTN system, such as an NTN IAB-donor or an NTN miIAB-donor. The second node supports movement, meaning its location can be moved, such as a miIAB-donor. The second node does not support movement, meaning its location is fixed, such as a non-mIAB-donor, an IAB-donor, or a stationary/fixed IAB-donor. In this way, the first node can reselect its node based on the type of the second node. For example, if the second node is an NTN mIAB-donor, and the coverage of the NTN mIAB-donor changes due to relocation, the first node can reselect a TN IAB-donor from the original NTN mIAB-donor to reside in.

Coverage information can be used to indicate the service coverage of the second node.

As can be seen, the second node can inform the first node of its service coverage through coverage information, so that the first node can reselect the second node based on the coverage information.

In some possible examples, coverage information includes the reference location and distance threshold of the second node, and/or the service validity time information and service validity time threshold of the second node. The coverage area of the second node is the range where the distance between the second node and its reference location is less than the distance threshold.

It should be noted that the reference location of the second node can represent its geographical location. The second node can have one or more reference locations. When the second node is located on the ground/land (e.g., TN IAB-donor), its reference location can be determined based on the location deployment of the frequent mobility network system, and this reference location is fixed. Thus, the first node can determine whether it is within the coverage area of the second node based on whether the distance between its own location and the second node's reference location is less than a distance threshold. Specifically, if the distance between the first node's location and the second node's reference location is less than the distance threshold, then the first node is within the second node's coverage area. If the distance between the first node's location and the second node's reference location is greater than or equal to the distance threshold, then the first node may not be within the second node's coverage area, and in this case, the first node needs to perform a node reselection.

The service validity period information of the second node indicates the valid time during which the second node can provide services to the first node. Thus, the first node can determine whether the second node can continue to provide access services based on whether the service validity period indicated by the second node's service validity period information is less than a service validity period threshold, or whether the service validity period indicated by the second node's service validity period information has ended. Specifically, if the service validity period indicated by the second node's service validity period information is greater than or equal to the service validity period threshold, or if the service validity period indicated by the second node's service validity period information has not ended, then it is determined that the second node can continue to provide access services to the first node. If the service validity period indicated by the second node's service validity period information is less than the service validity period threshold, or if the service validity period indicated by the second node's service validity period information has ended, then it is determined that the second node cannot continue to provide access services to the first node, and the first node needs to perform node reselection.

In some possible examples, the coverage information includes at least one of the following: satellite ephemeris information of the second node, service validity time information and service validity time threshold of the second node, coverage area information of the second node, or reference location information of the core network anchor point associated with the second node.

It should be noted that when the second node is located outside the ground (such as an NTN IAB-donor), the coverage information may include at least one of the following: the second node's satellite ephemeris information (such as satellite position, velocity, orbit, etc.), the second node's service validity time information and service validity time threshold, the second node's coverage area information (such as spectral position, etc.), and the reference location information of the core network anchor point associated with the second node. The reference location information of the core network anchor point may include the reference location of the NTN gateway.

Path information can be used to indicate the transmission path of the second node.

As can be seen, the second node can tell the first node its transmission path through the path information, so that the first node can reselect the second node based on the path information.

In some possible examples, the path information includes at least one of the following: the number of hops, the number of hops, the first delay, the second delay, the first distance, or the second distance.

The first hop count information can be used to indicate the number of hops on the transmission path from the node served by the second node to the second node itself. It should be noted that the number of hops on the transmission path from the node served by the second node to the second node can be understood as the number of intermediate nodes through which data passes from the node served by the second node to the second node, i.e., the number of hops. The nodes served by the second node include the first node. Thus, the second node can use the first hop count information to inform the first node of the number of hops on the transmission path from the first node to the second node, so that the first node can determine whether to perform node reselection based on this number. For example, when the number of hops exceeds the first hop count threshold, the first node performs node reselection.

The second hop count information can be used to indicate the number of hops on the transmission path from the terminal device served by the second node to the second node. It should be noted that the number of hops on the transmission path from the terminal device served by the second node to the second node can be understood as the number of intermediate nodes through which data passes from the terminal device served by the second node to the second node, i.e., the number of hops. In this way, the second node can use the second hop count information to inform the terminal device of the number of hops on the transmission path from the terminal device to the second node, so that the terminal device can determine whether to perform node reselection based on this hop count. For example, when the hop count is greater than the second hop count threshold, the terminal device performs node reselection.

The first delay information can be used to indicate the transmission delay from the node served by the second node to the second node itself. The nodes served by the second node include the first node. Thus, the second node can use the first delay information to inform the first node of the transmission delay from the first node to the second node, so that the first node can determine whether to perform node reselection based on this transmission delay. For example, when the transmission delay is greater than a first transmission time domain threshold, the first node performs node reselection.

The second delay information can be used to indicate the transmission delay from the terminal device served by the second node to the second node. In this way, the second node can inform the terminal device of the transmission delay from the terminal device to the second node through the second delay information, so that the terminal device can determine whether to perform node reselection based on the transmission delay. For example, when the transmission delay is greater than a second transmission time domain threshold, the terminal device performs node reselection.

The first distance information can be used to indicate the distance from the nodes served by the second node to the second node itself. The nodes served by the second node include the first node. Thus, the second node can use the first distance information to inform the first node of the distance from the first node to the second node, so that the first node can determine whether to perform node reselection based on this distance. For example, when the distance is greater than a first distance threshold, the first node performs node reselection.

The second distance information can be used to indicate the distance from the terminal device served by the second node to the second node. In this way, the second node can use the second distance information to inform the terminal device of the distance from the terminal device to the second node, so that the terminal device can determine whether to perform node reselection based on this distance. For example, when the distance is greater than the second distance threshold, the terminal device performs node reselection.

Valid information can be used to indicate the validity period of the F1 interface of the second node.

As can be seen, the second node can inform the first node of the validity period of its F1 interface through valid information, so that the first node can reselect the second node based on the valid information.

It should be noted that the second node can connect to the first node via the F1 interface. In this way, the first node can determine whether the second node can continue to provide access services based on whether the validity period of the second node's F1 interface is less than the F1 interface validity period threshold, or whether the validity period of the second node's F1 interface has expired. Specifically, if the validity period of the second node's F1 interface is greater than or equal to the F1 interface validity period threshold, or if the validity period of the second node's F1 interface has not expired, then the second node can continue to provide access services to the first node. If the validity period of the second node's F1 interface is less than the F1 interface validity period threshold, or if the validity period of the second node's F1 interface has expired, then the second node cannot continue to provide access services to the first node, and in this case, the second node needs to perform node reselection.

In some possible examples, valid information includes a valid time period or a timer; the valid time period is the valid time period of the F1 interface between the second node and the nodes served by the second node; the runtime of the timer is the valid duration of the F1 interface between the second node and the nodes served by the second node.

In this way, the effective time of the F1 interface of the second node is determined by the effective time period or timer.

In some possible examples, after S1801, the process also includes the following steps:

The first node sends node residency reselection information to the child nodes or terminal devices it serves. In this way, the child nodes or terminal devices served by the first node can determine whether to perform node residency reselection based on the node residency reselection information.

For example, taking the first node as IAB-node, and IAB-node as containing IAB-node DU and IAB-node MT, IAB-node DU can send node reselection information to the child IAB-node or terminal device it serves.

In some possible examples, after S1801, the process also includes the following steps:

The first node determines the third node based on the node reselection information.

In this way, when the first node resides on the second node, the first node determines the third node based on the node residency reselection information, and thus chooses to reside on the third node, thereby realizing node residency reselection.

