WO2025023778A1

WO2025023778A1 - Node and user equipment in wireless communication system and method performed by the same

Info

Publication number: WO2025023778A1
Application number: PCT/KR2024/010904
Authority: WO
Inventors: Yanru Wang; Lixiang Xu; Hong Wang; Yu Pan
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2023-07-26
Filing date: 2024-07-26
Publication date: 2025-01-30
Anticipated expiration: 2026-01-26
Also published as: CN119383689A

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a master node (MN) in a wireless communication system, the method comprising: identifying whether an early data forwarding of secondary node (SN) is needed; and transmitting, to the SN, address indication message associated with the early data forwarding, wherein the early data forwarding to other candidate SNs is performed based on the address indication message.

Description

NODE AND USER EQUIPMENT IN WIRELESS COMMUNICATION SYSTEM AND METHOD PERFORMED BY THE SAME

The present disclosure relates to a technical field of wireless communication, and more specifically, to a node and user equipment in a wireless communication system and methods performed by the same.

In order to meet an increasing demand for wireless data communication services since a deployment of 4G communication system, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called "beyond 4G network" or "post LTE system".

Wireless communication is one of the most successful innovations in modern history. Recently, a number of subscribers of wireless communication services has exceeded 5 billion, and it continues growing rapidly. With the increasing popularity of smart phones and other mobile data devices (such as tablet computers, notebook computers, netbooks, e-book readers and machine-type devices) in consumers and enterprises, a demand for wireless data services is growing rapidly. In order to meet rapid growth of mobile data services and support new applications and deployments, it is very important to improve efficiency and coverage of wireless interfaces.

5th generation (5G) or new radio (NR) mobile communications is recently gathering increased momentum with all the worldwide technical activities on the various candidate technologies from industry and academia. The candidate enablers for the 5G/NR mobile communications include massive antenna technologies, from legacy cellular frequency bands up to high frequencies, to provide beamforming gain and support increased capacity, new waveform (e.g., a new radio access technology (RAT)) to flexibly accommodate various services/applications with different requirements, new multiple access schemes to support massive connections, and so on.

5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

Moreover, there has been ongoing standardization in air interface architecture/protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture/service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

In a handover process, a source node may transmit relevant data of a user to a target node before the user accesses the target node, so that the user can quickly obtain the relevant data after accessing the target node, so as to avoid service interruption caused by handover.

In a process of conditional secondary node change and/or addition, the UE and candidate target secondary nodes may keep configuration thereof as the configuration for a subsequent secondary node change and/or addition. This process has at least one of the following problems:

1. In this case, a candidate target secondary node needs to reserve resources for a long time. Due to the limitation of resources, reserving resources for a long time may lead to performance damage of other users due to resource shortage.

2. After a user switches to a target secondary node, when the user has a subsequent change of the secondary node, the target secondary node cannot forward data to other target secondary nodes, thus service continuity cannot be guaranteed.

3. Because the configuration can be kept for a long time, with the movement of users, etc., there is no need to forward data for each candidate target node, which would lead to the waste of data transmission.

How to select the target node for data forwarding and when to trigger data forwarding have great influence on improving the effectiveness of data forwarding.

A method performed by a master node (MN) in a wireless communication system, the method comprising: identifying whether an early data forwarding of secondary node (SN) is needed; and transmitting, to the SN, address indication message associated with the early data forwarding, wherein the early data forwarding to other candidate SNs is performed based on the address indication message.

A method performed by a secondary node (SN) in a wireless communication system, the method comprising: performing a random access procedure with a user equipment (UE); receiving, from a master node (MN), address indication message associated with an early data forwarding; identifying whether to perform the early data forwarding; and performing the early data forwarding to other candidate SNs.

A master node (MN) in a wireless communication system, the MN comprising: a transceiver; and a controller coupled with the transceiver and configured to: identify whether an early data forwarding of secondary node (SN) is needed, transmit, to the SN, address indication message associated with the early data forwarding, and wherein the early data forwarding to other candidate SNs is performed based on the address indication message.

A secondary node (SN) in a wireless communication system, the SN comprising: a transceiver; and a controller coupled with the transceiver and configured to: perform a random access procedure with a user equipment (UE), receive, from a master node (MN), address indication message associated with an early data forwarding, identify whether to perform the early data forwarding, and perform the early data forwarding to other candidate SNs.

The above and other aspects, features and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exemplary system architecture 100 of System Architecture Evolution (SAE);

FIG. 2 is an exemplary system architecture 200 according to various embodiments of the present disclosure;

FIGs. 3A-3L respectively show schematic diagrams of an aspect of a method for supporting mobility management according to embodiments of the present disclosure;

FIGs. 4A-4K respectively show schematic diagrams of an aspect of a method for supporting mobility management according to embodiments of the present disclosure;

FIGs. 5A-5G respectively show schematic diagrams of an aspect of a method for supporting mobility management according to embodiments of the present disclosure;

FIG. 6 shows a flowchart of a method performed by a first node in a wireless communication system according to embodiments of the present disclosure;

FIG. 7 shows a flowchart of a method performed by a second node in a wireless communication system according to embodiments of the present disclosure;

FIG. 8 shows a flowchart of a method performed by a user equipment in a wireless communication system according to embodiments of the present disclosure;

FIG. 9 shows a schematic diagram of a first node according to embodiments of the present disclosure;

FIG. 10 shows a schematic diagram of a second node according to embodiments of the present disclosure;

FIG. 11 shows a schematic diagram of user equipment according to embodiments of the present disclosure; and

FIGs. 11A-11B respectively show schematic diagrams of an aspect of a method performed by a node according to embodiments of the present disclosure.

Embodiments of the present disclosure provide a method performed by a first node in a wireless communication system, which includes: transmitting a fourth message to a second node, wherein the fourth message includes information related to resource reservation time in a conditional handover; receiving a second message including a data transmission address of a candidate target cell from the second node; receiving a sixth message from the second node or a user equipment (UE), wherein the sixth message includes prediction information related to the conditional handover; determining whether to perform data transmission based on the prediction information related to the conditional handover; and in case that it is determined to perform data transmission, performing data transmission based on the data transmission address.

Embodiments of the present disclosure provide a method performed by a second node in a wireless communication system, including: receiving a fourth message from a first node, wherein the fourth message includes information related to resource reservation time in a conditional handover; transmitting a second message including a data transmission address of a candidate target cell to the first node; and transmitting a sixth message to the first node, wherein the sixth message includes prediction information related to the conditional handover; wherein the prediction information related to the conditional handover is used for the first node to determine whether to perform data transmission; and wherein in case that it is determined to perform data transmission, the first node performs data transmission based on the data transmission address.

Embodiments of the present disclosure provide a method performed by a user equipment (UE) in a wireless communication system, which includes: receiving a fourth message from a second node, wherein the fourth message includes an RRC container, which includes information related to resource reservation time in a conditional handover; and transmitting a sixth message to the second node or a first node, wherein the sixth message includes prediction information related to the conditional handover, wherein the prediction information related to the conditional handover is used for the first node to determine whether to perform data transmission.

Embodiments of the present disclosure provide a first node device in a wireless communication system, including a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to perform a method performed by a first node in a wireless communication system according to embodiments of the present disclosure.

Embodiments of the present disclosure provide a second node device in a wireless communication system, including a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to perform a method performed by a second node in a wireless communication system according to embodiments of the present disclosure.

Embodiments of the present disclosure provide a user equipment (UE) in a wireless communication system, including a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to perform a method performed by a user equipment (UE) in a wireless communication system according to embodiments of the present disclosure.

Embodiments of the present disclosure provide a computer-readable medium having stored thereon computer-readable instructions which, when executed by a processor, implement methods performed by a first node and/or a second node and/or a user equipment in a wireless communication system according to embodiments of the present disclosure.

The methods implemented by the first node and/or the second node and/or the user equipment in the wireless communication system provided by the present disclosure can ensure the continuity of service by exchanging information related to a conditional handover between nodes.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

The term "include" or "may include" refers to the existence of a corresponding disclosed function, operation or component which can be used in various embodiments of the present disclosure and does not limit one or more additional functions, operations, or components. The terms such as "include" and/or "have" may be construed to denote a certain characteristic, number, step, operation, constituent element, component or a combination thereof, but may not be construed to exclude the existence of or a possibility of addition of one or more other characteristics, numbers, steps, operations, constituent elements, components or combinations thereof.

The term "or" used in various embodiments of the present disclosure includes any or all of combinations of listed words. For example, the expression "A or B" may include A, may include B, or may include both A and B.

Unless defined differently, all terms used herein, which include technical terminologies or scientific terminologies, have the same meaning as that understood by a person skilled in the art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted to have the meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.

According to embodiments of the present disclosure, before receiving a second message including a data transmission address of a candidate target cell from the second node, a radio resource control (RRC) reconfiguration complete message is transmitted by the UE to the second node.

According to embodiments of the present disclosure, the information related to resource reservation time in a conditional handover is used for the second node to determine whether to take the first node as a candidate target node.

According to embodiments of the present disclosure, the method further includes: transmitting a first message including a request for a data transmission address to the second node, wherein the second message is transmitted from the second node based on the first message.

According to embodiments of the present disclosure, the method further includes: receiving a third message from the second node, wherein the third message includes information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, wherein the fourth message is transmitted to the second node based on the third message.

According to embodiments of the present disclosure, the method further includes: transmitting a fifth message to the second node, wherein the fifth message includes a request for reporting the prediction information related to the conditional handover, wherein the sixth message is transmitted from the second node based on the fifth message.

According to embodiments of the present disclosure, the data transmission includes one or more of normal data transmission and data forwarding, wherein the data forwarding includes one or more of early data forwarding, late data forwarding and normal data forwarding.

According to embodiments of the present disclosure, the second message includes one or more of the following: an identifier of a UE performing conditional handover, a request index corresponding to the second message, an accepted Quality of Service (QoS) flow identifier, a transmission address, a data transmission direction corresponding to the transmission address, information about whether to trigger data transmission, identification for triggering data transmission, event to trigger data transmission, a cell identifier corresponding to the transmission address, a node identifier corresponding to the transmission address, a slice identifier corresponding to the transmission address, a Protocol Data Unit (PDU) session identifier corresponding to the transmission address, a radio bearer identifier corresponding to the transmission address, a Quality of Service (QoS) flow identifier corresponding to the transmission address, and information that can be used for data transmission.

According to embodiments of the present disclosure, the first message includes one or more of the following: an identifier of a UE performing conditional handover, a request index, identification for requesting address reporting, a direction of data transmission, a cell identifier corresponding to the requested transmission address, a node identifier corresponding to the requested transmission address, a slice identifier corresponding to the requested transmission address, a Protocol Data Unit (PDU) session identifier corresponding to the requested transmission address, a radio bearer identifier corresponding to the requested transmission address, a Quality of Service (QoS) flow identifier corresponding to the requested transmission address, and requested information for data transmission

According to embodiments of the present disclosure, the fourth message includes one or more of the following: a cell identifier corresponding to information related to resource reservation time in a conditional handover, a node identifier corresponding to information related to resource reservation time in a conditional handover, a slice identifier corresponding to information related to resource reservation time in a conditional handover, a UE identifier corresponding to information related to resource reservation time in a conditional handover, maximum resource reservation time, minimum resource reservation time, resource reservation time interval, and applicable time corresponding to a handover configuration.

According to embodiments of the present disclosure, the third message includes one or more of the following: a cell identifier corresponding to information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, a node identifier corresponding to information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, a slice identifier corresponding to information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, a UE identifier for conditional handover corresponding to information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, an estimated maximum arrival probability of a UE, time corresponding to the estimated maximum arrival probability of the UE, an estimated minimum arrival probability of a UE, time corresponding to the estimated minimum arrival probability of the UE, an estimated arrival time of a UE, an estimated arrival probability of a UE, time corresponding to the estimated arrival probability of the UE, requested maximum resource reservation time, requested minimum resource reservation time, requested resource reservation time interval, requested resource reservation time, indication of whether to allow setting resource reservation time, and prediction confidence.

According to embodiments of the present disclosure, the sixth message includes one or more of the following: request identification corresponding to the sixth message, an identifier of a transmitting node, an identifier of a receiving node, a user identifier corresponding to reported information, measurement content and/or prediction content, reported content, an event to trigger the reporting, applicable time corresponding to the measurement content, and applicable time corresponding to the reported content.

According to embodiments of the present disclosure, the fifth message includes one or more of the following: request identification, an identifier of a transmitting node, an identifier of a receiving node, a UE identifier corresponding to requested information, reporting mode, reporting time, reporting period, reporting trigger event, measurement mode and/or prediction mode, measurement time and/or prediction time, measurement period and/or prediction period, requested measurement content and/or prediction content, requested reporting content, applicable time corresponding to the requested reporting content, requested prediction time, requested confidence requirement for reporting, and prediction confidence.

According to embodiments of the present disclosure, before transmitting the second message including a data transmission address of a candidate target cell to the first node, the method further includes: receiving a radio resource control (RRC) reconfiguration complete message from a user equipment (UE).

According to embodiments of the present disclosure, the method further includes: determining whether to take the first node as a candidate target node based on the information related to resource reservation time in a conditional handover.

According to embodiments of the present disclosure, the method further includes: receiving a first message including a request for a data transmission address from the first node, wherein the second message is transmitted to the first node based on the first message.

According to embodiments of the present disclosure, the method further includes: transmitting a third message to the first node, wherein the third message includes information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, wherein the fourth message is transmitted from the first node based on the third message.

According to embodiments of the present disclosure, the method further includes: receiving a fifth message from the first node, wherein the fifth message includes a request for reporting the prediction information related to the conditional handover, wherein the sixth message is transmitted to the first node based on the fifth message.

According to embodiments of the present disclosure, the method further includes: detecting whether an execution event is met based on the information related to resource reservation time in a conditional handover.

Embodiments of the present disclosure provide a first node device in a wireless communication system, including: a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to perform methods performed by a first node in a wireless communication system according to embodiments of the present disclosure.

Embodiments of the present disclosure provide a second node device in a wireless communication system, including: a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to perform methods performed by a second node in a wireless communication system according to embodiments of the present disclosure.

Embodiments of the present disclosure provide a user equipment (UE) in a wireless communication system, including: a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to perform methods performed by a user equipment (UE) in a wireless communication system according to embodiments of the present disclosure.

Figures discussed below and various embodiments for describing the principles of the present disclosure in this patent document are only for illustration and should not be interpreted as limiting the scope of the present disclosure in any way. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

FIG. 1 is an exemplary system architecture 100 of system architecture evolution (SAE). User equipment (UE) 101 is a terminal device for receiving data. An evolved universal terrestrial radio access network (E-UTRAN) 102 is a radio access network, which includes a macro base station (eNodeB/NodeB) that provides UE with interfaces to access the radio network. A mobility management entity (MME) 103 is responsible for managing mobility context, session context and security information of the UE. A serving gateway (SGW) 104 mainly provides functions of user plane, and the MME 103 and the SGW 104 may be in the same physical entity. A packet data network gateway (PGW) 105 is responsible for functions of charging, lawful interception, etc., and may be in the same physical entity as the SGW 104. A policy and charging rules function entity (PCRF) 106 provides quality of service (QoS) policies and charging criteria. A general packet radio service support node (SGSN) 108 is a network node device that provides routing for data transmission in a universal mobile telecommunications system (UMTS). A home subscriber server (HSS)109 is a home subsystem of the UE, and is responsible for protecting user information including a current location of the user equipment, an address of a serving node, user security information, and packet data context of the user equipment, etc.

FIG. 2 is an exemplary system architecture 200 according to various embodiments of the present disclosure. Other embodiments of the system architecture 200 can be used without departing from the scope of the present disclosure.

User equipment (UE) 201 is a terminal device for receiving data. A next generation radio access network (NG-RAN) 202 is a radio access network, which includes a base station (a gNB or an eNB connected to 5G core network 5GC, and the eNB connected to the 5GC is also called ng-gNB) that provides UE with interfaces to access the radio network. An access control and mobility management function entity (AMF) 203 is responsible for managing mobility context and security information of the UE. A user plane function entity (UPF) 204 mainly provides functions of user plane. A session management function entity SMF 205 is responsible for session management. A data network (DN) 206 includes, for example, services of operators, access of Internet and service of third parties.

Entities and/or nodes mentioned in the present disclosure may include: gNB, gNB Central Unit (gNB-CU), gNB Distributed Unit (gNB-DU), gNB Central Unit control plane (gNB-CU-CP), gNB Central Unit user plane (gNB CU-UP), en-gNB, eNB, ng-eNB, UE, Access and Mobility Management Function (AMF), Session Management Function (SMF), Mobility Management Entity (MME) and other network entities or network logic units.

