WO2025000238A1 - Uplink synchronization method and apparatus, and storage medium - Google Patents

Abstract

The present disclosure provides an uplink synchronization method and apparatus, and a storage medium. The method comprises: receiving time information sent by a network device, wherein the time information is used for indicating a first time point when a cell ends a service and/or a second time point when a terminal executes uplink synchronization; and starting to execute uplink synchronization from the second time point. According to the present disclosure, the terminal can start to execute uplink synchronization from the second time point on the basis of the time information sent by the network device, thereby improving the availability and reliability of NTN communications.

Description

Uplink synchronization method, device, and storage medium Technical Field

The present disclosure relates to the field of communications, and in particular to an uplink synchronization method and device, and a storage medium.

Background Art

Currently, the application scenarios of non-terrestrial networks (NTN) are becoming more and more extensive. In NTN scenarios, access network equipment can be deployed on satellites, or still deployed on the ground and communicate with terminals via satellites.

Summary of the invention

In order to achieve uplink synchronization in an NTN scenario, embodiments of the present disclosure provide an uplink synchronization method and device, and a storage medium.

According to a first aspect of an embodiment of the present disclosure, an uplink synchronization method is provided, the method being executed by a terminal and comprising:

Receiving time information sent by a network device, where the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization;

The uplink synchronization is performed starting from the second time point.

According to a second aspect of an embodiment of the present disclosure, an uplink synchronization method is provided, the method being executed by a network device, including:

Sending time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization;

Determine that the terminal starts to perform uplink synchronization from the second time point.

According to a third aspect of an embodiment of the present disclosure, a terminal is provided, the terminal including:

A transceiver module, configured to receive time information sent by a network device, wherein the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization;

The processing module is configured to perform uplink synchronization starting from the second time point.

According to a fourth aspect of an embodiment of the present disclosure, a network device is provided, the network device comprising:

A transceiver module, configured to send time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization;

The processing module is configured to determine that the terminal performs uplink synchronization starting from the second time point.

According to a fifth aspect of an embodiment of the present disclosure, a terminal is provided, including:

one or more processors;

Wherein, the terminal is used to execute the uplink synchronization method described in any one of the first aspects.

According to a sixth aspect of an embodiment of the present disclosure, a network device is provided, including:

one or more processors;

Wherein, the network device is used to execute the uplink synchronization method described in any one of the second aspects.

According to the seventh aspect of an embodiment of the present disclosure, a communication system is provided, including a terminal and a network device, wherein the terminal is configured to implement the uplink synchronization method described in any one of the first aspect, and the network device is configured to implement the uplink synchronization method described in any one of the second aspect.

According to an eighth aspect of an embodiment of the present disclosure, a storage medium is provided, wherein the storage medium stores instructions, and when the instructions are executed on a communication device, the communication device executes the uplink synchronization method as described in any one of the first aspect or the second aspect.

In the disclosed embodiment, the terminal can execute the operation from the second time point based on the time information sent by the network device. The upstream and downstream synchronization clarifies the terminal behavior and improves the availability and reliability of NTN communication.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

FIG1 is an exemplary schematic diagram of the architecture of a communication system provided according to an embodiment of the present disclosure.

FIG2 is an exemplary interaction diagram of an uplink synchronization method provided according to an embodiment of the present disclosure.

FIG3A is an exemplary interaction diagram of an uplink synchronization method provided according to an embodiment of the present disclosure.

FIG3B is an exemplary interaction diagram of an uplink synchronization method provided according to an embodiment of the present disclosure.

FIG4A is an exemplary interaction diagram of an uplink synchronization method provided according to an embodiment of the present disclosure.

FIG4B is an exemplary interaction diagram of an uplink synchronization method provided according to an embodiment of the present disclosure.

FIG5A is a schematic diagram of an exemplary interaction of an uplink synchronization device provided according to an embodiment of the present disclosure.

FIG5B is a schematic diagram of an exemplary interaction of an uplink synchronization device provided according to an embodiment of the present disclosure.

FIG6A is a schematic diagram of an exemplary interaction of a communication device provided according to an embodiment of the present disclosure.

FIG6B is an exemplary interaction diagram of a chip provided according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and/or" used herein refers to and includes any or all possible combinations of at least one associated listed item.

It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various messages, these messages should not be limited to these terms. These terms are only used to distinguish messages of the same type from each other. For example, without departing from the scope of the present disclosure, a first message may also be referred to as a second message, and similarly, a second message may also be referred to as a first message. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

The embodiments of the present disclosure provide an uplink synchronization method, an uplink synchronization device, and a storage medium.

In a first aspect, an embodiment of the present disclosure provides an uplink synchronization method, which is executed by a terminal and includes:

Receiving time information sent by a network device, where the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization;

The uplink synchronization is performed starting from the second time point.

In the above embodiment, the terminal can determine the first time point when the current cell ends service and/or the second time point when uplink synchronization is performed based on the time information sent by the network device, and perform uplink synchronization from the second time point, thereby clarifying the terminal behavior and improving the availability and reliability of NTN communication.

In combination with some embodiments of the first aspect, in some embodiments, when the time information is at least used to indicate the second time point, the time information includes any one of the following:

information at the second time point;

Duration information of the interval between the second time point and the first time point.

In the above embodiment, the terminal may directly determine the second time point for performing uplink synchronization based on the time information. Or the duration between the second time point and the first time point at which the cell ends service is determined based on the time information, ensuring that the terminal can determine the second time point for performing uplink synchronization based on the time information sent by the network device, thereby initiating uplink synchronization in a timely manner with high availability.

In combination with some embodiments of the first aspect, in some embodiments, when the time information is used to indicate the first time point, the method further includes:

Based on a predefined rule, the second time point is determined.

In the above embodiment, when the time information sent by the network device is used to indicate the first time point when the cell ends service, the terminal can determine the second time point for performing uplink synchronization based on predefined rules, without the need for the network device to separately indicate the second time point, thereby saving signaling resources.

In conjunction with some embodiments of the first aspect, in some embodiments, determining the second time point includes any one of:

Determine that the second time point reuses the first time point;

Determine the duration of the interval between the second time point and the first time point.

In the above embodiment, when the time information sent by the network device is used to indicate the first time point when the cell ends the service, the terminal can reuse the first time point when the cell ends the service as the second time point for performing uplink synchronization based on the predefined rule, and the network device does not need to indicate the second time point separately, thus saving signaling resources. Alternatively, the terminal can determine the duration between the second time point and the first time point based on the predefined rule, and perform uplink synchronization after waiting for the duration when the cell ends the service, thus improving the success rate of uplink synchronization.

In combination with some embodiments of the first aspect, in some embodiments, when the time information is used to indicate the first time point, the method further includes:

Receive indication information sent by the network device, where the indication information is used to indicate whether the second time point reuses the first time point.

In the above embodiment, the terminal can determine whether to reuse the first time point when the cell ends service as the second time point for performing uplink synchronization based on the indication information sent by the network device, so that uplink synchronization can be initiated in time with high availability.

In conjunction with some embodiments of the first aspect, in some embodiments, the method further includes at least one of the following:

During a time period between the first time point and the second time point, no wireless link monitoring operation is performed;

During the time period between the first time point and the second time point, no radio resource control RRC reconstruction operation is performed.

In the above embodiment, when the physical cell identifier (PCI) remains unchanged, the terminal can be prevented from performing unnecessary operations during the period between the first time point when the cell ends service and the second time point when the terminal starts to perform uplink synchronization, thereby saving terminal power consumption and achieving high availability.

In conjunction with some embodiments of the first aspect, in some embodiments, not performing the wireless link monitoring operation includes at least one of the following:

No physical layer problem detection operation is performed;

The out-of-step indication counting operation is not performed;

A first timer start operation is not performed, wherein the first timer is a timer for monitoring a radio link failure.

In the above embodiment, when the PCI remains unchanged, the terminal can avoid performing the above wireless link monitoring operation in the above time period, thereby achieving the purpose of saving terminal power consumption.

In combination with some embodiments of the first aspect, in some embodiments, the method further includes:

In response to determining that the first timer has been started, the first timer is suspended.