For example, taking the first node as IAB-node, and IAB-node containing IAB-node DU and IAB-node MT, IAB-node MT can determine the third node based on the node relocation information.

Optionally, the first node may reselect a suitable third node to reside on based on the type information. For example, if the second node is an NTN mIAB-donor, the first node may reselect a TN IAB-donor from the NTN mIAB-donor to reside on.

Optionally, the first node may reselect a suitable third node to reside on based on coverage information. For example, if the distance between the location of the first node and the reference location of the second node is greater than or equal to a distance threshold, the first node may not be within the coverage area of the second node, and in this case, the first node may reselect a suitable third node to reside on. As another example, if the service validity period indicated by the service validity period information of the second node is less than the service validity period threshold, or if the service validity period indicated by the service validity period information of the second node has expired, it is determined that the second node cannot continue to provide access service to the first node, and in this case, the first node may reselect a suitable IAB-donor to reside on.

Optionally, the first node may reselect a suitable third node to reside on based on the path information. For example, if the number of hops on the transmission path from the first node to the second node is greater than a first hop count threshold, the first node may reselect a suitable third node to reside on. Similarly, if the transmission delay from the first node to the second node is greater than a first transmission time threshold, the first node may reselect a suitable third node to reside on. Furthermore, if the distance from the first node to the second node is greater than a first distance threshold, the first node may reselect a suitable third node to reside on.

The following example illustrates Figure 18, with the first node being the IAB-node and the second node being the first IAB-donor.

The first IAB-donor sends node relocation information to one or more IAB-nodes within its service range. The sending method can be unicast, multicast, or broadcast, such as carrying node relocation information via RRC messages, F1-AP messages, or Xn-AP messages. The node relocation information includes at least one of the following: type information, coverage information, path information, or validity information.

Regarding type information, type information can be used to indicate that the first IAB-donor is one of TN IAB-donor, NTN donor, stationary IAB-donor, or mIAB-donor.

For coverage information, if the first IAB-donor is a TN IAB-donor, the coverage information may include the reference positions and distance thresholds of one or more TN IAB-donors. Specifically, the range where the distance to the reference position of a TN IAB-donor is less than or equal to the distance threshold belongs to the coverage area of that TN IAB-donor. If the first IAB-donor is an NTN IAB-donor, the coverage information may include the satellite ephemeris information (i.e., satellite position, velocity, orbit, etc.), service validity period information, coverage area information, and the reference position information of the core network anchor point associated with that NTN IAB-donor.

The path information may include hop count, latency, distance, etc., which are used to indicate the hop count, latency, and distance of the transmission path from the IAB-node served by the first IAB-donor or the UE to the first IAB-donor.

For valid information, it may include the valid time period or timer of the F1 interface between the first IAB-donor and the IAB-node served by the first IAB-donor.

The IAB-node DU served by the first IAB-donor can receive node reselection information and send it to its served child IAB-nodes and/or UEs. The sending method can be unicast, multicast, or broadcast, such as carrying node reselection information through RRC messages or Uu messages. In this way, the node reselection information assists the served child IAB-nodes and/or UEs in performing node reselection.

The IAB-node MT served by the first IAB-donor can receive node relocation reselection information and reselect a suitable IAB-donor to reside in based on the reselection information.

Optionally, the IAB-node MT may reselect a suitable IAB-donor based on the type information. For example, if the first IAB-donor is an NTN mIAB-donor, the IAB-node MT may reselect a TN IAB-donor from the NTN mIAB-donor for access.

Optionally, the IAB-node MT may reselect a suitable IAB-donor based on coverage information. For example, if the distance between the location of the IAB-node MT and the reference location of the first IAB-donor is greater than or equal to a distance threshold, the IAB-node MT may not be within the coverage area of the first IAB-donor, and in this case, the IAB-node MT may reselect a suitable IAB-donor. As another example, if the service validity period indicated by the service validity period information of the first IAB-donor is less than the service validity period threshold, or if the service validity period indicated by the service validity period information of the first IAB-donor has ended, it is determined that the first IAB-donor cannot continue to provide access service to the IAB-node MT, and in this case, the IAB-node MT may reselect a suitable IAB-donor.

Optionally, the IAB-node MT can reselect a suitable IAB-donor based on the path information. For example, if the number of hops on the transmission path from the IAB-node MT to the first IAB-donor is greater than a first hop count threshold, the IAB-node MT will reselect a suitable IAB-donor. Similarly, if the transmission delay from the IAB-node MT to the first IAB-donor is greater than a first transmission time threshold, the IAB-node MT will reselect a suitable IAB-donor. Furthermore, if the distance from the IAB-node MT to the first IAB-donor is greater than a first distance threshold, the IAB-node MT will reselect a suitable IAB-donor.

It should be noted that, for the sub-IAB-node MT side served by the IAB-node DU, the sub-IAB-node MT can receive node relocation reselection information from the IAB-node DU, and reselect a suitable IAB-donor or IAB-node to reside in based on the reselection information. This will not be elaborated further.

As shown in Figure 19, Figure 19 is a flowchart illustrating another node relocation method in a frequently moving network system according to this embodiment.

Figure 19 includes the following steps:

S1901. The second node sends node reselection information to the terminal device.

Correspondingly, the terminal device receives node relocation information and performs node relocation relocation for the second node based on the node relocation information.

The node residency reselection information is used to indicate at least one of the following: type information, coverage information, or path information.

It should be noted that the explanations of type information, coverage information, and path information can be found in the description in Figure 18 above, and will not be repeated here.

It is evident that the second node assists the terminal device in reselecting the node's relocation information.

In some possible examples, after S1901, the process also includes the following steps:

The terminal device determines the third node based on the node reselection information.

In this way, when the second node provides access services to the terminal device, the terminal device determines the third node based on the node relocation information, and then chooses to relocate to the third node, thus realizing node relocation.

Optionally, the terminal device may reselect a suitable third node to reside on based on the type information. For example, if the second node is an NTN mIAB-donor, the terminal device may reselect a TN IAB-donor from the NTN mIAB-donor to reside on.

Optionally, the terminal device may reselect a suitable third node to reside on based on coverage information. For example, if the distance between the terminal device's location and the reference location of the second node is greater than or equal to a distance threshold, the terminal device may not be within the coverage area of the second node, and in this case, the terminal device may reselect a suitable third node to reside on. As another example, if the service validity period indicated by the service validity period information of the second node is less than the service validity period threshold, or if the service validity period indicated by the service validity period information of the second node has expired, it is determined that the second node cannot continue to provide access service to the terminal device, and in this case, the terminal device may reselect a suitable IAB-donor to reside on.

Optionally, the terminal device may reselect a suitable third node to reside on based on the path information. For example, if the number of hops on the transmission path from the terminal device to the second node is greater than a first hop count threshold, the terminal device may reselect a suitable third node to reside on. Similarly, if the transmission delay from the terminal device to the second node is greater than a first transmission time threshold, the terminal device may reselect a suitable third node to reside on. Furthermore, if the distance from the terminal device to the second node is greater than a first distance threshold, the terminal device may reselect a suitable third node to reside on.

In some possible examples, after S1901, the process also includes the following steps:

The terminal device updates the PDCP layer system configuration information of the second node based on the node relocation information.

It should be noted that if the second node can continue to provide access services to the terminal device, the terminal device only needs to update the PDCP layer configuration information of the second node according to the node relocation information, and does not need to update the relevant PHY/MAC/RLC layer configuration information.