The signal strength and/or signal quality described in the present disclosure may be a Received Signal Strength Indicator (RSSI), a Reference Signal Receiving Power, RSRP), a Reference Signal Receiving Quality (RSRQ), and a Signal to Interference plus Noise Ratio (SINR), etc.

The handover described in the present disclosure may include any situation where a user's accessed node and/or cell change, for example, it may include one or more of the following: handover, secondary node addition, secondary node change, master node change, and the like.

The data transmission described in the present disclosure may include (normal) Data Transmission, Data Forwarding, and the like. Herein, the data forwarding includes Early Data Forwarding, Late Data Forwarding, (normal) Data Forwarding, data transmission of Packet Data Convergence Protocol (PDCP) duplication, etc.

The data transmission described in the present disclosure may be from one node to another, from an old node to a new node, from a source node to a target node, from a master node to a secondary node, from a source master node to a target secondary node, from an old secondary node to a new secondary node, from a source secondary node to a new secondary node, from an old master node to a new master node, from a source master node to a target master node, or from a secondary node to a master node, etc.

In the present disclosure, a node may refer to a node or a cell managed by the node. For example, a target node may refer to both a target node and a target cell.

In the present disclosure, a cell may refer to a cell or a node where the cell is located.

In the present disclosure, a source node may refer to a source node in any handover, such as handover of a source node, a source secondary node, or a source master node, etc.

In the present disclosure, a target node may also refer to a candidate target secondary node.

In the present disclosure, a target node may refer to a target node in any handover, such as handover of a target node, a target secondary node, a target master node, a candidate target node, a candidate target secondary node, a candidate target master node, etc.

In the present disclosure, an execution event and an execution condition may refer to each other.

The method performed by a first node and/or a second node and/or a user equipment in a wireless communication system provided by the present disclosure may also be called a method for supporting mobility management.

Example 1

In some implementations, the present disclosure provides a method for supporting mobility management, which may include: a first node transmits a first message containing a request for a data transmission address to a second node for the second node to transmit the related data transmission address to the first node. After obtaining the data transmission address, the first node transmits data according to the obtained address and/or its own stored address, or the first node may store the data transmission address and not trigger data transmission after the first node obtains the address, and provide it as reference information for subsequent data transmission. In some implementations, for example, after the first node obtains the address of data transmission (for example, it may be data forwarding), before the user accesses a target node and/or cell, the first node performs data forwarding to transmit the relevant data to the related target node and/or cell, so as to ensure that the UE can quickly receive relevant data after handover and ensure the service continuity for the UE.

In some implementations, the first message may be or may be carried by one or more of the following messages: a XN-U ADDRESS INDICATION message or an EARLY STATUS TRANSFER message or a HANDOVER SUCCESS message or a S-NODE ADDITION REQUEST ACKNOWLEDGE message or a S-NODE MODIFICATION REQUEST ACKNOWLEDGE message of Xn, or an other and/or newly defined RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or a RRC container.

In some implementations, the first message may include one or more of the following fields or related information:

· UE identifier: used to identify the UE performing (conditional) handover. It may include one or more of the following: a user identifier assigned by a new node, a user identifier assigned by an old node, a user identifier assigned by a source node, a user identifier assigned by a secondary node, a user identifier assigned by a master node, a user identifier assigned by a candidate secondary node, a user identifier assigned by a transmitting node of the first message, a user identifier assigned by a receiving node of the first message, etc. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Request index: used to identify this request.

● Identification for requesting address reporting: used to indicate whether address information is requested to be reported. The identification may be represented by a single bit. For example, when the bit is 1, it means that reporting address information is requested, and when the bit is 0, it means that reporting address information is not requested. It may also be that when this field appears, it means that reporting address information is requested, and when this field does not appear, it means that reporting address information is not requested.

● Direction of data transmission: used to indicate a direction of data transmission corresponding to the requested address. The direction includes one or more of the following: uplink, downlink, uplink or downlink, uplink and downlink.

● Cell identifier: a cell identifier corresponding to the requested transmission address, which is used to indicate which cell and/or cells the requested address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Node identifier: a node identifier corresponding to the requested transmission address, which is used to identify which node and/or nodes the requested address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Slice identifier: a slice identifier corresponding to the requested transmission address, which is used to identify which slice and/or slices the requested address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Protocol Data Unit (PDU) session identifier: a Protocol Data Unit (PDU) session identifier corresponding to the requested transmission address, which is used to identify which PDU session and/or PDU sessions the requested address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Radio bearer identifier: a radio bearer identifier corresponding to the requested transmission address, which is used to identify which radio bearer and/or radio bearers the requested address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers. The radio bearer may be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB).

● Quality of Service (QoS) Flow identifier: a Quality of Service (QoS) flow identifier corresponding to the requested transmission address, which is used to identify which QoS flow and/or QoS flows the requested address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Requested information for data transmission, which may include one or more of the following:

o QoS flow identifier: an identifier used to identify the requested QoS flow for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Radio bearer identifier: an identifier used to identify the requested radio bearer for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers. The radio bearer may be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB).

o PDU session identifier: an identifier used to identify the requested PDU session for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Cell identifier: an identifier used to identify the requested cell for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Node identifier: an identifier used to identify the requested node for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Slice identifier: an identifier used to identify the requested slice for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

In some implementations, the second node may transmit a second message containing a data transmission address (for example, the data transmission address of a candidate target cell) to the first node according to its own situation and/or reception of a first message containing a request for a data transmission address. After receiving the address, the first node may perform related data transmission, such as (normal) Data Transmission and Data Forwarding, etc. Herein, the Data Forwarding includes Early Data Forwarding, Late Data Forwarding and (normal) Data Forwarding, etc. After receiving the address, the first node may also forward it to other nodes for related data transmission, where the other nodes may be any nodes other than the second node. In some implementations, for example, after the first node obtains the address of data transmission (for example, it may be data forwarding), before the user accesses a target node and/or cell, the first node performs data forwarding to transmit the relevant data to the related target node and/or cell, so as to ensure that the UE can quickly receive relevant data after handover and ensure the service continuity for the UE.

In some implementations, the second message may be or may be carried by one or more of the following messages: a XN-U ADDRESS INDICATION message or an EARLY STATUS TRANSFER message of Xn, or an other and/or newly defined RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or a RRC container.

In some implementations, the second message may include one or more of the following fields or related information:

● UE identifier: used to identify the UE performing (conditional) handover. It may include one or more of the following: a user identifier assigned by a new node, a user identifier assigned by an old node, a user identifier assigned by a source node, a user identifier assigned by a secondary node, a user identifier assigned by a master node, a user identifier assigned by a candidate secondary node, a user identifier assigned by a transmitting node of the first message, a user identifier assigned by a receiving node of the first message, etc. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Request index corresponding to the reporting: used to identify the request index corresponding to the reporting. It may also be called a request index corresponding to the second message. The request index may be used to inform the receiving node of the message which request the content reported is for.

● Accepted QoS flow identifier: an identifier used to identify a QoS flow accepted for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Transmission address: this address may be transport layer information, which may include one or more of the following: transport layer address, Tunnel Endpoint Identifier (TEID), QoS mapping relationship, etc. Herein, the QoS mapping relationship may include one or more of the following: Flow Label, Differentiated Services Code Point, etc. The address may be for one or more of uplink transmission, downlink transmission, uplink transmission or downlink transmission, uplink transmission and downlink transmission.

● Transmission direction corresponding to the transmission address: the direction includes one or more of the following: uplink, downlink, uplink or downlink, uplink and downlink.

● Information about whether to trigger data transmission: it may include one or more of the following:

o Identification for retaining address information but not performing data transmission: used to inform the node that receives the message and/or other nodes to retain the address information but not trigger data transmission.

o Identification for triggering data transmission: used to indicate that the message may trigger the receiving node of the message and/or other nodes to perform data transmission.

o Event to trigger data transmission: when an event to trigger data transmission is met, data transmission may be triggered. This information can avoid unnecessary data transmission, such as early data transmission, late data transmission, unnecessary data transmission, etc. For example, it can effectively prevent a user from performing unnecessary data transmission when the user has just accessed a certain cell for a short time and/or when the user would not access a certain cell for a long time. It may include one of the following events or the combination of multiple events (for example, it may be that multiple events need to be met at the same time, or it may be that at least one of the multiple events need to be met) and the corresponding information in the events:

· Event 1: when the user has accessed the cell for a predetermined time which, for example, is greater than and/or equal to and/or less than a threshold time, data transmission may be triggered. The event needs to include event type, event content, predetermined time-related information, etc. The predetermined time-related information may be a threshold time or a timer. For example, when the user accesses the cell, a timer is started, and data transmission may be triggered when the timer expires; or, data transmission may be triggered within the timer time.

· Event 2: a predetermined time passes after the address information is received. For example, it may start counting after receiving the address, and when the counted time is greater than and/or equal to and/or less than a threshold time, data transmission may be triggered. The event needs to include event type, event content, predetermined time-related information, etc. The predetermined time-related information may be a threshold time or a timer. For example, a timer is started when the address information is received, and data transmission may be triggered when the timer expires; or, data transmission may be triggered within the timer time.

· Event 3: when a user accesses the cell, data transmission may be triggered.

· Event 4: when address information is received, data transmission may be triggered.

· Event 5: when signal quality measured by the user and/or a node meets a certain condition, data transmission may be triggered. For example, when the signal quality is greater than and/or equal to and/or less than a threshold value (or when the signal quality is within a certain interval) and/or the time when an event meets the condition is greater than and/or equal to and/or less than a threshold time, data transmission may be triggered. The event needs to include event type, event content, condition-related information, etc. The condition-related information may be a threshold value of signal quality, a threshold time for the signal quality to meet the condition, and the like.

· Event 6: data transmission may be triggered when the user's trajectory is within a certain scope and/or when the user's trajectory is outside a certain scope. The event needs to include event type, event content, scope-related information, etc. The scope may be a certain geographical area, one or more cells, the coverage of one or more nodes, and the coverage of one or more beams. The scope-related information may include one or more of the following: geographical coordinate corresponding to a geographical area, cell identifier and/or identifier list, node identifier and/or identifier list, beam identifier and/or identifier list.

· Event 7: when handover needs to be performed on the user, data transmission may be triggered.

· Event 8: when a node decides to switch its energy-saving mode, data transmission may be triggered. For example, when the node is about to enter an energy-saving mode, data transmission may be triggered.

· Event 9: data transmission may be triggered when a time from the current time to the time when the node expects to enter an energy-saving mode meets a certain predetermined time which, for example, is greater than and/or equal to and/or less than a certain time threshold. The event needs to include event type, event content, predetermined time-related information, etc. The predetermined time-related information may be a threshold time or a timer. For example, data transmission may be triggered when the time from the current time to the time when the node expects to enter an energy-saving mode is less than a certain time threshold.

· Event 10: data transmission may be triggered when information that the target node for data transmission is about to enter an energy-saving mode is received. For example, when information that the target node for data transmission is going to change from an energy-saving mode to a non-energy-saving mode is received, data transmission may be triggered.

● Cell identifier: a cell identifier corresponding to the transmission address, which is used to indicate which cell and/or cells the reported address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Node identifier: a node identifier corresponding to the transmission address, which is used to identify which node and/or nodes the reported address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Slice identifier: a slice identifier corresponding to the transmission address, which is used to identify which slice and/or slices the reported address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Protocol Data Unit (PDU) session identifier: a Protocol Data Unit (PDU) session identifier corresponding to the transmission address, which is used to identify which PDU session and/or PDU sessions the reported address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Radio bearer identifier: a radio bearer identifier corresponding to the transmission address, which is used to identify which radio bearer and/or radio bearers the reported address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers. The radio bearer may be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB).

● Quality of Service (QoS) Flow identifier: a Quality of Service (QoS) flow identifier corresponding to the transmission address, which is used to identify which QoS flow and/or QoS flows the reported address is directed to. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Information that can be used for data transmission: it may include one or more of the following:

o QoS flow identifier: an identifier used to identify a (accepted) QoS flow that can be used for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Radio bearer identifier: an identifier used to identify a (accepted) radio bearer that can be used for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers. The radio bearer may be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB).

o PDU session: an identifier used to identify a (accepted) PDU sessions that can be used for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Cell identifier: an identifier used to identify a (accepted) cell that can be used for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Node identifier: an identifier used to identify a (accepted) node that can be used for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Slice identifier: an identifier used to identify a (accepted) slice that can be used for data transmission. The identifier may be one identifier, multiple identifiers or a list of identifiers.

o Transmission address: used to identify the address information that can be used for data transmission. This address may be transport layer information, which may include one or more of the following: transport layer address, Tunnel Endpoint Identifier (TEID), QoS mapping relationship, etc. Herein, the QoS mapping relationship may include one or more of the following: Flow Label, Differentiated Services Code Point, etc. The address may be for one or more of uplink transmission, downlink transmission, uplink transmission or downlink transmission, uplink transmission and downlink transmission.

In some implementations, the first node may be a target node in handover, and the second node may be a source node in handover; or the first node may be a source node in handover, and the second node may be a target node in handover; or the first node is a secondary node in dual-connectivity, and the second node is a master node in dual-connectivity; or the first node is a master node in dual-connectivity, and the second node is a secondary node in dual-connectivity; or the first node is a secondary node newly accessed by the UE, and the second node is a secondary node originally accessed by the UE; or the first node is a secondary node originally accessed by the UE, and the second node is a secondary node newly accessed by the UE; or the first node may be a gNB or a gNB DU or a gNB CU or a gNB CU UP, and the second node may be a UE; or the first node may be a UE, and the second node may be a gNB or a gNB DU or a gNB CU or a gNB CU UP; or the first node may be a source node in handover, and the second node may be a user in handover; or the first node is a user in handover, and the second node may be a source node in handover; or the first node may be a target node in handover, and the second node may be a user in handover; or the first node may be a user in handover, and the second node may be a target node in handover.

Fields and/or information contained in the first message may be information for data transmission or information for secondary data transmission.

Fields and/or information contained in the second message may be information for data transmission or information for secondary data transmission.

Example 2

In some implementations, the present disclosure provides a method for supporting mobility management, which may include: a third node transmits a third message containing information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover to a fourth node for providing reference information for the fourth node in performing resource reservation and/or resource allocation. After receiving the third message, the fourth node may also forward the information to other nodes to provide reference information for other nodes in performing resource reservation and/or resource allocation. In some implementations, in the case of a conditional handover, the configuration can be kept after the conditional handover as a configuration for a subsequent conditional handover, and the target node can reserve and/or release resources prepared for the conditional handover as appropriate after obtaining the information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover. For example, when an estimated arrival time of a user is a certain time, the target node may not need to reserve resources for the conditional handover before the estimated arrival time, and/or may start to reserve resources at a certain time before the estimated arrival time, and/or may reserve resources before the estimated arrival time, and/or may use reserved resources for other users if they need resources before the estimated arrival time.

In some implementations, the third message may be or may be carried by one or more of the following messages: a HANDOVER REQUEST message or a RETRIEVE UE CONTEXT RESPONSE message or a RETRIEVE UE CONTEXT FAILURE message of X2 or Xn; or a SENB ADDITION REQUEST message or a SGNB ADDITION REQUEST message of X2; or a S-NODE ADDITION REQUEST message or a S-NODE ADDITION REQUEST ACKNOWLEDGE message or a S-NODE MODIFICATION REQUIRED message or a S-NODE MODIFICATION CONFIRM message or a S-NODE CHANGE REQUIRED message or a S-NODE CHANGE CONFIRM message or a S-NODE MODIFICATION REQUEST message or a S-NODE MODIFICATION REQUEST ACKNOWLEDGE message of Xn; or a UE CONTEXT SETUP REQUEST message or a UE CONTEXT SETUP RESPONSE message or a UE CONTEXT MODIFICATION REQUEST message or a UE CONTEXT MODIFICATION RESPONSE message of F1; or an other and/or newly defined RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or a RRC container.

In some implementations, the third message may include one or more of the following fields or related information:

● Cell identifier corresponding to the following information. Or it may be called a cell identifier corresponding to the third message, or a cell identifier corresponding to the information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover.