In the above embodiment, if the terminal has started the first timer for monitoring the failure of the wireless link, the terminal can suspend the first timer to avoid triggering the failure of the wireless link after the expiration of the first timer, thereby saving the power consumption of the terminal during the above time period when the PCI remains unchanged.

In conjunction with some embodiments of the first aspect, in some embodiments, not performing the RRC reestablishment operation includes at least one of the following:

No cell selection operation is performed;

The second timer start operation is not performed, and the second timer is a timer that switches to an idle state after detecting a radio link failure.

In the above embodiment, the terminal can avoid performing the above RRC reconstruction operation, thereby achieving the purpose of saving terminal power consumption within the above time period when the PCI remains unchanged.

In combination with some embodiments of the first aspect, in some embodiments, the method further includes:

In response to determining that the second timer has been started, the second timer is suspended.

In the above embodiment, if the terminal has started the second timer for switching to the idle state after detecting a radio link failure, the terminal can suspend the second timer to avoid performing RRC reconstruction after the second timer expires, thereby saving terminal power consumption without changing the PCI.

In combination with some embodiments of the first aspect, in some embodiments, the method further includes:

During a time period between the first time point and the second time point, the RRC connected state is maintained.

In the above embodiment, the terminal can maintain the RRC connection state between the first time point when the cell ends the service and the second time point when the uplink synchronization starts, avoiding the terminal from performing unnecessary operations when the PCI remains unchanged, saving terminal power consumption and having high availability.

In combination with some embodiments of the first aspect, in some embodiments, the performing uplink synchronization from the second time point includes:

Receiving a system message broadcasted by the network device;

Based on the system message, a random access request message is sent to the network device at the second time point.

In the above embodiment, the terminal can send a random access request message to the network device at the second time point based on the system message broadcast by the network device, thereby completing uplink synchronization and improving the availability and reliability of NTN communication.

In a second aspect, an embodiment of the present disclosure provides an uplink synchronization method, which is performed by a network device and includes:

Sending time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization;

Determine that the terminal starts to perform uplink synchronization from the second time point.

In the above embodiment, the network device can send time information to the terminal to inform the terminal of the first time point when the cell ends the service and/or the second time point when the terminal starts to perform uplink synchronization, thereby clarifying the terminal behavior, ensuring that the network device and the terminal have a consistent understanding of the terminal behavior, and improving the availability and reliability of NTN communications.

In conjunction with some embodiments of the second aspect, in some embodiments, when the time information is at least used to indicate the second time point, the time information includes any one of the following:

information at the second time point;

Duration information of the interval between the second time point and the first time point.

In conjunction with some embodiments of the second aspect, in some embodiments, when the time information is used to indicate the first time point, the method further includes:

Based on a predefined rule, the second time point is determined.

In the above embodiment, when the time information sent by the network device is used to indicate the first time point when the cell ends service, the network device can determine the second time point when the terminal performs uplink synchronization based on predefined rules. The network device does not need to indicate the second time point separately, saving signaling resources.

In conjunction with some embodiments of the second aspect, in some embodiments, determining the second time point includes any one of:

Determine that the second time point reuses the first time point;

Determine the duration of the interval between the second time point and the first time point.

In the above embodiment, when the time information sent by the network device is used to indicate the first time point when the cell ends service, the network device can determine, based on predefined rules, the first time point when the terminal reuses the cell to end service as the second time point for performing uplink synchronization. The network device does not need to separately indicate the second time point, thereby saving signaling resources. Alternatively, the network device may determine the duration of the interval between the second time point and the first time point based on a predefined rule, and determine that the terminal performs uplink synchronization after waiting for the duration after the cell ends service, thereby improving the success rate of uplink synchronization.

In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes:

Sending indication information to the terminal, where the indication information is used to indicate whether the second time point reuses the first time point.

In the above embodiment, the network device can send an indication message to inform the terminal whether to reuse the first time point when the cell ends the service as the second time point for performing uplink synchronization, so that the terminal can initiate uplink synchronization in time, ensuring that the network device and the terminal have a consistent understanding of the terminal behavior and high availability.

In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes at least one of the following:

During a time period between the first time point and the second time point, the terminal is not expected to perform a radio link monitoring operation;

During a time period between the first time point and the second time point, the terminal is not expected to perform a radio resource control RRC reestablishment operation.

In the above embodiment, when the PCI remains unchanged, during the period between the first time point when the cell ends service and the second time point when the terminal starts to perform uplink synchronization, the network device does not expect the terminal to perform unnecessary operations, thereby ensuring that the network device and the terminal have a consistent understanding of the terminal behavior, thereby achieving the purpose of saving terminal power consumption.

In conjunction with some embodiments of the second aspect, in some embodiments, not expecting the terminal to perform a radio link monitoring operation includes at least one of the following:

not expecting the terminal to perform a physical layer problem detection operation;

not expecting the terminal to perform an out-of-sync indication counting operation;

The terminal is not expected to perform a first timer start operation, the first timer being a timer for monitoring a radio link failure.

In the above embodiment, when the PCI remains unchanged, the network device does not expect the terminal to perform the above wireless link monitoring operation within the above time period, ensuring that the network device and the terminal have a consistent understanding of the terminal behavior.

In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes:

In response to determining that the terminal has started the first timer, the terminal is determined to suspend the first timer.

In the above embodiment, the network device may determine that the terminal will suspend the started first timer, ensuring that the network device and the terminal have consistent understandings of the terminal behavior.

In conjunction with some embodiments of the second aspect, in some embodiments, not expecting the terminal to perform an RRC reestablishment operation includes at least one of the following:

not expecting the terminal to perform a cell selection operation;

The terminal is not expected to execute a second timer start operation, where the second timer is a timer for switching to an idle state after detecting a radio link failure.

In the above embodiment, when the PCI remains unchanged, the network device does not expect the terminal to perform the above RRC reconstruction operation within the above time period, ensuring that the network device and the terminal have a consistent understanding of the terminal behavior.

In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes:

In response to determining that the terminal has started the second timer, the terminal is determined to suspend the second timer.

In the above embodiment, the network device may determine that the terminal will suspend the started second timer, ensuring that the network device and the terminal have consistent understandings of the terminal behavior.

In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes:

During a time period between the first time point and the second time point, it is determined that the terminal remains in the RRC connected state.

In the above embodiment, the network device can determine that the terminal always remains in the RRC connected state during the above time period, ensuring that the network device and the terminal have a consistent understanding of the terminal behavior.

In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes:

Broadcast system messages;

receiving a random access request message sent by the terminal at the second time point based on the system message.

In the above embodiment, the network device may broadcast a system message, and receive a random access request message sent by the terminal at the second time point based on the system message, thereby clarifying the terminal behavior and achieving high availability.

In a third aspect, an embodiment of the present disclosure provides a terminal, wherein the terminal includes:

A transceiver module, configured to receive time information sent by a network device, wherein the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization;

The processing module is configured to perform uplink synchronization starting from the second time point.

In a fourth aspect, an embodiment of the present disclosure provides a network device, the network device comprising:

A transceiver module, configured to send time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization;

The processing module is configured to determine that the terminal performs uplink synchronization starting from the second time point.

In a fifth aspect, an embodiment of the present disclosure provides a terminal, including:

one or more processors;

Wherein, the terminal is used to execute the uplink synchronization method described in any one of the first aspects.

In a sixth aspect, an embodiment of the present disclosure provides a network device, including:

one or more processors;

Wherein, the network device is used to execute the uplink synchronization method described in any one of the second aspects.

In the seventh aspect, an embodiment of the present disclosure proposes a communication system, including a terminal and a network device, wherein the terminal is configured to implement the uplink synchronization method described in any one of the first aspect, and the network device is configured to implement the uplink synchronization method described in any one of the second aspect.

In an eighth aspect, an embodiment of the present disclosure proposes a storage medium, wherein the storage medium stores instructions, and when the instructions are executed on a communication device, the communication device executes the uplink synchronization method as described in any one of the first aspect or the second aspect.

It is understandable that the above-mentioned terminals, network devices, communication systems, storage media, and computer programs are all used to execute the methods proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods, which will not be repeated here.