For example, if the distance between the location of the terminal device and the reference location of the second node is less than or equal to the distance threshold, the terminal device may be within the coverage area of the second node. If the second node can continue to provide access services to the terminal device, the terminal device only needs to update the PDCP layer configuration information of the second node.

For example, if the service validity period indicated by the service validity period information of the second node is greater than the service validity period threshold, or if the service validity period indicated by the service validity period information of the second node has ended, then it is determined that the second node can continue to provide access services to the terminal device. In this case, the terminal device only needs to update the PDCP layer configuration information of the second node.

As shown in Figure 20, Figure 20 is a flowchart illustrating another node relocation method in a frequently moving network system according to this embodiment.

Figure 20 includes the following steps:

S2001. The first node sends node reselection information to the terminal device.

Correspondingly, the terminal device receives node relocation information and performs node relocation relocation for the second node based on the node relocation information.

The node residency reselection information is used to indicate at least one of the following: type information, coverage information, or path information.

It should be noted that the explanations of type information, coverage information, and path information can be found in the description in Figure 18 above, and will not be repeated here.

It is evident that the first node assists the terminal device in reselecting the second node's node residency through node residency reselection information.

In some possible examples, following S2001, the following steps are also included:

The terminal device determines the third node based on the node reselection information.

In this way, when the first node provides access services to the terminal device, the terminal device determines the third node based on the node relocation information, and then chooses to relocate to the third node, thus realizing node relocation.

In some possible examples, after S2001, the process also includes the following steps:

The terminal device updates the PDCP layer system configuration information of the first node based on the node relocation information.

It should be noted that if the first node can continue to provide access services to the terminal device, the terminal device only needs to update the PDCP layer configuration information of the first node according to the node relocation information, and does not need to update the relevant PHY/MAC/RLC layer configuration information.

The following is an example description of a communication device according to this embodiment.

The above mainly describes the scheme of the first node from the methodological perspective. The following is an example illustration of the functional units of a communication device in this embodiment. It is understood that, in order to achieve the above functions, the first node includes hardware structures and/or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the examples described in the embodiments disclosed herein, this embodiment can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this embodiment.

This application embodiment can divide the first node into functional units according to the above method example. For example, each function can be divided into different functional units, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software program module. It should be noted that the unit division in this application embodiment is illustrative and only represents a logical functional division, while other division methods may be used in actual implementation.

In the case of using integrated units, FIG21 is a functional unit composition block diagram of a communication device according to an embodiment of the present application. The communication device 2100 includes a receiving unit 2101.

Optionally, the receiving unit 2101 can be a module unit for receiving and processing signals, information, etc., and there are no specific limitations on this.

Optionally, the communication device 2100 may also include a transmitting unit. The transmitting unit can be a module unit used for transmitting signals, information, etc., and there are no specific limitations on this.

Optionally, the communication device 2100 may further include a storage unit for storing computer program code or instructions executed by the communication device 2100. The storage unit may be a memory.

Optionally, the communication device 2100 may be a chip or a chip module.

Optionally, the receiving unit 2101 can be integrated into the same unit or into different units.

For example, the receiving unit 2101 can be integrated into the communication unit. The communication unit can be a communication interface, transceiver, transceiver circuit, etc.

Optionally, the communication device 2100 may also include a processing unit.

It should be noted that the processing unit can be a processor or controller, such as a baseband processor, baseband chip, central processing unit (CPU), general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this embodiment. The processing unit can also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of DSP and microprocessor, etc.

Optionally, the communication device 2100 is used to perform any of the steps performed by the first node/chip/chip module, etc., as described in the above method embodiments.

In specific implementation, the receiving unit 2101 is used to perform any of the steps in the above method embodiments, and when performing actions such as sending, it can selectively call other units to complete the corresponding operations. A detailed description follows.

In some possible examples, the receiving unit 2101 is used for:

Receive switching information from the second node, the switching information is used to instruct the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment informs the first node via handover information to switch the first functional unit and the second functional unit of the first node from the second node to the third node. In this way, by switching the first and second functional units of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed using the same handover process. This helps to reduce signaling overhead, reduce resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

Optionally, the switching information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information;

The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node.

The second piece of information is used to configure the transmission path from the second node to the third node;

The third information is used to configure resources on the transmission path from the second node to the third node;

The fourth piece of information is used to configure backhaul radio link control;

The fifth piece of information is used to configure the F1 application protocol;

The sixth piece of information is used to configure the second functional unit of the first node.

Optionally, the sixth piece of information includes at least one of the following: a list of physical cell identifiers, resource configuration information, tracking area identifier configuration information, or tracking area code configuration information.

Optionally, if the first functional unit and the second functional unit of the first node switch from the second node to the third node, then the terminal equipment or sub-node served by the first node switches from the second node to the fourth node, whereby the fourth node is used to provide core network connection functions or to provide backhaul access functions.

Optionally, the communication device 2100 also includes a transmitting unit;

The sending unit is used to send capability indication information to the second node. The capability indication information is used to indicate whether the first node supports or does not support the access switching of the first functional unit and/or the second functional unit of the first node.

In some possible examples, the receiving unit 2101 is used for:

Receive condition switching information from the second node. The condition switching information is used to configure the first functional unit and the second functional unit of the first node to switch conditions.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node to perform conditional handover of its first and second functional units through conditional handover information. In this way, by performing conditional handover of the first and second functional units of the first node, the conditional handover of the first and second functional units of the first node is executed together using the same handover process. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

Optionally, the condition switching information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information;

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node, and the third node is used to provide core network connectivity functions.

The first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node;

The second piece of information is used to configure the transmission path from the second node to the third node;

The third information is used to configure resources on the transmission path from the second node to the third node;

The fourth piece of information is used to configure BH-RLC;

The fifth piece of information is used to configure F1-AP;

The sixth piece of information is used to configure the second functional unit of the first node.

Optionally, the conditions indicated by the switching condition information include:

The distance to the reference position of the second node is greater than the first distance threshold, and/or the distance to the reference position of the third node is less than the second distance threshold; and/or,

There is at least one relay node on the transmission path to the second node whose BH-RLC validity time is less than the validity time threshold.

Optionally, after receiving the condition switching command from the second node, the method further includes:

If the conditions indicated by the switching condition information are met, the first functional unit and the second functional unit of the first node will be switched from the second node to the third node.

Optionally, the communication device 2100 also includes a transmitting unit;

The sending unit is used to send capability indication information to the second node. The capability indication information is used to instruct the first node to support or not support the first functional unit and/or the second functional unit of the first node to perform condition switching.

In some possible examples, the receiving unit 2101 is used for:

Receive node residency reselection information, which indicates at least one of the following: type information, coverage information, path information, or valid information;

Type information is used to indicate the type of the second node, which is used to provide core network connectivity functions;

Coverage information is used to indicate the service coverage of the second node;

Path information is used to indicate the transmission path of the second node;

The valid information is used to indicate the validity period of the F1 interface of the second node.

As can be seen, for the first node and the second node in a frequent mobility network system, when the first node camps on the second node, this embodiment assists the first node in reselecting the second node through node camp reselection information, thereby realizing node camp reselection in a frequent mobility network system and achieving efficient mobility management.

Optionally, the communication device 2100 also includes a transmitting unit;

The sending unit is used to send node reselection information to the child nodes or terminal devices served by the first node.

Optionally, the communication device 2100 also includes a reselection unit;

The reselection unit is used to determine the third node based on the node reselection information. The third node is used to provide core network connectivity.

