RRC connection resume method and apparatus, and medium, communication system and chip system

Abstract

Disclosed in the present application are an RRC connection resume method and apparatus, and a medium, a communication system and a chip system, which can be applied to the field of satellite communications. When a link between a satellite to which a first access network device belongs and a mobility management network element is connected, the first access network device sends resume information to the mobility management network element, wherein the resume information is used for resuming an RRC connection of a terminal device that is suspended under the first access network device; furthermore, when a link between the mobility management network element and a satellite to which a second access network device belongs is connected, the mobility management network element sends the resume information to the second access network device, such that the second access network device stores the resume information in advance. When the terminal device subsequently initiates an RRC connection resume, since both the first access network device and the second access network device store the resume information, an improvement in the success rate of resuming the RRC connection is facilitated.

Description

RRC connection recovery method, apparatus, medium, communication system and chip system

[0001] The present application claims priority from the Chinese patent application No. 202410965355.8 filed on July 17, 2024, and entitled "RRC connection recovery method, apparatus, medium, communication system and chip system", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to an RRC connection recovery method, apparatus, medium, communication system and chip system. BACKGROUND

[0003] Non Terrestrial Network (NTN) technology generally adopts a satellite communication mode to provide communication services to ground users. The NTN network architecture includes a regenerative forwarding NTN network architecture, in which the access network device is deployed on a satellite. In the regenerative forwarding NTN network architecture, a store-and-forward scenario is involved.

[0004] In the store-and-forward scenario, the service link and the feeder link cannot be in an available state at the same time. The service link refers to a link between a satellite and a terminal device for communication, and the feeder link refers to a link between the satellite and an NTN gateway for communication. For example, in the time period t1-t2, the service link is in an available state, and the feeder link is in an unavailable state; in the time period t3-t4, the service link is in an unavailable state, and the feeder link is in an available state. In the store-and-forward scenario, it can result in a low success rate of recovering the RRC connection. SUMMARY

[0005] The present application discloses an RRC connection recovery method, apparatus, medium, communication system and chip system. The first access network device sends recovery information to the mobility management network element in advance, which is beneficial for other access network devices to obtain the recovery information from the mobility management network element, thereby improving the success rate of recovering the RRC connection in the store-and-forward scenario.

[0006] In a first aspect, an embodiment of the present application provides a method for RRC connection recovery. The method can be applied to a first access network device, and can also be applied to an apparatus (for example, a chip or a chip system or a circuit) in the first access network device or an apparatus that can be used in conjunction with the first access network device. The method is described below by taking the first access network device as an example. The method can include: in response to a link between a satellite to which the first access network device belongs and a mobility management network element being connected, sending, by the first access network device, recovery information to the mobility management network element, the recovery information being used to recover a radio resource control (RRC) connection of a first terminal device suspended under the first access network device.

[0007] In the technical solution, the first access network device sends the recovery information to the mobility management network element in advance, which is conducive to other access network devices (for example, a second access network device) obtaining the recovery information from the mobility management network element, and increasing the number of access network devices that have the recovery information, thereby facilitating an increase in the success rate of recovering the RRC connection in a store-and-forward scenario.

[0008] In a possible implementation, the recovery information includes one or more of a first recovery identifier, a first parameter of a token used for authentication, a context of the first terminal device, an identifier of the satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a last cell accessed by the first terminal device, a next hop (NH) parameter used for encryption and integrity protection after the connection is recovered, and a next hop chaining counter (NCC) used for encryption and integrity protection after the connection is recovered.

[0009] In a possible implementation, the method further includes: in response to a link between the satellite to which the first access network device belongs and the first terminal device being connected, sending, by the first access network device, first indication information to the first terminal device, the first indication information indicating one or more of the following: support for a store-and-forward mode, and support for recovering the RRC connection of the first terminal device by M access network devices, M being a positive integer.

[0010] In the technical solution, the first access network device indicates, to the first terminal device, that the M access network devices support recovering the RRC connection of the first terminal device, so that when the first terminal device needs to recover the RRC connection, the first terminal device can successfully recover the RRC connection of the first terminal device by initiating the RRC connection recovery to any one of the M access network devices, thereby facilitating an increase in the success rate of recovering the RRC connection in a store-and-forward scenario.

[0011] In a possible implementation, the first indication information further indicates one or more of the following: an identifier of each of the M access network devices; an identifier of a satellite to which each of the M access network devices belongs; a first time period corresponding to each of the M access network devices, wherein the RRC connection of the first terminal device is supported to be resumed at the access network device in the first time period corresponding to the access network device; and a start time of the first time period corresponding to each of the M access network devices.

[0012] In a possible implementation, the method further includes: in response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the first access network device sending, to the mobility management network element, second indication information, the second indication information indicating that the mobility management network element sends the resumption information to the M access network devices, M being a positive integer.

[0013] In this technical solution, the first access network device indicates to the mobility management network element which access network device or which access network devices the resumption information is to be sent to, and further, the M access network devices respectively receive the resumption information from the mobility management network element and store the received resumption information, in which case, the M access network devices all save the resumption information, so that the M access network devices all support the RRC connection of the first terminal device to be resumed, and as the number of access network devices that save the resumption information increases, the success rate of the RRC connection to be resumed in the store-and-forward scenario is improved.

[0014] In a possible implementation, the second indication information includes an identifier of each of the M access network devices and / or an identifier of a satellite to which each of the M access network devices belongs.

[0015] In a possible implementation, the first indication information is determined based on ephemeris information.

[0016] In a possible implementation, the method further includes: in response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the first access network device receiving third indication information from the mobility management network element, the third indication information being used to determine the first indication information.

[0017] In a possible implementation, the first parameter includes a short resume media access control identifier (short Resume MAC-I) or a resume media access control identifier (Resume MAC-I).

[0018] In a second aspect, the embodiments of the present application provide another method for RRC connection recovery. The method can be applied to a second access network device, and can also be applied to an apparatus (for example, a chip, or a chip system, or a circuit) in the second access network device, or an apparatus that can be used with the second access network device. The method is described below by taking the second access network device as an example. The method can include: in response to a link between a satellite to which the second access network device belongs and a mobility management network element being connected, the second access network device receiving recovery information from the mobility management network element, the recovery information being used to recover an RRC connection of a first terminal device that is suspended under a first access network device; the second access network device storing the recovery information; and in response to a link between the satellite to which the second access network device belongs and the first terminal device being connected, the second access network device receiving a recovery request from the first terminal device, and verifying the first terminal device based on information in the stored recovery information and the recovery request.

[0019] In the technical solution, after the second access network device receives the recovery information, the second access network device stores the recovery information, so that when the first terminal device needs to recover the RRC connection, the first terminal device can successfully recover the RRC connection of the first terminal device by initiating the RRC connection recovery to the second access network device, thereby facilitating to improve a success rate of recovering the RRC connection in a store-and-forward scenario.

[0020] In a possible implementation, the recovery information includes one or more of a first recovery identifier, a first parameter of a token used for authentication, a context of the first terminal device, an identifier of a satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a last cell accessed by the first terminal device, a next hop parameter NH used for encryption and integrity protection after the RRC connection is recovered, and a next hop count NCC used for encryption and integrity protection after the RRC connection is recovered.

[0021] In a possible implementation, the method further includes: broadcasting, by the second access network device, fourth indication information, the fourth indication information indicating that the second access network device supports recovering a first RRC connection, wherein the first RRC connection includes an RRC connection that is suspended under any access network device of N access network devices, the N access network devices at least including the first access network device, and N is a positive integer.

[0022] In the technical solution, the second access network device broadcasts the fourth indication information, so that the first terminal device can determine whether the second access network device supports recovering the RRC connection of the first terminal device based on the fourth indication information, and then the first terminal device can initiate the RRC connection recovery to the second access network device in a case where the second access network device supports recovering the RRC connection of the first terminal device, thereby facilitating to improve the success rate of recovering the RRC connection in the store-and-forward scenario.

[0023] In a possible implementation, the fourth indication information includes an identifier of each of the N access network devices and / or an identifier of a satellite to which each of the N access network devices belongs.

[0024] In a possible implementation, the method further includes: in response to a link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the second access network device receiving a first paging message for paging the first terminal device from the mobility management network element; and in response to the second access network device storing the recovery information of the first terminal device and a link between the satellite to which the second access network device belongs and the first terminal device being in communication, the second access network device sending a second paging message to the first terminal device, the second paging message including fifth indication information, the fifth indication information indicating that the first terminal device sends a recovery request.

[0025] In this technical solution, the second access network device indicates to the first terminal device through the paging message whether the second access network device supports resuming the RRC connection of the first terminal device, and then in the case where the second access network device supports resuming the RRC connection of the first terminal device, the first terminal device can initiate the RRC connection resumption to the second access network device, which on the one hand helps to improve the success rate of resuming the RRC connection in the store-and-forward scenario, and on the other hand helps to save signaling overhead.

[0026] In a possible implementation, the method further includes: in response to the first terminal device passing the verification, the second access network device sending an RRC connection resumption message to the first terminal device; and in response to a link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the second access network device sending sixth indication information to the mobility management network element, the sixth indication information indicating that a third access network device storing the recovery information releases the recovery information or indicating that the RRC connection resumption is completed at the second access network device.

[0027] In this technical solution, indicating that the third access network device releases the recovery information can avoid wasting the storage resources of the third access network device, and helps to improve the utilization rate of the storage resources of the third access network device.

[0028] In a possible implementation, the first parameter includes a short Resume MAC-I or a Resume MAC-I.

[0029] In a third aspect, an embodiment of the present application provides another method for RRC connection recovery, which can be applied to a terminal device, a device (for example, a chip or a chip system or a circuit) in the terminal device, or a device that can be used with the terminal device. The method can include: in response to a link between the first terminal device and a satellite to which a second access network device belongs being connected, the first terminal device sending a recovery request to the second access network device, wherein the second access network device stores recovery information, and the recovery information is used to recover an RRC connection of the first terminal device that is suspended under a first access network device, and the recovery request is used to request recovery of the RRC connection of the first terminal device.

[0030] In this technical solution, the first terminal device sends a recovery request to the second access network device that stores the recovery information, which is beneficial to improve the success rate of recovering the RRC connection in the store-and-forward scenario.

[0031] In a possible implementation, the recovery information includes one or more of a first recovery identifier, a first parameter of a token used for authentication, a context of the first terminal device, an identifier of a satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a historical cell that the first terminal device has accessed recently, a next hop parameter NH used for encryption and integrity protection after the connection is recovered, and a next hop link number NCC used for encryption and integrity protection after the connection is recovered.

[0032] In a possible implementation, the method further includes: in response to the link between the first terminal device and the satellite to which the first access network device belongs being connected, the first terminal device receiving first indication information from the first access network device, and the first indication information indicates one or more of the following: support for a store-and-forward mode, and support for recovering the RRC connection of the first terminal device at M access network devices, wherein the M access network devices at least include the second access network device, and M is a positive integer.

[0033] In this technical solution, the first terminal device can learn from the first indication information that the M access network devices support recovery of the RRC connection of the first terminal device, so that when the first terminal device needs to recover the RRC connection, the RRC connection of the first terminal device can be successfully recovered by initiating the RRC connection recovery to any one of the M access network devices, thereby being beneficial to improve the success rate of recovering the RRC connection in the store-and-forward scenario.

[0034] In a possible implementation, the first indication information further indicates one or more of the following: an identity of each of the M access network devices; an identity of a satellite to which each of the M access network devices belongs; a first time period corresponding to each of the M access network devices, wherein the RRC connection of the first terminal device is supported to be resumed at the access network device in the first time period corresponding to the access network device; and a start time of the first time period corresponding to each of the M access network devices.

[0035] In a possible implementation, the method further includes: receiving, by the first terminal device, fourth indication information broadcast by a second access network device, the fourth indication information indicating that the RRC connection of the first terminal device is supported to be resumed at the second access network device, wherein the RRC connection of the first terminal device includes an RRC connection suspended at any one of N access network devices, and the N access network devices at least include the first access network device, and N is a positive integer.

[0036] In this technical solution, the first terminal device can determine, based on the fourth indication information, whether the RRC connection of the first terminal device is supported to be resumed at the second access network device, and then the first terminal device can initiate the RRC connection resumption to the second access network device in a case where the RRC connection of the first terminal device is supported to be resumed at the second access network device, thereby facilitating to improve the success rate of the RRC connection resumption in the store-and-forward scenario.

[0037] In a possible implementation, the fourth indication information includes an identity of each of the N access network devices and / or an identity of a satellite to which each of the N access network devices belongs.

[0038] In a possible implementation, the method further includes: in response to a link between the first terminal device and a satellite to which the second access network device belongs being in communication, receiving, by the first terminal device, a second paging message from the second access network device, the second paging message including fifth indication information, the second paging message being sent in a case where the second access network device stores the resumption information of the first terminal device, and the fifth indication information indicating that the first terminal device sends a resumption request.

[0039] In this technical solution, the first terminal device can determine, based on the second paging message, whether the RRC connection of the first terminal device is supported to be resumed at the second access network device, and then the first terminal device can initiate the RRC connection resumption to the second access network device in a case where the RRC connection of the first terminal device is supported to be resumed at the second access network device, thereby on one hand facilitating to improve the success rate of the RRC connection resumption in the store-and-forward scenario, and on the other hand facilitating to save signaling overhead.

[0040] In a possible implementation, the first parameter comprises a short Resume MAC-I or a Resume MAC-I.