The embodiments of the present disclosure provide an uplink synchronization method, device, and storage medium. In some embodiments, the terms uplink synchronization method, information processing method, communication method, etc. can be replaced with each other, the terms uplink synchronization device, information processing device, communication device, etc. can be replaced with each other, and the terms information processing system, communication system, etc. can be replaced with each other.

The embodiments of the present disclosure are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

In each embodiment of the present disclosure, unless otherwise specified or there is a logical conflict, the terms and/or descriptions between the embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.

The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "said", "aforementioned", "this", etc., may mean "one and only one" or may mean "One or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article can be understood as a singular expression or a plural expression.

In the embodiments of the present disclosure, “plurality” refers to two or more.

In some embodiments, the terms "at least one of", "one or more", "a plurality of", "multiple", etc. can be used interchangeably.

In some embodiments, "at least one of A and B", "A and/or B", "A in one case, B in another case", "in response to one case A, in response to another case B", etc., may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); in some embodiments, A and B (both A and B are executed). When there are more branches such as A, B, C, etc., the above is also similar.

In some embodiments, the recording method of "A or B" may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). When there are more branches such as A, B, C, etc., the above is also similar.

The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, quantity or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute unnecessary restrictions due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields", and the "first" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number, and can be one or more. Taking the "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes may be the same or different. For example, if the description object is "device", then the "first device" and the "second device" may be the same device or different devices, and their types may be the same or different. For another example, if the description object is "information", then the "first information" and the "second information" may be the same information or different information, and their contents may be the same or different.

In some embodiments, “including A”, “comprising A”, “used to indicate A”, and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

In some embodiments, terms such as "in response to ...", "in response to determining ...", "in the case of ...", "at the time of ...", "when ...", "if ...", "if ...", etc. can be used interchangeably.

In some embodiments, devices and equipment may be interpreted as physical or virtual, and their names are not limited to the names described in the embodiments. In some cases, they may also be understood as "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "entity", "subject", etc.

In some embodiments, "network" can be interpreted as devices included in the network, such as access network equipment, core network equipment, etc.

In some embodiments, "access network device (AN device)" may also be referred to as "radio access network device (RAN device)", "base station (BS)", "radio base station (radio base station)", "fixed station (fixed station)", and in some embodiments may also be understood as "node (node)", "access point (access point)", "transmission point (transmission point, TP)", "reception point (reception point, RP)", "transmission and/or reception point (transmission/reception point, TRP)", "panel (panel)", "antenna panel (antenna panel)", "antenna array (antenna array)", "cell (cell)", "macro cell (macro cell)", "small cell (small cell)", "femto cell (femto cell)", "pico cell (pico cell)", "sector (sector)", "cell group (cell group)", "Serving cell", "carrier", "component carrier", "bandwidth part (BWP)", etc.

In some embodiments, the term "terminal" or "terminal device" may be referred to as "user equipment (UE)", "user terminal (user terminal)", "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc.

In some embodiments, acquisition of data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

In some embodiments, data, information, etc. may be obtained with the user's consent.

In addition, each element, each row, or each column in the table of the embodiments of the present disclosure may be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns may also be implemented as an independent embodiment.

FIG1 is a schematic diagram of the architecture of a communication system according to an embodiment of the present disclosure.

As shown in FIG. 1 , a communication system 100 includes a terminal 101 and a network device 102 .

In some embodiments, the terminal 101 includes, for example, a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, and at least one of a wireless terminal device in a smart home, but is not limited to these.

In some embodiments, the network device 102 includes an access network device 1021, for example, a node or device that accesses a terminal to a wireless network. The access network device 1021 may include an evolved Node B (eNB), a next generation evolved Node B (ng-eNB), a next generation Node B (gNB), a node B (NB), a home node B (HNB), a home evolved node B (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an open base station (Open RAN), a cloud base station (Cloud RAN), a base station in other communication systems, and at least one of an access node in a Wi-Fi system, but is not limited thereto.

In some embodiments, the technical solution of the present disclosure may be applicable to the Open RAN architecture. In this case, the interfaces between access network devices or within access network devices involved in the embodiments of the present disclosure may become internal interfaces of Open RAN, and the processes and information interactions between these internal interfaces may be implemented through software or programs.

In some embodiments, the access network device 1021 may be composed of a centralized unit (CU) and a distributed unit (DU), wherein the CU may also be referred to as a control unit (control unit). The CU-DU structure may be used to split the protocol layer of the access network device 1021, with some functions of the protocol layer being centrally controlled by the CU, and the remaining part or all of the functions of the protocol layer being distributed in the DU, and the DU being centrally controlled by the CU, but not limited to this.

In some embodiments, the network device 102 includes a core network device 1022, which may be one device, or multiple devices or a group of devices. The network element may be virtual or physical. The core network may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), and a Next Generation Core (NGC).

Exemplarily, the core network device 1022 may include but is not limited to access management function (Access and Mobility Management Function, AMF), user plane function (User Plane Function, UPF), etc.

It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution proposed in the embodiment of the present disclosure. A person of ordinary skill in the art can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present disclosure is also applicable to similar technical problems.

The following embodiments of the present disclosure may be applied to the communication system 100 shown in FIG1 , or part of the subject, but are not limited thereto. The subjects shown in FIG1 are examples, and the communication system may include all or part of the subjects in FIG1 , or may include other subjects other than FIG1 , and the number and form of the subjects are arbitrary, and the subjects may be physical or virtual, and the connection relationship between the subjects is an example, and the subjects may be connected or disconnected, and the connection may be in any manner, and may be a direct connection or an indirect connection, and may be a wired connection or a wireless connection.

The embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, the fourth generation mobile communication system (4G), the fifth generation mobile communication system (5G), 5G new radio (NR), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New Radio (NR), and New Radio Access ( The present invention relates to wireless communication systems such as LTE, New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) network, systems using other communication methods, and next-generation systems expanded therefrom. In addition, a combination of multiple systems (for example, a combination of LTE or LTE-A with 5G, etc.) may also be used.

In the embodiment of the present disclosure, the interface between the access network device 1021 and the core network device 1022 may be an NG interface.

In the disclosed embodiment, the access network device 1021 may include but is not limited to a gateway device (Gateway) and a satellite (payload), wherein the NTN gateway is connected to the satellite via a feeder link (feeder link).

In the disclosed embodiment, the interface between the access network device 1021 and the terminal 101 may be a New Radio (NR) Uu interface. The link between the satellite and the terminal 101 is a service link.

For satellites in non-geosynchronous orbit, there are dynamic cells (earth moving) and semi-static cells (quasi earth fixed).

For dynamic cells, the service cells provided by satellites will continue to move on the ground over time.

For semi-static cells, the service cell provided by the satellite is fixed at a certain place during a certain period of time, and then fixed to another place during another period of time.

As shown in Figure 1 above, the satellite is connected to the NTN gateway through a feeder link. As the satellite moves, the satellite needs to switch between different NTN gateways. In a semi-static cell scenario, when one satellite moves away and another satellite moves in, two different satellites are connected to the same ground gateway. From the perspective of the terminal, if the PCI of the service cell provided by the two satellites has not changed (that is, the PCI of the service cell provided by the two satellites is the same), then the service cell of the terminal may not have changed (the ground gateway has not changed), and the terminal does not need to perform cell switching.

For terminal switching, the following switching situations are included:

Hard satellite switching, non-overlapping satellite coverage during switching.

Soft satellite switching, overlapping satellite coverage during switching.

For hard satellite switching and/or soft satellite switching, the terminal needs to reacquire uplink synchronization.

Fig. 2 is an interactive schematic diagram of an uplink synchronization method according to an embodiment of the present disclosure. As shown in Fig. 2, an embodiment of the present disclosure relates to an uplink synchronization method, and the method includes:

Step S2101 , the network device 102 sends time information to the terminal 101 .

In some embodiments, the terminal 101 receives the time information. In some embodiments, the name of the time information is not limited, and it is, for example, a time message, a first message, a first signaling, and the like.

In some embodiments, the time information is used to indicate the first time point when the cell ends service.