● Node identifier corresponding to the following information. Or it may be called a node identifier corresponding to the third message, or a node identifier corresponding to the information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover. It may include one or more of the following: a user identifier assigned by a new node, a user identifier assigned by an old node, a user identifier assigned by a source node, a user identifier assigned by a secondary node, a user identifier assigned by a master node, a user identifier assigned by a candidate secondary node, a user identifier assigned by a transmitting node of the first message, a user identifier assigned by a receiving node of the first message, etc. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Slice identifier corresponding to the following information. Or it may be called a slice identifier corresponding to the third message, or a slice identifier corresponding to the information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover.

● User identifier for handover corresponding to the following information. Or it may be called a user identifier for (conditional) handover corresponding to the third message, or a UE identifier for conditional handover corresponding to the information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover.

● Estimated maximum arrival probability: indicates the maximum probability that a user arrives at a cell and/or node. The arrival probability may be an estimated maximum arrival probability within a period of time in the future or an estimated maximum arrival probability at the current time.

● Time corresponding to the estimated maximum arrival probability: indicates time information corresponding to the maximum probability that a user arrives at a cell and/or node.

● Estimated minimum arrival probability: indicates the minimum probability that a user arrives at a cell and/or node. The arrival probability may be an estimated minimum arrival probability within a period of time in the future or an estimated minimum arrival probability at the current time.

● Time corresponding to the estimated minimum arrival probability: indicates time information corresponding to the minimum probability that a user arrives at a cell and/or node.

● Estimated arrival time: indicates the time when the user arrives at a cell and/or node.

● Estimated arrival probability: indicates the arrival probability that a user arrives at a cell and/or node. In some implementations, it may be one or more estimated arrival probabilities, or it may be a list thereof. The arrival probability may be an estimated arrival probability within a period of time in the future or an estimated arrival probability at the current time.

● Time corresponding to the estimated arrival probability: indicates time information corresponding to the probability that a user arrives at a cell and/or node. In some implementations, it may be the time corresponding to one or more estimated arrival probabilities, or it may be a list thereof.

● Requested maximum resource reservation time: indicates the maximum resource reservation time requested for the target node to perform resource reservation. This information is mainly used to provide reference information for the receiving node of the message to perform resource reservation, so as to improve the resource utilization and avoid the performance damage of other users caused by long-term resource reservation. In some implementations, for example, the receiving node of the message may reserve resources based on the information. For example, resource reservation is only made within the requested maximum resource reservation time; and resource reservation would not be made outside this time. In some other implementations, for example, the receiving node of the message may set a resource reservation time based on the information, and only perform resource reservation within the resource reservation time, which may be transmitted to the transmitting node of the third message through the fourth message.

● Requested minimum resource reservation time: indicates the minimum resource reservation time requested for the target node to perform resource reservation. This information is mainly used to provide reference information for the receiving node of the message to perform resource reservation, so as to improve the resource utilization and avoid the performance damage of other users caused by long-term resource reservation. In some implementations, for example, the receiving node of the message may reserve resources based on the information. For example, resource reservation is only made within the requested minimum resource reservation time; and resource reservation would not be made outside this time. In some other implementations, for example, the receiving node of the message may set a resource reservation time based on the information (In some implementations, for example, the set resource reservation time should include the requested minimum resource reservation time), and only perform resource reservation within the resource reservation time, which may be transmitted to the transmitting node of the third message through the fourth message.

● Requested resource reservation time interval: indicates the time interval requested for the target node to perform resource reservation. This information is mainly used to provide reference information for the receiving node of the message to perform resource reservation, so as to improve the resource utilization and avoid the performance damage of other users caused by long-term resource reservation. In some implementations, for example, the receiving node of the message may reserve resources based on the information. For example, resource reservation is only performed within the requested resource reservation time interval; and resource reservation would not be made outside this time. In some other implementations, for example, the receiving node of the message may set a resource reservation time based on the information (In some implementations, for example, the set resource reservation time should include the requested resource reservation time interval), and only perform resource reservation within the resource reservation time, which may be transmitted to the transmitting node of the third message through the fourth message.

● Requested resource reservation time: indicates the time requested for the target node to perform resource reservation. This information is mainly used to provide reference information for the receiving node of the message to perform resource reservation, so as to improve the resource utilization and avoid the performance damage of other users caused by long-term resource reservation. In some implementations, for example, the receiving node of the message may reserve resources based on the information. For example, resource reservation is only performed within the requested resource reservation time; and resource reservation would not be made outside this time. In some other implementations, for example, the receiving node of the message may set a resource reservation time based on the information (In some implementations, for example, the set resource reservation time should include the requested resource reservation time), and only perform resource reservation within the resource reservation time, which may be transmitted to the transmitting node of the third message through the fourth message.

● Indication of whether to allow setting resource reservation time: an indication about whether to allow the target node to set resource reservation time. If the indication indicates that setting resource reservation time is allowed, the target node can set a resource reservation time. In an implementation, for example, the resource reservation time set by the target node may be transmitted through a fourth message. If the indication indicates that setting resource reservation time is not allowed, the target node cannot set the resource reservation time. In some implementations, the target node needs to reserve resources from receiving a handover request for the user until the user accesses the target node and/or the target node receives a message of handover cancellation and/or a message that the user accesses other target nodes.

● Confidence: used to indicate the confidence/accuracy of estimation and/or prediction.

In some implementations, the fourth node may transmit a fourth message containing information related to resource reservation (time) in a conditional handover to the third node according to its own situation and/or receiving a third message containing information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, for the third node to confirm the time for which the fourth node and/or the target node (which may be another node except for the third node and the fourth node) will reserve resources for the UE for the handover, and the third node may select the target node and/or perform UE configuration and/or perform cell selection based on this information. For example, when the resource reservation time set by a node is too short, the source node may not select the node as a target node and/or cell.

In some implementations, the fourth message may be or may be carried by one or more of the following messages: a HANDOVER REQUEST ACKNOWLEDGE message or a RETRIEVE UE CONTEXT REQUEST message or a HANDOVER SUCCESS message of X2 or Xn; or a SENB ADDITION REQUEST ACKNOWLEDGE message or a SGNB ADDITION REQUEST ACKNOWLEDGE message of X2; or a S-NODE ADDITION REQUEST ACKNOWLEDGE of Xn; or a UE CONTEXT SETUP REQUEST message or a UE CONTEXT SETUP RESPONSE message or a UE CONTEXT MODIFICATION REQUEST message or a UE CONTEXT MODIFICATION RESPONSE message of F1; or an other and/or newly defined RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or a RRC container.

In some implementations, the fourth message may include one or more of the following fields or related information:

● Cell identifier corresponding to the following information, or it may also be called a cell identifier corresponding to the fourth message or a cell identifier corresponding to the information related to resource reservation (time) in a conditional handover.

● Node identifier corresponding to the following information, or it may also be called a node identifier corresponding to the fourth message or a node identifier corresponding to the information related to resource reservation (time) in a conditional handover.

● Slice identifier corresponding to the following information, or it may also be called a slice identifier corresponding to the fourth message or a slice identifier corresponding to the information related to resource reservation (time) in a conditional handover.

● User identifier for handover corresponding to the following information, or it may also be called a user identifier for conditional handover corresponding to the fourth message or a UE identifier for conditional handover corresponding to the information related to resource reservation (time) in a conditional handover. It may include one or more of the following: a user identifier assigned by a new node, a user identifier assigned by an old node, a user identifier assigned by a source node, a user identifier assigned by a secondary node, a user identifier assigned by a master node, a user identifier assigned by a candidate secondary node, a user identifier assigned by a transmitting node of the first message, a user identifier assigned by a receiving node of the first message, etc. The identifier may be one identifier, multiple identifiers or a list of identifiers.

● Maximum resource reservation time: indicates the maximum time that the target node can reserve resources.

● Resource reservation time: indicates the time for which the target node can reserve resources. In some implementations, the target node only reserves resources for the conditional handover during this time, and the resource reservation for the conditional handover cannot be ensured outside this time (interval). In some other implementations, if the source node and/or the master node inform the target node that setting the resource reservation time is allowed through the third message, the target node (which may be a target master node or a target secondary node) may set the resource reservation time and transmit it to the source node through this field and the fourth message. In still other implementations, if the source node and/or the master node inform the target node of the information related to the resource reservation time requested by the third message, the target node resets the resource reservation time according to its own situation, and the reset resource reservation time is transmitted to the source node through this field and the fourth message.

● Time information corresponding to a handover configuration: indicates an applicable time of a handover configuration. In some implementations, the handover configuration is valid only within the applicable time, and it is invalid outside the applicable time. In an implementation, after receiving the information, the source node transmits a handover command to the user only within the applicable time. In another implementation, after receiving the information, the user performs a handover process only within the applicable time (for example, detecting whether a configured conditional handover execution condition is met), and/or accessing the target cell within the applicable time.

In some implementations, the third node may be a target node in handover, and the fourth node may be a source node in handover; or the third node may be a source node in handover, and the fourth node may be a target node in handover; or the third node is a secondary node in dual-connectivity, and the fourth node is a master node in dual-connectivity; or the third node is a master node in dual-connectivity, and the fourth node is a secondary node in dual-connectivity; or the third node is a secondary node newly accessed by the UE, and the fourth node is a secondary node originally accessed by the UE; or the third node is a secondary node originally accessed by the UE, and the fourth node is a secondary node newly accessed by the UE; or the third node may be a gNB or a gNB DU or a gNB CU or a gNB CU UP, and the fourth node may be a UE; or the third node may be a UE, and the fourth node may be a gNB or a gNB DU or a gNB CU or a gNB CU UP; or the third node may be a source node in handover, and the fourth node may be a user in handover; or the third node is a user in handover, and the fourth node may be a source node in handover; or the third node may be a target node in handover, and the fourth node may be a user in handover; or the third node may be a user in handover, and the fourth node may be a target node in handover.

Example 3

In some implementations, the present disclosure provides a method for supporting mobility management, which may include: a fifth node transmits a fifth message containing a request for reporting prediction information related to a conditional handover to a sixth node, in order for the sixth node to report a prediction result related to the conditional handover, so that the fifth node may make relevant decisions and/or conduct subsequent configuration and/or behavior of the conditional handover, such as triggering early data forwarding and the like, and the fifth node may also forward it to other nodes in order for the other nodes to make relevant decisions. In this solution, subsequent behaviors can be carried out according to predicted user information, and unnecessary subsequent behaviors and/or data transmission may be avoided. In some implementations, for example, when it is predicted that the UE will not meet an execution event in a short time, the target node may use the reserved resources for other users, so as to improve the resource utilization and avoid unnecessary resource reservation. In some other implementations, for example, the node may reserve resources when it is predicted that the UE will meet an execution event. In still other implementations, for example, when the node predicts that the UE will meet a handover condition, the node may perform early data forwarding on a candidate target node to avoid invalid data transmission, etc. For example, the node may only perform early data forwarding on a cell corresponding to the handover condition that to be met, and do not perform data transmission to other candidate target cells.

In some implementations, the fifth message may be or may be carried by one or more of the following messages: a HANDOVER REQUEST ACKNOWLEDGE message of Xn; or a HANDOVER COMMAND message or a HANDOVER REQUEST ACKNOWLEDGE message of NG; or an RRCReconfiguration message or an RRCReestablishment message or an RRCSetup message or an RRCRelease message of Radio Resource Control (RRC); or an XN SETUP REQUEST message or an XN SETUP RESPONSE message of Xn; or an ENB CONFIGURATION UPDATE message or an ENB CONFIGURATION UPDATE ACKNOWLEDGE message or an EN-DC CONFIGURATION UPDATE message or an EN-DC CONFIGURATION UPDATE ACKNOWLEDGE message of X2; or an NG-RAN NODE CONFIGURATION UPDATE message or an NG-RAN NODE CONFIGURATION UPDATE ACKNOWLEDGE message of Xn; or a RESET REQUEST message of X2 or Xn; or a MOBILITY CHANGE REQUEST message of X2; or a F1 SETUP REQUEST message or a F1 SETUP RESPONSE message or a GNB-DU CONFIGURATION UPDATE message or a GNB-DU CONFIGURATION UPDATE ACKNOWLEDGE message or a GNB-CU CONFIGURATION UPDATE message or a GNB-CU CONFIGURATION UPDATE ACKNOWLEDGE message or a GNB-DU RESOURCE COORDINATION REQUEST message or a GNB-DU RESOURCE COORDINATION RESPONSE message of F1; or a GNB-CU-UP E1 SETUP REQUEST message or a GNB-CU-UP E1 SETUP RESPONSE message or a GNB-CU-CP E1 SETUP REQUEST message or a GNB-CU-CP E1 SETUP RESPONSE message or a GNB-CU-UP CONFIGURATION UPDATE message or a GNB-CU-UP CONFIGURATION UPDATE ACKNOWLEDGE message or a GNB-CU-CP CONFIGURATION UPDATE message or a gNB-CU-CP CONFIGURATION UPDATE ACKNOWLEDGE message of E1; or a RESOURCE STATUS REQUEST message of X2 or Xn or F1 or E1; or an EN-DC RESOURCE STATUS REQUEST message of X2; or an UPLINK RAN CONFIGURATION TRANSFER message or a DOWNLINK RAN CONFIGURATION TRANSFER message of NG; or a HANDOVER REQUEST ACKNOWLEDGE message or a RETRIEVE UE CONTEXT REQUEST message or a HANDOVER SUCCESS message of X2 or Xn; or a SENB ADDITION REQUEST ACKNOWLEDGE message or a SGNB ADDITION REQUEST ACKNOWLEDGE message of X2; or a S-NODE ADDITION REQUEST ACKNOWLEDGE of Xn; or an other and/or newly defined RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or a RRC container.

In some implementations, the fifth message may include one or more of the following fields or related information:

● Request identification: used to identify the request.

● Transmitting node identifier: the identifier of the node that transmits the fifth message.

● Receiving node identifier: the identifier of the node that receives the fifth message.

● User identifier corresponding to requested information.

● Reporting mode: it may include single reporting, On-demand reporting, periodic reporting, etc.

● Reporting time: used to indicate the reporting time.

● Reporting period: used to indicate the reporting period in a case of periodic reporting.

● Reporting trigger event: used to indicate an event that triggers the reporting. The event may include:

o a predicted time when an execution event is met is less than and/or equal to a threshold value

o a predicted time when an execution event is met is within a certain time interval

o a predicted time when an execution event is met is greater than and/or equal to a threshold value

● Measurement mode and/or prediction mode: it may include single measurement and/or prediction, On-demand measurement and/or prediction, periodic measurement and/or prediction, etc.

● Measurement time and/or prediction time: used to indicate the time for measurement and/or prediction.

● Measurement and/or prediction period: used to indicate the time period of measurement and/or prediction. The period may be a time period for periodic measurement and/or prediction in a case of periodic reporting and/or periodic measurement and/or prediction.

● Requested measurement content and/or prediction content: parameters requested for measurement and/or prediction. It may include one or more of the following:

o a predicted cell identifier corresponding to that an execution event is met

o a predicted time when an execution event is met

o a predicted execution event to be met

o a predicted arrival time

o applicable time: the applicable time of a predicted and/or predicted result.

o confidence: the confidence of a predicted and/or predicted result.

● Requested reporting content: parameters requested for reporting. It may include one or more of the following:

o a predicted cell identifier corresponding to that an execution event is met

o a predicted time when an execution event is met

o a predicted execution event to be met

o a predicted arrival time

o applicable time: the applicable time of a predicted and/or predicted result.

o confidence: the confidence of a predicted and/or predicted result.

● Applicable time corresponding to the requested reporting content: indicates the applicable time of the content requested for reporting.

● Requested prediction time: indicates the requested time for prediction.

● Requested confidence requirement for reporting: used to indicate the accuracy requirement for prediction. In some implementations, when the confidence and/or accuracy of a prediction result meet the requirements, it may be reported.

In some implementations, the sixth node may transmit a sixth message containing prediction information related to the conditional handover to the fifth node according to its own situation and/or according to the received fifth message containing a request for reporting prediction information related to a conditional handover, so that the fifth node can obtain prediction results related to the conditional handover, and the fifth node may make handover-related decisions according to the message, for example, reserving resources, releasing resources, deciding whether to perform early data forwarding, deciding when to perform early data forwarding, and performing early data forwarding. In some implementations, for example, when it is predicted that the UE will not meet an execution event in a short time, the target node may use the reserved resources for other users, so as to improve the resource utilization and avoid unnecessary resource reservation. In some other implementations, for example, the node may reserve resources when it is predicted that the UE will meet an execution event. In still other implementations, for example, when the node predicts that the UE will meet a handover condition, the node may perform early data forwarding on a candidate target node, and do not transmit data to other candidate target nodes, so as to avoid invalid data transmission.