Optionally, the coverage information includes the reference location and distance threshold of the second node, and/or the service validity time information and service validity time threshold of the second node; the coverage area of the second node is the area where the distance between the second node and its reference location is less than the distance threshold; or,

The coverage information includes at least one of the following: satellite ephemeris information of the second node, service validity time information and service validity time threshold of the second node, coverage area information of the second node, or reference location information of the core network anchor point associated with the second node.

Optionally, the path information includes at least one of the following: first hop count information, second hop count information, first latency information, second latency information, first distance information, or second distance information;

The first hop count information is used to indicate the number of hops on the transmission path from the node served by the second node to the second node;

The second hop count information is used to indicate the number of hops on the transmission path from the terminal device served by the second node to the second node;

The first delay information is used to indicate the transmission delay from the node served by the second node to the second node;

The second delay information is used to indicate the transmission delay from the terminal device served by the second node to the second node;

The first distance information is used to indicate the distance from the node served by the second node to the second node;

The second distance information is used to indicate the distance from the terminal device served by the second node to the second node.

Optional, valid information may include a valid time period or a timer;

The valid time period is the valid time period of the F1 interface between the second node and the node served by the second node;

The timer's runtime is the effective duration of the F1 interface between the second node and the nodes it serves.

It should be noted that the specific implementation of each operation in the embodiment shown in Figure 21 can be found in the description of the method embodiment shown above, and will not be repeated here.

The following is an example description of another communication device in this embodiment.

The above mainly describes the solution involved in the second node from the methodological perspective. The following is an example illustrating the functional unit of another communication device in this embodiment. It is understood that, in order to achieve the above functions, the second node includes the corresponding hardware structure and/or software modules for executing each function.

In the case of using integrated units, FIG22 is a functional unit block diagram of another communication device according to an embodiment of the present application. The communication device 2200 includes a transmitting unit 2201.

Optionally, the transmitting unit 2201 can be a module unit used for transmitting signals, information, etc., and there are no specific limitations on this.

Optionally, the communication device 2200 may also include a receiving unit. The receiving unit can be a module unit for receiving and processing signals, information, etc., and there are no specific limitations on this.

Optionally, the communication device 2200 may further include a storage unit for storing computer program code or instructions executed by the communication device 2200. The storage unit may be a memory.

Optionally, the communication device 2200 may be a chip or a chip module.

Optionally, the transmitting unit 2201 can be integrated into the communication unit. The communication unit can be a communication interface, transceiver, transceiver circuit, etc.

Optionally, the communication device 2200 may also include a processing unit.

It should be noted that the processing unit can be a processor or controller, such as a baseband processor, baseband chip, CPU, general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this embodiment. The processing unit can also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of DSP and microprocessor, etc.

Optionally, the communication device 2200 is used to perform any of the steps performed by the chip/chip module/SMF, etc., as described in the above method embodiments.

In specific implementation, the sending unit 2201 is used to perform any of the steps in the above method embodiments, and when performing actions such as sending, it can selectively call other units to complete the corresponding operations. A detailed description follows.

In some possible examples, the sending unit 2201 is used for:

A switching message is sent to the first node, which instructs the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node via handover information to switch its first functional unit and second functional unit from the second node to the third node. In this way, by switching the first and second functional units of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed using the same handover procedure. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thus achieving efficient mobility management.

Optionally, the communication device 2200 includes a receiving unit;

The sending unit 2201 is also used to send a switching request information to the third node. The switching request information is used to request the first functional unit of the first IAB node and the second functional unit of the first node to be switched from the second node to the third node.

The receiving unit is used to receive handover response information from the third node. The handover response information is used to indicate that the first functional unit and the second functional unit of the first node are permitted to switch from the second node to the third node.

Optionally, the communication device 2200 includes a receiving unit:

The receiving unit is used to receive capability indication information from the first node. The capability indication information is used to indicate whether the first node supports or does not support the first functional unit and/or the second functional unit of the first node to perform access switching.

Optionally, the switching request information includes first identification information and second identification information;

The first identification information is used to indicate the identification of the first functional unit of the first node, and the second identification information is used to indicate the identification of the second functional unit of the first node.

Optionally, the handover request information may also include at least one of the following: third identification information, first context information, fourth identification information, or second context information;

The third identification information is used to indicate the identification of the terminal device served by the first node;

The first context information is used to indicate the context of the terminal device served by the first node; the fourth identification information is used to indicate the identifier of the first functional unit of the sub-node served by the first node and the identifier of the second functional unit of the sub-node served by the first node.

The second context information is used to indicate the context of the child nodes served by the first node.

Optionally, the switching response information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information;

The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node.

The second piece of information is used to configure the transmission path from the second node to the third node;

The third information is used to configure resources on the transmission path from the second node to the third node;

The fourth piece of information is used to configure backhaul radio link control;

The fifth piece of information is used to configure the F1 application protocol;

The sixth piece of information is used to configure the second functional unit of the first node.

Optionally, the sixth piece of information includes at least one of the following: a list of physical cell identifiers, resource configuration information, tracking area identifier configuration information, or tracking area code configuration information.

In some possible examples, the sending unit 2201 is used for:

Send condition switching information to the first node. The condition switching information is used to configure the first functional unit and the second functional unit of the first node to switch conditions.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node to perform conditional handover of its first and second functional units through conditional handover information. In this way, by performing conditional handover of the first and second functional units of the first node, the conditional handover of the first and second functional units of the first node is executed together using the same handover process. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

Optionally, the transmitting unit 2201 is also used for:

Send a conditional switching request message to the third node. The conditional switching request message is used to request the first functional unit and the second functional unit of the first node to perform conditional switching. The third node is used to provide core network connection functions.

Receive condition switching response information from the third node. The condition switching response information is used to instruct the first functional unit and the second functional unit of the first node to perform condition switching.

Optionally, the communication device 2200 may also include a receiving unit;

The receiving unit is used to receive capability indication information from the first node. The capability indication information is used to instruct the first node to support or not support the first functional unit and/or the second functional unit of the first node to perform condition switching.

Optionally, the condition switching request information includes first identification information and second identification information;

The first identification information is used to indicate the identification of the first functional unit of the first node, and the second identification information is used to indicate the identification of the second functional unit of the first node.

Optionally, the condition switching request information may also include at least one of the following: third identification information, first context information, fourth identification information, or second context information;

The third identification information is used to indicate the identification of the terminal device served by the first node;

The first context information is used to indicate the context of the terminal device served by the first node;

The fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node;

The second context information is used to indicate the context of the child nodes served by the first node.

Optionally, the condition switching response information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information;

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node must meet to switch from the second node to the third node;

The first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node;

The second piece of information is used to configure the transmission path from the second node to the third node;

The third information is used to configure resources on the transmission path from the second node to the third node;

The fourth piece of information is used to configure BH-RLC;

The fifth piece of information is used to configure F1-AP; or,

The sixth piece of information is used to configure the second functional unit of the first node.

Optionally, the conditions indicated by the switching condition information include:

The distance to the reference position of the second node is greater than the first distance threshold, and/or the distance to the reference position of the third node is less than the second distance threshold; or,

There is at least one relay node on the transmission path to the second node whose BH-RLC validity time is less than the validity time threshold.

In some possible examples, the sending unit 2201 is used for:

Send node relocation information, which includes at least one of the following: type information, coverage information, path information, or valid information;

Type information is used to indicate the type of the second node;

Coverage information is used to indicate the service coverage of the second node;

Path information is used to indicate the transmission path of the second node;

The valid information is used to indicate the validity period of the F1 interface of the second node.

As can be seen, for the first node and the second node in a frequent mobility network system, when the first node camps on the second node, this embodiment assists the first node in reselecting the second node through node camp reselection information, thereby realizing node camp reselection in a frequent mobility network system and achieving efficient mobility management.