Exemplarily, the first time point may be expressed as t-service, and accordingly, the time information is used to indicate t-service.

In some embodiments, the time information sent by the network device 102 is used to indicate a first time point, and the terminal 101 can determine a second time point for performing uplink synchronization based on a predefined rule.

Exemplarily, the predefined rule may be used to indicate any one of the following: whether the second time point reuses the first time point; or the duration of the interval between the second time point and the first time point.

Exemplarily, the terminal 101 may reuse the first time point as the second time point for performing uplink synchronization according to a predefined rule, and determine to immediately start performing uplink synchronization at the first time point when the cell ends service.

Exemplarily, the terminal 101 may determine the duration of the interval according to a predefined rule. The terminal 101 jointly determines a second time point for performing uplink synchronization based on the first time point and the duration of the interval.

The duration of the interval may be expressed as t-gap. Exemplarily, t-gap may be a non-negative number, for example, t-gap may be 0 or a positive number.

In the embodiment of the present disclosure, when t-gap is 0, the terminal 101 determines to immediately start uplink synchronization at the first time point. When t-gap is a positive number, the terminal 101 determines to start uplink synchronization after the cell ends service for a time interval of t-gap.

In some embodiments, the time information sent by the network device 102 is used to indicate a first time point, and the network device 102 also sends indication information, where the indication information is used to indicate whether the second time point reuses the first time point.

If the terminal 101 determines to reuse the t-service as the second time point according to the indication information, the terminal 101 determines to immediately perform uplink synchronization at the first time point when the cell ends the service. However, in this case, if the next satellite has not yet moved to the cell, that is, there is no network device that can provide services for the terminal 101 at this time, it may cause the uplink synchronization of the terminal 101 to fail, and thus the terminal 101 cannot access the cell corresponding to the target satellite.

If the terminal 101 determines not to reuse the t-service as the second time point according to the indication information, the terminal 101 can determine the second time point according to the predefined rules and perform uplink synchronization at the second time point, wherein the method of determining the second time point according to the predefined rules has been introduced in the above embodiment and will not be repeated here.

If the duration of the interval between the second time point and the first time point is not 0, the success rate of the terminal performing uplink synchronization can be effectively improved.

In some embodiments, the time information is used to indicate a second time point at which the terminal performs uplink synchronization.

Exemplarily, the time information may include information of the second time point, that is, the network device 102 directly informs the terminal 101 of the second time point for performing uplink synchronization through the time information.

Exemplarily, the second time point is represented as t-start, and the time information is used to indicate t-start.

Exemplarily, the time information may include duration information of an interval between the second time point and the first time point.

This duration can also be expressed as t-gap.

The terminal 101 may determine the first time point when the cell ends service based on the system message, configuration information or scheduling information sent by the network device 101, and then determine the second time point for performing uplink synchronization based on the t-gap indicated by the time indication information.

Exemplarily, the terminal 101 may determine the first time point based on a predefined rule of the protocol, for example, if the terminal 101 cannot receive any signaling or message sent by the network device 102 within a period exceeding a preset time length, the terminal 101 determines this moment as the first time point. For another example, the terminal 101 may determine the first time point based on ephemeris information, etc.

In some embodiments, the time information is used to indicate the first time point when the cell ends the service and the time point when the terminal performs the uplink The second time point of synchronization.

Exemplarily, the time information may include information of the second time point, that is, the network device 102 directly informs the terminal 101 of the second time point for performing uplink synchronization through the time information.

Exemplarily, the time information may include duration information of an interval between the second time point and the first time point.

Exemplarily, the first time point may be expressed as t-service.

Exemplarily, the second time point may be expressed as t-start.

Exemplarily, the duration of the interval between the second time point and the first time point may be expressed as t-gap.

Exemplarily, the time information is used to indicate t-service and t-start, wherein t-start may be at the same time as t-service, or t-start may be at a certain time after t-service, which is not limited in the present disclosure.

Exemplarily, the time information is used to indicate t-service and t-gap, wherein t-gap may be a non-negative number, and the terminal determines t-start based on t-service and t-gap.

In some embodiments, in addition to sending the time information, the network device 102 also sends an indication message, which is used to indicate that the second time point multiplexes other time points, such as other time points different from the first time point, and the terminal 101 performs uplink synchronization at the time point indicated by the indication message.

In some embodiments, the network device 102 may send a time information to indicate a first time point when the cell ends service and/or a second time point when the terminal performs uplink synchronization.

In some embodiments, the network device 102 may send different time information to indicate the first time point and the second time point, respectively. For example, the first time point is indicated by the first time information, and the second time point is indicated by the second time information. In some embodiments, other methods for the terminal 101 to determine the first time point and/or the second time point based on at least the time information should also fall within the scope of protection of the present disclosure.

Step S2102: During the time period between the first time point and the second time point, the terminal 101 does not perform a wireless link monitoring operation.

In some embodiments, during a time period between a first time point and a second time point, terminal 101 does not perform a physical layer problems detection operation.

Exemplarily, the physical layer of terminal 101 does not send out-of-sync indications to higher layers.

In some embodiments, during a time period between a first time point and a second time point, terminal 101 does not perform an out-of-sync indication counting operation.

In some embodiments, during a time period between a first time point and a second time point, the terminal 101 does not perform a first timer start operation.

Exemplarily, the first timer is a timer for monitoring radio link failure.

Exemplarily, the first timer is a T310 timer.

Exemplarily, the RRC layer of terminal 101 receives N310 consecutive out-of-sync indications sent by the physical layer and does not start the first timer.

In some embodiments, during a time period between a first time point and a second time point, the terminal 101 does not perform two or three of a physical layer problem detection operation, an out-of-sync indication counting operation, and a first timer start operation.

Step S2103: During the time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform a wireless link monitoring operation.

In some embodiments, during a time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform a physical layer problem detection operation.

In some embodiments, during a time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform an out-of-sync indication counting operation.

In some embodiments, during a time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform a first timer start operation.

Exemplarily, the first timer is a timer for monitoring radio link failure.

Exemplarily, the first timer is a T310 timer.

In some embodiments, during the time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform two or three of the physical layer problem detection operation, the out-of-sync indication counting operation, and the first timer start operation.

Step S2104: During a time period between the first time point and the second time point, the terminal 101 suspends the first timer in response to determining that the first timer has been started.

In some embodiments, during the time period between the first time point and the second time point, if the terminal 101 has started the first timer, the terminal 101 may suspend or stop the first timer. Exemplarily, after the terminal 101 suspends or stops the first timer, the terminal 101 will not detect a radio link failure.

Exemplarily, the first timer is a timer for monitoring radio link failure.

Exemplarily, the first timer is a T310 timer.

Step S2105: During a time period between the first time point and the second time point, the network device 102 determines that the terminal 101 suspends the first timer in response to determining that the terminal 101 has started the first timer.

Step S2106: During the time period between the first time point and the second time point, the terminal 101 does not perform a radio resource control (RRC) reconstruction operation.

In some embodiments, during a time period between a first time point and a second time point, the terminal 101 does not perform a cell selection operation.

Exemplarily, the terminal 101 not performing cell selection includes the terminal 101 not measuring neighboring cells and/or the terminal 101 not sending an RRC reestablishment request to the neighboring cells.

In some embodiments, during the time period between the first time and the second time point, the terminal 101 meets the condition for performing RRC reconstruction, and the terminal 101 does not perform RRC reconstruction. Exemplarily, during the time period between the first time and the second time point, the satisfying the RRC reconstruction condition includes: the terminal 101 detects a radio link failure.

Exemplarily, terminal 101 not performing RRC re-establishment includes terminal 101 not performing one or more operations related to RRC re-establishment in the 3rd Generation Partnership Project (3GPP) protocol.

In some embodiments, during a time period between the first time point and the second time point, the terminal 101 does not perform a second timer start operation.

Exemplarily, the second timer is a timer for switching to an idle state after detecting a radio link failure.

Exemplarily, the second timer is a T311 timer.

In some embodiments, during a time period between a first time point and a second time point, the terminal 101 does not perform a cell selection operation and does not perform a second timer start operation.

Step S2107: During the time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform an RRC reconstruction operation.