In some implementations, the sixth message may be or may be carried by one or more of the following messages: RRCSetupComplete or RRCResumeComplete or RRCReconfigurationComplete or RRCReestablishmentComplete or UE-MeasurementsAvailable of RRC; or a HANDOVER REQUEST message or a RETRIEVE UE CONTEXT RESPONSE message or a RETRIEVE UE CONTEXT FAILURE message of X2 or Xn; or a SENB ADDITION REQUEST message or a SGNB ADDITION REQUEST message of X2; or a S-NODE ADDITION REQUEST message or a S-NODE ADDITION REQUEST ACKNOWLEDGE message or a S-NODE MODIFICATION REQUIRED message or a S-NODE MODIFICATION CONFIRM message or a S-NODE CHANGE REQUIRED message or a S-NODE CHANGE CONFIRM message or a S-NODE MODIFICATION REQUEST message or a S-NODE MODIFICATION REQUEST ACKNOWLEDGE message of Xn; or a UE CONTEXT SETUP REQUEST message or a UE CONTEXT SETUP RESPONSE message or a UE CONTEXT MODIFICATION REQUEST message or a UE CONTEXT MODIFICATION RESPONSE message of F1; or an other and/or newly defined RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or a RRC container.

In some implementations, the sixth message may include one or more of the following fields or related information:

● Request identification corresponding to the reporting: used to indicate the request identification corresponding to the reporting. Or it may be called the request identification corresponding to the sixth message.

● Transmitting node identifier: the identifier of the node that transmits the sixth message.

● Receiving node identifier: the identifier of the node that receives the sixth message.

● User identifier corresponding to the reported information.

● Measurement content and/or prediction content: parameters for measurement and/or prediction. It may include one or more of the following:

o a predicted cell identifier corresponding to that an execution event is met

o a predicted time when an execution event is met

o a predicted execution event to be met

o a predicted arrival time

o applicable time: the applicable time of a predicted and/or predicted result.

o confidence: the confidence of a predicted and/or predicted result.

● Reported content: parameters to be reported. It may include one or more of the following:

o a predicted cell identifier corresponding to that an execution event is met

o a predicted time when an execution event is met

o a predicted execution event to be met

o a predicted arrival time

o applicable time: the applicable time of a predicted and/or predicted result.

o confidence: the confidence of a predicted and/or predicted result.

● Event that triggers the reporting: used to indicate the event that triggers the reporting.

● Applicable time corresponding to the measurement content: indicates information of the applicable time corresponding to the measurement content. The measurement content is valid only within the applicable time. The information may enable the receiving node to know when the information is valid, so as to prevent the receiving node from misusing the information and/or preventing the receiving node from using the information at an invalid time.

● Applicable time corresponding to the reported content: indicates information of the applicable time corresponding to the reported content. The reported content is valid only within the applicable time. The information may enable the receiving node to know when the information is valid, so as to prevent the receiving node from misusing the information and/or preventing the receiving node from using the information at an invalid time.

In some implementations, the fifth node may be a target node in handover, and the sixth node may be a source node in handover; or the fifth node may be a source node in handover, and the sixth node may be a target node in handover; or the fifth node is a secondary node in dual-connectivity, and the sixth node is a master node in dual-connectivity; or the fifth node is a master node in dual-connectivity, and the sixth node is a secondary node in dual-connectivity; or the fifth node is a secondary node newly accessed by the UE, and the sixth node is a secondary node originally accessed by the UE; or the fifth node is a secondary node originally accessed by the UE, and the sixth node is a secondary node newly accessed by the UE; or the fifth node may be a gNB or a gNB DU or a gNB CU or a gNB CU UP, and the sixth node may be a UE; or the fifth node may be a UE, and the sixth node may be a gNB or a gNB DU or a gNB CU or a gNB CU UP; or the fifth node may be a source node in handover, and the sixth node may be a user in handover; or the fifth node is a user in handover, and the sixth node may be a source node in handover; or the fifth node may be a target node in handover, and the sixth node may be a user in handover; or the fifth node may be a user in handover and the sixth node may be a target node in handover. The fifth node may be a source secondary node and/or a target secondary node, and the sixth node may be a UE. In still other implementations, the fifth node may be a source master node and/or a target master node, and the sixth node may be a UE.

In some implementations, the information exchange between users and nodes may be transmitted transparently through another node by means of an RRC container. For example, a message transmitted by a UE to a master node may be transmitted to the master node by using an RRC container carrying the information through a secondary node, or a message transmitted by a UE to a secondary node may be transmitted to the secondary node by using an RRC container carrying the information through a master node, or a message transmitted by a UE to a target node may be transmitted to the target node by using an RRC container carrying the information through a source node.

In the present disclosure, a user may refer to each other with a user equipment, a UE, etc.

In the present disclosure, estimation and prediction may refer to each other.

In the present disclosure, credibility, confidence and accuracy may refer to each other.

In the present disclosure, handover related decisions and/or handover decisions may include one or more of the following: whether to trigger handover, selection of target cells and/or nodes, selection of handover time, whether to add secondary nodes, whether to change secondary nodes, resource reservation, resource release, decide whether to perform early data forwarding, decide when to perform early data forwarding, perform early data forwarding, and perform data transmission, etc.

In the present disclosure, time may be represented by one or more of the following: timestamp, time point, time interval, timer, period of time, time length, time period/periodicity, time spacing, etc. Herein, the time length may be a length of time from a certain time point, which may be the current time. The time may be a relative time or an absolute time. In some implementations, a period of time may be represented by separate fields, for example, by a combination of a start time and an end time, or by a combination of a start time and a time period.

Exemplary embodiments of the present disclosure are further described below with reference to the accompanying drawings.

The text and drawings are provided as examples only to help understand the present disclosure. They should not be construed as limiting the scope of the present disclosure in any way. Although certain embodiments and examples have been provided, based on the disclosure herein, it is apparent to those skilled in the art that changes can be made to the illustrated embodiments and examples without departing from the scope of the present disclosure.

FIG. 3A shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3A shows a process of exchanging information of data transmission address between two nodes, so that the first node may obtain relevant information of data transmission address, and the first node may transmit data to relevant nodes according to the obtained address information. In some implementations, for example, the first node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the second node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the first node may be an AMF or an SMF or an MME, and the second node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the first node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the second node may be an AMF or an SMF or an MME. In yet other implementations, for example, the first node may be a UE, and the second node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the first node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the second node may be a master node in dual-connectivity. In still other implementations, for example, the first node may be a master node in dual-connectivity, and the second node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the first node may be a source node in handover, and the second node may be a target node and/or a candidate target node in handover.

Step 301A: the second node transmits a data transmission address related information to the first node. The data transmission address related information may be the aforementioned second message.

Step 302A: the first node forwards the received data transmission address related information to other nodes, and/or performs data transmission to relevant nodes based on the received data transmission address.

FIG. 3B shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3B shows a process of exchanging information of data transmission address between two nodes, so that the first node may obtain relevant information of data transmission address, and the first node may transmit data to relevant nodes according to the obtained address information. In some implementations, for example, the first node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the second node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the first node may be an AMF or an SMF or an MME, and the second node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the first node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the second node may be an AMF or an SMF or an MME. In yet other implementations, for example, the first node may be a UE, and the second node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the first node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the second node may be a master node in dual-connectivity. In still other implementations, for example, the first node may be a master node in dual-connectivity, and the second node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the first node may be a source node in handover, and the second node may be a target node and/or a candidate target node in handover.

Step 301B: the first node transmits a request for a data transmission address to the second node to request the second node to feed back a related data transmission address to the first node. The request for the data transmission address may be the aforementioned first message.

Step 302B: the second node transmits a data transmission address related information to the first node. The data transmission address related information may be the aforementioned second message.

Step 303B: the first node forwards the received data transmission address related information to other nodes, and/or performs data transmission to relevant nodes based on the received data transmission address.

FIG. 3C shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3C shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN), in order for the candidate target secondary node to obtain the data transmission address, so that after the UE accesses a candidate target secondary node, the candidate target secondary node can perform data transmission for subsequent handover.

Step 301C: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to a candidate target secondary node (for example, T-SN1 and/or other candidate T-SNs).

Step 302C: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 303C: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 304C: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 305C.a: the master node transmits an Xn-U address indication (XN-U ADDRESS INDICATION) message to the source secondary node.

In some implementations, the UE may be in a single connectivity, and may be connected only to a single node (for example, it may be the MN in the drawing), so there is no S-SN in the process. In this case, the above steps 301C to 304C are a secondary node addition process, but not a secondary node change process, and step 305C.a is replaced by the following step 305C.b.

Step 305C.b: the master node transmits the data transmission address to all candidate target secondary nodes, so that the candidate target secondary nodes can obtain the data transmission address. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the second message mentioned above. In some implementations, the message may be carried by an Xn-U address indication (XN-U ADDRESS INDICATION) message. In some implementations, after receiving the message, the candidate target secondary node saves the address to prepare for the subsequent data transmission without triggering an actual data transmission. The actual data transmission is triggered by the subsequent step 310C.

Step 306C: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN addition is taken as an example.

Step 307C: the master node and the source secondary node perform a secondary node release and/or modification process. If the source secondary node continues to serve as a target secondary node for the subsequent conditional handover, a secondary node modification process is performed. If the source secondary node will not serve as a target secondary node for the subsequent conditional handover, a secondary node release process is performed. If the source secondary node is one of the target secondary nodes, there is no such step.

Step 308C: the UE performs a random access process with T-SN1.

Step 309C: other processes of secondary node change and/or addition are performed.

Step 310C: the accessed secondary node (e.g., T-SN1 in this example) of the UE determines whether early data forwarding should be performed. In some implementations, the accessed secondary node may decide whether to perform early data forwarding according to one or more of the UE's measurement report, candidate target secondary nodes, execution events, etc.

Step 311C: if in step 310C, it determines to perform early data forwarding, the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 312C: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 313C: other processes of secondary node change and/or addition are performed.

FIG. 3D shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3D shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN). After the UE accesses one of the target secondary nodes (in this example, T-SN1 is taken as an example), the accessed secondary node can request the master node to transmit the data transmission address in order for the accessed secondary node to obtain the data transmission address, and the accessed secondary node may perform data transmission for the subsequent handover.

Step 301D: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 302D: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 303D: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 304D: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 305D: the master node transmits an Xn-U address indication (XN-U ADDRESS INDICATION) message to the source secondary node.

In some implementations, the UE may be in a single connectivity, and may be connected only to a single node (for example, it may be the MN in the drawing), so there is no S-SN in the process. In this case, the above steps 301D to 304D are a secondary node addition process, but not a secondary node change process, and there is no step 305D.

Step 306D: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 307D.a: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 307D.b: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

If the source secondary node continues to serve as the target secondary node for the subsequent conditional handover, step 307D performs a secondary node modification process. If the source secondary node will not serve as the target secondary node for the subsequent conditional handover, step 307D performs a secondary node release process without requesting and reporting the data transmission address. If the source secondary node is one of the target secondary nodes, there is no such step 307D.

Step 308d: the UE performs a random access process with T-SN1.

Step 309D: other processes of secondary node change and/or addition are performed.

Step 310D.a: the accessed secondary node of the UE (for example, T-SN1 in this example) transmits a request for a data transmission address to the master node, so as to request the master node to transmit the data transmission address to the accessed secondary node to prepare for subsequent data transmission and/or handover. The request for a data transmission address may be the aforementioned first message.

Step 310D.b: the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), so that the accessed secondary node of the UE (for example, T-SN1 in this example) can obtain the data transmission address, which may be used for subsequent data transmission, for example, early data forwarding, etc. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message.

Step 311D: the accessed secondary node (e.g., T-SN1 in this example) of the UE determines whether early data forwarding should be performed. In some implementations, the accessed secondary node may decide whether to perform early data forwarding according to one or more of the UE's measurement report, candidate target secondary nodes, execution events, etc.

Step 312D: if in step 310D, it determines to perform early data forwarding, the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 313D: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 314D: other processes of secondary node change and/or addition are performed.

FIG. 3E shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3E shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN). After the UE accesses one of the target secondary nodes (in this example, T-SN1 is taken as an example), the master node transmits the transmission address to the accessed secondary node, which may perform data transmission for subsequent handover.

Step 301E: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 302E: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 303E: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 304E: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 305E: the master node transmits an Xn-U address indication (XN-U ADDRESS INDICATION) message to the source secondary node.

In some implementations, the UE may be in a single connectivity, and may be connected only to a single node (for example, it may be the MN in the drawing), so there is no S-SN in the process. In this case, the above steps 301E to 304E are a secondary node addition process, but not a secondary node change process, and there is no step 305E.

Step 306E: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 307E.a: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 307E.b: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

If the source secondary node continues to serve as the target secondary node for the subsequent conditional handover, step 307E performs a secondary node modification process. If the source secondary node will not serve as the target secondary node for the subsequent conditional handover, step 307E performs a secondary node release process without requesting and reporting the data transmission address. If the source secondary node is one of the target secondary nodes, there is no such step 307E.

Step 308E: the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), so that the accessed secondary node of the UE (for example, T-SN1 in this example) can obtain the data transmission address, which may be used for subsequent data transmission, for example, early data forwarding, etc. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message. This step may be performed before, at the same time (simultaneously) with, and after step 309E and step 310E.

Step 309E: the UE performs a random access process with T-SN1.

Step 310E: other processes of secondary node change and/or addition are performed.

Step 311E: the accessed secondary node (e.g., T-SN1 in this example) of the UE determines whether early data forwarding should be performed. In some implementations, the accessed secondary node may decide whether to perform early data forwarding according to one or more of the UE's measurement report, candidate target secondary nodes, execution events, etc.

Step 312E: if in step 311E, it determines to perform early data forwarding, the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 313E: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 314E: other processes of secondary node change and/or addition are performed.

FIG. 3F shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3F shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN), in order for the candidate target secondary node to obtain the data transmission address, so that after the UE accesses a candidate target secondary node, the candidate target secondary node can perform data transmission for subsequent handover.

Step 301F: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 302F: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 303F: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 304F: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 305F.a: the master node transmits an Xn-U address indication (XN-U ADDRESS INDICATION) message to the source secondary node.

In some implementations, the UE may be in a single connectivity, and may be connected only to a single node (for example, it may be the MN in the drawing), so there is no S-SN in the process. In this case, the above steps 301F to 304F are a secondary node addition process, but not a secondary node change process, and step 305F.a is replaced by the following step 305F.b.

Step 305F.b: the master node transmits the data transmission address to all candidate target secondary nodes, so that the candidate target secondary nodes can obtain the data transmission address. The data transmission address may be the second message mentioned above. In some implementations, the message may be carried by an Xn-U address indication (XN-U ADDRESS INDICATION) message. In some implementations, after receiving the message, the candidate target secondary node saves the address to prepare for the subsequent data transmission without triggering an actual data transmission. The actual data transmission is triggered by the

subsequent steps

310F and 311F.

Step 306F: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 307F.a: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 307F.b: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

If the source secondary node continues to serve as the target secondary node for the subsequent conditional handover, step 307F performs a secondary node modification process. If the source secondary node will not serve as the target secondary node for the subsequent conditional handover, step 307F performs a secondary node release process without requesting and reporting the data transmission address. If the source secondary node is one of the target secondary nodes, there is no such step 307F.

Step 308F: the UE performs a random access process with T-SN1.

Step 309F: other processes of secondary node change and/or addition are performed.

Step 310F: the master node determines whether early data forwarding should be performed. In some implementations, the master node may decide whether to perform early data forwarding according to one or more of the measurement report of the UE, candidate target secondary nodes, execution events, etc.

Step 311F: if step 310F, it determines to perform early data forwarding, the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), which may be used for early data forwarding. The data transmission address may be one or more of the following: data transmission addresses of all candidate target secondary nodes, only data transmission addresses of the source secondary nodes, identification for triggering data transmission, and events for triggering data transmission. The data transmission address may be the aforementioned second message.

Step 312F: the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 313F: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 314F: other processes of secondary node change and/or addition are performed.

FIG. 3G shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3G shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN). After the UE accesses one of the target secondary nodes (in this example, T-SN1 is taken as an example), the master node transmits the transmission address to the accessed secondary node, which may perform data transmission for subsequent handover.

Step 301G: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 302G: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 303G: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 304G: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 305G: the master node transmits an Xn-U address indication (XN-U ADDRESS INDICATION) message to the source secondary node.

In some implementations, the UE may be in a single connectivity, and may be connected only to a single node (for example, it may be the MN in the drawing), so there is no S-SN in the process. In this case, the above steps 301G to 304G are a secondary node addition process, but not a secondary node change process, and there is no step 305G.