Optionally, the coverage information includes the reference location and distance threshold of the second node, and/or the service validity time information and service validity time threshold of the second node; the coverage area of the second node is the area where the distance between the second node and its reference location is less than the distance threshold; or,

The coverage information includes at least one of the following: satellite ephemeris information of the second node, service validity time information and service validity time threshold of the second node, coverage area information of the second node, or reference location information of the core network anchor point associated with the second node.

Optionally, the path information includes at least one of the following: first hop count information, second hop count information, first latency information, second latency information, first distance information, or second distance information;

The first hop count information is used to indicate the number of hops on the transmission path from the node served by the second node to the second node;

The second hop count information is used to indicate the number of hops on the transmission path from the terminal device served by the second node to the second node;

The first delay information is used to indicate the transmission delay from the node served by the second node to the second node;

The second delay information is used to indicate the transmission delay from the terminal device served by the second node to the second node;

The first distance information is used to indicate the distance from the node served by the second node to the second node;

The second distance information is used to indicate the distance from the terminal device served by the second node to the second node.

Optional, valid information may include a valid time period or a timer;

The valid time period is the valid time period of the F1 interface between the second node and the node served by the second node;

The timer's runtime is the effective duration of the F1 interface between the second node and the nodes it serves.

It should be noted that the specific implementation of each operation in the embodiment shown in Figure 22 can be found in the description of the method embodiment shown above, and will not be repeated here.

The following is an example description of another communication device in this embodiment.

The above mainly describes the solutions involved in the third node from the methodological perspective. The following section provides an example of another functional unit of the communication device in this embodiment. It is understood that, in order to achieve the above functions, the third node includes the corresponding hardware structure and/or software modules for executing each function.

In the case of using integrated units, FIG23 is a functional unit block diagram of another communication device according to an embodiment of the present application. The communication device 2300 includes a receiving unit 2301 and a transmitting unit 2302.

Optionally, the receiving unit 2301 can be a module unit for receiving and processing signals, information, etc., and there are no specific limitations on this.

Optionally, the transmitting unit 2302 can be a module unit used for transmitting signals, information, etc., and there are no specific limitations on this.

Optionally, the communication device 2300 may further include a storage unit for storing computer program code or instructions executed by the communication device 2300. The storage unit may be a memory.

Optionally, the communication device 2300 may be a chip or a chip module.

Optionally, the receiving unit 2301 and the transmitting unit 2302 can be integrated into the communication unit. The communication unit can be a communication interface, transceiver, transceiver circuit, etc.

Optionally, the communication device 2300 may also include a processing unit.

It should be noted that the processing unit can be a processor or controller, such as a baseband processor, baseband chip, CPU, general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this embodiment. The processing unit can also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of DSP and microprocessor, etc.

Optionally, the communication device 2300 is used to perform any of the steps performed by the chip/chip module/SMF, etc., as described in the above method embodiments.

In specific implementation, the receiving unit 2301 and the sending unit 2302 are used to perform any of the steps in the above method embodiments, and when performing actions such as sending, other units can be selectively invoked to complete the corresponding operation. A detailed description follows.

In some possible examples, receiving unit 2301 is used to receive switching request information from the second node, the switching request information being used to request the first functional unit and the second functional unit of the first node to be switched from the second node to the third node.

The sending unit 2302 is used to send a handover response information to the second node. The handover response information is used to indicate that the first functional unit and the second functional unit of the first node are allowed to switch from the second node to the third node.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment can determine whether an access handover to the first node is necessary. When the second node decides that the first functional unit and the second functional unit of the first node need to be switched from the second node to the third node, the second node requests the third node to switch the first functional unit and the second functional unit of the first node from the second node to the third node through a handover request message, so that the third node can perform handover admission control. In this way, by switching the first functional unit and the second functional unit of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed together using the same handover process, which helps to reduce signaling overhead, reduce resource overhead, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

Optionally, the switching request information includes first identification information and second identification information;

The first identification information is used to indicate the identification of the first functional unit of the first node, and the second identification information is used to indicate the identification of the second functional unit of the first node.

Optionally, the handover request information may also include at least one of the following: third identification information, first context information, fourth identification information, or second context information;

The third identification information is used to indicate the identification of the terminal device served by the first node;

The first context information is used to indicate the context of the terminal device served by the first node; the fourth identification information is used to indicate the identifier of the first functional unit of the sub-node served by the first node and the identifier of the second functional unit of the sub-node served by the first node.

The second context information is used to indicate the context of the child nodes served by the first node.

Optionally, the switching response information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information;

The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node.

The second piece of information is used to configure the transmission path from the second node to the third node;

The third information is used to configure resources on the transmission path from the second node to the third node;

The fourth piece of information is used to configure backhaul radio link control;

The fifth piece of information is used to configure the F1 application protocol;

The sixth piece of information is used to configure the second functional unit of the first node.

Optionally, the sixth piece of information includes at least one of the following: a list of physical cell identifiers, resource configuration information, tracking area identifier configuration information, or tracking area code configuration information.

In some possible examples, receiving unit 2301 is used to receive condition switching request information from the second node, the condition switching request information being used to request the first functional unit and the second functional unit of the first node to perform condition switching.

The sending unit 2302 is used to send condition switching response information to the second node. The condition switching response information is used to instruct the first functional unit and the second functional unit of the first node to perform condition switching.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment can determine whether a conditional handover of the first node is necessary. When the second node decides that a conditional handover of the first node's first and second functional units is required, the second node requests the third node to perform the conditional handover of the first node's first and second functional units through a conditional handover request message, so that the third node can execute conditional handover admission control. In this way, by performing a conditional handover of the first node's first and second functional units, the conditional handover of the first node's first and second functional units can be executed together using the same handover process, thereby reducing signaling overhead, reducing resource overhead, shortening mobility interruption time, and improving handover efficiency, achieving efficient mobility management.

Optionally, the condition switching request information includes first identification information and second identification information;

The first identification information is used to indicate the identification of the first functional unit of the first node, and the second identification information is used to indicate the identification of the second functional unit of the first node.

Optionally, the condition switching request information may also include at least one of the following: third identification information, first context information, fourth identification information, or second context information;

The third identification information is used to indicate the identification of the terminal device served by the first node;

The first context information is used to indicate the context of the terminal device served by the first node;

The fourth identification information is used to indicate the identifier of the first functional unit of the child node served by the first node and the identifier of the second functional unit of the child node served by the first node;

The second context information is used to indicate the context of the child nodes served by the first node.

Optionally, the condition switching response information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information;

The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node must meet to switch from the second node to the third node;

The first information is used to configure the BAP address required for the first functional unit and the second functional unit of the first node to switch to the third node;

The second piece of information is used to configure the transmission path from the second node to the third node;

The third information is used to configure resources on the transmission path from the second node to the third node;

The fourth piece of information is used to configure BH-RLC;

The fifth piece of information is used to configure F1-AP; or,

The sixth piece of information is used to configure the second functional unit of the first node.

Optionally, the conditions indicated by the switching condition information include:

The distance to the reference position of the second node is greater than the first distance threshold, and/or the distance to the reference position of the third node is less than the second distance threshold; or,

There is at least one relay node on the transmission path to the second node whose BH-RLC validity time is less than the validity time threshold.

It should be noted that the specific implementation of each operation in the embodiment shown in Figure 23 can be found in the description of the method embodiment shown above, and will not be repeated here.

The following is an example description of another communication device in this embodiment.