[0041] In a fourth aspect, an embodiment of the present application provides a communication apparatus, which comprises a module / unit for performing the method in the first aspect or any possible implementation of the first aspect. The apparatus can be a first access network device, or a module (for example, a chip, a chip system, or a processor) applied to the first access network device, or a logic node, a logic module, or software capable of realizing all or part of the functions of the first access network device.

[0042] In a fifth aspect, an embodiment of the present application provides a communication apparatus, which comprises a module / unit for performing the method in the second aspect or any possible implementation of the second aspect. The apparatus can be a second access network device, or a module (for example, a chip, a chip system, or a processor) applied to the second access network device, or a logic node, a logic module, or software capable of realizing all or part of the functions of the second access network device.

[0043] In a sixth aspect, an embodiment of the present application provides a communication apparatus, which comprises a module / unit for performing the method in the third aspect or any possible implementation of the third aspect. The apparatus can be a terminal device, or a module (for example, a chip, a chip system, or a processor) applied to the terminal device, or a logic node, a logic module, or software capable of realizing all or part of the functions of the terminal device.

[0044] In a seventh aspect, an embodiment of the present application provides a communication apparatus, which can be a first access network device, or a device (for example, a chip, or a chip system, or a circuit) in the first access network device. The communication apparatus can comprise a processor coupled with a memory, and the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the communication apparatus performs the method executed by the first access network device, or the device in the first access network device, in the above method embodiments.

[0045] In an eighth aspect, an embodiment of the present application provides a communication apparatus, which can be a second access network device, or a device (for example, a chip, or a chip system, or a circuit) in the second access network device. The communication apparatus can comprise a processor coupled with a memory, and the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the communication apparatus performs the method executed by the second access network device, or the device in the second access network device, in the above method embodiments.

[0046] In a ninth aspect, an embodiment of the present application provides a communication apparatus, which can be a terminal device or a device (for example, a chip or a chip system or a circuit) in the terminal device. The communication apparatus can include a processor and a memory coupled to the processor. The memory is configured to store a program or an instruction. When the program or the instruction is executed by the processor, the communication apparatus performs the method performed by the terminal device or the device in the terminal device in the above method embodiments.

[0047] In a tenth aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program or computer instructions. When the computer program or computer instructions are run on a computer, the computer is caused to perform any one of the methods in the first aspect or any possible implementation of the first aspect, the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect.

[0048] In an eleventh aspect, an embodiment of the present application provides a computer program product containing program instructions, which when run on a computer, causes the computer to perform any one of the methods in the first aspect or any possible implementation of the first aspect, the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect.

[0049] In a twelfth aspect, an embodiment of the present application provides a chip system, which includes at least one processor and an interface circuit. The interface circuit and the at least one processor are interconnected by a line. The at least one processor is configured to execute a computer program or instructions, so that any one of the methods in the first aspect or any possible implementation of the first aspect, the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect is executed. In a possible implementation, the chip system can further include at least one memory. The interface circuit, the at least one memory and the at least one processor are interconnected by a line. The at least one memory stores instructions. When the instructions are executed by the processor, any one of the methods in the first aspect or any possible implementation of the first aspect, the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect is executed. The chip system can be composed of a chip or include a chip and other discrete devices.

[0050] In a thirteenth aspect, an embodiment of the present application provides a communication system, which comprises a first access network device and a second access network device. Optionally, the communication system can further comprise a terminal device. Optionally, the communication system can further comprise a mobility management network element. When the first access network device, the second access network device, the terminal device, and the mobility management network element operate in the communication system, the first aspect or any possible implementation manner of the first aspect, the second aspect or any possible implementation manner of the second aspect, the third aspect or any possible implementation manner of the third aspect can be executed. BRIEF DESCRIPTION OF DRAWINGS

[0051] FIG. 1 is a schematic diagram of an NTN network architecture of transparent forwarding;

[0052] FIG. 2 is a schematic diagram of an NTN network architecture of regenerative forwarding;

[0053] FIG. 3 is a schematic diagram of an RRC suspension process;

[0054] FIG. 4 is a schematic diagram of a process of performing RRC connection recovery at an original suspension base station;

[0055] FIG. 5 is a schematic diagram of a process of performing RRC connection recovery at a non-original suspension base station;

[0056] FIG. 6 is a schematic diagram of a system architecture to which an embodiment of the present application is applied;

[0057] FIG. 7 is a schematic diagram of a process of an RRC connection recovery method provided by an embodiment of the present application;

[0058] FIG. 8 is a schematic diagram of another RRC connection recovery method provided by an embodiment of the present application;

[0059] FIG. 9 is a schematic diagram of still another RRC connection recovery method provided by an embodiment of the present application;

[0060] FIG. 10 is a schematic diagram of still another RRC connection recovery method provided by an embodiment of the present application;

[0061] FIG. 11 is a schematic diagram of still another RRC connection recovery method provided by an embodiment of the present application;

[0062] FIG. 12 is a schematic diagram of still another RRC connection recovery method provided by an embodiment of the present application;

[0063] FIG. 13 is a schematic diagram of a structure of a communication apparatus provided by an embodiment of the present application;

[0064] FIG. 14 is a schematic diagram of a structure of another communication apparatus provided by an embodiment of the present application;

[0065] FIG. 15 is a structural schematic diagram of another communication apparatus according to an embodiment of the present application;

[0066] FIG. 16 is a structural schematic diagram of a terminal device according to an embodiment of the present application. DETAILED DESCRIPTION

[0067] It should be understood that the terms "first", "second" and the like in the embodiments of the present application are used to distinguish different objects, and are not used to describe a specific sequence. In the embodiments of the present application, "at least one" means one or more, and multiple means two or more. In the embodiments of the present application, "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. Wherein, A and B can be singular or plural. The character " / " can represent that the associated objects before and after it are in an "or" relationship. In addition, the symbol " / " can also represent the division sign, that is, to perform division operation.

[0068] In the embodiments of the present application, "at least one of the following" or the like means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b or c can represent the following seven cases: a, b, c, a and b, a and c, b and c, a, b and c. Wherein, each of a, b and c can be an element or a set containing one or more elements.

[0069] In the embodiments of the present application, "corresponding", "associated", "relevant", "mapped" can be used interchangeably. It should be pointed out that when there is no emphasis on the distinction, the concepts or meanings to be expressed are consistent.

[0070] First, some concepts or technologies related to the embodiments of the present application are introduced.

[0071] 1. Terminal device

[0072] The terminal device can also be referred to as a user equipment (UE), a mobile station (MS), a mobile terminal (MT), or the like, or a device for providing voice or data connectivity to a user, or an Internet of Things device. For example, the terminal device includes a handheld device having wireless connectivity, a vehicle-mounted device, and the like. At present, the terminal device can be a mobile phone, a tablet computer, a notebook computer, a palm computer, a mobile Internet device (MID), a wearable device, a vehicle-mounted device (for example, a car, a bicycle, an electric vehicle, an airplane, a ship, a train, a high-speed rail, and the like), a satellite terminal, a virtual reality (VR) device, an augmented reality (AR) device, a smart point of sale (POS) machine, a customer-premises equipment (CPE), a wireless terminal in industrial control, a smart home device (for example, a refrigerator, a television, an air conditioner, an electricity meter, and the like), a smart robot, a mechanical arm, a plant device, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, or a wireless terminal in a smart home, a flight device (for example, a smart robot, a hot air balloon, a drone, an airplane), and the like. The terminal device can also be other devices having terminal functions, for example, the terminal device can also be a device assuming terminal functions in D2D communication. The terminal device in the application embodiments can also be a terminal device supporting satellite communication.

[0073] As an example but not limitation, the wearable device in the application embodiments can also be referred to as a wearable smart device, which is a general term of devices that are designed and developed by applying wearable technology to daily wear, such as glasses, gloves, watches, clothing, and shoes. The wearable device is a portable device that is directly worn on the body or integrated into the clothes or accessories of the user. The wearable device is not only a hardware device, but also a device that realizes powerful functions through software support and data interaction and cloud interaction. The wearable smart device in a broad sense includes devices with full functions, large sizes, and the ability to realize complete or partial functions without relying on a smart phone, such as smart watches or smart glasses, and devices that focus on a certain application function and need to be used in cooperation with other devices such as a smart phone, such as various smart wristbands and smart jewelry for monitoring vital signs.

[0074] Embodiments of the present application do not limit the device form of the terminal device, and the device for implementing the function of the terminal device can be a terminal device, or can be a device capable of supporting the terminal device to implement the function, such as a chip system. The device can be installed in the terminal device or used with the terminal device. In embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices.

[0075] 2. Non Terrestrial Network (NTN) network architecture with transparent forwarding

[0076] The NTN network architecture can include: an NTN network architecture with transparent forwarding, and an NTN network architecture with regenerative forwarding.

[0077] In the NTN network architecture with transparent forwarding, the terminal device and the access network device perform data transmission, which passes through satellite forwarding. The satellite does not perform protocol stack processing on the data in the forwarding process, thereby realizing transparent forwarding.

[0078] For example, FIG. 1 is a schematic diagram of an NTN network architecture with transparent forwarding. As shown in FIG. 1, the NTN network architecture with transparent forwarding includes a terminal device, an access network, and a core network. The access network can include an access network device, a satellite, and a gateway.

[0079] The satellite in FIG. 1 can provide wireless frequency filtering, frequency conversion, and amplification functions. Alternatively, the satellite in FIG. 1 only provides transparent forwarding of signals, and does not change the waveform signals forwarded thereby.

[0080] The satellite in embodiments of the present application can include a low-Earth orbit (LEO) satellite, a medium-Earth orbit (MEO) satellite, a geostationary Earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, or other satellites.

[0081] In embodiments of the present application, the gateway is used to connect the satellite and the ground public network. The network element can be deployed on the ground, and the gateway can also be referred to as a ground network element or an NTN gateway. In embodiments of the present application, the service link refers to a link for communication between the satellite and the terminal device, and the feeder link refers to a link for communication between the satellite and the gateway.

[0082] The access network is used to implement access-related functions, can provide access functions for authorized users in a specific area, and can determine transmission tunnels of different qualities to transmit user data according to the level of a user, the demand of a service, and the like. The access network forwards control signals and user data between a terminal device and a core network. The access network device can be a device that provides access for a terminal device.

[0083] In a possible scenario, the access network device can be a base station, an evolved NodeB (eNB), a transmitting and receiving point (TRP), a transmitting point (TP), a next generation NodeB (gNB), a next generation base station in a 6th generation (6G) mobile communication system, a base station in a future mobile communication system, a satellite, an integrated access and backhaul (IAB) node, an access network device in a mobile switching center non-terrestrial network (NTN) communication system, i.e., can be deployed in a high-altitude platform or a satellite, and the like. The access network device can be a macro base station, a micro base station, or an indoor station, a relay node or a donor node, or a wireless controller in a CRAN scenario. The access network device can also be a device that plays a base station function in device to device (D2D) communication, vehicle-to-everything (V2X) communication, unmanned aerial vehicle communication, and machine communication. Optionally, the access network device can also be a server, a wearable device, a vehicle or a vehicle-mounted device, and the like. For example, the access network device in the V2X technology can be a road side unit (RSU). All or part of the functions of the access network device in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform). The access network device in the present application can also be a logical node, a logical module, or software that can implement all or part of the functions of the access network device.

[0084] In another possible scenario, a terminal device accesses a network device through multiple access network devices. The multiple access network devices can be CU nodes, or DU nodes, or devices including CU nodes and DU nodes. The multiple access network devices can be centrally controlled by a network device, or can be distributed.

[0085] In different systems, the CU (or CU-CP and CU-UP), DU or RU can also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU can also be referred to as O-CU (open CU), the DU can also be referred to as O-DU, the CU-CP can also be referred to as O-CU-CP, the CU-UP can also be referred to as O-CU-UP, and the RU can also be referred to as O-RU. For the convenience of description, the CU, CU-CP, CU-UP, DU and RU are taken as examples for description in this application. Any one of the CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0086] In the embodiments of this application, the form of the access network device is not limited, and the device for implementing the function of the access network device can be the access network device; or can be a device capable of supporting the access network device to implement the function, such as a chip system. The device can be installed in the access network device or used in matching with the access network device.

[0087] The core network is responsible for maintaining the subscription data of the mobile network, and provides session management, mobility management, policy management, security authentication and other functions for the terminal device. The core network in FIG. 1 can be a core network in a long term evolution (LTE) system, a core network in a 5th generation mobile communication (5G) system, a core network in a 6th generation mobile communication (6G) system, or a core network in other future communication systems, etc.

[0088] Taking the core network in FIG. 1 as an example, the core network in the LTE system can include, but is not limited to, the following network elements: a mobility management entity (MME), a serving gateway (S-GW), a packet data network gateway (PGW), and a home subscriber server (HSS). The MME is mainly responsible for mobility management and control, including user authentication, paging, location updating, handover and the like. The S-GW is mainly responsible for the management of the terminal device context session and the routing and forwarding of data packets. The PGW is mainly responsible for session management, bearer control, IP address allocation, charging support and the like. The HSS is mainly used for call and session establishment support, user authentication and access authorization.

[0089] Taking the core network in FIG. 1 as an example, the core network in the 5G system can include, but is not limited to, the following network elements: an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), an authentication server function (AUSF), a network slice selection function (NSSF), a network exposure function (NEF), a network function repository function (NRF), a policy control function (PCF), a unified data management (UDM), and an application function (AF).