In some embodiments, during a time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform a cell selection operation.

In some embodiments, during a time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform a second timer start operation.

Exemplarily, the second timer is a timer for switching to an idle state after detecting a radio link failure.

Exemplarily, the second timer is a T311 timer.

In some embodiments, during a time period between the first time point and the second time point, the network device 102 does not expect the terminal 101 to perform a cell selection operation and a second timer start operation.

Step S2108: During a time period between the first time point and the second time point, the terminal 101 suspends the second timer in response to determining that the second timer has been started.

In some embodiments, during the time period between the first time point and the second time point, if the terminal 101 has started the second timer, the terminal 101 may suspend or stop the second timer.

Exemplarily, after the terminal 101 suspends or stops the second timer, the terminal 101 will not enter the RRC idle state due to the expiration of the second timer.

Exemplarily, the second timer is a timer for switching to an idle state after detecting a radio link failure.

Exemplarily, the second timer is a T311 timer.

Step S2109: During a time period between the first time point and the second time point, the network device 102 determines that the terminal 101 suspends the second timer in response to determining that the terminal 101 has started the second timer.

Step S2110: During the time period between the first time point and the second time point, the terminal 101 remains in the RRC connected state.

Step S2111: During the time period between the first time point and the second time point, the network device 102 determines that the terminal 101 remains in the RRC connected state.

In the disclosed embodiment, considering that satellite switching requires a certain amount of time, especially during the hard satellite switching process, the terminal 101 will first disconnect the link with the previous satellite and then access another satellite. If the previous satellite ends the service. The next satellite cannot cover the cell where the terminal 101 is currently located in time, which will cause an interval in the time period when the satellite provides services. The terminal 101 cannot receive the downlink signal during this interval, which will cause the physical link to fail, thereby triggering RRC reconstruction. RRC reconstruction is a cell search process, which may cause the terminal 101 to search for other cells and then perform RRC reconstruction in other cells. It is also possible that the terminal 101 cannot search for a cell at all when performing RRC reconstruction (for example, the next satellite has not completed the switch), causing the terminal 101 to enter an idle state and fail to complete the switching process. In addition, when the PCI does not change, the terminal actually only needs to perform uplink synchronization at a specified time. Therefore, the operation of the terminal 101 during the time period from the first time point to the second time point is meaningless, which will waste the terminal power consumption.

In the disclosed embodiment, the terminal 101 does not perform wireless link monitoring operations and/or RRC reconstruction operations during the above time period, which can improve the success rate of uplink synchronization and avoid wasting terminal power consumption. It can also ensure that the network device 102 and the terminal 101 have a consistent understanding of the terminal behavior, thereby improving the reliability and availability of NTN communications.

Step S2112, the network device 102 broadcasts a system message.

In some embodiments, terminal 101 receives a system message.

In some embodiments, the system message is used by the terminal 101 to obtain ephemeris information, complete downlink synchronization, and initiate random access, thereby accessing the network device 102 .

Step S2113: Terminal 101 performs uplink synchronization starting from the second time point.

In some embodiments, the terminal 101 sends a random access request message to the network device 102 at the second time point based on the received system message.

In some embodiments, the network device 102 receives a random access request message sent by the terminal 101 at a second time point.

In some embodiments, the names of information, etc. are not limited to the names recorded in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "code element", "codebook", "codeword", "codepoint", "bit", "data", "program", and "chip" can be used interchangeably.

In some embodiments, the terms "uplink", "uplink", "physical uplink", etc. can be used interchangeably.

In some embodiments, the terms "radio", "wireless", "radio access network (RAN)", "access network (AN)", "RAN-based" and the like may be used interchangeably.

In some embodiments, terms such as "send", "transmit", "report", "send", "transmit", "bidirectional transmission", "send and/or receive" can be used interchangeably.

In some embodiments, "obtain", "obtain", "get", "receive", "transmit", "bidirectional transmission", "send and/or receive" can be interchangeable, and can be interpreted as receiving from other entities, obtaining from protocols, obtaining from high levels, obtaining by self-processing, autonomous implementation, etc.

In some embodiments, "certain", "preset", "preset", "set", "directive" The terms "indicated", "a certain", "any", "first", etc. can be used interchangeably, and "specific A", "predetermined A", "preset A", "set A", "indicate A", "a certain A", "any A", "first A" can be interpreted as A pre-defined in a protocol, etc., or as A obtained through setting, configuration, or indication, etc., and can also be interpreted as specific A, a certain A, any A, or the first A, etc., but are not limited to this.

In some embodiments, "not expecting to receive" can be interpreted as not receiving on time domain resources and/or frequency domain resources, or as not performing subsequent processing on the data after receiving the data; "not expecting to send" can be interpreted as not sending, or as sending but not expecting the recipient to respond to the sent content.

In some embodiments, the uplink synchronization method involved in the embodiments of the present disclosure may include at least one of steps S2101 to S2113. For example, step S2101 may be implemented as an independent embodiment, step S2102 and step S2106 may be implemented as independent embodiments, step S2113 may be implemented as an independent embodiment, step S2101+S2113 may be implemented as an independent embodiment, step S2102+S2104 may be implemented as an independent embodiment, step S2106+S2108 may be implemented as an independent embodiment, step S2102+S2103 may be implemented as an independent embodiment, and step S2106+S2107 may be implemented as an independent embodiment, but is not limited thereto.

In some embodiments, step S2102 and step S2106 may be executed in an interchangeable order or simultaneously.

In some embodiments, steps S2102 to S2111 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

In some embodiments, step S2112 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In some embodiments, steps S2101 to S2113 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

In the above embodiment, the terminal can perform uplink synchronization from the second time point based on the time information sent by the network device, thereby improving the availability and reliability of NTN communication, and avoiding the terminal from performing unnecessary operations during the period between the first time point when the cell ends the service and the second time point when the terminal starts to perform uplink synchronization, thereby saving terminal power consumption.

FIG3A is a flow chart of an uplink synchronization method according to an embodiment of the present disclosure. As shown in FIG3A , the embodiment of the present disclosure relates to an uplink synchronization method, which can be executed by a terminal 101, and includes:

Step S3101, obtain time information.

In some embodiments, the terminal 101 obtains the time information sent by the network device 102, but is not limited thereto and may also receive the time information sent by other entities.

In some embodiments, terminal 101 obtains time information specified by the protocol.

In some embodiments, terminal 101 performs processing to obtain time information.

In some embodiments, step S3101 is omitted, and the terminal 101 autonomously implements the function indicated by the time information, or the above function is default or acquiescent.

In some embodiments, the optional implementation of step S3101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S3102, perform uplink synchronization.

In some embodiments, terminal 101 performs uplink synchronization starting from the second time point.

In some embodiments, the optional implementation of step S3102 can refer to the optional implementation of step S2113 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

The communication method involved in the embodiment of the present disclosure may include at least one of step S3101 to step S3102. For example, step S3101 may be implemented as an independent embodiment, step S3102 may be implemented as an independent embodiment, and steps S3101 to step S3102 may be implemented as independent embodiments, but are not limited thereto.

In some embodiments, step S3102 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In some embodiments, step S3101 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In the above embodiment, the terminal can determine the second time point for performing uplink synchronization based on the acquired time information, and perform uplink synchronization from the second time point, thereby improving the availability and reliability of NTN communication.

FIG3B is a flow chart of an uplink synchronization method according to an embodiment of the present disclosure. As shown in FIG3B , the embodiment of the present disclosure relates to an uplink synchronization method, which can be executed by the terminal 101, and the method includes:

Step S3201, obtain time information.

In some embodiments, the terminal 101 obtains the time information sent by the network device 102, but is not limited thereto and may also receive the time information sent by other entities.

In some embodiments, terminal 101 obtains time information specified by the protocol.

In some embodiments, terminal 101 performs processing to obtain time information.

In some embodiments, step S3101 is omitted, and the terminal 101 autonomously implements the time information and the indicated functions, or the above functions are default or acquiescent.

In some embodiments, the optional implementation of step S3201 can refer to the optional implementation of step S2101 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S3202: do not perform a radio link monitoring operation and/or do not perform an RRC reestablishment operation.