Step 306G: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 307G.a: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 307G.b: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

If the source secondary node continues to serve as the target secondary node for the subsequent conditional handover, step 307G performs a secondary node modification process. If the source secondary node will not serve as the target secondary node for the subsequent conditional handover, step 307G performs a secondary node release process without requesting and reporting the data transmission address. If the source secondary node is one of the target secondary nodes, there is no such step 307G.

Step 308G: the UE performs a random access process with T-SN1.

Step 309G: other processes of secondary node change and/or addition are performed.

Step 310G: the master node determines whether early data forwarding should be performed. In some implementations, the master node may decide whether to perform early data forwarding according to one or more of the measurement report of the UE, candidate target secondary nodes, execution events, etc.

Step 311G: the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), in order for the accessed secondary node of the UE (for example, T-SN1 in this example) to obtain the data transmission address and/or trigger data transmission, for example, early data forwarding. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message.

Step 312 G: the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 313G: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 314G: other processes of secondary node change and/or addition are performed.

FIG. 3H shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3H shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN), in order for the candidate target secondary node to obtain the data transmission address, so that after the UE accesses a candidate target secondary node, the candidate target secondary node can perform data transmission for subsequent handover.

Step 301H: the source secondary node transmits a secondary node change required (S-NODE CHANGE REQUIRED) message to the master node.

Step 302H: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 303H: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 304H: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 305H: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

Step 306H: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 307H: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 308H: the master node transmits a secondary node change confirm (S-NODE CHANGE CONFIRM) message to the source secondary node.

Step 309H: the master node transmits the data transmission address to all candidate target secondary nodes, so that the candidate target secondary nodes can obtain the data transmission address. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the second message mentioned above. In some implementations, the message may be carried by an Xn-U address indication (XN-U ADDRESS INDICATION) message. In some implementations, after receiving the message, the candidate target secondary node saves the address to prepare for the subsequent data transmission without triggering an actual data transmission. The actual data transmission is triggered by the subsequent step 313H.

Step 310H: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 311H: the UE performs a random access process with T-SN1.

Step 312H: other processes of secondary node change and/or addition are performed.

Step 313H: the accessed secondary node (e.g., T-SN1 in this example) of the UE determines whether early data forwarding should be performed. In some implementations, the accessed secondary node may decide whether to perform early data forwarding according to one or more of the UE's measurement report, candidate target secondary nodes, execution events, etc.

Step 314H: if in step 314H, it determines to perform early data forwarding, the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 315H: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 316H: other processes of secondary node change and/or addition are performed.

FIG. 3I shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3I shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN). After the UE accesses one of the target secondary nodes (in this example, T-SN1 is taken as an example), the accessed secondary node can request the master node to transmit the data transmission address in order for the accessed secondary node to obtain the data transmission address, and the accessed secondary node may perform data transmission for the subsequent handover.

Step 301I: the source secondary node transmits a secondary node change required (S-NODE CHANGE REQUIRED) message to the master node.

Step 302I: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 303I: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 304I: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 305I: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

Step 306I: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 307I: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 308I: the master node transmits a secondary node change confirm (S-NODE CHANGE CONFIRM) message to the source secondary node.

Step 309I: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 310I: the UE performs a random access process with T-SN1.

Step 311I: other processes of secondary node change and/or addition are performed.

Step 312I.a: the accessed secondary node of the UE (for example, T-SN1 in this example) transmits a request for a data transmission address to the master node, so as to request the master node to transmit the data transmission address to the accessed secondary node to prepare for subsequent data transmission and/or handover. The request for a data transmission address may be the aforementioned first message.

Step 312I.b: the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), so that the accessed secondary node of the UE (for example, T-SN1 in this example) can obtain the data transmission address, which may be used for subsequent data transmission, for example, early data forwarding, etc. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message.

Step 313I: the accessed secondary node (e.g., T-SN1 in this example) of the UE determines whether early data forwarding should be performed. In some implementations, the accessed secondary node may decide whether to perform early data forwarding according to one or more of the UE's measurement report, candidate target secondary nodes, execution events, etc.

Step 314I: if in step 310D, it determines to perform early data forwarding, the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 314I: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 316I: other processes of secondary node change and/or addition are performed.

FIG. 3J shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3J shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN). After the UE accesses one of the target secondary nodes (in this example, T-SN1 is taken as an example), the master node transmits the transmission address to the accessed secondary node, which may perform data transmission for subsequent handover.

Step 301J: the source secondary node transmits a secondary node change required (S-NODE CHANGE REQUIRED) message to the master node.

Step 302J: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 303J: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 304J: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 305J: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

Step 306J: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 307J: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 308J: the master node transmits a secondary node change confirm (S-NODE CHANGE CONFIRM) message to the source secondary node.

Step 309J: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 310J: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 311J: the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), so that the accessed secondary node of the UE (for example, T-SN1 in this example) can obtain the data transmission address, which may be used for subsequent data transmission, for example, early data forwarding, etc. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message. This step may be performed before, at the same time (simultaneously) with, and after step 311J and step 312J.

Step 311J: the UE performs a random access process with T-SN1.

Step 312J: other processes of secondary node change and/or addition are performed.

Step 313J: the accessed secondary node (e.g., T-SN1 in this example) of the UE determines whether early data forwarding should be performed. In some implementations, the accessed secondary node may decide whether to perform early data forwarding according to one or more of the UE's measurement report, candidate target secondary nodes, execution events, etc.

Step 314J: if in step 313J, it determines to perform early data forwarding, the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 315J: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 316J: other processes of secondary node change and/or addition are performed.

FIG. 3K shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3K shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN), in order for the candidate target secondary node to obtain the data transmission address, so that after the UE accesses a candidate target secondary node, the candidate target secondary node can perform data transmission for subsequent handover.

Step 301K: the source secondary node transmits a secondary node change required (S-NODE CHANGE REQUIRED) message to the master node.

Step 302K: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 303K: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 304K: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 305K: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

Step 306K: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 307K: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 308K: the master node transmits a secondary node change confirm (S-NODE CHANGE CONFIRM) message to the source secondary node.

Step 309K: the master node transmits the data transmission address to all candidate target secondary nodes, so that the candidate target secondary nodes can obtain the data transmission address. The data transmission address may be the second message mentioned above. In some implementations, the message may be carried by an Xn-U address indication (XN-U ADDRESS INDICATION) message. In some implementations, after receiving the message, the candidate target secondary node saves the address to prepare for the subsequent data transmission without triggering an actual data transmission. The actual data transmission is triggered by the

subsequent steps

313K and 314K.

Step 310K: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 311K: the UE performs a random access process with T-SN1.

Step 312K: other processes of secondary node change and/or addition are performed.

Step 313K: the master node determines whether early data forwarding should be performed. In some implementations, the master node may decide whether to perform early data forwarding according to one or more of the measurement report of the UE, candidate target secondary nodes, execution events, etc.

Step 314K: if in step 310F, it determines to perform early data forwarding, the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), which may be used for early data forwarding. The data transmission address may be one or more of the following: data transmission addresses of all candidate target secondary nodes, only data transmission addresses of the source secondary nodes, identification for triggering data transmission, and events for triggering data transmission. The data transmission address may be the aforementioned second message.

Step 315K: the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 316K: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 317K: other processes of secondary node change and/or addition are performed.

FIG. 3L shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 3L shows a process of exchanging data transmission address information among a Master Node (MN), a Source Secondary Node (S-SN) and a candidate Target Secondary Node (T-SN). After the UE accesses one of the target secondary nodes (in this example, T-SN1 is taken as an example), the master node transmits the transmission address to the accessed secondary node, which may perform data transmission for subsequent handover.

Step 301L: the source secondary node transmits a secondary node change required (S-NODE CHANGE REQUIRED) message to the master node.

Step 302L: the master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the candidate target secondary node.

Step 303L: the candidate target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the master node.

Step 304L: the master node transmits a request for a data transmission address to the source secondary node to request the source secondary node to transmit its data transmission address to the master node. The request for a data transmission address may be the aforementioned first message. In some implementations, the message may be carried by a secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 305L: the source secondary node transmits the data transmission address to the master node, in order for the master node to obtain the data transmission address of the source secondary node, which can be forwarded by the master node to other target secondary nodes to prepare for subsequent data transmission and handover. The data transmission address may be the aforementioned second message. In some implementations, the message may be carried by a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message.

Step 306L: the master node transmits an RRC reconfiguration (RRCReconfiguration) message to the UE, which includes an execution event of conditional addition and/or change of the secondary node, configuration of the target cell, etc.

Step 307L: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the master node.

Step 308L: the master node transmits a secondary node change confirm (S-NODE CHANGE CONFIRM) message to the source secondary node.

Step 309L: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message. In this example, the UE meeting an execution condition for handover to T-SN1 and/or T-SN1 addition is taken as an example.

Step 310L: the UE performs a random access process with T-SN1.

Step 311L: other processes of secondary node change and/or addition are performed.

Step 312L: the master node determines whether early data forwarding should be performed. In some implementations, the master node may decide whether to perform early data forwarding according to one or more of the measurement report of the UE, candidate target secondary nodes, execution events, etc.

Step 313L: the master node transmits a data transmission address to the accessed secondary node of the UE (for example, T-SN1 in this example), in order for the accessed secondary node of the UE (for example, T-SN1 in this example) to obtain the data transmission address and/or trigger data transmission, for example, early data forwarding. The data transmission address may be the data transmission addresses of all candidate target secondary nodes. The data transmission address may be the aforementioned second message.

Step 314L: the accessed secondary node of the UE (for example, T-SN1 in this example) performs early data forwarding to other candidate target secondary nodes.

Step 315L: when a configured execution event is met, the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message.

Step 316L: other processes of secondary node change and/or addition are performed.

FIG. 4A shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4A shows a process of exchanging information related to resource reservation in a conditional handover (herein, it may also be called information related to resource reservation for conditional handover) between two nodes, so that the third node can obtain information related to resource reservation for conditional handover of the fourth node and/or other nodes, and the third node can perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to other nodes. In some implementations, for example, the third node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the fourth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the third node may be an AMF or an SMF or an MME, and the fourth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the third node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the fourth node may be an AMF or an SMF or an MME. In yet other implementations, for example, the third node may be a UE, and the fourth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the third node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the fourth node may be a master node in dual-connectivity. In still other implementations, for example, the third node may be a master node in dual-connectivity, and the fourth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the third node may be a source node in handover, and the fourth node may be a target node and/or a candidate target node in handover.

Step 401A: the fourth node transmits information related to resource reservation (time) in a conditional handover to the third node. The information related to resource reservation (time) in a conditional handover may be the aforementioned fourth message. In an implementation, the target node only reserves resources during the resource reservation time, and the resources may be used for other users during the remaining time to improve the resource utilization, for example, it can avoid the situation that the resource reservation time is too long and other users are short of resources due to conditional handover.

Step 402A: the third node makes a handover decision and/or configuration and/or performs handover based on the received resource reservation related information, and may also forward the received resource reservation related information to other nodes for other nodes to make a handover decision and/or configuration and/or perform handover. In some implementations, the user may detect whether an execution event is met based on the resource reservation related information. In some implementations, for example, the user can only switch to the target node when the execution event is met within the resource reservation time. In some other implementations, for example, the source node may determine whether the resource reservation time of the target node is appropriate based on the user's measurement report, moving trajectory, moving speed, etc. If the source node determines that the resource reservation time of the target node is appropriate, the subsequent handover process will be performed, and if the source node determines that the resource reservation time of the target node is inappropriate, the handover will be cancelled.

FIG. 4B shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4B shows a process of exchanging information related to resource reservation in a conditional handover between two nodes, so that the third node can obtain information related to resource reservation for conditional handover of the fourth node and/or other nodes, and the third node can perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to other nodes. In some implementations, for example, the third node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the fourth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the third node may be an AMF or an SMF or an MME, and the fourth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the third node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the fourth node may be an AMF or an SMF or an MME. In yet other implementations, for example, the third node may be a UE, and the fourth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the third node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the fourth node may be a master node in dual-connectivity. In still other implementations, for example, the third node may be a master node in dual-connectivity, and the fourth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the third node may be a source node in handover, and the fourth node may be a target node and/or a candidate target node in handover.

Step 401B: the third node transmits the information of the user and/or the resource reservation request in the conditional handover (that is, the information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover) to the fourth node. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In an implementation, the source node may determine the probability and/or time when the user arrives at the target cell and/or node according to the user's measurement report, moving trajectory, moving speed, etc. The source node transmits this information to the target node, and the target node may use this information to make a resource reservation strategy, for example, to reserve resources when the user is about to arrive at the target cell and/or node, so as to improve the resource utilization, for example, to avoid resource waste caused by long-time resource reservation due to that the user has not arrived at the target cell and/or node yet for a long time. In some other implementations, the source node may determine whether the target node is allowed to set the resource reservation time, and if it is allowed, the target node can set this information and/or transmit it to the source node and/or the user through subsequent processes.

Step 402B: the fourth node transmits information related to resource reservation (time) in a conditional handover to the third node. The information related to resource reservation (time) in a conditional handover may be the aforementioned fourth message. In an implementation, the target node only reserves resources during the resource reservation time, and the resources may be used for other users during the remaining time to improve the resource utilization, for example, it can avoid the situation that the resource reservation time is too long and other users are short of resources due to conditional handover. In some implementations, the fourth node may determine whether to set the resource reservation related information according to its own situation. In some other implementations, if setting the resource reservation time is allowed in step 410B, the fourth node may set the resource reservation time and/or transmit the resource reservation time to the third node through this step.

Step 403B: the third node makes a handover decision and/or configuration and/or performs handover based on the received resource reservation related information, and may also forward the received resource reservation related information to other nodes for other nodes to make a handover decision and/or configuration and/or perform handover. In some implementations, for example, the user can only switch to the target node when the execution event is met within the resource reservation time. In some other implementations, for example, the source node may determine whether the resource reservation time of the target node is appropriate based on the user's measurement report, moving trajectory, moving speed, etc. If the source node determines that the resource reservation time of the target node is appropriate, the subsequent handover process will be performed, and if the source node determines that the resource reservation time of the target node is inappropriate, the handover will be cancelled.

FIG. 4C shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4C shows a process of exchanging information related to resource reservation in a conditional handover between the source master node and the target secondary node, so that the source master node can obtain information related to resource reservation for conditional handover of the target secondary node, and the source master node may perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to users, etc.

Step 401C: the source master node and/or the source master node CU transmit a secondary node addition request (S-NODE ADDITION REQUEST) message to the target secondary node and/or the target secondary node CU.

Step 402C: the target secondary node CU transmits a UE context setup request (UE CONTEXT SETUP REQUEST) message to the target secondary node DU.

Step 403C: the target secondary node DU makes a resource reservation decision for conditional handover, and transmits the resource reservation information in the conditional handover to the target secondary node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In some implementations, the message may be carried by a user context setup response (UE CONTEXT SETUP RESPONSE) message. In an implementation, the target secondary node only reserves resources during the resource reservation time, and the resources may be used for other users during the remaining time to improve the resource utilization, for example, it can avoid the situation that the resource reservation time is too long and other users are short of resources due to conditional handover.

Step 404C: the target secondary node and/or the target secondary node CU transmit the resource reservation information in the conditional handover to the source master node and/or the source master node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message. In some implementations, for example, the source master node may determine whether the resource reservation time of the target secondary node is suitable based on the user's measurement report, moving trajectory, moving speed, etc. If the source master node determines that the resource reservation time of the target node is suitable, the subsequent handover process is performed, for example, the information is transmitted to the user, and if the source master node determines that the resource reservation time of the target node is not suitable, the handover is cancelled.

Step 405C: the source master node and/or the source master node CU transmit the resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. Herein, it may also be that the fourth message includes an RRC container, and the RRC container includes the resource reservation information in the conditional handover (or information related to resource reservation time in a conditional handover). In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time.

Step 406C: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 407 C: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4D shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4D shows a process of exchanging information related to resource reservation in a conditional handover between the source master node and the target secondary node, so that the source master node can obtain information related to resource reservation for conditional handover of the target secondary node, and the source master node may perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to users, etc.