[0090] AMF network element, mainly responsible for mobility management in the mobile network, such as user location update, user registration network, user handover, etc. UPF network element, mainly responsible for forwarding and receiving user data, which can receive user data from the data network and transmit it to the UE through the access network device; it can also receive user data from the UE through the access network device and forward it to the data network. SMF network element, mainly responsible for session management in the mobile network, such as session establishment, modification, release. Specific functions such as allocating an internet protocol (IP) address for a user, selecting a UPF that provides message forwarding functions, etc. AUSF network element, used to perform security authentication of the UE. NSSF network element, used to select network slices for the UE. NEF network element, mainly used to support the opening of capabilities and events. PCF network element, mainly supports providing a unified policy framework to control network behavior, providing policy rules to control layer network functions, and being responsible for obtaining user subscription information related to policy decision. The PCF network element can provide policies such as quality of service (QoS) policies and slice selection policies to the AMF network element and the SMF network element. UDM network element, used to store user data such as subscription data and authentication / authorization data. AF network element, mainly supports interaction with the 3GPP core network to provide services, such as influencing data routing decisions, policy control functions, or providing third-party services to the network side. NRF network element, mainly provides service registration, discovery and authorization, and maintains information about available network function (NF) instances, and can implement on-demand configuration of network functions and services and interconnection between NFs. Among them, service registration means that the NF network element needs to be registered with the NRF network element before it can provide services. Service discovery means that when an NF network element needs other NF network elements to provide services for it, it needs to perform service discovery through the NRF network element first to discover the desired NF network element that provides services for it. For example, when NF network element 1 needs NF network element 2 to provide services for it, it needs to perform service discovery through the NRF network element first to discover NF network element 2.

[0091] 3. Regenerative forwarding NTN network architecture

[0092] In the regenerative forwarding NTN network architecture, during the process of data transmission between the terminal device and the access network device, satellite forwarding is performed, and the satellite performs protocol stack processing on the data during the forwarding process, thereby realizing regenerative forwarding.

[0093] For example, FIG. 2 is a schematic diagram of a regenerative forwarding NTN network architecture. As shown in FIG. 2, the regenerative forwarding NTN network architecture includes a terminal device, an access network, and a core network.

[0094] As shown in FIG. 2, the access network can include an access network device, a satellite, and a gateway. For related descriptions of the access network, the access network device, and the gateway, refer to the foregoing descriptions of the access network device in FIG. 1.

[0095] The satellite in FIG. 2 can provide demodulation / decoding, routing / conversion, encoding / modulation, and the like in addition to the functions of wireless frequency filtering, frequency conversion, and amplification. The satellite in FIG. 2 can be understood as having part or all of the functions of the access network device.

[0096] As shown in FIG. 2, in the regenerative NTN network architecture, the access network device is deployed on the satellite. However, as shown in FIG. 1, in the transparent NTN network architecture, the satellite and the access network device are separately deployed.

[0097] The core network in FIG. 2 can be a core network in an LTE system, a core network in a 5G system, a core network in a 6G system, or a core network in other future communication systems, and the like. For related descriptions of the core network, refer to the foregoing descriptions of the core network in FIG. 2, which are not repeated here.

[0098] 4. Store-and-forward scenario

[0099] In the regenerative NTN network architecture, a store-and-forward scenario is involved. In the store-and-forward scenario, the service link and the feeder link cannot be in the available state at the same time. For example, in the time period of t1-t2, the service link is in the available state, and the feeder link is in the unavailable state; in the time period of t3-t4, the service link is in the unavailable state, and the feeder link is in the available state.

[0100] In the store-and-forward scenario, after the satellite receives uplink information from the terminal device, the satellite stores the uplink information first, and then sends the stored uplink information to the core network when the feeder link is in the available state. Similarly, after the satellite receives downlink information from the core network, the satellite stores the downlink information first, and then sends the stored downlink information to the terminal device when the service link is in the available state. The uplink information includes uplink data and / or uplink signaling, and the downlink information includes downlink data and / or downlink signaling.

[0101] 5. Radio Resource Control (RRC) suspension procedure

[0102] For example, taking the eNB-triggered RRC suspension procedure as an example, FIG. 3 is a schematic diagram of the RRC suspension procedure. The RRC suspension procedure can include but is not limited to the following steps:

[0103] S300: The UE performs uplink and downlink transmission with the S-GW, the UPF, or the SMF.

[0104] The eNB can access a 4G core network and a 5G core network. Assuming that the core network accessed by the eNB is the 4G core network, S300 specifically refers to uplink and downlink transmission between the UE and the S-GW. Assuming that the core network accessed by the eNB is the 5G core network, S300 specifically refers to uplink and downlink transmission between the UE and the UPF, or S300 specifically refers to uplink and downlink transmission between the UE and the SMF.

[0105] After the uplink and downlink transmission ends, the eNB can trigger an RRC suspension procedure.

[0106] S301: The eNB determines to suspend the RRC connection.

[0107] In the case that the eNB determines to suspend the RRC connection, the eNB can trigger a UE context suspension procedure. The UE context can include a UE access-stratum (AS) context and a UE non-access-stratum context.

[0108] S302: The eNB sends a UE context suspension request to the MME or the AMF. Correspondingly, the MME or the AMF receives the UE context suspension request from the eNB.

[0109] The eNB can access a 4G core network and a 5G core network. Assuming that the core network accessed by the eNB is the 4G core network, the UE context suspension procedure can include: the eNB requests the MME to suspend the UE context; and the MME responds to suspend the UE context. Assuming that the core network accessed by the eNB is the 5G core network, the UE context suspension procedure can include: the eNB requests the AMF to suspend the UE context; and the AMF responds to suspend the UE context.

[0110] S303: The MME or the AMF releases access bearers.

[0111] After the MME receives the UE context suspension request from the eNB, the MME can instruct the MME to release access bearers.

[0112] S304: The MME or the AMF sends a UE context suspension response to the eNB. Correspondingly, the eNB receives the UE context suspension response from the MME or the AMF.

[0113] The eNB receiving the UE context suspension response from the MME or the AMF can indicate that the network side successfully suspends the UE context.

[0114] S305: The eNB sends an RRC connection release message to the UE, and the RRC connection release message includes a release cause and a resume ID. Correspondingly, the UE receives the RRC connection release message from the eNB.

[0115] The resume ID carried in the RRC connection release message is used to resume the RRC connection, and the release cause can be specifically rrc-suspend. The release cause rrc-suspend indicates that the flow is an RRC suspend flow, rather than a complete release of the RRC.

[0116] S306: The UE stores the UE AS context, suspends the SRB and the DRB, and enters an RRC idle state.

[0117] After receiving the RRC connection release message, the UE can store the UE AS context, suspend the SRB and the DRB, and then enter an RRC idle state.

[0118] 6. Perform RRC connection resume at the original suspended base station

[0119] Taking the access network device as a base station as an example, performing the RRC connection resume can be divided into performing the RRC connection resume at the original suspended base station and performing the RRC connection resume at a non-original base station.

[0120] Taking the original suspended base station as an eNB as an example, FIG. 4 is a flowchart of performing the RRC connection resume at the original suspended base station. The flow of performing the RRC connection resume at the original suspended base station can include but is not limited to the following steps:

[0121] S400a: The UE sends a random access preamble (RA preamble) to the eNB. Correspondingly, the eNB receives the random access preamble from the UE. It should be noted that S400a is an optional step, that is, the UE can perform S400a or can not perform S400a. The steps shown by the dashed line in FIG. 4 are optional steps.

[0122] The RA preamble is used to request access to the network, that is, the main role of the RA preamble is to inform the eNB that there is a random access request, and to enable the eNB to estimate the transmission delay between the eNB and the UE.

[0123] S400b: The eNB sends a random access response to the UE. Correspondingly, the UE receives the random access response from the eNB. It should be noted that S400b is an optional step, that is, the eNB can perform S400b or not perform S400b.

[0124] After the eNB receives the RA preamble, the eNB can send a random access response (RAR) to the UE. Through S400a and S400b, the time synchronization of the uplink is mainly completed.

[0125] S401: The UE sends an RRC connection resume request to the eNB, and the RRC connection resume request includes a resume ID, a resume cause, and a short resume MAC-I. Correspondingly, the eNB receives the RRC connection resume request from the UE.

[0126] After the UE receives the random access response, the UE can send an RRC connection resume request (RRC Connection Resume Request) to the eNB of the original suspended RRC connection. The RRC connection resume request can include a resume ID, a resume cause, and a short resume MAC-I.

[0127] The short resume MAC-I can include but is not limited to the following information: an ID of a current cell, an ID of a cell of the original suspended RRC connection, and an ID of the UE in the cell of the original suspended RRC connection. The ID of the cell can be a physical cell identifier (PCI). The ID of the UE in the cell of the original suspended RRC connection can be a cell radio network temporary identifier (C-RNTI).

[0128] S402: The eNB sends an RRC connection resume message to the UE. Correspondingly, the UE receives the RRC connection resume message from the eNB.

[0129] After the eNB receives the RRC connection resume request, the eNB can verify the UE context according to the resume ID and the short resume MAC-I in the RRC connection resume request and the resume ID and the short resume MAC-I stored by the eNB; after the verification is successful, the eNB can send an RRC connection resume message to the UE.

[0130] S403: The UE resumes the SRB and the DRB, reestablishes the access layer security, and enters the RRC connected state.

[0131] S404: The UE sends an RRC connection resume complete message to the eNB. Correspondingly, the eNB receives the RRC connection resume complete message from the UE.

[0132] S405: The eNB sends a UE context resume request to the MME or the AMF. Correspondingly, the MME or the AMF receives the UE context resume request from the eNB.

[0133] If the core network accessed by the eNB is a 4G core network, the UE context resume request is used to request the MME to resume the UE context. If the core network accessed by the eNB is a 5G core network, the UE context resume request is used to request the AMF to resume the UE context.

[0134] S406: The MME or the AMF activates a bearer.

[0135] After the MME or the AMF resumes the UE context, the MME or the AMF can further activate a bearer.

[0136] The activation of the bearer can include activation of a user plane interface (S1-U) bearer, wherein the S1 interface is a communication interface between the eNB and the core network.

[0137] S407: The MME or the AMF sends a UE context resume response to the eNB. Correspondingly, the eNB receives the UE context resume response from the MME or the AMF.

[0138] After the eNB receives the UE context resume response from the MME, the eNB can indicate that the RRC connection is resumed under the eNB, and the UE can perform uplink and downlink transmission with the S-GW. After the eNB receives the UE context resume response from the AMF, the eNB can indicate that the RRC connection is resumed under the eNB, and the UE can perform uplink and downlink transmission with the UPF or the AMF.

[0139] S408: The UE performs uplink and downlink transmission with the S-GW, the UPF, or the AMF.

[0140] 7、In the non-original suspended base station, an RRC connection resume is performed

[0141] Exemplarily, taking an example of both the original suspending base station and the non-original suspending base station being eNBs, FIG. 5 is a flowchart of performing RRC connection resumption by the non-original suspending base station. In FIG. 5, the old eNB represents the original suspending base station, and the new eNB represents the base station performing RRC resumption. The old eNB and the new eNB are different base stations. The flow of performing RRC connection resumption by the non-original suspending base station can include, but is not limited to, the following steps:

[0142] S500a: The UE sends a random access preamble (RA preamble) to the new eNB. Correspondingly, the new eNB receives the random access preamble from the UE. It should be noted that S500a is an optional step, that is, the UE can perform S500a, or can not perform S500a. The steps shown by the dashed line in FIG. 5 are optional steps.

[0143] The RA preamble is used to request access to the network, that is, the main role of the RA preamble is to inform the new eNB that there is a random access request, and to enable the new eNB to estimate the transmission delay between the UE.

[0144] S500b: The new eNB sends a random access response to the UE. Correspondingly, the UE receives the random access response from the new eNB. It should be noted that S500b is an optional step, that is, the new eNB can perform S500b, or can not perform S500b.

[0145] After the new eNB receives the RA preamble, the new eNB can send a random access response (RAR) to the UE. Through S500a and S500b, the uplink time synchronization is mainly completed.

[0146] S501: The UE sends an RRC connection resumption request to the new eNB, and the RRC connection resumption request includes a resume identifier, a resume cause, and a short resume MAC-I. Correspondingly, the new eNB receives the RRC connection resumption request from the UE.

[0147] After the UE receives the random access response, the UE can send an RRC connection resumption request (RRC Connection Resume Request) to the new eNB (that is, the eNB that is not the original suspending RRC connection). The RRC connection resumption request can include a resume identifier (resume ID), a resume cause (resume Cause), and a short resume media access control identifier (short Resume MAC-I).

[0148] For details regarding the short resume MAC-I command, please refer to the specific description in S401 of Figure 4, which will not be repeated here.

[0149] S502: The new eNB sends a UE context acquisition request to the old eNB. Correspondingly, the old eNB receives the UE context acquisition request from the new eNB.

[0150] After receiving the RRC connection restoration request, the new eNB requests the UE context from the old eNB based on the resume id and short resume MAC-I in the RRC connection restoration request.

[0151] S503: The old eNB sends a UE context acquisition response to the new eNB, which includes the UE context. Correspondingly, the new eNB receives the UE context acquisition response from the old eNB.

[0152] The old eNB verifies the UE context based on the resume ID and short resume MAC-I in the RRC connection recovery request, as well as the resume ID and short resume MAC-I stored in itself; after successful verification, the old eNB can send the UE context to the new eNB.

[0153] S504: The new eNB sends an RRC connection restoration message to the UE. Correspondingly, the UE receives the RRC connection restoration message from the new eNB.