The above mainly describes the solutions involved in the terminal device from the methodological perspective. The following section provides an example of the functional units of another communication device in this embodiment. It is understood that, in order to achieve the above functions, the terminal device includes the corresponding hardware structure and/or software modules for executing each function.

In the case of using integrated units, FIG24 is a functional unit block diagram of another communication device according to an embodiment of the present application. The communication device 2400 includes a receiving unit 2401.

Optionally, the receiving unit 2401 can be a module unit for receiving and processing signals, information, etc., and there are no specific limitations on this.

Optionally, the communication device 2400 may also include a transmitting unit. This transmitting unit can be a module unit used for transmitting signals, information, etc., and there are no specific limitations on its use.

Optionally, the communication device 2400 may further include a storage unit for storing computer program code or instructions executed by the communication device 2400. The storage unit may be a memory.

Optionally, the communication device 2400 may be a chip or a chip module.

Optionally, the receiving unit 2401 can be integrated into the communication unit. The communication unit can be a communication interface, transceiver, transceiver circuit, etc.

Optionally, the communication device 2400 may also include a processing unit.

It should be noted that the processing unit can be a processor or controller, such as a baseband processor, baseband chip, CPU, general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this embodiment. The processing unit can also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of DSP and microprocessor, etc.

Optionally, the communication device 2400 is used to perform any of the steps performed by the chip/chip module/SMF, etc., as described in the above method embodiments.

In specific implementation, the receiving unit 2401 is used to perform any of the steps in the above method embodiments, and when performing actions such as sending, it can selectively call other units to complete the corresponding operations. A detailed description follows.

The receiving unit 2401 is used to receive node relocation information, which indicates at least one of the following: type information, coverage information, path information, or valid information;

Type information is used to indicate the type of the second node, which is used to provide core network connectivity functions;

Coverage information is used to indicate the service coverage of the second node;

Path information is used to indicate the transmission path of the second node;

The valid information is used to indicate the validity period of the F1 interface of the second node.

As can be seen, for the second node and terminal device in a frequent mobility network system, when the terminal device camps on the second node, this embodiment assists the terminal device in reselecting the second node through node camping reselection information, thereby realizing node camping reselection in a frequent mobility network system and achieving efficient mobility management.

Optionally, the communication device 2400 also includes a reselection unit;

The reselection unit is used to determine the third node based on the node reselection information.

Optionally, the communication device 2400 also includes an update unit;

The update unit is used to update the PDCP layer configuration information of the first node or the second node based on the node residency reselection information.

Optionally, the coverage information includes the reference location and distance threshold of the second node, and/or the service validity time information and service validity time threshold of the second node; the coverage area of the second node is the area where the distance between the second node and its reference location is less than the distance threshold; or,

The coverage information includes at least one of the following: satellite ephemeris information of the second node, service validity time information and service validity time threshold of the second node, coverage area information of the second node, or reference location information of the core network anchor point associated with the second node.

Optionally, the path information includes at least one of the following: first hop count information, second hop count information, first latency information, second latency information, first distance information, or second distance information;

The first hop count information is used to indicate the number of hops on the transmission path from the node served by the second node to the second node;

The second hop count information is used to indicate the number of hops on the transmission path from the terminal device served by the second node to the second node;

The first delay information is used to indicate the transmission delay from the node served by the second node to the second node;

The second delay information is used to indicate the transmission delay from the terminal device served by the second node to the second node;

The first distance information is used to indicate the distance from the node served by the second node to the second node;

The second distance information is used to indicate the distance from the terminal device served by the second node to the second node.

Optional, valid information may include a valid time period or a timer;

The valid time period is the valid time period of the F1 interface between the second node and the node served by the second node;

The timer's runtime is the effective duration of the F1 interface between the second node and the nodes it serves.

The following is an example illustration of the structure of a node in this embodiment.

Please refer to Figure 25, which is a schematic diagram of the structure of a node according to an embodiment of this application. The node 2500 may include a processor 2510, a memory 2520, and a communication bus for connecting the processor 2510 and the memory 2520.

Optionally, the memory 2520 may include, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM). The memory 2520 is used to store the program code executed by the UPF2500 and the data transmitted.

Optionally, Node 2500 also includes a communication interface for receiving and sending data.

Optionally, node 2500 can be the first UPF mentioned above.

Optionally, the processor 2510 can be one or more CPUs. If the processor 2510 is a CPU, the CPU can be a single-core CPU or a multi-core CPU.

Optionally, the processor 2510 can be a baseband chip, chip, CPU, general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component or any combination thereof.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Receive switching information from the second node, the switching information is used to instruct the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment informs the first node via handover information to switch the first functional unit and the second functional unit of the first node from the second node to the third node. In this way, by switching the first and second functional units of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed using the same handover process. This helps to reduce signaling overhead, reduce resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Receive condition switching information from the second node. The condition switching information is used to configure the first functional unit and the second functional unit of the first node to switch conditions.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node to perform conditional handover of its first and second functional units through conditional handover information. In this way, by performing conditional handover of the first and second functional units of the first node, the conditional handover of the first and second functional units of the first node is executed together using the same handover process. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Receive node residency reselection information, which indicates at least one of the following: type information, coverage information, path information, or valid information;

Type information is used to indicate the type of the second node, which is used to provide core network connectivity functions;

Coverage information is used to indicate the service coverage of the second node;

Path information is used to indicate the transmission path of the second node;

The valid information is used to indicate the validity period of the F1 interface of the second node.

As can be seen, for the first node and the second node in a frequent mobility network system, when the first node camps on the second node, this embodiment assists the first node in reselecting the second node through node camp reselection information, thereby realizing node camp reselection in a frequent mobility network system and achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

A switching message is sent to the first node, which instructs the first functional unit and the second functional unit of the first node to switch from the second node to the third node.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node via handover information to switch its first functional unit and second functional unit from the second node to the third node. In this way, by switching the first and second functional units of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed using the same handover procedure. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thus achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Send condition switching information to the first node. The condition switching information is used to configure the first functional unit and the second functional unit of the first node to switch conditions.

As can be seen, for the first, second, and third nodes in a frequently moving network system, this embodiment informs the first node to perform conditional handover of its first and second functional units through conditional handover information. In this way, by performing conditional handover of the first and second functional units of the first node, the conditional handover of the first and second functional units of the first node is executed together using the same handover process. This helps to reduce signaling overhead, lower resource consumption, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Send node relocation information, which includes at least one of the following: type information, coverage information, path information, or valid information;

Type information is used to indicate the type of the second node;

Coverage information is used to indicate the service coverage of the second node;

Path information is used to indicate the transmission path of the second node;

The valid information is used to indicate the validity period of the F1 interface of the second node.

As can be seen, for the first node and the second node in a frequent mobility network system, when the first node camps on the second node, this embodiment assists the first node in reselecting the second node through node camp reselection information, thereby realizing node camp reselection in a frequent mobility network system and achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Receive a switching request message from the second node. The switching request message is used to request that the first functional unit and the second functional unit of the first node be switched from the second node to the third node.

A handover response message is sent to the second node. The handover response message is used to indicate that the first functional unit and the second functional unit of the first node are permitted to switch from the second node to the third node.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment can determine whether an access handover to the first node is necessary. When the second node decides that the first functional unit and the second functional unit of the first node need to be switched from the second node to the third node, the second node requests the third node to switch the first functional unit and the second functional unit of the first node from the second node to the third node through a handover request message, so that the third node can perform handover admission control. In this way, by switching the first functional unit and the second functional unit of the first node from the second node to the third node, the access handover of the first functional unit and the access handover of the second functional unit of the first node are performed together using the same handover process, which helps to reduce signaling overhead, reduce resource overhead, shorten mobility interruption time, and improve handover efficiency, thereby achieving efficient mobility management.