In some embodiments, the terminal 101 does not perform a wireless link monitoring operation and/or does not perform an RRC reconstruction operation during a time period between a first time point and a second time point.

In some embodiments, the optional implementation of step S3202 can refer to the optional implementation of steps S2102 and S2107 in Figure 2, and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S3203, suspend (or stop) the first timer and/or suspend (or stop) the second timer.

In some embodiments, the optional implementation of step S3203 can refer to the optional implementation of steps S2104 and S2108 in Figure 2, and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S3204, start uplink synchronization.

In some embodiments, the terminal starts to perform uplink synchronization at a second time point.

In some embodiments, the optional implementation of step S3204 can refer to the optional implementation of step S2113 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

The communication method involved in the embodiment of the present disclosure may include at least one of step S3201 to step S3204. For example, step S3201 may be implemented as an independent embodiment, step S3204 may be implemented as an independent embodiment, and step S3201+step S3204 may be implemented as independent embodiments, but are not limited thereto.

In some embodiments, step S3202 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In some embodiments, step S3203 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In the above embodiment, when the PCI remains unchanged, the terminal can avoid performing the above radio link monitoring operation and/or RRC reconstruction operation within the above time period, thereby achieving the purpose of saving terminal power consumption.

FIG4A is a flow chart of an uplink synchronization method according to an embodiment of the present disclosure. As shown in FIG4A , the embodiment of the present disclosure relates to an uplink synchronization method, which can be executed by a network device 102, and the method includes:

Step S4101, sending time information.

In some embodiments, the network device 102 sends time information to the terminal 101 .

In some embodiments, terminal 101 receives time information.

In some embodiments, the optional implementation of step S4101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S4102, determine that terminal 101 starts to perform uplink synchronization.

In some embodiments, the network device 102 determines that the terminal starts to perform uplink synchronization from the second time point.

In some embodiments, the optional implementation of step S4102 can refer to the optional implementation of step S2113 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

The communication method involved in the embodiment of the present disclosure may include at least one of step S4101 to step S4102. For example, step S4101 may be implemented as an independent embodiment, step S4102 may be implemented as an independent embodiment, and steps S4101 to S4102 may be implemented as independent embodiments, but are not limited thereto.

In some embodiments, step S4102 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In some embodiments, step S4101 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In the above embodiment, the network device can send time information to the terminal to inform the terminal of the first time point when the cell ends service and/or the second time point when the terminal starts to perform uplink synchronization, thereby improving the availability and reliability of NTN communication.

FIG4B is a flow chart of an uplink synchronization method according to an embodiment of the present disclosure. As shown in FIG4B , the embodiment of the present disclosure relates to an uplink synchronization method, which can be executed by the network device 102, and the method includes:

Step S4201, sending time information.

In some embodiments, the network device 102 sends time information to the terminal 101 .

In some embodiments, terminal 101 receives time information.

In some embodiments, the optional implementation of step S4201 can refer to the optional implementation of step S2101 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S4202: Terminal 101 is not expected to perform wireless link monitoring operations and/or RRC reestablishment operations.

In some embodiments, the network device 102 does not expect the terminal 101 to perform a radio link monitoring operation and/or an RRC reestablishment operation during a time period between the first time point and the second time point.

In some embodiments, the optional implementation of step S3202 can refer to the optional implementation of steps S2103 and S2108 in Figure 2, and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S4203: Determine whether terminal 101 suspends (or stops) the first timer and/or the second timer.

In some embodiments, the optional implementation of step S3202 can refer to the optional implementation of steps S2105 and S2109 in Figure 2, and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

Step S4204, determine that terminal 101 starts to perform uplink synchronization.

In some embodiments, the network device 102 determines that the terminal starts to perform uplink synchronization from the second time point.

In some embodiments, the optional implementation of step S4202 can refer to the optional implementation of step S2113 in Figure 2 and other related parts of the embodiment involved in Figure 2, which will not be repeated here.

The communication method involved in the embodiment of the present disclosure may include at least one of step S4201 to step S4204. For example, step S4201 may be implemented as an independent embodiment, step S4204 may be implemented as an independent embodiment, and step S4201+step S4204 may be implemented as independent embodiments, but are not limited thereto.

In some embodiments, step S4202 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In some embodiments, step S4203 is optional, and one or more of these steps may be omitted or replaced in different embodiments.

In the above embodiment, when the PCI remains unchanged, the network device does not expect the terminal to perform the above wireless link monitoring operation and/or RRC reconstruction operation within the above time period, so as to ensure that the network device and the terminal have consistent understanding.

The above-mentioned solution provided in the embodiment of the present disclosure is further illustrated as follows.

The embodiment of the present disclosure provides a method for uplink synchronization in a PCI unchanged scenario, including:

If the network device 102 provides the time when the cell ends service and the time when the terminal is instructed to perform uplink synchronization, then:

The terminal 101 does not perform radio link monitoring after the cell service end time and before the uplink synchronization time, including:

No physical layer problem detection is performed;

The out-of-step indication is not counted;

Do not start the T310.

If the T310 is already started, suspend the T310.

After the cell service end time and before the uplink synchronization time, if the terminal 101 detects a radio link failure (RLF), the terminal 101 does not perform RRC reconstruction, including:

The cell selection process is not performed;

Do not start T311.

If T311 has been started, the terminal 101 suspends T311.

Terminal 101 remains in the RRC connected state after the cell service end time and before the uplink synchronization time.

The uplink synchronization method provided by the embodiment of the present disclosure includes:

First, the network device provides the time information of ending the service and the time of uplink synchronization.

Secondly, the end service time indicates the end time of the service provided by the current cell, and the uplink synchronization time indicates that the terminal 101 performs uplink synchronization in the cell at the time.

Again, the uplink synchronization time may be a certain moment, or a time period between the uplink synchronization time and the service end time.

Again, the terminal 101 does not perform wireless link monitoring between the end of service time and the uplink synchronization time.

Again, not performing wireless link monitoring includes one of the following:

No physical layer problem detection is performed;

The out-of-step indication is not counted;

Do not start T310;

If T310 is already started, suspend T310;

Terminal 101 remains in the RRC connected state.

Again, the terminal 101 does not perform RRC reconstruction between the end of service time and the uplink synchronization time.

Again, not performing RRC reestablishment includes one of the following:

The cell selection process is not performed;

Do not start T311;

If T311 is already started, suspend T311;

Remain in RRC connected state.

Again, the terminal 101 performs uplink synchronization in the cell at the uplink synchronization time, for example, initiates random access.

In the above embodiment, the terminal can determine the second time point for performing uplink synchronization based on the time information sent by the network device, and perform uplink synchronization from the second time point, thereby improving the availability and reliability of NTN communication. It can also avoid the terminal from performing unnecessary operations in the time period between the first time point when the cell ends the service and the second time point when the uplink synchronization is performed, thereby saving the power consumption of the terminal.

The embodiments of the present disclosure also propose a device for implementing any of the above methods, for example, a device is proposed, the above device includes a unit or module for implementing each step performed by the terminal in any of the above methods. For another example, another device is also proposed, including a unit or module for implementing each step performed by a network device (such as an access network device, etc.) in any of the above methods.

It should be understood that the division of the units or modules in the above devices is only a division of logical functions, which can be fully or partially integrated into one physical entity or physically separated in actual implementation. In addition, the units or modules in the device can be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, instructions are stored in the memory, and the processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the units or modules of the above devices, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory inside the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits, and the above hardware circuits can be understood as one or more processors; for example, in one implementation, the above hardware circuit is an application-specific integrated circuit (ASIC), and the functions of some or all of the above units or modules are realized by designing the logical relationship of the components in the circuit; for example, in another implementation, the above hardware circuit is a programmable logic device that can be used. (Programmable logic device, PLD) is implemented. Taking Field Programmable Gate Array (FPGA) as an example, it can include a large number of logic gate circuits. The connection relationship between the logic gate circuits is configured through a configuration file to realize the functions of some or all of the above units or modules. All units or modules of the above devices can be implemented in the form of software called by the processor, or in the form of hardware circuits, or in part in the form of software called by the processor, and the rest in the form of hardware circuits.