[0154] S505: The UE restores SRB and DRB and rebuilds access layer security; the UE enters RRC connected state.

[0155] S506: The UE sends an RRC connection restoration complete message to the new eNB. Correspondingly, the new eNB receives the RRC connection restoration complete message from the UE.

[0156] S507: The new eNB sends a path switching request to the MME or AMF. Correspondingly, the MME or AMF receives the path switching request from the new eNB.

[0157] If the new eNB accesses a 4G core network, it will send a path switching request to the MME. If the new eNB accesses a 5G core network, it will send a path switching request to the AMF.

[0158] After receiving the RRC connection restoration complete message, the new eNB requests a path switch to establish a connection with the MME or AMF and further activate the bearer.

[0159] S508: The MME or AMF activates the bearer.

[0160] S509: The MME or AMF sends a path switch request acknowledgement message to the new eNB. Correspondingly, the new eNB receives the path switch request acknowledgement message.

[0161] After the MME or AMF activates the bearer, the MME or AMF can send a path switch request acknowledgement message (Path Switch Request ACK) to the new eNB.

[0162] S510: The new eNB sends a UE context release message to the old eNB. Correspondingly, the old eNB receives the UE context release message from the new eNB.

[0163] After receiving the UE context release message, the old eNB can release the UE context.

[0164] S511: The UE performs uplink and downlink transmission with the S-GW, UPF or AMF.

[0165] 8. Method for processing after RRC connection recovery failure

[0166] In a possible implementation, after receiving an RRC connection recovery request from a terminal device, if the RRC connection fails to be recovered, the access network device (such as a base station that originally suspends the RRC connection or a base station that performs RRC recovery) can send an RRC connection rejection (RRC connection Reject) message to the terminal device. The RRC connection rejection message can include an extended wait time (extendedWaitTime).

[0167] If the RRC connection rejection message indicates RRC suspension (rrc-Suspend), the terminal device can continue to save the UE access layer context, and then re-initiate RRC connection recovery after the indicated wait time.

[0168] If the RRC connection rejection message does not indicate RRC suspension (rrc-Suspend), the terminal device can discard the previously saved recovery identifier and UE access layer context, and enter an RRC idle state.

[0169] In another possible implementation, after receiving an RRC connection recovery request from a terminal device, if the RRC connection fails to be recovered, the access network device (such as a base station that originally suspends the RRC connection or a base station that performs RRC recovery) can send an RRC connection setup (RRC Setup) message to the terminal device. The reason why the access network device sends the RRC connection setup message can include that the access network device fails to obtain the UE access layer context.

[0170] The above is a brief introduction of some concepts or technologies involved in the embodiments of the present application.

[0171] Next, the system architecture involved in the embodiments of the present application is described.

[0172] The embodiments of the present application can be applied to a wireless communication system such as an LTE system, a 5G system, a 6G system or a communication system evolved after 6G, satellite communication, etc.

[0173] The embodiments of the present application can be applied to the system architecture shown in FIG. 6.

[0174] The system architecture shown in FIG. 6 can include, but is not limited to, a terminal device, a satellite a, a first access network device deployed on the satellite a, a gateway a, a satellite b, a second access network device deployed on the satellite b, a gateway b, and a core network element.

[0175] As shown in FIG. 6, the first access network device suspends the RRC connection of the terminal device, and then the terminal device can request the first access network device to perform RRC connection recovery, or the terminal device can request the second access network device to perform RRC connection recovery.

[0176] The core network element in FIG. 6 can be a core network element in an LTE system, a core network element in a 5G system, a core network element in a 6G system, or a core network element in a communication system evolved after 6G.

[0177] Taking the core network element in FIG. 6 as a core network element in an LTE system as an example, the core network element in FIG. 6 can be specifically an MME. Taking the core network element in FIG. 6 as a core network element in a 5G system as an example, the core network element in FIG. 6 can be specifically an AMF.

[0178] It should be noted that the first access network device and the second access network device can be deployed on the same satellite, or can be deployed on different satellites. The satellite a and the satellite b shown in FIG. 6 are different satellites, which do not constitute a limitation on the embodiments of the present application. In other possible implementation manners, the satellite a and the satellite b can be the same satellite. Similarly, the gateway a and the gateway b shown in FIG. 6 are different gateways, which do not constitute a limitation on the embodiments of the present application. In other possible implementation manners, the gateway a and the gateway b can be the same gateway.

[0179] It should be further noted that one or more access network devices can be deployed on one satellite.

[0180] It can be understood that the system architecture described in the embodiments of the present application is for more clearly illustrating the technical solutions of the embodiments of the present application, and does not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of system architecture and the appearance of new business scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0181] In the store-and-forward scenario, the service link and the feeder link of the same satellite cannot be in the available state at the same time. The service link refers to the link between the satellite and the terminal device, and the feeder link refers to the link between the satellite and the NTN gateway. For example, in the t1-t2 time, the service link of the satellite is in the available state, but the feeder link of the satellite is in the unavailable state; in the t3-t4 time, the service link of the satellite is in the unavailable state, and the feeder link of the satellite is in the available state. In the store-and-forward scenario, it can cause a low success rate of recovering the RRC connection.

[0182] The RRC connection recovery method provided by the embodiments of the present application will be described in detail below based on the system architecture shown in FIG. 6. By executing the RRC connection recovery method, the first access network device can send the recovery information to the mobility management network element in advance, which is beneficial for other access network devices to obtain the recovery information from the mobility management network element and store the recovery information in advance, thereby being beneficial for improving the success rate of recovering the RRC connection in the store-and-forward scenario.

[0183] The first terminal device in the following embodiments (the embodiments corresponding to FIGS. 7-12 described below) can be the terminal device in the network architecture shown in FIG. 6. The functions performed by the first terminal device in this embodiment can also be performed by a device (for example, a chip, or a chip system, or a circuit) in the first terminal device.

[0184] The first access network device in the following embodiments can be the first access network device in the network architecture shown in FIG. 6. The functions performed by the first access network device in this embodiment can also be performed by a device (for example, a chip, or a chip system, or a circuit) in the first access network device.

[0185] The second access network device in the following embodiments can be the second access network device in the network architecture shown in FIG. 6. The functions performed by the second access network device in this embodiment can also be performed by a device (for example, a chip, or a chip system, or a circuit) in the second access network device.

[0186] The core network device in the following embodiments can be a core network device in the network architecture shown in FIG. 6, and the functions performed by the core network device in the embodiments can also be performed by an apparatus (for example, a chip, or a chip system, or a circuit) in the core network device. The following embodiments take a mobility management network element as an example, which can be an MME in an LTE system, an AMF in a 5G system, or a mobility management network element in a 6G system or a communication system evolved after 6G.

[0187] The embodiments of the present application are uniformly described here, and will not be repeated later.

[0188] Please refer to FIG. 7, which is a flowchart of an RRC connection recovery method provided by an embodiment of the present application. The RRC connection recovery method can be applied to a store-and-forward scenario. As shown in FIG. 7, the RRC connection recovery method can include but is not limited to the following steps.

[0189] S701: In response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the first access network device sends recovery information to the mobility management network element, where the recovery information is used to recover the RRC connection of the first terminal device suspended under the first access network device. Correspondingly, the mobility management network element receives the recovery information from the first access network device.

[0190] As known from the foregoing, in the store-and-forward scenario, the service link and the feeder link cannot be in the available state at the same time. The service link of the satellite to which a certain access network device (for example, the first access network device, the second access network device mentioned below) belongs refers to the link between the satellite to which the access network device belongs and the first terminal device. The feeder link of the satellite to which the access network device belongs refers to the link between the satellite to which the access network device belongs and the NTN gateway.

[0191] It can be understood that the service link of the satellite to which a certain access network device (for example, the first access network device, the second access network device mentioned below) belongs being in communication can mean that the feeder link of the satellite to which the access network device belongs is not in communication. Similarly, the feeder link of the satellite to which the access network device belongs being in communication can mean that the service link of the satellite to which the access network device belongs is not in communication.

[0192] The link connectivity between the satellite to which the certain access network device (e.g., the first access network device, the second access network device mentioned below) belongs and the mobility management network element can represent that the feeder link of the satellite to which the access network device belongs is connected, and the link connectivity between the NTN gateway and the mobility management network element. Therefore, the link connectivity between the satellite to which the certain access network device (e.g., the first access network device, the second access network device mentioned below) belongs and the mobility management network element can represent that the feeder link of the satellite to which the access network device belongs is connected, and the service link of the satellite to which the first access network device belongs is not connected. Similarly, the service link connectivity of the satellite to which the certain access network device (e.g., the first access network device, the second access network device mentioned below) belongs can represent that the feeder link of the satellite to which the access network device belongs is not connected, that is, the link between the satellite to which the access network device belongs and the mobility management network element is also not connected.

[0193] It should be noted that the connectivity status of the feeder link and the service link of the satellite to which the access network device belongs is indicated by the dashed line in FIGS. 7-12. Only when the corresponding link is connected, transmission can be performed through the link. It can be understood that if data needs to be transmitted through a certain link, but the link is currently not connected, the data needs to be transmitted after the link is connected. Before the link is connected, the satellite to which the access network device belongs can store the data. The present application makes a unified description here, and the following will not be repeated.

[0194] Specifically, optionally, in the case that the feeder link of the first access network device is connected, after the first access network device establishes an S1 connection with the mobility management network element, the first access network device can send recovery information to the mobility management network element through the NTN gateway. The recovery information is used to recover the RRC connection of the first terminal device suspended under the first access network device, or in other words, the recovery information includes information required to recover the RRC connection of the first terminal device to other access network devices. That is, which access network device or access network devices obtain the recovery information, then the access network device can support recovering the RRC connection of the first terminal device, or in other words, the first terminal device can recover the RRC connection under the access network device. Wherein, the S1 interface is the communication interface between the first access network device and the mobility management network element.

[0195] Optionally, before S701, in the case that the first access network device determines to suspend the RRC connection of the first terminal device, the service link of the satellite to which the first access network device belongs is connected, but the feeder link of the satellite to which the first access network device belongs is not connected, in this case, the first access network device can skip (i.e. not perform) the step of requesting the mobile management network element to suspend the UE context, and send an RRC connection release message to the first terminal device through the connected service link, the RRC connection release message including a resume identifier (hereinafter referred to as a first resume identifier) and a release cause, the release cause being RRC suspend (rrc-suspend). Correspondingly, after the first terminal device receives the RRC connection release message, the first terminal device can store the access layer context of the first terminal device, suspend the SRB and the DRB, and enter the RRC idle state. That is, in the case that the first access network device determines to suspend the RRC connection of the first terminal device, the first access network device can skip S302-S304 shown in FIG. 3, and directly perform S305 and S306. In this way, S302-S304 do not need to be performed after the feeder link of the satellite to which the first access network device belongs is connected, and S305 does not need to be performed after S304 is performed, and the service link of the satellite to which the first access network device belongs is connected. Instead, S305 is directly performed using the currently connected service link, thereby facilitating improvement of the efficiency of suspending the RRC connection.

[0196] The resume information can include, but is not limited to, one or more of the following: a resume identifier (hereinafter referred to as a first resume identifier), a parameter (hereinafter referred to as a first parameter) of a token used for authentication, a context of the first terminal device, an identifier of the satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a historical cell accessed by the first terminal device most recently, a next hop (NH) parameter used for encryption and integrity protection after resuming the connection, and a next hop chaining counter (NCC) used for encryption and integrity protection after resuming the connection. The historical cell accessed by the first terminal device most recently can be understood as a cell accessed by the first terminal device before the RRC of the first terminal device is suspended, i.e. an original cell corresponding to the first terminal device. The identifier of the cell can be a physical cell identifier (PCI) of the cell or other information that can identify the cell.

[0197] The first parameter can be sent by the first terminal device to the first access network device in a process in which the first terminal device accesses the first access network device, and thus the first access network device stores the first parameter. The first parameter can include a short resume media access control identifier (short Resume MAC-I) or a resume media access control identifier (Resume MAC-I). For example, in the case of application to an LTE system, the first parameter can be a short Resume MAC-I; in the case of application to a 5G system, the first parameter can be a Resume MAC-I.

[0198] Optionally, the first parameter can be a sequence, and the number of bits occupied by the first parameter is not limited in the embodiments of the present application. For example, the first parameter can be a 16-bit sequence, or the first parameter can be a sequence of more than 16 bits.

[0199] S702: In response to the link between the mobility management network element and the satellite to which the second access network device belongs being connected, the mobility management network element sends the recovery information to the second access network device. Correspondingly, the second access network device receives the recovery information from the mobility management network element.

[0200] After the mobility management network element receives the recovery information, assuming that the link between the mobility management network element and the satellite to which the second access network device belongs is connected, and the second access network device establishes an S1 connection with the mobility management network element, the mobility management network element can send the recovery information to the second access network device.

[0201] Optionally, the second access network device can send the recovery information to one or more access network devices (hereinafter referred to as M access network devices, M being a positive integer), and the second access network device is one of the M access network devices.

[0202] Optionally, the M access network devices can be determined by the mobility management network element itself. For example, the M access network devices can include access network devices whose links with the mobility management network element are connected, that is, after the mobility management network element receives the recovery information, the mobility management network element can determine part or all of the one or more access network devices whose links with the mobility management network element are connected as the M access network devices.