In some possible examples, the processor 2510 in node 2500 is used to execute a computer program or instruction 2521 stored in memory 2520, and to perform the following operations:

Receive condition switching request information from the second node. The condition switching request information is used to request the first functional unit and the second functional unit of the first node to perform condition switching.

Send a condition switching response message to the second node. The condition switching response message is used to instruct the first functional unit and the second functional unit of the first node to perform condition switching.

As can be seen, for the first, second, and third nodes in a frequently moving network system, the second node in this embodiment can determine whether a conditional handover of the first node is necessary. When the second node decides that a conditional handover of the first node's first and second functional units is required, the second node requests the third node to perform the conditional handover of the first node's first and second functional units through a conditional handover request message, so that the third node can execute conditional handover admission control. In this way, by performing a conditional handover of the first node's first and second functional units, the conditional handover of the first node's first and second functional units can be executed together using the same handover process, thereby reducing signaling overhead, reducing resource overhead, shortening mobility interruption time, and improving handover efficiency, achieving efficient mobility management.

It should be noted that the specific implementation of each operation can adopt the corresponding description of the method embodiment shown above. Node 2500 can be used to execute the method embodiment described above in this embodiment, and will not be described again here.

The structure of a terminal device in this embodiment is illustrated below.

Please refer to Figure 26, which is a schematic diagram of the structure of a terminal device according to an embodiment of this application. The terminal device 2600 may include a processor 2610, a memory 2620, and a communication bus for connecting the processor 2610 and the memory 2620.

Optionally, the memory 2620 may include, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM). The memory 2620 is used to store the program code executed by the SMF2600 and the data transmitted.

Optionally, the terminal device 2600 also includes a communication interface for receiving and sending data.

Optionally, the terminal device 2600 can be the first SMF mentioned above.

Optionally, the processor 2610 can be one or more CPUs. If the processor 2610 is a CPU, the CPU can be a single-core CPU or a multi-core CPU.

Optionally, the processor 2610 can be a baseband chip, chip, CPU, general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component or any combination thereof.

In specific implementation, the processor 2610 in the terminal device 2600 executes the computer program or instruction 2621 stored in the memory 2620 to perform the following operations:

Receive node reselection information, which indicates at least one of the following: type information, coverage information, path information, or validity information; type information indicates the type of the second node, which is used to provide core network connectivity functions; coverage information indicates the service coverage of the second node; path information indicates the transmission path of the second node; validity information indicates the validity period of the F1 interface of the second node.

As can be seen, for the second node and terminal device in a frequent mobility network system, when the terminal device camps on the second node, this embodiment assists the terminal device in reselecting the second node through node camping reselection information, thereby realizing node camping reselection in a frequent mobility network system and achieving efficient mobility management.

It should be noted that the specific implementation of each operation can adopt the corresponding description of the method embodiment shown above. The terminal device 2600 can be used to execute the method embodiment described above in this embodiment, and will not be described again.

The following provides examples illustrating other relevant aspects of this embodiment.

This application also provides a chip, including a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps described in the above method embodiments.

This application also provides a chip module, including a transceiver component and a chip. The chip includes a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps described in the above method embodiments.

This application also provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the steps described in the above method embodiments.

This application also provides a computer program product, including a computer program or instructions that, when executed, implement the steps described in the above method embodiments.

It should be noted that, for the sake of simplicity, the above embodiments are all described as a series of actions. Those skilled in the art should understand that this application is not limited to the described order of actions, as some steps in the embodiments of this application can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions, steps, modules, or units involved are not necessarily essential to the embodiments of this application.

In the above embodiments, the descriptions of each embodiment in this application have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

The steps of the methods or algorithms described in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in RAM, flash memory, ROM, EPROM, electrically erasable programmable read-only memory (EEPROM), registers, hard disk, portable hard disk, read-only optical disk (CD-ROM), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Additionally, the ASIC can reside in a terminal device or management device. Alternatively, the processor and storage medium can exist as discrete components in the terminal device or management device.

Those skilled in the art will recognize that, in one or more of the examples above, the functions described in the embodiments of this application can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state drives (SSDs)).

The modules/units included in the various devices and products described in the above embodiments can be software modules/units, hardware modules/units, or a combination of both. For example, for devices and products applied to or integrated into a chip, all modules/units can be implemented using hardware methods such as circuits, or at least some modules/units can be implemented using software programs that run on a processor integrated within the chip, while the remaining (if any) modules/units can be implemented using hardware methods such as circuits. For devices and products applied to or integrated into a chip module, all modules/units can be implemented using hardware methods such as circuits. Different modules/units can be located in the same component (e.g., chip, circuit module, etc.) or different components of the chip module, or at least some modules/units can be implemented using hardware methods such as circuits. The implementation is achieved through a software program that runs on a processor integrated within the chip module. The remaining modules/units (if any) can be implemented using hardware methods such as circuits. For various devices and products applied to or integrated into terminal equipment, each of their modules/units can be implemented using hardware methods such as circuits. Different modules/units can be located in the same component (e.g., chip, circuit module, etc.) or different components within the terminal equipment. Alternatively, at least some modules/units can be implemented using a software program that runs on a processor integrated within the terminal equipment, while the remaining modules/units (if any) can be implemented using hardware methods such as circuits.

The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above descriptions are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims (30)