In the disclosed embodiments, the processor is a circuit with signal processing capability. In one implementation, the processor may be a circuit with instruction reading and running capability, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which may be understood as a microprocessor), or a digital signal processor (DSP); in another implementation, the processor may implement certain functions through the logical relationship of a hardware circuit, and the logical relationship of the above hardware circuit may be fixed or reconfigurable, such as a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document to implement the hardware circuit configuration may be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as ASIC, such as Neural Network Processing Unit (NPU), Tensor Processing Unit (TPU), Deep Learning Processing Unit (DPU), etc.

FIG5A is a schematic diagram of the structure of a terminal proposed in an embodiment of the present disclosure. As shown in FIG5A , a terminal 5100 may include: a transceiver module 5101 and a processing module 5102 .

In some embodiments, the transceiver module 5101 is configured to receive time information sent by a network device, where the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization.

In some embodiments, the processing module 5102 is configured to perform uplink synchronization starting from the second time point.

Optionally, the above-mentioned transceiver module 5101 is used to execute at least one of the other steps (such as step S2101, step S2112, step S2113, but not limited to these) performed by the terminal 101 in any of the above methods, which will not be repeated here.

Optionally, the processing module 5102 is used to execute at least one of the communication steps such as sending and/or receiving performed by the terminal 101 in any of the above methods (for example, step S2102, step S2104, step S2106, step S2108, step S2110, but not limited to these), which will not be repeated here.

In some embodiments, when the time information is used at least to indicate the second time point, the time information includes any one of the following:

information at the second time point;

Duration information of the interval between the second time point and the first time point.

In some embodiments, when the time information is used to indicate the first time point, the processing module 5102 is further configured to:

Based on a predefined rule, the second time point is determined.

In some embodiments, the processing module 5102 is further configured to:

Determine that the second time point reuses the first time point;

Determine the duration of the interval between the second time point and the first time point.

In some embodiments, when the time information is used to indicate the first time point, the transceiver module 5101 is further configured to:

Receive indication information sent by the network device, where the indication information is used to indicate whether the second time point reuses the first time point.

In some embodiments, the processing module 5102 is further configured to do at least one of the following:

During a time period between the first time point and the second time point, no wireless link monitoring operation is performed;

During the time period between the first time point and the second time point, no radio resource control RRC is performed. Rebuild operation.

In some embodiments, the processing module 5102 is further configured to do at least one of the following:

No physical layer problem detection operation is performed;

The out-of-step indication counting operation is not performed;

A first timer start operation is not performed, wherein the first timer is a timer for monitoring a radio link failure.

In some embodiments, the processing module 5102 is further configured to:

In response to determining that the first timer has been started, the first timer is suspended.

In some embodiments, the processing module 5102 is further configured to do at least one of the following:

No cell selection operation is performed;

The second timer start operation is not performed, and the second timer is a timer that switches to an idle state after detecting a radio link failure.

In some embodiments, the processing module 5102 is further configured to:

In response to determining that the second timer has been started, the second timer is suspended.

In some embodiments, the processing module 5102 is further configured to:

During a time period between the first time point and the second time point, the RRC connected state is maintained.

In some embodiments, the transceiver module 5101 is further configured to:

Receiving a system message broadcasted by the network device;

Based on the system message, a random access request message is sent to the network device at the second time point.

FIG5B is a schematic diagram of the structure of a network device according to an embodiment of the present disclosure. As shown in FIG5B , the network device 5200 may include: a transceiver module 5201 and a processing module 5202 .

In some embodiments, the transceiver module 5201 is configured to send time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization.

In some embodiments, the processing module 5102 is configured to determine that the terminal starts to perform uplink synchronization from the second time point.

Optionally, the above-mentioned transceiver module 5201 is used to execute at least one of the other steps (such as step S2101, step S2112, step S2113, but not limited to these) performed by the network device 102 in any of the above methods, which will not be repeated here.

Optionally, the processing module 5202 is used to execute at least one of the communication steps such as sending and/or receiving performed by the network device 102 in any of the above methods (for example, step S2103, step S2105, step S2107, step S2109, step S2111, but not limited to these), which will not be repeated here.

In some embodiments, when the time information is used at least to indicate the second time point, the time information includes any one of the following:

information at the second time point;

Duration information of the interval between the second time point and the first time point.

In some embodiments, when the time information is used to indicate the first time point, the processing module 5202 is further configured to:

Based on a predefined rule, the second time point is determined.

In some embodiments, the processing module 5202 is further configured to:

Determine that the second time point reuses the first time point;

Determine the duration of the interval between the second time point and the first time point.

In some embodiments, the transceiver module 5201 is further configured to:

Sending indication information to the terminal, where the indication information is used to indicate whether the second time point reuses the first time point.

In some embodiments, the processing module 5202 is further configured to do at least one of the following:

During a time period between the first time point and the second time point, the terminal is not expected to perform a radio link monitoring operation;

During a time period between the first time point and the second time point, the terminal is not expected to perform a radio resource control RRC reestablishment operation.

In some embodiments, the processing module 5202 is further configured to do at least one of the following:

not expecting the terminal to perform a physical layer problem detection operation;

not expecting the terminal to perform an out-of-sync indication counting operation;

The terminal is not expected to perform a first timer start operation, the first timer being a timer for monitoring a radio link failure.

In some embodiments, the processing module 5202 is further configured to:

In response to determining that the terminal has started the first timer, the terminal is determined to suspend the first timer.

In some embodiments, the processing module 5202 is further configured to do at least one of the following:

not expecting the terminal to perform a cell selection operation;

The terminal is not expected to execute a second timer start operation, where the second timer is a timer for switching to an idle state after detecting a radio link failure.

In some embodiments, the processing module 5202 is further configured to:

In response to determining that the terminal has started the second timer, the terminal is determined to suspend the second timer.

In some embodiments, the processing module 5202 is further configured to:

During a time period between the first time point and the second time point, it is determined that the terminal remains in the RRC connected state.

In some embodiments, the transceiver module 5201 is further configured to:

Broadcast system messages;

receiving a random access request message sent by the terminal at the second time point based on the system message.

In some embodiments, the above-mentioned transceiver module may include a sending module and/or a receiving module, and the sending module and the receiving module may be separated or integrated together. Optionally, the transceiver module may be interchangeable with the transceiver.

In some embodiments, the processing module may be a single module or may include multiple submodules. Optionally, the multiple submodules respectively execute all or part of the steps required to be executed by the processing module. Optionally, the processing module may be interchangeable with the processor.

6A is a schematic diagram of the structure of a communication device 6100 proposed in an embodiment of the present disclosure. The communication device 6100 may be a network device (e.g., an access network device, etc.), or a terminal (e.g., a user device, etc.), or a chip, a chip system, or a processor that supports a core network device to implement any of the above methods, or a chip, a chip system, or a processor that supports a terminal to implement any of the above methods. The communication device 6100 may be used to implement the method described in the above method embodiment, and the details may refer to the description in the above method embodiment.

As shown in FIG6A , the communication device 6100 includes one or more processors 6101. The processor 6101 may be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor may be used to process the communication protocol and the communication data, and the central processing unit may be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute a program, and process the data of the program. The communication device 6100 is used to execute any of the above methods.

In some embodiments, the communication device 6100 further includes one or more memories 6102 for storing instructions. Optionally, all or part of the memory 6102 may also be outside the communication device 6100.

In some embodiments, the communication device 6100 further includes one or more transceivers 6103. When the communication device 6100 includes one or more transceivers 6103, the transceiver 6103 performs at least one of the communication steps such as sending and/or receiving in the above method (for example, step S2101, but not limited thereto), and the processor 6101 performs at least one of the other steps (step S2102, step S2103, but not limited thereto).

In some embodiments, the transceiver may include a receiver and/or a transmitter, and the receiver and the transmitter may be separate devices. Optionally, the terms transceiver, transceiver unit, transceiver, transceiver circuit, etc. can be replaced with each other, the terms transmitter, transmission unit, transmitter, transmission circuit, etc. can be replaced with each other, and the terms receiver, receiving unit, receiver, receiving circuit, etc. can be replaced with each other.