[0203] Optionally, the first access network device can indicate the M access network devices to the mobility management network element, i.e., the first access network device indicates to the mobility management network element which access network device(s) to send the recovery information to. Specifically, in response to the link between the satellite to which the first access network device belongs and the mobility management network element being connected, the first access network device can send second indication information to the mobility management network element, the second indication information indicating that the mobility management network element sends the recovery information to the M access network devices. Correspondingly, the mobility management network element receives the second indication information and learns which access network device(s) the recovery information needs to be sent to.

[0204] Optionally, the first access network device can determine the M access network devices based on ephemeris information and indicate the M access network devices to the mobility management network element. Alternatively, the satellite to which the first access network device belongs determines the M access network devices based on ephemeris information and supports the M access network devices to the first access network device. Further, the first access network device indicates the M access network devices to the mobility management network element. Alternatively, the first access network device receives assistance information from the mobility management network element, determines the M access network devices based on the assistance information, and the assistance information is used to determine which access network device(s) the context (including the context of the first terminal device) suspended under the first access network device needs to be transmitted to. Optionally, the assistance information can be received in the case that the first access network device is in a connected state with the mobility management network element for the last time.

[0205] Ephemeris information refers to the accurate position or trajectory table of a celestial body changing with time in Global Positioning System (GPS) measurement. The ephemeris information is a function of time. The ephemeris information can accurately calculate, predict, depict, and track the time, position, speed, and other operating states of satellites and flying bodies; and can express the accurate parameters of celestial bodies, satellites, spacecraft, missiles, space junk, and other flying bodies.

[0206] Optionally, the second indication information can include the identity of each access network device in the M access network devices and / or the identity of the satellite to which each access network device in the M access network devices belongs. For example, taking the case that the second indication information includes the identity of the satellite to which each access network device in the M access network devices belongs as an example, after the mobility management network element receives the second indication information, based on the satellite identity, the mobility management network element can learn to send the recovery information to the access network device deployed on the satellite.

[0207] Optionally, the identity of the M access network devices and / or the identity of the satellite to which the M access network devices belong can be organized in the form of a table, in the form of a set, or in other ways, which are not limited by the embodiments of the present application.

[0208] Optionally, the second indication information can be sent together with the recovery information or separately, and the embodiments of the present application do not make any limitation in this aspect.

[0209] S703: The second access network device stores the recovery information.

[0210] After receiving the recovery information, the second access network device can store the recovery information. After obtaining the recovery information, the second access network device can support the recovery of the RRC connection of the first terminal device.

[0211] Optionally, the second access network device can store the recovery information in the memory of the second access network device or in the cloud storage space accessible by the second access network device, and the embodiments of the present application do not make any limitation in this aspect.

[0212] S704: In response to the link between the first terminal device and the satellite to which the second access network device belongs being connected, the first terminal device sends a resume request to the second access network device, and the resume request is used to request the recovery of the RRC connection of the first terminal device. Correspondingly, the second access network device receives the resume request from the first terminal device.

[0213] When the first terminal device decides to initiate the recovery of the RRC connection, and the link between the first terminal device and the satellite to which the second access network device belongs is connected (i.e., the service link of the satellite to which the second access network device belongs is connected, and the feeder link of the satellite to which the second access network device belongs is not connected), the first terminal device can send a resume request to the second access network device that stores the recovery information. Since the second access network device stores the recovery information of the first terminal device, it is beneficial to improve the success rate of the recovery of the RRC connection.

[0214] Optionally, there can be one or more links between the satellite to which the access network device belongs and the first terminal device connected at the same time, and the first terminal device can randomly select one access network device from the one or more access network devices as the second access network device and attempt to recover the RRC connection under the second access network device. Alternatively, the first terminal device can determine the access network device with the highest signal strength as the second access network device in the order from high to low of the signal strength between the access network device and the first terminal device. Alternatively, the first terminal device can determine the second access network device according to the indication of the first access network device, and the specific description can be referred to in the corresponding embodiment of FIG. 8. Optionally, the first terminal device can attempt to recover the RRC connection under each access network device in turn until the RRC connection is successfully recovered under a certain access network device.

[0215] Optionally, the resume request can include, but is not limited to, one or more of the following: a resume identity, a parameter for authentication, and a resume cause. To distinguish from the resume identity (i.e., the first resume identity) in the resume information, the resume identity in the resume request is referred to as the second resume identity hereinafter. To distinguish from the parameter for authentication (i.e., the first parameter) in the resume information, the parameter for authentication in the resume request is referred to as the second parameter hereinafter.

[0216] The second parameter can include a short Resume MAC-I or a Resume MAC-I. For example, in the case of applying to an LTE system, the second parameter can be a short Resume MAC-I; in the case of applying to a 5G system, the second parameter can be a Resume MAC-I.

[0217] Optionally, before S704, S500a-S500b can also be performed, which are described above and will not be repeated here.

[0218] S705: The second access network device verifies the first terminal device based on the stored resume information and the information in the resume request.

[0219] After receiving the resume request, the second access network device can verify the first terminal device based on the stored resume information and the information in the resume request. For example, the second access network device verifies the first terminal device based on the first resume identity, the first parameter, the second resume identity, and the second parameter.

[0220] If the second access network device verifies the first terminal device successfully, it means that the RRC connection recovery is successful, and the recovery process is completed. If the second access network device verifies the first terminal device unsuccessfully, it means that the RRC connection recovery fails.

[0221] In one possible implementation, after receiving the resume request, if the second access network device has not obtained the resume information of the first terminal device, the second access network device can perform the processing method after the RRC connection recovery fails, which is described above and will not be repeated here.

[0222] S706: In response to verifying the first terminal device successfully, the second access network device sends an RRC connection resume message to the first terminal device. Correspondingly, the first terminal device receives the RRC connection resume message from the second access network device.

[0223] Optionally, after S706, S505-S511 can also be performed, which are described above and will not be repeated here.

[0224] In the embodiments of the present application, the first access network device sends the recovery information to the mobility management network element in advance, which is beneficial for other access network devices (such as the second access network device) to obtain the recovery information from the mobility management network element, and the number of access network devices that have the recovery information is increased, thereby being beneficial for improving the success rate of recovering the RRC connection in the store-and-forward scenario.

[0225] Please refer to FIG. 8, which is a flowchart of another method for recovering an RRC connection provided in the embodiments of the present application. The method mainly describes that the first access network device indicates to the first terminal device which access network device or which access network devices support recovering the RRC connection of the first terminal device. As shown in FIG. 8, the method for recovering an RRC connection can include S701-S706 in the corresponding embodiment of FIG. 7, and can further include but is not limited to the following steps (represented by thick lines in FIG. 8). The specific content of S701-S706 can be referred to the detailed description in the corresponding embodiment of FIG. 7, which will not be repeated here.

[0226] S800: In response to the link between the satellite to which the first access network device belongs and the first terminal device being connected, the first access network device sends first indication information to the first terminal device, and the first indication information indicates at least one or more of the following: supporting a store-and-forward mode, supporting recovering the RRC connection of the first terminal device by M access network devices. Correspondingly, the first terminal device receives the first indication information from the first access network device.

[0227] S800 can be performed before S701.

[0228] The first access network device indicates to the first terminal device that the M access network devices support recovering the RRC connection of the first terminal device, so that when the first terminal device needs to recover the RRC connection, the RRC connection of the first terminal device can be successfully recovered by initiating an RRC connection recovery to any one of the M access network devices, which is beneficial for improving the success rate of recovering the RRC connection. Wherein, M is a positive integer.

[0229] The "supporting a store-and-forward mode" indicated by the first indication information means that the satellite to which the first access network device belongs supports the store-and-forward mode, or in other words, the first access network device supports the store-and-forward mode.

[0230] In the embodiments of the present application, the following descriptions represent the same meaning and can be used interchangeably: the satellite to which the access network device (such as the first access network device or the second access network device) belongs supports the store-and-forward mode; the access network device supports the store-and-forward mode; the satellite to which the access network device belongs supports the store-and-forward scenario; the access network device supports the store-and-forward scenario; the service link and the feeder link of the satellite to which the access network device belongs are not simultaneously in an available state.

[0231] The first access network device is not included in the M access network devices, and the first indication information indicating that the M access network devices support resuming the RRC connection of the first terminal device can also be described as: supporting resuming the RRC connection of the first terminal device under other access network devices; or supporting the first terminal device resuming the RRC connection of the first terminal device under other access network devices; or supporting resuming to other access network devices; or other access network devices storing resuming information of the first terminal device. The other access network devices refer to part or all of the access network devices other than the first access network device.

[0232] Optionally, the first indication information can be carried in an RRC connection release message (the release reason is RRC suspension), or the first indication information can be carried in other dedicated RRC signaling (such as RRC signaling a). The RRC signaling a can be sent by the first access network device to the first terminal device before suspending the RRC connection. In other words, the first indication information can be sent together with the RRC connection release message or separately.

[0233] Optionally, the first indication information can also indicate one or more of the following: an identifier of each access network device in the M access network devices; an identifier of a satellite to which each access network device in the M access network devices belongs; a first time period corresponding to each access network device in the M access network devices, wherein the RRC connection of the first terminal device is supported to be resumed at the access network device in the first time period corresponding to the access network device; and a start time of the first time period corresponding to each access network device in the M access network devices.

[0234] For example, taking the first indication information including the identifier of the satellite to which each access network device in the M access network devices belongs as an example, after the first terminal device receives the first indication information, based on the satellite identifier, it can be known that the access network device deployed on the satellite supports resuming the RRC connection of the first terminal device, or it can be known that the access network device deployed on the satellite stores the resuming information of the first terminal device.

[0235] For example, taking one access network device (such as access network device a) in the M access network devices as an example, the first time period corresponding to the access network device a refers to a time period in which the access network device a can perform RRC connection resumption, that is, the RRC connection of the first terminal device is supported to be resumed at the access network device a in the first time period corresponding to the access network device a. The start time of the first time period corresponding to the access network device a refers to the earliest time at which the access network device a can perform RRC connection resumption.

[0236] Optionally, the identity of the M access network devices and / or the identity of the satellite to which the M access network devices belong indicated by the first indication information can be organized in a form of a table, in a form of a set, or in other forms, and the embodiments of the present application do not limit this.

[0237] In a possible implementation, the first indication information can be determined based on ephemeris information, or in other words, the M access network devices can be determined based on ephemeris information. For example, the first access network device can determine the M access network devices based on ephemeris information, and indicate the M access network devices to the first terminal device. Alternatively, the satellite to which the first access network device belongs determines the M access network devices based on ephemeris information, and supports the M access network devices to the first access network device. Further, the first access network device indicates the M access network devices to the first terminal device.

[0238] In a possible implementation, in response to the link between the satellite to which the first access network device belongs and the mobility management network element being connected, the first access network device can receive third indication information from the mobility management network element, the third indication information being used to determine the first indication information, or in other words, the third indication information being used to determine the M access network devices. Optionally, the third indication information can be received in the case that the first access network device is in a connected state with the mobility management network element for the last time.

[0239] Optionally, the RRC connection resuming method can further include S801. It should be noted that S801 is an optional step, that is, the first access network device can execute S801, or can not execute S801, and the steps shown by the dashed line in FIG. 8 are optional steps.

[0240] S801: In response to the link between the satellite to which the first access network device belongs and the mobility management network element being connected, the first access network device can send second indication information to the mobility management network element, the second indication information indicating that the mobility management network element sends resuming information to the M access network devices. Correspondingly, the mobility management network element receives the second indication information from the first access network device.

[0241] It should be noted that the second indication information can be sent together with the resuming information, that is, S801 and S701 can be executed at the same time. Alternatively, the second indication information can be sent separately from the resuming information, that is, S801 can be executed first and then S701 can be executed, or S701 can be executed first and then S801 can be executed.

[0242] By performing S801, the first access network device can indicate the M access network devices to the mobility management network element, that is, the first access network device indicates to the mobility management network element which access network device or which access network devices to send the recovery information to, further, the M access network devices respectively receive the recovery information from the mobility management network element, and store the received recovery information, in this case, the M access network devices all save the recovery information, so that the M access network devices all support the recovery of the RRC connection of the first terminal device, and as the number of access network devices that save the recovery information increases, the success rate of the recovery of the RRC connection in the store-and-forward scenario is improved.

[0243] For other contents of the second indication information, refer to the specific description of S702 in the corresponding embodiment of FIG. 7, which will not be repeated here.

[0244] Optionally, taking the M access network devices including the second access network device and the third access network device as an example, the RRC connection recovery method can further include S802-S803. It should be noted that S802-S803 are optional steps, that is, S802-S803 can be performed or not performed. It should be further noted that S802-S803 are similar to S702-S703 in the corresponding embodiment of FIG. 7, and refer to the specific description in S702-S703, which will not be repeated here. It should be further noted that the number of the third access network devices can be one or more, and FIG. 8 takes the number of the third access network devices as one for description, which does not constitute a limitation to the embodiments of the present application.

[0245] S802: In response to the link between the mobility management network element and the satellite to which the third access network device belongs being connected, the mobility management network element sends the recovery information to the third access network device. Correspondingly, the third access network device receives the recovery information from the mobility management network element.

[0246] S803: The third access network device stores the recovery information.

[0247] Optionally, the RRC connection recovery method can further include S804-S806. It should be noted that S804-S806 are optional steps, that is, S804-S806 can be performed or not performed.

[0248] S804: In response to the link between the satellite to which the second access network device belongs and the mobility management network element being connected, the second access network device sends sixth indication information to the mobility management network element, the sixth indication information indicating the third access network device storing the recovery information to release the recovery information or indicating the completion of the RRC connection recovery at the second access network device. Correspondingly, the mobility management network element receives the sixth indication information from the second access network device.