A communication method, characterized in that it is applied to a first node, the first node being used to provide backhaul access functionality; the method includes: The system receives handover information from a second node, which instructs the first functional unit and the second functional unit of the first node to switch from the second node to the third node. The second node and the third node are used to provide core network connectivity, the first functional unit of the first node is used to provide backhaul functionality, and the second functional unit of the first node is used to provide access functionality. The method according to claim 1, wherein the switching information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information; The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; The second information is used to configure the transmission path from the second node to the third node; The third information is used to configure resources on the transmission path from the second node to the third node; The fourth piece of information is used to configure backhaul radio link control; The fifth piece of information is used to configure the F1 application protocol; The sixth piece of information is used to configure the second functional unit of the first node. The method according to claim 1 or 2, characterized in that, if the first functional unit and the second functional unit of the first node switch from the second node to the third node, then The terminal device or sub-node served by the first node switches from the second node to the fourth node, whereby the fourth node is used to provide core network connectivity or backhaul access functionality. The method according to any one of claims 1-3, characterized in that, before receiving the handover information from the second node, the method further comprises: The first node sends capability indication information to the second node, the capability indication information being used to indicate whether the first node supports or does not support the first functional unit and/or the second functional unit of the first node for access switching. A communication method, characterized in that it is applied to a second node, the second node being used to provide core network connectivity functions; the method includes: Send switching information to the first node, the switching information being used to instruct the first functional unit and the second functional unit of the first node to switch from the second node to the third node; The third node is used to provide core network connectivity, the first functional unit of the first node is used to provide backhaul functionality, and the second functional unit of the first node is used to provide access functionality. The method according to claim 5, characterized in that, before sending the handover information to the first node, the method further includes: Send a switching request message to the third node, the switching request message being used to request the first functional unit and the second functional unit of the first node to be switched from the second node to the third node; The system receives a handover response information from the third node, which instructs the first functional unit and the second functional unit of the first node to switch from the second node to the third node. The method according to claim 5, characterized in that, before sending the handover information to the first node, the method further includes: The first node receives capability indication information, which is used to indicate whether the first node supports or does not support the first functional unit and/or the second functional unit of the first node for access switching. According to the method of claim 6, the switching request information includes first identification information and second identification information; The first identification information is used to indicate the identification of the first functional unit of the first node, and the second identification information is used to indicate the identification of the second functional unit of the first node. According to the method of claim 6, the switching response information includes at least one of the following: first information, second information, third information, fourth information, fifth information, or sixth information; The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; The second information is used to configure the transmission path from the second node to the third node; The third information is used to configure resources on the transmission path from the second node to the third node; The fourth piece of information is used to configure backhaul radio link control; The fifth piece of information is used to configure the F1 application protocol; The sixth piece of information is used to configure the second functional unit of the first node. A communication method, characterized in that it is applied to a first node, the first node being used to provide backhaul access functionality; the method includes: Receive condition switching information from the second node, the condition switching information being used to configure the first functional unit of the first node and the second functional unit of the first node to perform condition switching; The second node is used to provide core network connectivity, the first functional unit of the first node is used to provide backhaul functionality, and the second functional unit of the first node is used to provide access functionality. According to the method of claim 10, the condition switching information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information; The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node, wherein the third node is used to provide core network connectivity functions. The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; The second information is used to configure the transmission path from the second node to the third node; The third information is used to configure resources on the transmission path from the second node to the third node; The fourth piece of information is used to configure backhaul radio link control; The fifth piece of information is used to configure the F1 application protocol; The sixth piece of information is used to configure the second functional unit of the first node. According to the method of claim 11, the conditions indicated by the switching condition information include: The distance between the reference position of the second node and the reference position of the third node is greater than a first distance threshold, and/or the distance between the reference position of the third node and the reference position of the third node is less than a second distance threshold; and/or, The backhaul radio link control validity time of at least one relay node on the transmission path to the second node is less than the validity time threshold. The method according to claim 11 or 12, characterized in that, after receiving the condition switching command from the second node, the method further includes: If the conditions indicated by the switching condition information are met, then the first functional unit and the second functional unit of the first node are switched from the second node to the third node. The method according to any one of claims 10-13, characterized in that, before receiving condition switching information from the second node, the method further comprises: The first node sends capability indication information to the second node, the capability indication information being used to instruct the first node to support or not support condition switching of the first functional unit and/or the second functional unit of the first node. A communication method, characterized in that it is applied to a second node, the second node being used to provide core network connectivity functions; the method includes: Send condition switching information to the first node, the condition switching information being used to configure the first functional unit and the second functional unit of the first node to perform condition switching; The first functional unit of the first node is used to provide backhaul functionality, and the second functional unit of the first node is used to provide access functionality. The method according to claim 15, characterized in that, before sending condition switching information to the first node, the method further includes: Send a condition switching request message to the third node. The condition switching request message is used to request the first functional unit and the second functional unit of the first node to perform condition switching. The third node is used to provide core network connection function. The condition switching response information is received from the third node, which is used to instruct the first functional unit and the second functional unit of the first node to perform condition switching. The method according to claim 15, characterized in that, before sending condition switching information to the first node, the method further includes: The first node receives capability indication information, which is used to instruct the first node to support or not support condition switching of the first functional unit and/or the second functional unit of the first node. According to the method of claim 16, the condition switching request information includes first identification information and second identification information; The first identification information is used to indicate the identification of the first functional unit of the first node, and the second identification information is used to indicate the identification of the second functional unit of the first node. According to the method of claim 16, the condition switching response information includes at least one of the following: switching condition information, first information, second information, third information, fourth information, fifth information, or sixth information; The switching condition information is used to indicate the conditions that the first functional unit and the second functional unit of the first node need to meet to switch from the second node to the third node; The first information is used to configure the backhaul adaptation protocol address required for the first functional unit and the second functional unit of the first node to switch to the third node; The second information is used to configure the transmission path from the second node to the third node; The third information is used to configure resources on the transmission path from the second node to the third node; The fourth piece of information is used to configure backhaul radio link control; The fifth piece of information is used to configure the F1 application protocol; or, The sixth piece of information is used to configure the second functional unit of the first node. The method according to claim 19, wherein the conditions indicated by the switching condition information include: The distance between the reference position of the second node and the reference position of the third node is greater than a first distance threshold, and/or the distance between the reference position of the third node and the reference position of the third node is less than a second distance threshold; or, The backhaul radio link control validity time of at least one relay node on the transmission path to the second node is less than the validity time threshold. A communication method, characterized in that it is applied to a first node, the first node being used to provide backhaul access functionality; the method includes: Receive node residency reselection information, wherein the node residency reselection information is used to indicate at least one of the following: type information, coverage information, path information, or valid information; The type information is used to indicate the type of the second node, which is used to provide core network connectivity functions. The coverage information is used to indicate the service coverage of the second node; The path information is used to indicate the transmission path of the second node; The valid information is used to indicate the validity period of the F1 interface of the second node. The method according to claim 21, characterized in that, after receiving the node reselection information, the method further includes: Send the node relocation information to the child nodes or terminal devices served by the first node. The method according to claim 21, characterized in that, after receiving the node reselection information, the method further includes: A third node is determined based on the node relocation information, and the third node is used to provide core network connectivity functions. A communication method, characterized in that it is applied to a second node, the second node being used to provide core network connectivity functions; the method includes: Send node relocation information, wherein the node relocation information includes at least one of the following: type information, coverage information, path information, or valid information; The type information is used to indicate the type of the second node; The coverage information is used to indicate the service coverage of the second node; The path information is used to indicate the transmission path of the second node; The valid information is used to indicate the validity period of the F1 interface of the second node. The method according to any one of claims 21-24, characterized in that the coverage information includes the reference location and distance threshold of the second node, and/or the service validity time information and service validity time threshold of the second node; the coverage range of the second node is the range where the distance between it and the reference location of the second node is less than the distance threshold; or, The coverage information includes at least one of the following: satellite ephemeris information of the second node, service validity time information and service validity time threshold of the second node, coverage area information of the second node, or reference location information of the core network anchor point associated with the second node. The method according to any one of claims 21-24, wherein the path information includes at least one of the following: first hop count information, second hop count information, first delay information, second delay information, first distance information, or second distance information; The first hop count information is used to indicate the number of hops on the transmission path from the node served by the second node to the second node; The second hop count information is used to indicate the number of hops on the transmission path from the terminal device served by the second node to the second node; The first delay information is used to indicate the transmission delay from the node served by the second node to the second node; The second delay information is used to indicate the transmission delay from the terminal device served by the second node to the second node; The first distance information is used to indicate the distance from the node served by the second node to the second node; The second distance information is used to indicate the distance from the terminal device served by the second node to the second node. A communication device, characterized in that it includes a processing unit, the processing unit being configured to perform the steps of the method according to any one of claims 1-4, 10-14, 21-23, or 25-26, or the processing unit being configured to perform the steps of the method according to any one of claims 5-9, 15-20, or 24-26. A communication device includes a processor, a memory, and a computer program or instructions stored in the memory, characterized in that the processor executes the computer program or instructions to implement the steps of the method according to any one of claims 1-4, 10-14, 21-23, or 25-26, or the processor executes the computer program or instructions to implement the steps of the method according to any one of claims 5-9, 15-20, or 24-26. A chip, comprising a processor, characterized in that the processor performs the steps of the method according to any one of claims 1-26. A computer-readable storage medium, characterized in that it stores a computer program or instructions, wherein when the computer program or instructions are executed, the steps of the method according to any one of claims 1-26 are performed.