Step 401D: the source master node and/or the source master node CU transmit the information of the user and/or the resource reservation request in the conditional handover to the target secondary node and/or the target secondary node CU. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In some implementations, the message may be carried by a secondary node addition request (S-NODE ADDITION REQUEST) message. In an implementation, the source master node may determine the probability and/or time when the user arrives at the target cell and/or node according to the user's measurement report, moving trajectory, moving speed, etc. The source master node transmits this information to the target secondary node, and the target secondary node can use this information to make a resource reservation strategy, for example, to reserve resources when the user is about to arrive at the target cell and/or node, so as to improve the resource utilization, for example, to avoid resource waste caused by long-time resource reservation due to that the user has not arrived at the target cell and/or node yet for a long time. In some other implementations, the source master node may determine whether the secondary node is allowed to set the resource reservation time, and if it is allowed, the target secondary node can set this information and/or transmit it to the source master node and/or the user through subsequent processes.

Step 402D: the target secondary node CU transmits the information of the user and/or the resource reservation request in the conditional handover to the target secondary node DU. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In some implementations, the message may be carried by a UE context setup request (UE CONTEXT SETUP REQUEST) message.

Step 403D: the target secondary node DU makes a resource reservation decision for conditional handover, and transmits the resource reservation information in the conditional handover to the target secondary node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In some implementations, the message may be carried by a user context setup response (UE CONTEXT SETUP RESPONSE) message. In an implementation, the target secondary node only reserves resources during the resource reservation time, and the resources may be used for other users during the remaining time to improve the resource utilization, for example, it can avoid the situation that the resource reservation time is too long and other users are short of resources due to conditional handover.

Step 404D: the target secondary node and/or the target secondary node CU transmit the resource reservation information in the conditional handover to the source master node and/or the source master node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message. In some implementations, for example, the source master node may determine whether the resource reservation time of the target secondary node is suitable based on the user's measurement report, moving trajectory, moving speed, etc. If the source master node determines that the resource reservation time of the target node is suitable, the subsequent handover process is performed, for example, the information is transmitted to the user, and if the source master node determines that the resource reservation time of the target node is not suitable, the handover is cancelled.

Step 405D: the source master node and/or the source master node CU transmit the resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time.

Step 406D: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 407D: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4E shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4E shows a process of exchanging information related to resource reservation in a conditional handover between the source master node and the target secondary node, so that the source master node can obtain information related to resource reservation for conditional handover of the target secondary node, and the source master node may perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to users, etc.

Step 401E: the source master node and/or the source master node CU transmit a secondary node addition request (S-NODE ADDITION REQUEST) message to the target secondary node and/or the target secondary node CU.

Step 402E: the target secondary node CU sets the resource reservation information in the conditional handover, and transmits the information to the target secondary node DU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In some implementations, the message may be carried by a UE context setup request (UE CONTEXT SETUP REQUEST) message.

Step 403E: after receiving the resource reservation information in the conditional handover set by CU in step 402E, the target secondary node DU modifies and/or accepts and/or rejects the resource reservation information in the conditional handover based on the resource reservation information in the conditional handover set by CU, or sets the resource reservation information in the conditional handover itself and transmits the setting and/or decision of the resource reservation information in the conditional handover to the target secondary node CU according to its own situation. The resource reservation information in the conditional handover may be the aforementioned fourth message. In some implementations, the message may be carried by a UE context setup response (UE CONTEXT SETUP RESPONSE) message.

Step 404E: the target secondary node and/or the target secondary node CU transmit the resource reservation information in the conditional handover to the source master node and/or the source master node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message. In some implementations, for example, the source master node may determine whether the resource reservation time of the target secondary node is suitable based on the user's measurement report, moving trajectory, moving speed, etc. If the source master node determines that the resource reservation time of the target node is suitable, the subsequent handover process is performed, for example, the information is transmitted to the user, and if the source master node determines that the resource reservation time of the target node is not suitable, the handover is cancelled.

Step 405E: the source master node and/or the source master node CU transmit the resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time.

Step 406E: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 407E: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4F shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4F shows a process of exchanging information related to resource reservation in a conditional handover between the source master node and the target secondary node, so that the source master node can obtain information related to resource reservation for conditional handover of the target secondary node, and the source master node may perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to users, etc.

Step 401F: the source master node and/or the source master node CU transmit a secondary node addition request (S-NODE ADDITION REQUEST) message to the target secondary node and/or the target secondary node CU.

Step 402F: the target secondary node CU transmits a UE context setup request (UE CONTEXT SETUP REQUEST) message to the target secondary node DU.

Step 403F: the target secondary node DU transmits a UE context setup response (UE CONTEXT SETUP RESPONSE) message to the target secondary node CU.

Step 404F: the target secondary node CU sets the resource reservation information in the conditional handover, and the target secondary node and/or the target secondary node CU transmit the resource reservation information in the conditional handover to the source master node and/or the source master node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message. In some implementations, for example, the source master node may determine whether the resource reservation time of the target secondary node is suitable based on the user's measurement report, moving trajectory, moving speed, etc. If the source master node determines that the resource reservation time of the target node is suitable, the subsequent handover process is performed, for example, the information is transmitted to the user, and if the source master node determines that the resource reservation time of the target node is not suitable, the handover is cancelled.

Step 405F: the source master node and/or the source master node CU transmit the resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time.

Step 406F: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 407F: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4G shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4G shows a process of exchanging information related to resource reservation in a conditional handover between the source master node and the target secondary node, so that the source master node can obtain information related to resource reservation for conditional handover of the target secondary node, and the source master node may perform conditional handover configuration and/or cancel conditional handover according to this information, and/or forward it to users, etc.

Step 401G: the source master node and/or the source master node CU transmit a secondary node addition request (S-NODE ADDITION REQUEST) message to the target secondary node and/or the target secondary node CU.

Step 402G: the target secondary node CU transmits a UE context setup request (UE CONTEXT SETUP REQUEST) message to the target secondary node DU.

Step 403G: the target secondary node DU transmits a UE context setup response (UE CONTEXT SETUP RESPONSE) message to the target secondary node CU.

Step 404G: the target secondary node CU sets the resource reservation information in the conditional handover, and the target secondary node and/or the target secondary node CU transmit the resource reservation information in the conditional handover to the source master node and/or the source master node CU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message. In some implementations, for example, the source master node may determine whether the resource reservation time of the target secondary node is suitable based on the user's measurement report, moving trajectory, moving speed, etc. If the source master node determines that the resource reservation time of the target node is suitable, the subsequent handover process is performed, for example, the information is transmitted to the user, and if the source master node determines that the resource reservation time of the target node is not suitable, the handover is cancelled.

Step 405G: the target secondary node CU transmits the resource reservation information in the conditional handover to the target secondary node DU. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message. In an implementation, for example, the target secondary node DU can perform resource reservation according to the received resource reservation information.

Step 406G: the target secondary node DU transmits a UE context setup response (UE CONTEXT SETUP RESPONSE) message to the target secondary node CU.

Step 407G: the source master node and/or the source master node CU transmit the resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time.

Step 408G: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 409G: the UE performs subsequent handover processes such as random access with the target secondary node.

Herein, step 405G and step 406G may be performed before, at the same time (simultaneously) with, and/or after step 407G. After the target secondary node CU sets the resource reservation information in the conditional handover, step 405G may be performed before and/or at the same time (simultaneously) with step 404G, and the target secondary node CU may inform the target secondary node DU first and then the source master node, or the target secondary node CU may inform the target secondary node DU and the source master node simultaneously.

FIG. 4H shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4H shows the exchanging of information of a user and/or a resource reservation request in a conditional handover between the source master node, the source secondary node and the target secondary node, and the target secondary node can make a handover decision according to the information of the user and/or the resource reservation request in the conditional handover, for example, whether to receive the handover request and/or secondary node addition request, and the resource reservation information in the conditional handover, etc.

Step 401H: the source master node transmits the information of the user and/or the resource reservation request in the conditional handover to the target secondary node. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In some implementations, the message may be carried by a secondary node addition request (S-NODE ADDITION REQUEST) message. The target secondary node can make a handover decision according to the information of the user and/or the resource reservation request in the conditional handover, for example, whether to receive the handover request and/or secondary node addition request, and the resource reservation information in the conditional handover, etc.

Step 402H: the target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the source master node.

Step 403H: the source master node may set the resource reservation information in the conditional handover according to the information of the user and/or the resource reservation request in the conditional handover. The source mast node transmits that resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time. In some implementations, the set resource reservation information in the conditional handover may be consistent with the requested resource reservation information.

Step 404H: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 405H: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4I shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4I shows the exchanging of resource reservation information in a conditional handover between the source master node, the source secondary node and the target secondary node. The target secondary node can set the resource reservation information in the conditional handover according to its own situation, and transmit it to the source master node and then to the user.

Step 401I: the source master node transmits a secondary node addition request (S-NODE ADDITION REQUEST) message to the target secondary node.

Step 402I: the target secondary node sets the resource reservation information in the conditional handover, and the target secondary node transmits the resource reservation information in the conditional handover to the source master node. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message. In some implementations, for example, the source master node may determine whether the resource reservation time of the target secondary node is suitable based on the user's measurement report, moving trajectory, moving speed, etc. If the source master node determines that the resource reservation time of the target node is suitable, the subsequent handover process is performed, for example, the information is transmitted to the user, and if the source master node determines that the resource reservation time of the target node is not suitable, the handover is cancelled.

Step 403I: the source master node transmits the resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time.

Step 404I: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 405I: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4J shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4J shows the exchanging of information of a user and/or a resource reservation request in a conditional handover between the source master node, the source secondary node and the target secondary node, and the target secondary node can make a handover decision according to the information of the user and/or the resource reservation request in the conditional handover, for example, whether to receive the handover request and/or secondary node addition request, and the resource reservation information in the conditional handover, etc.

Step 401J: the source secondary node transmits the information of the user and/or the resource reservation request in the conditional handover to the source master node. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In some implementations, that message may be carried by a secondary node change required (S-NODE CHANGE REQUIRED) message.

Step 402J: the source master node transmits the information of the user and/or the resource reservation request in the conditional handover to the target secondary node. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In some implementations, the message may be carried by a secondary node addition request (S-NODE ADDITION REQUEST) message. The target secondary node can make a handover decision according to the information of the user and/or the resource reservation request in the conditional handover, for example, whether to receive the handover request and/or secondary node addition request, and the resource reservation information in the conditional handover, etc.

Step 403J: the target secondary node transmits a secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message to the source master node.

Step 404J: the source master node transmits a secondary node change confirm (S-NODE CHANGE CONFIRM) message to the source secondary node.

Step 405J: the source master node may set the resource reservation information in the conditional handover according to the information of the user and/or the resource reservation request in the conditional handover. The source mast node transmits that resource reservation information in the conditional handover to the UE. The resource reservation information in the conditional handover may be the aforementioned fourth message. In an implementation, the message may be carried by an RRC reconfiguration (RRCReconfiguration) message. In some implementations, for example, the UE may handover to the target secondary node only when an execution event is met within the resource reservation time. In some implementations, the set resource reservation information in the conditional handover may be consistent with the requested resource reservation information.

Step 406J: the UE transmits an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source master node.

Step 407J: the UE performs subsequent handover processes such as random access with the target secondary node.

FIG. 4K shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 4K shows a process of exchanging information related to resource reservation in a conditional handover between two nodes, so that the fourth node can obtain information related to users and/or resource reservation request in a conditional handover from the third node, and the fourth node may receive and/or reject the conditional handover request according to this information, and may also perform resource reservation decisions according to this information. In some implementations, for example, the third node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the fourth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the third node may be an AMF or an SMF or an MME, and the fourth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the third node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the fourth node may be an AMF or an SMF or an MME. In yet other implementations, for example, the third node may be a UE, and the fourth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the third node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the fourth node may be a master node in dual-connectivity. In still other implementations, for example, the third node may be a master node in dual-connectivity, and the fourth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the third node may be a source node in handover, and the fourth node may be a target node and/or a candidate target node in handover.

Step 401K: the third node transmits the information of the user and/or the resource reservation request in the conditional handover to the fourth node. The information of the user and/or the resource reservation request in the conditional handover may be the aforementioned third message. In an implementation, the source node may determine the probability and/or time when the user arrives at the target cell and/or node according to the user's measurement report, moving trajectory, moving speed, etc. The source node transmits this information to the target node, and the target node may use this information to make a resource reservation strategy, for example, to reserve resources when the user is about to arrive at the target cell and/or node, so as to improve the resource utilization, for example, to avoid resource waste caused by long-time resource reservation due to that the user has not arrived at the target cell and/or node yet for a long time.

Step 402K: the fourth node decides to receive and/or reject the conditional handover request according to the received information related to users and/or resource reservation request in the conditional handover. The fourth node transmits a conditional handover acknowledge to the third node.

Step 403K: the fourth node makes a resource reservation decision according to the received information related to users and/or resource reservation request in the conditional handover, for example, to reserve resources when the user is about to arrive at the target cell and/or node, so as to improve the resource utilization, for example, to avoid resource waste caused by long-time resource reservation due to that the user has not arrived at the target cell and/or node yet for a long time.

Step 404K: the third node makes a handover decision and/or configuration and/or performs handover and/or forwards it to other nodes.

FIG. 5A shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5A shows a process of exchanging prediction information related to a conditional handover between two nodes, so that the fifth node can obtain prediction results related to the conditional handover of the fourth node and/or other nodes, and the fifth information may set handover related decisions and/or forward them to other nodes. In some implementations, for example, the fifth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the sixth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the fifth node may be an AMF or an SMF or an MME, and the sixth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the fifth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the sixth node may be an AMF or an SMF or an MME. In yet other implementations, for example, the sixth node may be a UE, and the fifth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the fifth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the sixth node may be a master node in dual-connectivity. In still other implementations, for example, the fifth node may be a master node in dual-connectivity, and the sixth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the fifth node may be a source node in handover, and the sixth node may be a target node and/or a candidate target node in handover. In still other implementations, the fifth node may be a target node and/or a candidate target node in handover, and the sixth node may be a source node in handover. In still other implementations, the fifth node may be a source secondary node and/or a target secondary node, and the sixth node may be a UE. In still other implementations, the fifth node may be a source master node and/or a target master node, and the sixth node may be a UE.

Step 501A: the sixth node transmits conditional handover related prediction information to the fifth node. The conditional handover related prediction information may be the aforementioned sixth message.

Step 502A: the fifth node makes a handover related decision based on the received conditional handover related prediction information, and/or forwards it to other nodes for the other nodes to make handover related decisions. In some implementations, this information may be used to determine whether to trigger early data forwarding, and if so, the fifth node can perform data forwarding to the target node. If it is determined to trigger but there is no relevant transmission address, the fifth node (for example, it may be a secondary node) may request the data transmission address from the master node and/or other nodes by using the first message; or if it is determined to trigger but there is no relevant transmission address, the fifth node (for example, it may be a master node) may inform the secondary node of the data transmission address by using the second message and/or trigger the secondary node to perform data forwarding to other target secondary nodes. In some other implementations, this information may be used to make decisions related to resource reservation, such as resource reservation time, etc. For example, it may be that the fifth node (which may be a source node) sets the information of the user and/or the resource reservation request in the conditional handover, and transmits the set information of the user and/or the resource reservation request in the conditional handover to the target node, which may be referred to FIG. 4 for details. Alternatively, the fifth node (which may be a target node) may set the resource reservation information in the conditional handover, which may be referred to FIG. 4 for details. This embodiment can be combined with other embodiments in the present disclosure.

FIG. 5B shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5B shows a process of exchanging prediction information related to a conditional handover between two nodes, so that the fifth node can obtain prediction results related to the conditional handover of the fourth node and/or other nodes, and the fifth information may set handover related decisions and/or forward them to other nodes. In some implementations, for example, the fifth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the sixth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the fifth node may be an AMF or an SMF or an MME, and the sixth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the fifth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the sixth node may be an AMF or an SMF or an MME. In yet other implementations, for example, the sixth node may be a UE, and the fifth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the fifth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the sixth node may be a master node in dual-connectivity. In still other implementations, for example, the fifth node may be a master node in dual-connectivity, and the sixth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the fifth node may be a source node in handover, and the sixth node may be a target node and/or a candidate target node in handover. In still other implementations, the fifth node may be a target node and/or a candidate target node in handover, and the sixth node may be a source node in handover. In still other implementations, the fifth node may be a source secondary node and/or a target secondary node, and the sixth node may be a UE. In still other implementations, the fifth node may be a source master node and/or a target master node, and the sixth node may be a UE.

Step 501B: the fifth node transmits a request for reporting the conditional handover related prediction information to the sixth node, which is used to request the sixth node to transmit the conditional handover related prediction information to the fifth node. The request for reporting the conditional handover related prediction information may be the aforementioned fifth message.