[0249] After receiving the sixth indication information, the mobility management network element can learn that the RRC connection of the first terminal device is resumed at the second access network device, so that the resume information stored in the third access network device (i.e., the other access network devices in the M access network devices except the second access network device) is not needed. In this case, the mobility management network element instructs the third access network device to release the resume information, which can avoid wasting the storage resources of the third access network device and is beneficial to improve the utilization rate of the storage resources of the third access network device.

[0250] S805: In response to the link between the mobility management network element and the satellite to which the third access network device belongs being connected, the mobility management network element sends seventh indication information to the third access network device, where the seventh indication information indicates the third access network device to release the resume information or indicates that the RRC connection resume is completed at the second access network device. Correspondingly, the third access network device receives the seventh indication information from the mobility management network element.

[0251] S806: The third access network device releases the resume information.

[0252] After receiving the seventh indication information, the third access network device can release the resume information, i.e., release the first resume identifier, the first parameter of the token used for authentication, and the context of the first terminal device in the resume information. Optionally, releasing the resume information can mean deleting the resume information.

[0253] In the embodiments of the present application, the first access network device indicates that the M access network devices support resuming the RRC connection of the first terminal device to the first terminal device, so that when the first terminal device needs to resume the RRC connection, the RRC connection of the first terminal device can be successfully resumed by initiating the RRC connection resume to any one of the M access network devices, which is beneficial to improve the success rate of resuming the RRC connection.

[0254] Please refer to FIG. 9, which is a flowchart of another method for resuming the RRC connection according to an embodiment of the present application. The method mainly describes that the second access network device broadcasts an indication that it supports resuming the RRC connection suspended under which access network device or access network devices. As shown in FIG. 9, the method for resuming the RRC connection can include S701-S706 in the embodiment corresponding to FIG. 7, and can further include but is not limited to the following steps (represented by thick lines in FIG. 9). The specific content of S701-S706 can be referred to the detailed description in the embodiment corresponding to FIG. 7, which will not be repeated here.

[0255] S900: The second access network device broadcasts fourth indication information, and the fourth indication information indicates that the second access network device supports resuming the RRC connection suspended under any one of the N access network devices, where the N access network devices at least include the first access network device. Correspondingly, the first terminal device receives the fourth indication information broadcast by the second access network device.

[0256] S900 can be executed after S702. The embodiments of the present application do not limit the execution sequence between S900 and S702. S900 can be executed first, or S702 can be executed first, or S900 and S702 can be executed simultaneously.

[0257] The fourth indication information can also be described as: the second access network device stores the resumption information of the terminal device suspended under any one of the N access network devices.

[0258] The second access network device broadcasts the fourth indication information. It can be understood that the terminal device in communication with the link between the satellite to which the second access network device belongs can receive the fourth indication information, and the number of the terminal device in communication with the link between the satellite to which the second access network device belongs can be one or more, and the one or more terminal devices at least include the first terminal device. That is, in response to the link between the first terminal device and the satellite to which the second access network device belongs being in communication, the first terminal device can receive the fourth indication information.

[0259] The second access network device broadcasts the fourth indication information, which can indicate which RRC connection suspended under which access network device (i.e., the N access network devices, where N is a positive integer) is supported to be resumed by the current access network device (i.e., the second access network device). The first terminal device knows that the RRC connection suspended under the first access network device, and therefore, after receiving the fourth indication information, the first terminal device can determine whether the N access network devices include the first access network device. If the N access network devices include the first access network device, it indicates that the second access network device supports resuming the RRC connection suspended under the first access network device, and the RRC connection suspended under the first access network device at least includes the RRC connection of the first terminal device, that is, if the N access network devices include the first access network device, it indicates that the second access network device supports resuming the RRC connection of the first terminal device. If the N access network devices do not include the first access network device, it indicates that the second access network device does not support resuming the RRC connection suspended under the first access network device, that is, the second access network device does not support resuming the RRC connection of the first terminal device.

[0260] Optionally, the first terminal device can store the identity of the access network device suspending the RRC connection of the first terminal device and / or the identity of the satellite to which the access network device belongs, that is, the first terminal device can store the identity of the first access network and / or the identity of the satellite to which the first access network device belongs. In this way, the first terminal device can know the RRC connection suspended under which access network device, or in other words, the first terminal device can know the RRC connection suspended under which access network device deployed on which satellite.

[0261] In response to the second access network device supporting the resumption of the RRC connection of the first terminal device and the link between the first terminal device and the satellite to which the second access network device belongs being in communication, the first terminal device can send a resumption request to the second access network device (that is, perform S704).

[0262] Optionally, the fourth indication information can include the identity (such as an eNB identity) of each of the N access network devices and / or the identity of the satellite to which each of the N access network devices belongs. For example, taking the fourth indication information including the identity of the satellite to which each of the N access network devices belongs as an example, after the first terminal device receives the fourth indication information, the first terminal device can learn, based on the satellite identity, that the second access network device supports the resumption of the RRC connection suspended under the access network devices deployed on these satellites. If the first access network device is deployed on the satellite indicated by any of the satellite identities, it means that the second access network device supports the resumption of the RRC connection of the first terminal device.

[0263] Optionally, the identity of the N access network devices and / or the identity of the satellite to which the N access network devices belong can be organized in the form of a table, in the form of a set, or in other ways, which are not limited by the embodiments of the present application.

[0264] In the embodiments of the present application, the second access network device broadcasts the fourth indication information, so that the first terminal device can determine, based on the fourth indication information, whether the second access network device supports the resumption of the RRC connection of the first terminal device, and then the first terminal device can initiate the RRC connection resumption to the second access network device in the case that the second access network device supports the resumption of the RRC connection of the first terminal device, which is conducive to improving the success rate of resuming the RRC connection.

[0265] Please refer to FIG. 10, which is a flow diagram of another method for RRC connection resumption provided in the embodiments of the present application. The method mainly describes that the second access network device indicates whether it supports resuming the RRC connection of the first terminal device through a paging message. As shown in FIG. 10, the method for RRC connection resumption can include S701-S706 in the corresponding embodiment of FIG. 7, and can further include but is not limited to the following steps (represented by thick lines in FIG. 10). The specific contents of S701-S706 can be referred to the detailed description in the corresponding embodiment of FIG. 7, which will not be repeated here.

[0266] S1000: In response to the link between the satellite to which the second access network device belongs and the mobility management network element being connected, the mobility management network element sends a first paging message for paging the first terminal device to the second access network device. Correspondingly, the second access network device receives the first paging message for paging the first terminal device from the mobility management network element.

[0267] It should be noted that the execution sequence between S1000 and S702 is not limited in the embodiments of the present application. S1000 can be executed first, or S702 can be executed first, or S1000 and S702 can be executed simultaneously.

[0268] The first paging message can be used for paging one or more terminal devices (hereinafter referred to as P terminal devices, P is a positive integer), and the P terminal devices can at least include the first terminal device. The first paging message can include the identity of each terminal device in the P terminal devices that are paged.

[0269] After the second access network device receives the first paging message for paging the first terminal device, it judges whether the stored resumption information includes the resumption information of any terminal device that is paged based on the identity of the P terminal devices. If the stored resumption information includes the resumption information of some terminal device or terminal devices that are paged, the second access network device can carry an indication in the paging message sent to the terminal device or terminal devices, indicating that the terminal device or terminal devices can send a resumption request to the second access network device.

[0270] S1001: In response to the second access network device storing the resumption information of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device being connected, the second access network device sends a second paging message to the first terminal device, and the second paging message includes fifth indication information indicating that the first terminal device sends a resumption request. Correspondingly, the first terminal device receives the second paging message from the second access network device.

[0271] It should be noted that S1001 can be executed after S703.

[0272] The second access network device can carry fifth indication information in the second paging message sent to the first terminal device, where the fifth indication information indicates that the first terminal device sends a recovery request.

[0273] Optionally, the fifth indication information can also indicate that the second access network device supports recovery of the RRC connection of the first terminal device, or the second access network device stores the recovery information of the first terminal device.

[0274] It should be noted that the second paging message can be obtained by adding the fifth indication information to the first paging message.

[0275] After the first terminal device receives the second paging message, in response to the fact that the link between the satellite to which the second access network device belongs and the first terminal device is in communication, the first terminal device can send a recovery request to the second access network device (i.e., perform S704).

[0276] Optionally, in response to the fact that the second access network device does not store the recovery information of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device is in communication, the second access network device can send the first terminal device the first paging message. Correspondingly, after the first terminal device receives the first paging message from the second access network device, in response to the fact that the link between the satellite to which the second access network device belongs and the first terminal device is in communication, the first terminal device can initiate an RRC connection establishment message to the second access network device, where the RRC connection establishment message is used to request establishment of a new RRC connection between the first terminal device and the second access network device.

[0277] Optionally, in response to the fact that the second access network device does not store the recovery information of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device is in communication, the second access network device can send the first terminal device a third paging message, where the third paging message includes eighth indication information, and the eighth indication information indicates that the second access network device does not store the recovery information of the first terminal device, or the eighth indication information indicates that the second access network device does not support recovery of the RRC connection of the first terminal device. Correspondingly, after the first terminal device receives the third paging message from the second access network device, in response to the fact that the link between the satellite to which the second access network device belongs and the first terminal device is in communication, the first terminal device can initiate an RRC connection establishment message to the second access network device.

[0278] It should be noted that the third paging message can be obtained by adding the eighth indication information to the first paging message.

[0279] In the embodiments of the present application, the second access network device indicates whether the second access network device supports resuming the RRC connection of the first terminal device through the paging message, and then the first terminal device can initiate the RRC connection resumption to the second access network device in the case that the second access network device supports resuming the RRC connection of the first terminal device, which is beneficial to improve the success rate of resuming the RRC connection and save the signaling overhead.

[0280] Please refer to FIG. 11, which is a flow diagram of another method for resuming the RRC connection provided in the embodiments of the present application. The method mainly describes that the first access network device supports resuming only the RRC connection suspended under the first access network device through the broadcast indication. As shown in FIG. 11, the method for resuming the RRC connection can include S701-S703 in the corresponding embodiment of FIG. 7, and can further include but not limited to the following steps (represented by thick lines in FIG. 11). The specific contents of S701-S703 can be referred to the detailed description in the corresponding embodiment of FIG. 7, and will not be repeated here.

[0281] S1100: The first access network device broadcasts the ninth indication information, and the ninth indication information indicates that the RRC connection suspended under the first access network device is supported. Correspondingly, the first terminal device receives the ninth indication information broadcast by the first access network device.

[0282] The embodiments of the present application do not limit the execution order between S1100 and any one of S701-S703. For example, S1100 can be executed before S701, or S1100 can be executed after S703, or S1100 can be executed before any one of S701-S703, or S1100 can be executed after any one of S701-S703.

[0283] The ninth indication information can also be described as: supporting the resumption of the RRC connection of the terminal device suspended under the first access network device; or storing only the resumption information of the terminal device suspended under the first access network device.

[0284] As described in S900 in the corresponding embodiment of FIG. 9, the first terminal device can know the RRC connection suspended under which access network device, or in other words, the first terminal device can know the RRC connection suspended under which access network device deployed on which satellite. Therefore, after receiving the ninth indication information, the first terminal device can determine whether the access network device broadcasting the ninth indication information is the same as the access network device suspending the RRC connection of the first terminal device. If the access network device broadcasting the ninth indication information is the same as the access network device suspending the RRC connection of the first terminal device, it indicates that the access network device broadcasting the ninth indication information can support resuming the RRC connection of the first terminal device. Further, in response to the link between the satellite to which the first access network device belongs and the first terminal device being connected, the first terminal device can send an RRC connection resume request to the first access network device.

[0285] If the access network device broadcasting the ninth indication information is different from the access network device suspending the RRC connection of the first terminal device, it indicates that the access network device broadcasting the ninth indication information does not support resuming the RRC connection of the first terminal device.

[0286] S1101: In response to the link between the satellite to which the first access network device belongs and the first terminal device being connected, the first terminal device sends an RRC connection resume request to the first access network device, where the RRC connection resume request is used to request to resume the RRC connection of the first terminal device. Correspondingly, the first access network device receives the RRC connection resume request from the first terminal device.

[0287] It should be noted that the specific content of S1101 can be referred to the specific description of S401 in FIG. 4, which will not be repeated here.

[0288] Optionally, after S1101, the RRC connection resuming method can further include S402-S408 in FIG. 4.

[0289] Optionally, in response to the second access network device supporting resuming the RRC connection of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device being connected, the first terminal device can not perform S1101, but send a resuming request to the second access network device (i.e., perform S704). After S704, the RRC connection resuming method can further include S705-S706 in FIG. 7.

[0290] That is, the first terminal device can choose to initiate RRC connection resuming to the first access network device or the second access network device supporting resuming the RRC connection of the first terminal device, which is conducive to improving the success rate of resuming the RRC connection.

[0291] In the embodiment of the present application, the first access network device broadcasts the ninth indication information, so that the first terminal device determines whether the first access network device supports resuming the RRC connection of the first terminal device based on the ninth indication information, and then in the case that the first access network device supports resuming the RRC connection of the first terminal device, the first terminal device can initiate the RRC connection resumption to the first access network device, which is beneficial to improve the success rate of resuming the RRC connection.