In some embodiments, the communication device 6100 may include one or more interface circuits 6104. Optionally, the interface circuit 6104 is connected to the memory 6102, and the interface circuit 6104 may be used to receive signals from the memory 6102 or other devices, and may be used to send signals to the memory 6102 or other devices. For example, the interface circuit 6104 may read instructions stored in the memory 6102 and send the instructions to the processor 6101.

The communication device 6100 described in the above embodiment may be a network device or a terminal, but the scope of the communication device 6100 described in the present disclosure is not limited thereto, and the structure of the communication device 6100 may not be limited by FIG. 6A. The communication device may be an independent device or may be part of a larger device. For example, the communication device may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data and programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, a vehicle-mounted device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

6B is a schematic diagram of the structure of a chip 6200 provided in an embodiment of the present disclosure. In the case where the communication device 6200 may be a chip or a chip system, reference may be made to the schematic diagram of the structure of the chip 6200 shown in FIG6B , but the present disclosure is not limited thereto.

The chip 6200 includes one or more processors 6201, and the chip 6200 is used to execute any of the above methods.

In some embodiments, the chip 6200 further includes one or more interface circuits 6202. Optionally, the interface circuit 6202 is connected to the memory 6203. The interface circuit 6202 can be used to receive signals from the memory 6203 or other devices, and the interface circuit 6202 can be used to send signals to the memory 6203 or other devices. For example, the interface circuit 6202 can read instructions stored in the memory 6203 and send the instructions to the processor 6201.

In some embodiments, the interface circuit 6202 executes at least one of the communication steps such as sending and/or receiving in the above method (for example, step S2101, but not limited to this), and the processor 6201 executes at least one of the other steps (step S2102, step S2103, but not limited to this).

In some embodiments, terms such as interface circuit, interface, transceiver pin, and transceiver may be used interchangeably.

In some embodiments, the chip 6200 further includes one or more memories 6203 for storing instructions. Optionally, all or part of the memory 6203 may be outside the chip 6200.

The present disclosure also proposes a storage medium, on which instructions are stored, and when the instructions are executed on the communication device 6100, the communication device 6100 executes any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited to this, and it can also be a storage medium readable by other devices. Optionally, the storage medium can be a non-transitory storage medium, but is not limited to this, and it can also be a temporary storage medium.

The present disclosure also proposes a program product, which, when executed by the communication device 6100, enables the communication device 6100 to execute any of the above methods. Optionally, the program product is a computer program product.

The present disclosure also proposes a computer program, which, when executed on a computer, causes the computer to execute any one of the above methods.

Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (30)

An uplink synchronization method, characterized in that the method is executed by a terminal, comprising: Receiving time information sent by a network device, where the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization; The uplink synchronization is performed starting from the second time point. The method according to claim 1, characterized in that when the time information is used at least to indicate the second time point, the time information includes any one of the following: information at the second time point; Duration information of the interval between the second time point and the first time point. The method according to claim 1, characterized in that when the time information is used to indicate the first time point, the method further comprises: Based on a predefined rule, the second time point is determined. The method according to claim 3, characterized in that the determining the second time point comprises any one of: Determine that the second time point reuses the first time point; Determine the duration of the interval between the second time point and the first time point. The method according to claim 1, characterized in that when the time information is used to indicate the first time point, the method further comprises: Receive indication information sent by the network device, where the indication information is used to indicate whether the second time point reuses the first time point. The method according to any one of claims 1 to 5, characterized in that the method further comprises at least one of the following: During a time period between the first time point and the second time point, no wireless link monitoring operation is performed; During the time period between the first time point and the second time point, no radio resource control RRC reconstruction operation is performed. The method according to claim 6, wherein not performing the wireless link monitoring operation comprises at least one of the following: No physical layer problem detection operation is performed; The out-of-step indication counting operation is not performed; A first timer start operation is not performed, wherein the first timer is a timer for monitoring a radio link failure. The method according to claim 7, characterized in that the method further comprises: In response to determining that the first timer has been started, the first timer is suspended. The method according to any one of claims 6 to 8, wherein the not performing the RRC reestablishment operation comprises at least one of the following: No cell selection operation is performed; The second timer start operation is not performed, and the second timer is a timer that switches to an idle state after detecting a radio link failure. The method according to claim 9, characterized in that the method further comprises: In response to determining that the second timer has been started, the second timer is suspended. The method according to any one of claims 1 to 10, characterized in that the method further comprises: During a time period between the first time point and the second time point, the RRC connected state is maintained. The method according to any one of claims 1 to 11, characterized in that the performing uplink synchronization from the second time point comprises: Receiving a system message broadcasted by the network device; Based on the system message, a random access request message is sent to the network device at the second time point. An uplink synchronization method, characterized in that the method is executed by a network device, comprising: Sending time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization; Determine that the terminal starts to perform uplink synchronization from the second time point. The method according to claim 13, characterized in that when the time information is used at least to indicate the second time point, the time information includes any one of the following: information at the second time point; Duration information of the interval between the second time point and the first time point. The method according to claim 13, characterized in that when the time information is used to indicate the first time point, the method further comprises: Based on a predefined rule, the second time point is determined. The method according to claim 15, characterized in that the determining the second time point comprises any one of: Determine that the second time point reuses the first time point; Determine the duration of the interval between the second time point and the first time point. The method according to claim 13, characterized in that the method further comprises: Sending indication information to the terminal, where the indication information is used to indicate whether the second time point reuses the first time point. The method according to any one of claims 13 to 17, characterized in that the method further comprises at least one of the following: During a time period between the first time point and the second time point, the terminal is not expected to perform a radio link monitoring operation; During a time period between the first time point and the second time point, the terminal is not expected to perform a radio resource control RRC reestablishment operation. The method according to claim 18, wherein not expecting the terminal to perform a wireless link monitoring operation comprises at least one of the following: not expecting the terminal to perform a physical layer problem detection operation; not expecting the terminal to perform an out-of-sync indication counting operation; The terminal is not expected to perform a first timer start operation, the first timer being a timer for monitoring a radio link failure. The method according to claim 19, characterized in that the method further comprises: In response to determining that the terminal has started the first timer, the terminal is determined to suspend the first timer. The method according to any one of claims 18 to 20, characterized in that the not expecting the terminal to perform an RRC reestablishment operation comprises at least one of the following: not expecting the terminal to perform a cell selection operation; The terminal is not expected to execute a second timer start operation, where the second timer is a timer for switching to an idle state after detecting a radio link failure. The method according to claim 21, characterized in that the method further comprises: In response to determining that the terminal has started the second timer, the terminal is determined to suspend the second timer. The method according to any one of claims 13 to 22, characterized in that the method further comprises: During a time period between the first time point and the second time point, it is determined that the terminal remains in the RRC connected state. The method according to any one of claims 13 to 23, characterized in that the method further comprises: Broadcast system messages; receiving a random access request message sent by the terminal at the second time point based on the system message. A terminal, characterized in that the terminal comprises: A transceiver module, configured to receive time information sent by a network device, wherein the time information is used to indicate a first time point at which a cell ends service and/or a second time point at which a terminal performs uplink synchronization; The processing module is configured to perform uplink synchronization starting from the second time point. A network device, characterized in that the network device comprises: A transceiver module, configured to send time information to the terminal, where the time information is used to indicate a first time point at which the cell ends service and/or a second time point at which the terminal performs uplink synchronization; The processing module is configured to determine that the terminal performs uplink synchronization starting from the second time point. A terminal, characterized by comprising: one or more processors; The terminal is used to execute the uplink synchronization method according to any one of claims 1-12. A network device, comprising: one or more processors; Wherein, the network device is used to execute the uplink synchronization method described in any one of claims 13-24. A communication system, characterized in that it includes a terminal and a network device, wherein the terminal is configured to implement the uplink synchronization method described in any one of claims 1-12, and the network device is configured to implement the uplink synchronization method described in any one of claims 13-24. A storage medium storing instructions, characterized in that when the instructions are executed on a communication device, the communication device executes an uplink synchronization method as described in any one of claims 1-12 or 13-24.