Step 502B: the sixth node transmits the conditional handover related prediction information to the fifth node. The conditional handover related prediction information may be the aforementioned sixth message.

Step 503B: the fifth node makes a handover related decision based on the received conditional handover related prediction information, and/or forwards it to other nodes for the other nodes to make handover related decisions. In some implementations, this information may be used to determine whether to trigger early data forwarding, and if so, the fifth node can perform data forwarding to the target node. If it is determined to trigger but there is no relevant transmission address, the fifth node (for example, it may be a secondary node) may request the data transmission address from the master node and/or other nodes by using the first message; or if it is determined to trigger but there is no relevant transmission address, the fifth node (for example, it may be a master node) may inform the secondary node of the data transmission address by using the second message and/or trigger the secondary node to perform data forwarding to other target secondary nodes. In some other implementations, this information may be used to make decisions related to resource reservation, such as resource reservation time, etc. For example, it may be that the fifth node (which may be a source node) sets the information of the user and/or the resource reservation request in the conditional handover, and transmits the set information of the user and/or the resource reservation request in the conditional handover to the target node, which may be referred to FIG. 4 for details. Alternatively, the fifth node (which may be a target node) may set the resource reservation information in the conditional handover, which may be referred to FIG. 4 for details. This embodiment can be combined with other embodiments in the present disclosure.

FIG. 5C shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5C shows the exchanging of conditional handover related prediction information among the UE, the source master node, the source secondary node and the target secondary node. After receiving this information, the source secondary node uses it to decide whether to trigger early data forwarding, so that the source secondary node may trigger early data forwarding at an appropriate time, and/or select an appropriate cell and/or node for data forwarding, so as to avoid triggering early data forwarding too early and/or too late, and/or avoid unnecessary data forwarding, etc.

Step 500C: a conditional secondary node change/modification process.

Step 501C: the UE transmits conditional handover related prediction information to the source master node. The conditional handover related prediction information may be the aforementioned sixth message.

Step 502C: the source master node transmits conditional handover related prediction information to the source secondary node. The conditional handover related prediction information may be the aforementioned sixth message. In an implementation, the message may be carried by the secondary node modification request (S-NODE MODIFICATION REQUEST) message.

Step 503C: the source secondary node transmits a secondary node modification request acknowledge (S-NODE MODIFICATION REQUEST ACKNOWLEDGE) message to the source master node.

Step 504C: the source secondary node may determine whether to trigger early data forwarding and/or the target node of early data forwarding based on the collected conditional handover related prediction information.

Step 505C: if in step 504C, it is determined to perform early data forwarding, the source secondary node performs data forwarding on all and/or selected target secondary nodes.

FIG. 5D shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5D shows the exchanging of conditional handover related prediction information among the UE, the source master node, the source secondary node and the target secondary node. After receiving this information, the source secondary node uses it to decide whether to trigger early data forwarding, so that the source secondary node may trigger early data forwarding at an appropriate time, and/or select an appropriate cell and/or node for data forwarding, so as to avoid triggering early data forwarding too early and/or too late, and/or avoid unnecessary data forwarding, etc.

Step 500D: a conditional secondary node change/modification process.

Step 501D: the UE transmits conditional handover related prediction information to the source secondary node. The conditional handover related prediction information may be the aforementioned sixth message. The message may be directly transmitted by the UE to the source secondary node, or it may be transmitted to the source secondary node by the UE using an RRC container carrying the sixth message and through the forwarding of the source master node, that is, the user transmits the message to the source master node, and the source master node forwards it to the source secondary node.

Step 502D: the source secondary node may determine whether to trigger early data forwarding and/or the target node of early data forwarding based on the collected conditional handover related prediction information.

Step 503D: if in step 502D, it is determined to perform early data forwarding, the source secondary node performs data forwarding on all and/or selected target secondary nodes.

FIG. 5E shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5E shows the exchanging of conditional handover related prediction information among the UE, the source master node and the target secondary node. After receiving this information, the source master node uses it to decide whether to trigger early data forwarding, so that the source master node may trigger early data forwarding at an appropriate time, and/or select an appropriate cell and/or node for data forwarding, so as to avoid triggering early data forwarding too early and/or too late, and/or avoid unnecessary data forwarding, etc.

Step 500E: a conditional secondary node change and/or addition process.

Step 501E: the UE transmits conditional handover related prediction information to the source master node. The conditional handover related prediction information may be the aforementioned sixth message.

Step 502E: the source master node may determine whether to trigger early data forwarding and/or the target node of early data forwarding based on the collected conditional handover related prediction information.

Step 503E: if in step 502E, it is determined to perform early data forwarding, the source master node performs data forwarding on all and/or selected target secondary nodes.

FIG. 5F shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5F shows the exchanging of conditional handover related prediction information among the UE, the source node and the target node. After receiving this information, the source node uses it to decide whether to trigger early data forwarding, so that the source node may trigger early data forwarding at an appropriate time, and/or select an appropriate cell and/or node for data forwarding, so as to avoid triggering early data forwarding too early and/or too late, and/or avoid unnecessary data forwarding, etc.

Step 500F: a conditional handover process.

Step 501F: the UE transmits conditional handover related prediction information to the source node. The conditional handover related prediction information may be the aforementioned sixth message.

Step 502F: the source node may determine whether to trigger early data forwarding and/or the target node of early data forwarding based on the collected conditional handover related prediction information.

Step 503F: if in step 502F, it is determined to perform early data forwarding, the source node performs data forwarding on all and/or selected target nodes.

FIG. 5G shows a schematic diagram of an aspect of a method for supporting mobility management according to embodiments of the present disclosure. Specifically, FIG. 5G shows the exchanging of conditional handover related prediction information among the UE, the source master node, the source secondary node and the target secondary node. After receiving this information, the source master node uses it to decide whether to trigger early data forwarding, so that the source secondary node may trigger early data forwarding at an appropriate time, and/or select an appropriate cell and/or node for data forwarding, so as to avoid triggering early data forwarding too early and/or too late, and/or avoid unnecessary data forwarding, etc.

Step 500G: a conditional secondary node change/modification process.

Step 501G: the UE transmits conditional handover related prediction information to the source master node. The conditional handover related prediction information may be the aforementioned sixth message.

Step 502G: the source master node decides whether to trigger early data forwarding and which cells to select for early data forwarding.

Step 503G: the source master node transmits the data transmission address to the source secondary node. The source master node may transmit the selected cells for early data forwarding and/or the corresponding data transmission address to the source secondary node. In an implementation, the data transmission address may be the aforementioned second message.

Step 504G: the source secondary node performs data forwarding to the target secondary node.

FIG. 11A shows a schematic diagram of an aspect of a method performed by a node according to embodiments of the present disclosure. Specifically, FIG. 11A shows a process of exchanging Hybrid Automatic Repeat reQuest (HARQ) transmission related parameters between two nodes, so that the seventh node can obtain the parameters related to HARQ transmission of the eighth node and/or other nodes, and the seventh node may use the parameters to evaluate the radio resource quality. In an implementation, the seventh node can make relevant decisions according to the parameters related to HARQ transmission, for example, selecting transmission paths and/or making resource allocation strategies, for example, selecting relevant paths for Packet Data Convergence Protocol (PDCP) duplication. In some implementations, for example, the seventh node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the eighth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the seventh node may be an AMF or an SMF or an MME, and the eighth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the seventh node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the eighth node may be an AMF or an SMF or an MME. In yet other implementations, for example, the seventh node may be a node hosting PDCP entity, and the eighth node may be a node interacting with the node hosting PDCP entity. The node interacting with the node hosting PDCP entity may also be called a Cooresponding node. In still other implementations, for example, the seventh node may be a node interacting with the node hosting PDCP entity, and the eighth node may be a node hosting PDCP entity. In yet other implementations, for example, the seventh node may be a UE, and the eighth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the seventh node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the eighth node may be a master node in dual-connectivity. In still other implementations, for example, the seventh node may be a master node in dual-connectivity, and the eighth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the seventh node may be a source node in handover, and the eighth node may be a target node and/or a candidate target node in handover. In still other implementations, the seventh node may be a target node and/or a candidate target node in handover, and the eighth node may be a source node in handover. In still other implementations, the seventh node may be a source secondary node and/or a target secondary node, and the eighth node may be a UE. In still other implementations, the seventh node may be a source master node and/or a target master node, and the eighth node may be a UE.

Step 1101A: the eighth node transmits parameters related to HARQ transmission to the seventh node. The parameters related to HARQ transmission may include one or more of the following: HARQ transmission number, HARQ transmission number within a certain period of time, (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, (average) HARQ retransmission number for transmitting a certain amount of data, average retransmission number, average transmission number, event triggering the reporting, and indication information for the existence of the above parameters, etc. Herein, the average retransmission number may be the average number of retransmission required for transmitting one or more packets. The average transmission number may be the average number of transmission required for transmitting one or more packets, including the first transmission and retransmission. Herein, the indication information for the existence of the above parameters may include one or more of the following: indication information for the existence of HARQ transmission number, indication information for the existence of HARQ transmission number within a certain period of time, indication information for the existence of (average) HARQ transmission number for transmitting a certain amount of data, indication information for the existence of (average) HARQ failure number for transmitting a certain amount of data, indication information for the existence of (average) HARQ retransmission number for transmitting a certain amount of data, indication information for the existence of average retransmission number, indication information for the existence of average transmission number, etc.

The event triggering the reporting may include one or more of the following: the HARQ failure number reaches a predetermined threshold, the HARQ retransmission number reaches a predetermined threshold, the HARQ failure rate reaches a predetermined threshold, the HARQ retransmission rate reaches a predetermined threshold, and HARQ parameters reach a predetermined threshold. The HARQ parameters may include one or more of the following: HARQ transmission number, HARQ transmission number within a certain period of time, (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, (average) HARQ retransmission number for transmitting a certain amount of data, average retransmission number, average transmission number.

The parameters related to HARQ transmission may be carried by a downlink data delivery status (DL DATA DELIVERY STATUS) information frame, an assistance information data (ASSISTANCE INFORMATION DATA) information frame, a downlink user data (DL USER DATA) information frame, or a new information frame; or may be carried by an Assistance Information Type in the assistance information data. The indication information for the existence of the parameters related to HARQ transmission may be carried by the number of octets for Radio Quality Assistance Information Field in the assistance information data. The parameters related to HARQ transmission may also be carried by an RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or RRC container and/or a medium access control control element (MAC CE).

The seventh node may evaluate the radio resource status and/or radio transmission condition according to the parameters related to HARQ transmission.

Step 1102A: the seventh node makes relevant decisions and/or forwards them to other nodes. Herein, the relevant decisions may include one or more of the following: selecting transmission path, resource allocation strategy, selecting relevant path in PDCP duplication, etc.

FIG. 11B shows a schematic diagram of an aspect of a method performed by a node according to embodiments of the present disclosure. Specifically, FIG. 11B shows a process of exchanging Hybrid Automatic Repeat reQuest (HARQ) transmission related parameters between two nodes, so that the seventh node can obtain the parameters related to HARQ transmission of the eighth node and/or other nodes, and the seventh node may use the parameters to evaluate the radio resource quality. In an implementation, the seventh node can make relevant decisions according to the parameters related to HARQ transmission, for example, selecting transmission paths and/or making resource allocation strategies, for example, selecting relevant paths for Packet Data Convergence Protocol (PDCP) duplication. In some implementations, for example, the seventh node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB, and the eighth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In some other implementations, for example, the seventh node may be an AMF or an SMF or an MME, and the eighth node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB. In yet other implementations, for example, the seventh node may be a gNB or a gNB-CU or a gNB CU-CP or an en-gNB or an eNB or a ng-eNB, and the eighth node may be an AMF or an SMF or an MME. In still other implementations, for example, the seventh node may be a node hosting PDCP entity, and the eighth node may be a node interacting with the node hosting PDCP entity. In still other implementations, for example, the seventh node may be a node interacting with the node hosting PDCP entity, and the eighth node may be a node hosting PDCP entity. In yet other implementations, for example, the seventh node may be a UE, and the eighth node may be a gNB or a gNB-CU or a gNB-DU or a gNB CU-CP or a gNB CU-UP or an en-gNB or an eNB or a ng-eNB. In still other implementations, for example, the seventh node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity, and the eighth node may be a master node in dual-connectivity. In still other implementations, for example, the seventh node may be a master node in dual-connectivity, and the eighth node may be a secondary node and/or a target secondary node and/or a Candidate Target Secondary Node in dual-connectivity. In still other implementations, the seventh node may be a source node in handover, and the eighth node may be a target node and/or a candidate target node in handover. In still other implementations, the seventh node may be a target node and/or a candidate target node in handover, and the eighth node may be a source node in handover. In still other implementations, the seventh node may be a source secondary node and/or a target secondary node, and the eighth node may be a UE. In still other implementations, the seventh node may be a source master node and/or a target master node, and the eighth node may be a UE.

Step 1101B: the seventh node transmits a request for parameters related to HARQ transmission to the eighth node. The parameters related to HARQ transmission may include one or more of the following: HARQ transmission number, HARQ transmission number within a certain period of time, (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, (average) HARQ retransmission number for transmitting a certain amount of data, average retransmission number, average transmission number, and indication information for the existence of the above parameters. The average transmission number may be the average number of transmission required for transmitting one or more packets, including the first transmission and retransmission. Herein, the indication information for the existence of the above parameters may include one or more of the following: indication information for the existence of HARQ transmission number, indication information for the existence of HARQ transmission number within a certain period of time, indication information for the existence of (average) HARQ transmission number for transmitting a certain amount of data, indication information for the existence of (average) HARQ failure number for transmitting a certain amount of data, indication information for the existence of (average) HARQ retransmission number for transmitting a certain amount of data, indication information for the existence of average retransmission number, indication information for the existence of average transmission number, etc.

The request for parameters related to HARQ transmission may include one or more of the following:

- Request indication for parameters related to HARQ transmission: when the eighth node receives the request indication, it needs to report HARQ related parameters.

- Polling of the parameters related to HARQ transmission: when the eighth node receives the polling, it needs to report HARQ related parameters.

- Parameters requested to be reported: it may include one or more of the following: HARQ transmission number, HARQ transmission number within a certain period of time, (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, (average) HARQ retransmission number for transmitting a certain amount of data, average retransmission number, average transmission number, indication information for the existence of the above parameters, etc. Herein, the indication information for the existence of the above parameters may include one or more of the following: indication information for the existence of HARQ transmission number, indication information for the existence of HARQ transmission number within a certain period of time, indication information for the existence of (average) HARQ transmission number for transmitting a certain amount of data, indication information for the existence of (average) HARQ failure number for transmitting a certain amount of data, indication information for the existence of (average) HARQ retransmission number for transmitting a certain amount of data, indication information for the existence of average retransmission number, indication information for the existence of average transmission number, etc.

- HARQ parameter measurement time: used to identify the time of statistics and/or measurement of HARQ parameters.

- HARQ parameter reporting time: used to identify the reporting time of HARQ parameters.

- Data amount corresponding to HARQ parameter measurement: used to identify the data amount corresponding to statistics and/or measurement of HARQ parameters. For example, when the requested parameters are (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, and (average) HARQ retransmission number for transmitting a certain amount of data, the data amount indicates the "certain amount of data" involved in the (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, and (average) HARQ retransmission number for transmitting a certain amount of data.

- Reporting mode: it may include single reporting, on-demand reporting, periodic reporting and event-triggered reporting.

- Reporting period: used to indicate the reporting period of periodic reporting.

- Measurement period

- Event that triggers reporting: it may include one or more of the following:

o The HARQ failure number reaches a predetermined threshold: the event needs to indicate the predetermined threshold.

o The HARQ retransmission number reaches a predetermined threshold: the event needs to indicate the predetermined threshold.

o The HARQ failure rate reaches a predetermined threshold: the event needs to indicate the predetermined threshold.

o The HARQ retransmission rate reaches a predetermined threshold: the event needs to indicate the predetermined threshold.

o The HARQ parameters reach a predetermined threshold: the event needs to indicate the predetermined threshold. The HARQ parameters may include one or more of the following: HARQ transmission number, HARQ transmission number within a certain period of time, (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, (average) HARQ retransmission number for transmitting a certain amount of data, average retransmission number, average transmission number.

The request for parameters related to HARQ transmission may be carried by a downlink data delivery status (DL DATA DELIVERY STATUS) information frame, an assistance information data (ASSISTANCE INFORMATION DATA) information frame, a downlink user data (DL USER DATA) information frame, or a new information frame. The request for parameters related to HARQ transmission may also be carried by an RRC and/or Xn and/or X2 and/or F1 and/or E1 and/or NG message and/or RRC container and/or a medium access control control element (MAC CE). The eighth node may measure and/or collect and/or report the parameters related to HARQ transmission according to the received request for parameters related to HARQ transmission.