[0292] Please refer to FIG. 12, which is a flow diagram of another method for resuming the RRC connection provided in the embodiment of the present application. The method mainly describes that the first access network device indicates whether it supports resuming the RRC connection of the first terminal device through the paging message. As shown in FIG. 12, the method for resuming the RRC connection can include S701-S703 in the corresponding embodiment of FIG. 7, and can further include but not limited to the following steps (represented by thick lines in FIG. 12). The specific content of S701-S703 can be referred to the detailed description in the corresponding embodiment of FIG. 7, which will not be repeated here.

[0293] S1200: In response to the link between the satellite to which the first access network device belongs and the mobility management network element being connected, the mobility management network element sends a fourth paging message for paging the first terminal device to the first access network device. Correspondingly, the first access network device receives the fourth paging message for paging the first terminal device from the mobility management network element.

[0294] The embodiment of the present application does not limit the execution order between S1200 and any one of S701-S703. For example, S1200 can be executed before S701, or S1200 can be executed after S703, or S1200 can be executed before any one of S701-S703, or S1200 can be executed after any one of S701-S703.

[0295] The fourth paging message can be used to page one or more terminal devices (i.e., P terminal devices), and the P terminal devices can at least include the first terminal device. The fourth paging message can include the identity of each terminal device in the P terminal devices that are paged. The related content of the fourth paging message can be referred to the related description of the first paging message in the corresponding embodiment of FIG. 10, which will not be repeated here.

[0296] After the first access network device receives the fourth paging message for paging the first terminal device, it determines whether the stored resumption information includes the resumption information of any terminal device that is paged based on the identity of the P terminal devices. If the stored resumption information includes the resumption information of some terminal device or terminal devices that are paged, the first access network device can carry an indication in the paging message sent to the terminal device or terminal devices, indicating that the terminal device or terminal devices can send a resumption request to the first access network device.

[0297] S1201: In response to the first access network device storing the recovery information of the first terminal device and the link between the satellite to which the first access network device belongs and the first terminal device being in communication, the first access network device sends a fifth paging message to the first terminal device, the fifth paging message comprising tenth indication information, the tenth indication information indicating that the first terminal device sends an RRC connection recovery request. Correspondingly, the first terminal device receives the fifth paging message from the first access network device.

[0298] Taking an example in which the recovery information stored by the first access network device comprises the recovery information of the first terminal device that is paged, the first access network device can carry the tenth indication information in the fourth paging message sent to the first terminal device. It should be noted that the fifth paging message can be obtained by adding the tenth indication information in the fourth paging message.

[0299] Optionally, the tenth indication information can also be described as: the first access network device supports resuming the RRC connection of the first terminal device; or the first access network device stores the recovery information of the first terminal device; or the first access network device supports resuming the RRC connection suspended under the first access network device.

[0300] After the first terminal device receives the fifth paging message, in response to the link between the satellite to which the first access network device belongs and the first terminal device being in communication, the first terminal device can send an RRC connection recovery request to the first access network device.

[0301] S1202: In response to the link between the first terminal device and the satellite to which the first access network device belongs being in communication, the first terminal device sends an RRC connection recovery request to the first access network device, the RRC connection recovery request being used to request to resume the RRC connection of the first terminal device. Correspondingly, the first access network device receives the RRC connection recovery request from the first terminal device.

[0302] It should be noted that the specific content of S1202 can be referred to the specific description in S401 in FIG. 4, which will not be described here.

[0303] Optionally, after S1202, the RRC connection resuming method can further comprise S402-S408 in FIG. 4.

[0304] Optionally, in response to the second access network device supporting resuming the RRC connection of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device being in communication, the first terminal device can not perform S1202, but send a resuming request to the second access network device (i.e., perform S704). After S704, the RRC connection resuming method can further comprise S705-S706 in FIG. 7.

[0305] That is, the first terminal device can select to initiate RRC connection recovery to the first access network device or the second access network device that supports recovery of the RRC connection of the first terminal device, which is conducive to improving the success rate of recovering the RRC connection.

[0306] In the embodiment of the present application, the first access network device indicates to the first terminal device through the paging message whether the first access network device supports recovery of the RRC connection of the first terminal device, and then in the case where the first access network device supports recovery of the RRC connection of the first terminal device, the first terminal device can initiate RRC connection recovery to the first access network device, which is conducive to improving the success rate of recovering the RRC connection on the one hand, and saving signaling overhead on the other hand.

[0307] The above describes the method embodiments provided by the present application. In order to better implement the above-mentioned solutions of the embodiments of the present application, the embodiments of the present application also provide corresponding devices.

[0308] The embodiments of the present application can divide the functional modules of the communication device according to the above-mentioned method examples. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be realized in the form of hardware or in the form of a software functional module. It should be noted that the division of modules in the embodiments of the present application is illustrative, and is only a logical functional division. Actual implementation can have another division manner.

[0309] Please refer to FIG. 13, which is a structural schematic diagram of a communication device provided by an embodiment of the present application. The communication device 130 can be a first access network device, or a device (for example, a chip, or a chip system, or a circuit) in the first access network device. Alternatively, the communication device 130 can be a terminal device, or a device (for example, a chip, or a chip system, or a circuit) in the terminal device.

[0310] As shown in FIG. 13, the communication device 130 at least includes a communication unit 1301 and a processing unit 1302.

[0311] For the case where the communication device 130 is used to implement the function of the first access network device in the above-mentioned embodiments:

[0312] In response to the link between the satellite to which the first access network device belongs and the mobility management network element being connected, the processing unit 1302 is configured to invoke the communication unit 1301 to send recovery information to the mobility management network element, the recovery information being used to recover the RRC connection of the first terminal device suspended under the first access network device.

[0313] In a possible implementation, the recovery information comprises one or more of a first resume identity, a first parameter of a token for authentication, a context of the first terminal device, an identity of a satellite to which the first access network device belongs, an identity of the first access network device, an identity of a last cell accessed by the first terminal device, a next hop parameter NH for post-recovery connection ciphering and integrity protection, and a next hop chaining count NCC for post-recovery connection ciphering and integrity protection.

[0314] In a possible implementation, in response to the link between the satellite to which the first access network device belongs and the first terminal device being in communication, the processing unit 1302 is further configured to instruct the communication unit 1301 to send, to the first terminal device, first indication information indicating that one or more of the following is supported: the store-and-forward mode, and recovery of the RRC connection of the first terminal device at M access network devices, where M is a positive integer.

[0315] In a possible implementation, the first indication information further indicates one or more of the following: an identity of each of the M access network devices, an identity of a satellite to which each of the M access network devices belongs, a first time period corresponding to each of the M access network devices, where the RRC connection of the first terminal device is supported at the access network device in the first time period corresponding to the access network device, and a start time of the first time period corresponding to each of the M access network devices.

[0316] In a possible implementation, in response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the processing unit 1302 is further configured to instruct the communication unit 1301 to send, to the mobility management network element, second indication information indicating that the mobility management network element sends recovery information to M access network devices, where M is a positive integer.

[0317] In a possible implementation, the second indication information comprises an identity of each of the M access network devices and / or an identity of a satellite to which each of the M access network devices belongs.

[0318] In a possible implementation, the first indication information is determined based on ephemeris information.

[0319] In a possible implementation, in response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the processing unit 1302 is further configured to instruct the communication unit 1301 to receive, from the mobility management network element, third indication information used to determine the first indication information.

[0320] In a possible implementation, the first parameter comprises a short Resume MAC-I or a Resume MAC-I.

[0321] For the communication unit 1301, the processing unit 1302, the first access network device in the above-mentioned embodiments, please refer to the description of the corresponding embodiments of FIG. 7-FIG. 12, which will not be repeated here.

[0322] For the communication unit 1301, the processing unit 1302, the first access network device in the above-mentioned embodiments, please refer to the description of the corresponding embodiments of FIG. 7-FIG. 12, which will not be repeated here.

[0323] In response to the link between the first terminal device and the satellite to which the second access network device belongs being connected, the processing unit 1302 is configured to instruct the communication unit 1301 to send a resume request to the second access network device, wherein the second access network device stores the resume information, the resume information is used to resume the RRC connection of the first terminal device suspended under the first access network device, and the resume request is used to request to resume the RRC connection of the first terminal device.

[0324] In a possible implementation, the resume information includes one or more of the following: a first resume identifier, a first parameter of the token used for authentication, a context of the first terminal device, an identifier of the satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of the last cell accessed by the first terminal device, a next hop parameter NH used for post-connection encryption and integrity protection, and a next hop link number NCC used for post-connection encryption and integrity protection.

[0325] In a possible implementation, in response to the link between the first terminal device and the satellite to which the first access network device belongs being connected, the processing unit 1302 is further configured to instruct the communication unit 1301 to receive first indication information from the first access network device, and the first indication information indicates one or more of the following: support for the store-and-forward mode, support for resuming the RRC connection of the first terminal device at M access network devices, and the M access network devices at least include the second access network device, and M is a positive integer.

[0326] In a possible implementation, the first indication information further indicates one or more of the following: an identifier of each of the M access network devices; an identifier of the satellite to which each of the M access network devices belongs; a first time period corresponding to each of the M access network devices, wherein the RRC connection of the first terminal device is supported at the access network device in the first time period corresponding to the access network device; and a start time of the first time period corresponding to each of the M access network devices.

[0327] In a possible implementation, the processing unit 1302 is further configured to instruct the communication unit 1301 to receive fourth indication information broadcast by the second access network device, the fourth indication information indicating that the first RRC connection is supported to be resumed at the second access network device, wherein the first RRC connection comprises an RRC connection suspended at any one of N access network devices, and the N access network devices at least include the first access network device, and N is a positive integer.

[0328] In a possible implementation, the fourth indication information comprises an identifier of each of the N access network devices and / or an identifier of a satellite to which each of the N access network devices belongs.

[0329] In a possible implementation, in response to the link between the first terminal device and the satellite to which the second access network device belongs being in communication, the processing unit 1302 is further configured to instruct the communication unit 1301 to receive a second paging message from the second access network device, the second paging message comprising fifth indication information, the second paging message being sent in a case where the second access network device stores the resumption information of the first terminal device, and the fifth indication information indicating that the first terminal device sends a resumption request.

[0330] In a possible implementation, the first parameter comprises a short Resume MAC-I or a Resume MAC-I.

[0331] For more details of the communication unit 1301 and the processing unit 1302, refer to the descriptions of the terminal device in the embodiments corresponding to FIG. 7 to FIG. 12.

[0332] FIG. 14 is a structural schematic diagram of another communication apparatus provided by the embodiment of the present application. The communication apparatus 140 can be a second access network device, or a device (for example, a chip, or a chip system, or a circuit) in the second access network device.

[0333] As shown in FIG. 14, the communication apparatus 140 at least includes a communication unit 1401, a processing unit 1402, and a storage unit 1403.

[0334] In response to the link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the processing unit 1402 is configured to instruct the communication unit 1401 to receive, from the mobility management network element, recovery information for resuming the RRC connection of the first terminal device that is suspended under the first access network device; and the storage unit 1403 is configured to store the recovery information. In response to the link between the satellite to which the second access network device belongs and the first terminal device being in communication, the processing unit 1402 is further configured to instruct the communication unit 1401 to receive, from the first terminal device, a recovery request for resuming the RRC connection of the first terminal device, and to verify the first terminal device based on information in the stored recovery information and the recovery request.

[0335] In a possible implementation, the recovery information includes one or more of a first recovery identifier, a first parameter of a token for authentication, a context of the first terminal device, an identifier of the satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a last cell accessed by the first terminal device, a next hop parameter NH for post-recovery connection ciphering and integrity protection, and a next hop chaining count NCC for post-recovery connection ciphering and integrity protection.

[0336] In a possible implementation, the processing unit 1402 is further configured to instruct the communication unit 1401 to broadcast fourth indication information indicating that the second access network device supports resuming the first RRC connection, where the first RRC connection includes an RRC connection suspended under any of N access network devices, and the N access network devices at least include the first access network device, and N is a positive integer.

[0337] In a possible implementation, the fourth indication information includes an identifier of each of the N access network devices and / or an identifier of the satellite to which each of the N access network devices belongs.

[0338] In a possible implementation, in response to the link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the processing unit 1402 is further configured to instruct the communication unit 1401 to receive, from the mobility management network element, a first paging message for paging the first terminal device. In response to the second access network device storing the recovery information of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device being in communication, the processing unit 1402 is further configured to instruct the communication unit 1401 to send, to the first terminal device, a second paging message including fifth indication information indicating that the first terminal device sends the recovery request.

[0339] In a possible implementation, in response to the first terminal device passing the verification, the processing unit 1402 is further configured to instruct the communication unit 1401 to send an RRC connection resume message to the first terminal device; and in response to the link between the satellite to which the second access network device belongs and the mobility management network element being connected, the processing unit 1402 is further configured to instruct the communication unit 1401 to send sixth indication information to the mobility management network element, the sixth indication information indicating that the third access network device storing the resume information releases the resume information or indicating that the second access network device completes the RRC connection resume.

[0340] In a possible implementation, the first parameter includes a short Resume MAC-I or a Resume MAC-I.

[0341] For more details of the communication unit 1401 and the processing unit 1402, refer to the descriptions of the second access network device in the embodiments of FIGS. 7-12.

[0342] Referring to FIG. 15, FIG. 15 is a structural schematic diagram of another communication apparatus according to an embodiment of the present application. As shown in FIG. 15, the communication apparatus 150 can include one or more processors 1501, which can also be referred to as processing units, and can implement certain control functions. The processor 1501 can be a general purpose processor or a special purpose processor. For example, the processor 1501 can be a baseband processor or a central processing unit. The baseband processor can be configured to process communication protocols and communication data, and the central processing unit can be configured to control the communication apparatus (e.g., a base station, a baseband chip, a terminal, a terminal chip, a DU or a CU, etc.), execute software programs, and process data of the software programs.