Step 1102B: the eighth node transmits parameters related to HARQ transmission to the seventh node. The parameters related to HARQ transmission may include one or more of the following: HARQ transmission number, HARQ transmission number within a certain period of time, (average) HARQ transmission number for transmitting a certain amount of data, (average) HARQ failure number for transmitting a certain amount of data, (average) HARQ retransmission number for transmitting a certain amount of data, average retransmission number, average transmission number, event triggering the reporting, and indication information for the existence of the above parameters, etc. Herein, the average retransmission number may be the average number of retransmission required for transmitting one or more packets. The average transmission number may be the average number of transmission required for transmitting one or more packets, including the first transmission and retransmission. Herein, the indication information for the existence of the above parameters may include one or more of the following: indication information for the existence of HARQ transmission number, indication information for the existence of HARQ transmission number within a certain period of time, indication information for the existence of (average) HARQ transmission number for transmitting a certain amount of data, indication information for the existence of (average) HARQ failure number for transmitting a certain amount of data, indication information for the existence of (average) HARQ retransmission number for transmitting a certain amount of data, indication information for the existence of average retransmission number, indication information for the existence of average transmission number, etc.

Step 1103B: the seventh node makes relevant decisions and/or forwards them to other nodes. Herein, the relevant decisions may include one or more of the following: selecting transmission path, resource allocation strategy, selecting relevant path in PDCP duplication, etc.

In the present disclosure, a node interacting with the node hosting PDCP entity may also be called a Cooresponding node.

In the above example, a source master node and a target secondary node are used as examples, and the present disclosure is not limited to the sample contents. For example, the source master node may also be a source node in handover and the target secondary node may also be a secondary node in handover. In this case, in the above example, the secondary node addition request (S-NODE ADDITION REQUEST) message should be replaced with a handover request (HADOVER REQUEST) message, and the secondary node addition request acknowledge (S-NODE ADDITION REQUEST ACKNOWLEDGE) message should be replaced with a handover request acknowledge (HADOVER REQUEST ACKNOWLEDGE) message.

It should be understood that, depending on the application scenario, the various example aspects, methods, steps, processes, etc. shown above in conjunction with the drawings can be combined and implemented in any way, and are not limited herein.

Next, FIG. 6 shows a flowchart of a method 600 performed by a first node in a wireless communication system according to embodiments of the present disclosure.

As shown in FIG. 6, a method 600 perform by a first node in a wireless communication system according to embodiments of the present disclosure may include: in step S601, transmitting a fourth message to a second node, wherein the fourth message includes information related to resource reservation time in a conditional handover; in step S602, receiving a second message including a data transmission address of a candidate target cell from the second node; in step S603, receiving a sixth message from the second node or a user equipment (UE), wherein the sixth message includes prediction information related to the conditional handover; in step S604, determining whether to perform data transmission based on the prediction information related to the conditional handover; and in step S605, in case that it is determined to perform data transmission, performing data transmission based on the data transmission address.

According to embodiments of the present disclosure, the method 600 may further include: transmitting a first message including a request for a data transmission address to the second node, wherein the second message is transmitted from the second node based on the first message.

According to embodiments of the present disclosure, the method 600 may further include: receiving a third message from the second node, wherein the third message includes information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, wherein the fourth message is transmitted to the second node based on the third message.

According to embodiments of the present disclosure, the method 600 may further include: transmitting a fifth message to the second node, wherein the fifth message includes a request for reporting the prediction information related to the conditional handover, wherein the sixth message is transmitted from the second node based on the fifth message.

FIG. 7 shows a flowchart of a method 700 performed by a second node in a wireless communication system according to embodiments of the present disclosure.

As shown in FIG. 7, a method 700 performed by a second node in a wireless communication system according to embodiments of the present disclosure may include: in step S701, receiving a fourth message from a first node, wherein the fourth message includes information related to resource reservation time in a conditional handover; in step S702, transmitting a second message including a data transmission address of a candidate target cell to the first node; and in step S703, transmitting a sixth message to the first node, wherein the sixth message includes prediction information related to the conditional handover. In some implementations, the prediction information related to the conditional handover is used for the first node to determine whether to perform data transmission. In some implementations, in case that it is determined to perform data transmission, the first node performs data transmission based on the data transmission address.

According to embodiments of the present disclosure, before transmitting the second message including a data transmission address of a candidate target cell to the first node, the method 700 may further include receiving a radio resource control (RRC) reconfiguration complete message from a user equipment (UE).

According to embodiments of the present disclosure, the method 700 may further include determining whether to take the first node as a candidate target node based on the information related to resource reservation time in a conditional handover.

According to embodiments of the present disclosure, the method 700 may further include receiving a first message including a request for a data transmission address from the first node, wherein the second message is transmitted to the first node based on the first message.

According to embodiments of the present disclosure, the method 700 may further include transmitting a third message to the first node, wherein the third message includes information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, wherein the fourth message is transmitted from the first node based on the third message.

According to embodiments of the present disclosure, the method 700 may further include receiving a fifth message from the first node, wherein the fifth message includes a request for reporting the prediction information related to the conditional handover, wherein the sixth message is transmitted to the first node based on the fifth message.

FIG. 8 shows a flowchart of a method 800 performed by a user equipment in a wireless communication system according to embodiments of the present disclosure.

As shown in FIG. 8, a method 800 performed by a user equipment in a wireless communication system according to embodiments of the present disclosure may include: in step S801, receiving a fourth message from a second node, wherein the fourth message includes an RRC container, which includes information related to resource reservation time in a conditional handover; and in step S802, transmitting a sixth message to the second node or a first node, wherein the sixth message includes prediction information related to the conditional handover, wherein the prediction information related to the conditional handover is used for the first node to determine whether to perform data transmission.

According to embodiments of the present disclosure, the method 800 may further include detecting whether an execution event is met based on the information related to resource reservation time in a conditional handover.

It should be understood that

methods

600, 700, 800, etc. according to embodiments of the present disclosure may further include any steps described in connection with various examples, aspects, drawings, etc. of the present disclosure.

Next, FIG. 9 shows a schematic diagram of a first node 900 according to embodiments of the present disclosure.

As shown in FIG. 9, a first node (or first node device) 900 according to embodiments of the present disclosure may include a transceiver 910 and a processor 920. The transceiver 910 may be configured to transmit and receive signals. The processor 920 may be coupled to the transceiver 910 and may be configured to (e.g., control the transceiver 910 to) perform a method performed by a first node according to embodiments of the present disclosure.

FIG. 10 shows a schematic diagram of a second node 1000 according to embodiments of the present disclosure.

As shown in FIG. 10, a second node (or second node device) 1000 according to embodiments of the present disclosure may include a transceiver 1010 and a processor 1020. The transceiver 1010 may be configured to transmit and receive signals. The processor 1020 may be coupled to the transceiver 1010 and may be configured to (e.g., control the transceiver 1010 to) perform a method performed by a second node according to embodiments of the present disclosure. A processor may also be called a controller.

FIG. 11 shows a schematic diagram of a user equipment 1100 according to embodiments of the present disclosure.

As shown in FIG. 11, a user equipment 1100 according to embodiments of the present disclosure may include a transceiver 1110 and a processor 1120. The transceiver 1110 may be configured to transmit and receive signals. The processor 1120 may be coupled to the transceiver 1110 and may be configured to (e.g., control the transceiver 1110 to) perform a method performed by a user equipment according to embodiments of the present disclosure. In the present disclosure, a processor may also be referred to as a controller.

According to an embodiment of the disclosure, a method performed by a first node in a wireless communication system, comprising: transmitting a fourth message to a second node, wherein the fourth message includes information related to resource reservation time in a conditional handover; receiving a second message including a data transmission address of a candidate target cell from the second node; receiving a sixth message from the second node or a user equipment (UE), wherein the sixth message includes prediction information related to the conditional handover; determining whether to perform data transmission based on the prediction information related to the conditional handover; and in case that it is determined to perform data transmission, performing data transmission based on the data transmission address.

According to an embodiment of the disclosure, wherein, before receiving a second message including a data transmission address of a candidate target cell from the second node, a radio resource control (RRC) reconfiguration complete message is transmitted by the UE to the second node.

According to an embodiment of the disclosure, wherein, the information related to resource reservation time in a conditional handover is used for the second node to determine whether to take the first node as a candidate target node.

According to an embodiment of the disclosure, further comprising: transmitting a first message including a request for a data transmission address to the second node, wherein the second message is transmitted from the second node based on the first message.

According to an embodiment of the disclosure, further comprising: receiving a third message from the second node, wherein the third message includes information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, wherein the fourth message is transmitted to the second node based on the third message.

According to an embodiment of the disclosure, further comprising: transmitting a fifth message to the second node, wherein the fifth message includes a request for reporting the prediction information related to the conditional handover, wherein the sixth message is transmitted from the second node based on the fifth message.

According to an embodiment of the disclosure, wherein the data transmission includes one or more of normal data transmission and data forwarding, wherein the data forwarding includes one or more of early data forwarding, late data forwarding and normal data forwarding.

According to an embodiment of the disclosure, a method performed by a second node in a wireless communication system, comprising: receiving a fourth message from a first node, wherein the fourth message includes information related to resource reservation time in a conditional handover; transmitting a second message including a data transmission address of a candidate target cell to the first node; and transmitting a sixth message to the first node, wherein the sixth message includes prediction information related to the conditional handover; wherein the prediction information related to the conditional handover is used for the first node to determine whether to perform data transmission; and wherein in case that it is determined to perform data transmission, the first node performs data transmission based on the data transmission address.

According to an embodiment of the disclosure, before transmitting the second message including a data transmission address of a candidate target cell to the first node, further comprising: receiving a radio resource control (RRC) reconfiguration complete message from a user equipment (UE).

According to an embodiment of the disclosure, further comprising: determining whether to take the first node as a candidate target node based on the information related to resource reservation time in a conditional handover.

According to an embodiment of the disclosure, further comprising: receiving a first message including a request for a data transmission address from the first node, wherein the second message is transmitted to the first node based on the first message.

According to an embodiment of the disclosure, further comprising: transmitting a third message to the first node, wherein the third message includes information related to a user equipment (UE) in the conditional handover and/or information related to a resource reservation request in the conditional handover, wherein the fourth message is transmitted from the first node based on the third message.

According to an embodiment of the disclosure, further comprising: receiving a fifth message from the first node, wherein the fifth message includes a request for reporting the prediction information related to the conditional handover, wherein the sixth message is transmitted to the first node based on the fifth message.

According to an embodiment of the disclosure, a method performed by a user equipment (UE) in a wireless communication system, comprising: receiving a fourth message from a second node, wherein the fourth message includes an RRC container, which includes information related to resource reservation time in a conditional handover; and transmitting a sixth message to the second node or a first node, wherein the sixth message includes prediction information related to the conditional handover, wherein the prediction information related to the conditional handover is used for the first node to determine whether to perform data transmission.

According to an embodiment of the disclosure, further comprising: detecting whether an execution event is met based on the information related to resource reservation time in a conditional handover.

According to an embodiment of the disclosure, a node device in a wireless communication system, comprising: a transceiver; and a processor coupled to the transceiver and configured to perform the operations described above.

According to an embodiment of the disclosure, a user equipment in a wireless communication system, comprising: a transceiver; and a processor coupled to the transceiver and configured to perform the operations described above.

According to an embodiment of the disclosure, a computer-readable medium having stored thereon computer-readable instructions which, when executed by a processor, implement the method according to any one of operations described above.

Embodiments of the present disclosure also provide a computer-readable medium having stored thereon computer-readable instructions which, when executed by a processor, implement any method according to embodiments of the present disclosure.

Various embodiments of the present disclosure may be implemented as computer-readable codes embodied on a computer-readable recording medium from a specific perspective. A computer-readable recording medium is any data storage device that can store data readable by a computer system. Examples of computer-readable recording media may include read-only memory (ROM), random access memory (RAM), compact disk read-only memory (CD-ROM), magnetic tape, floppy disk, optical data storage device, carrier wave (e.g., data transmission via the Internet), etc. Computer-readable recording media can be distributed by computer systems connected via a network, and thus computer-readable codes can be stored and executed in a distributed manner. Furthermore, functional programs, codes and code segments for implementing various embodiments of the present disclosure can be easily explained by those skilled in the art to which the embodiments of the present disclosure are applied.

It will be understood that the embodiments of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software. The software may be stored as program instructions or computer-readable codes executable on a processor on a non-transitory computer-readable medium. Examples of non-transitory computer-readable recording media include magnetic storage media (such as ROM, floppy disk, hard disk, etc.) and optical recording media (such as CD-ROM, digital video disk (DVD), etc.). Non-transitory computer-readable recording media may also be distributed on computer systems coupled to a network, so that computer-readable codes are stored and executed in a distributed manner. The medium can be read by a computer, stored in a memory, and executed by a processor. Various embodiments may be implemented by a computer or a portable terminal including a controller and a memory, and the memory may be an example of a non-transitory computer-readable recording medium suitable for storing program (s) with instructions for implementing embodiments of the present disclosure. The present disclosure may be realized by a program with code for concretely implementing the apparatus and method described in the claims, which is stored in a machine (or computer)-readable storage medium. The program may be electronically carried on any medium, such as a communication signal transmitted via a wired or wireless connection, and the present disclosure suitably includes its equivalents.

What has been described above is only the specific implementation of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Anyone who is familiar with this technical field may make various changes or substitutions within the technical scope disclosed in the present disclosure, and these changes or substitutions should be covered within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

A method performed by a master node (MN) in a wireless communication system, the method comprising:

identifying whether an early data forwarding of secondary node (SN) is needed; and

transmitting, to the SN, address indication message associated with the early data forwarding,

wherein the early data forwarding to other candidate SNs is performed based on the address indication message.
The method of claim 1, wherein the address indication message includes addresses of the other candidate SNs.
The method of claim 1, further comprising:

receiving, from the SN, assistance information data including a parameter associated with hybrid automatic repeat request (HARQ) transmission,

wherein the assistance information data is used for user plane (UP) management.
The method of claim 3, wherein the parameter associated with hybrid automatic repeat request (HARQ) transmission includes HARQ process number, and

wherein the assistance information data further includes information associated with radio quality.
A method performed by a secondary node (SN) in a wireless communication system, the method comprising:

performing a random access procedure with a user equipment (UE);

receiving, from a master node (MN), address indication message associated with an early data forwarding;

identifying whether to perform the early data forwarding; and

performing the early data forwarding to other candidate SNs.
The method of claim 5, wherein the address indication message includes addresses of the other candidate SNs.
The method of claim 5, further comprising:

transmitting, to the MN, assistance information data including a parameter associated with hybrid automatic repeat request (HARQ) transmission,

wherein the assistance information data is used for user plane (UP) management.
The method of claim 7, wherein the parameter associated with hybrid automatic repeat request (HARQ) transmission includes HARQ process number, and

wherein the assistance information data further includes information associated with radio quality.
A master node (MN) in a wireless communication system, the MN comprising:

a transceiver; and

a controller coupled with the transceiver and configured to:

identify whether an early data forwarding of secondary node (SN) is needed,

transmit, to the SN, address indication message associated with the early data forwarding, and

wherein the early data forwarding to other candidate SNs is performed based on the address indication message.
The MN of claim 9, wherein the address indication message includes addresses of the other candidate SNs.
The MN of claim 9, wherein the controller is further configured to:

receive, from the SN, assistance information data including a parameter associated with hybrid automatic repeat request (HARQ) transmission,

wherein the assistance information data is used for user plane (UP) management.
The MN of claim 11, wherein the parameter associated with hybrid automatic repeat request (HARQ) transmission includes HARQ process number, and

wherein the assistance information data further includes information associated with radio quality.
A secondary node (SN) in a wireless communication system, the SN comprising:

a transceiver; and

a controller coupled with the transceiver and configured to:

perform a random access procedure with a user equipment (UE),

receive, from a master node (MN), address indication message associated with an early data forwarding,

identify whether to perform the early data forwarding, and

perform the early data forwarding to other candidate SNs.
The SN of claim 13, wherein the address indication message includes addresses of the other candidate SNs.
The SN of claim 13, wherein the controller is further configured to:

transmit, to the MN, assistance information data including a parameter associated with hybrid automatic repeat request (HARQ) transmission,

wherein the assistance information data is used for user plane (UP) management.