[0343] In an optional design, the processor 1501 can also store instructions 1503 and / or data, which can be executed by the processor to enable the communication apparatus 150 to perform the methods described in the above method embodiments.

[0344] In another optional design, the processor 1501 can include a transceiver unit for implementing receiving and sending functions. For example, the transceiver unit can be a transceiver circuit, or an interface, or an interface circuit, or a communication interface. The transceiver circuit, the interface, or the interface circuit for implementing the receiving and sending functions can be separate or integrated together. The transceiver circuit, the interface, or the interface circuit can be configured to read and write codes / data, or the transceiver circuit, the interface, or the interface circuit can be configured to transmit or transfer signals.

[0345] In yet another possible design, the communication apparatus 150 can include a circuit, which can implement the functions of sending or receiving or communicating in the foregoing method embodiments.

[0346] Optionally, the communication apparatus 150 can comprise one or more memories 1502 that can store instructions 1504 and / or data. The instructions 1504 and / or data can be executable by a processor, so that the communication apparatus 150 performs the methods described in the above method embodiments. Optionally, the memories can also store data. Optionally, the processor can also store instructions and / or data. The processor and the memories can be separately provided, or integrated together. For example, the correspondence described in the above method embodiments can be stored in the memories, or stored in the processor.

[0347] Optionally, the communication apparatus 150 can further comprise a transceiver 1505 and / or an antenna 1506. The processor 1501 can be referred to as a processing unit, and can control the communication apparatus 150. The transceiver 1505 can be referred to as a transceiving unit, a transceiver, a transceiving circuit, a transceiving apparatus, or a transceiving module, etc., and can be used to implement the transceiving function.

[0348] Optionally, the communication apparatus 150 in the embodiments of the present application can be used to perform the methods described in the corresponding embodiments of FIG. 7-FIG. 12.

[0349] In one embodiment, the communication apparatus 150 can be a first access network device, or a device (for example, a chip, or a chip system, or a circuit) in the first access network device. When the computer program instructions stored in the memory 1502 are executed, the transceiver 1505 is configured to perform the operations performed by the communication unit 1301 in the above embodiments, and the transceiver 1505 is further configured to send information to other communication apparatuses outside the communication apparatus. The above first access network device or the device in the first access network device can also be used to perform various methods performed by the first access network device in the corresponding embodiments of FIG. 7-FIG. 12, which will not be repeated here.

[0350] In one embodiment, the communication apparatus 150 can be a second access network device, or a device (for example, a chip, or a chip system, or a circuit) in the second access network device. When the computer program instructions stored in the memory 1502 are executed, the transceiver 1505 is configured to perform the operations performed by the communication unit 1401 in the above embodiments, and the transceiver 1505 is further configured to send information to other communication apparatuses outside the communication apparatus. The above second access network device or the device in the second access network device can also be used to perform various methods performed by the second access network device in the corresponding embodiments of FIG. 7-FIG. 12, which will not be repeated here.

[0351] In an embodiment, the communication apparatus 150 can be a terminal device, or a device (e.g., a chip, or a chip system, or a circuit) in a terminal device. The transceiver 1505 is configured to perform operations performed by the communication unit 1301 in the above-described embodiments when the computer program instructions stored in the memory 1502 are executed. The terminal device or the device in the terminal device can also be configured to perform various methods performed by the terminal device in the above-described embodiments of FIG. 7-FIG. 12, which will not be repeated here.

[0352] The processor and the transceiver described in this application can be implemented on an integrated circuit (IC), an analog IC, a radio frequency interface chip (RFIC), a mixed-signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and the transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), positive channel metal oxide semiconductor (PMOS), Bipolar Junction Transistor (BJT), BiCMOS, silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0353] The structure of the apparatus described in this application can not be limited by FIG. 15. The apparatus can be a standalone device or can be part of a larger device. For example, the apparatus can be:

[0354] (1) a standalone integrated circuit (IC), or a chip, or a chip system or subsystem;

[0355] (2) a set of one or more ICs, optionally including memory elements for storing data and / or instructions;

[0356] (3) an ASIC, such as a Mobile Station Modem (MSM);

[0357] (4) a module that can be embedded within other devices;

[0358] (5) receivers, terminals, intelligent terminals, cellular phones, wireless devices, handsets, mobile units, car kits, network devices, cloud devices, artificial intelligence devices, machine devices, home devices, medical devices, industrial devices, and the like;

[0359] (6) others, and the like.

[0360] Referring to FIG. 16, FIG. 16 is a structural schematic diagram of a terminal device provided in an embodiment of the present application. For ease of illustration, FIG. 16 only shows main components of the terminal device. As shown in FIG. 16, the terminal device 160 includes a processor, a memory, a control circuit, an antenna, and an input / output device. The processor is mainly used for processing communication protocols and communication data, controlling the whole terminal device, executing software programs, and processing data of the software programs. The memory is mainly used for storing software programs and data. The radio frequency circuit is mainly used for conversion between baseband signals and radio frequency signals and processing of the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touch screen, a display screen, a keyboard, and the like, is mainly used for receiving data input by a user and outputting data to the user.

[0361] When the terminal device is powered on, the processor can read software programs in the storage unit, parse and execute instructions of the software programs, and process data of the software programs. When data needs to be transmitted wirelessly, the processor performs baseband processing on the data to be transmitted, and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit processes the baseband signal to obtain a radio frequency signal, and transmits the radio frequency signal in the form of electromagnetic waves through the antenna. When data is transmitted to the terminal device, the radio frequency circuit receives a radio frequency signal through the antenna. The radio frequency signal is further converted into a baseband signal, and the baseband signal is output to the processor. The processor converts the baseband signal into data and processes the data.

[0362] For ease of illustration, FIG. 16 only shows one memory and one processor. In an actual terminal device, multiple processors and memories can exist. The memory can also be referred to as a storage medium or a storage device, and the like, and the embodiments of the present application do not limit this.

[0363] As an optional implementation, the processor can include a baseband processor and a central processor, the baseband processor is mainly used for processing communication protocols and communication data, and the central processor is mainly used for controlling the whole terminal device, executing a software program, and processing data of the software program. The processor in FIG. 16 integrates the functions of the baseband processor and the central processor, and those skilled in the art can understand that the baseband processor and the central processor can also be independent processors interconnected by a bus or the like. Those skilled in the art can understand that the terminal device can include multiple baseband processors to adapt to different network modes, and the terminal device can include multiple central processors to enhance its processing capability, and various components of the terminal device can be connected through various buses. The baseband processor can also be referred to as a baseband processing circuit or a baseband processing chip. The central processor can also be referred to as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data can be built into the processor, or stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.

[0364] In one example, the antenna and the control circuit with the transceiving function can be regarded as a transceiving unit 1601 of the terminal device 160, and the processor with the processing function can be regarded as a processing unit 1602 of the terminal device 160. As shown in FIG. 16, the terminal device 160 includes the transceiving unit 1601 and the processing unit 1602. The transceiving unit can also be referred to as a transceiver, a transceiver, a transceiving device, etc. Optionally, the device for realizing the receiving function in the transceiving unit 1601 can be regarded as a receiving unit, and the device for realizing the sending function in the transceiving unit 1601 can be regarded as a sending unit, that is, the transceiving unit 1601 includes the receiving unit and the sending unit. Exemplarily, the receiving unit can also be referred to as a receiver, a receiving circuit, etc., and the sending unit can be referred to as a transmitter, a transmitting circuit, etc. Optionally, the above-mentioned receiving unit and sending unit can be integrated into one unit, or can be multiple independent units. The above-mentioned receiving unit and sending unit can be in one geographical location, or can be dispersed in multiple geographical locations.

[0365] In one embodiment, the transceiving unit 1601 is configured to perform the operations performed by the communication unit 1301 in the above-described embodiments. The terminal device 160 can also be configured to perform various methods performed by the terminal device in the corresponding embodiments of FIGS. 7-12, which will not be described again.

[0366] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the process related to the first access network device in the method provided by the method embodiments.

[0367] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program. The program is executed by a processor to implement the method provided by the method embodiment.

[0368] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program. The program is executed by a processor to implement the method provided by the method embodiment.

[0369] The embodiment of the present application further provides a computer program product, which, when running on a computer or a processor, causes the computer or the processor to execute one or more steps in the above method. The constituent modules of the device involved above can be stored in a computer readable storage medium if they are realized in the form of software function units and sold or used as independent products.

[0370] The embodiment of the present application further provides a chip system, which comprises at least one processor and an interface circuit. The interface circuit and the at least one processor are interconnected through a circuit. The at least one processor is configured to execute a computer program or an instruction, so that part or all of the steps of any one of the embodiments described with reference to FIG. 7-FIG. 12 are executed. In a possible implementation, the chip system can further comprise at least one memory. The interface circuit, the at least one memory and the at least one processor are interconnected through a circuit. The at least one memory stores an instruction. When the instruction is executed by the processor, part or all of the steps of any one of the embodiments described with reference to FIG. 7-FIG. 12 are executed. The chip system can be composed of a chip, or can comprise a chip and other discrete devices.

[0371] The embodiment of the present application further provides a communication system, which comprises a first access network device and a second access network device. Optionally, the communication system can further comprise a terminal device. Optionally, the communication system can further comprise a mobility management network element. The specific description of the first access network device, the second access network device, the terminal device and the mobility management network element can refer to the method shown in the corresponding embodiments of FIG. 7-FIG. 12.

[0372] It should be appreciated that the memory mentioned in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a hard disk drive (HDD), a solid-state drive (SSD), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of RAM can be used, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM). The memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, used for storing program instructions and / or data.

[0373] It should also be understood that the processor mentioned in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0374] It should be noted that when the processor is a general processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) is integrated in the processor.

[0375] It should be noted that the memory described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0376] It should be understood that the size of the sequence number of the above-mentioned processes in various embodiments of the present application does not mean the order of execution, and the execution order of the processes should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0377] Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments provided herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0378] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the above-mentioned system, device and unit can be referred to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0379] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be realized by other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0380] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0381] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0382] If the functions are implemented in the form of software functional units and sold or used as independent products, the functions can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk, and various program code storage media.

[0383] The steps in the method of the embodiments of the present application can be adjusted, combined and reduced in sequence according to actual needs.

[0384] The modules / units in the device of the embodiments of the present application can be combined, divided and reduced according to actual needs.

[0385] The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A radio resource control (RRC) connection resume method, comprising: The method comprises: In response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the first access network device sends recovery information to the mobility management network element, the recovery information being used to recover the RRC connection of the first terminal device suspended under the first access network device.

2. The method of claim 1, wherein, The recovery information comprises one or more of the following: a first recovery identifier, a first parameter of a token used for authentication, a context of the first terminal device, an identifier of the satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a historical cell accessed by the first terminal device most recently, a next hop parameter NH used for post-recovery connection encryption and integrity protection, and a next hop link number NCC used for post-recovery connection encryption and integrity protection.

3. The method according to claim 1 or 2, characterized in that, The method further comprises: In response to the link between the satellite to which the first access network device belongs and the first terminal device being in communication, the first access network device sends first indication information to the first terminal device, the first indication information indicating one or more of the following: support for a store-and-forward mode, and support for recovery of the RRC connection of the first terminal device at M access network devices, M being a positive integer.

4. The method of claim 3, wherein, The first indication information further indicates one or more of the following: an identifier of each of the M access network devices; an identifier of the satellite to which each of the M access network devices belongs; a first time period corresponding to each of the M access network devices, wherein the RRC connection of the first terminal device is supported to be recovered at the access network device in the first time period corresponding to the access network device; a start time of the first time period corresponding to each of the M access network devices.

5. The method according to any one of claims 1 to 4, characterized in that, The method further comprises: In response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the first access network device sends second indication information to the mobility management network element, the second indication information indicating that the mobility management network element sends the recovery information to M access network devices, M being a positive integer.

6. The method of claim 5, wherein, The second indication information comprises an identifier of each of the M access network devices and / or an identifier of the satellite to which each of the M access network devices belongs.

7. The method according to claim 3 or 4, characterized in that, The first indication information is determined based on ephemeris information.

8. The method of claim 3 or 4, wherein, The method further comprises: In response to the link between the satellite to which the first access network device belongs and the mobility management network element being in communication, the first access network device receives third indication information from the mobility management network element, the third indication information being used to determine the first indication information.

9. The method of claim 2, wherein, The first parameter comprises a short recovery medium access control identifier or a recovery medium access control identifier.

10. A radio resource control (RRC) connection resume method, comprising: The method comprises: In response to the link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the second access network device receives recovery information from the mobility management network element, the recovery information being used to recover the RRC connection of the first terminal device suspended under the first access network device; The second access network device stores the recovery information; In response to the link between the satellite to which the second access network device belongs and the first terminal device being in communication, the second access network device receives a resume request from the first terminal device, and verifies the first terminal device based on information in the stored resume information and the resume request, wherein the resume request is used to request to resume the RRC connection of the first terminal device.

11. The method of claim 10, wherein, The resume information includes one or more of a first resume identifier, a first parameter of a token used for authentication, a context of the first terminal device, an identifier of the satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a last cell accessed by the first terminal device, a next hop parameter NH used for post-resume connection encryption and integrity protection, and a next hop count NCC used for post-resume connection encryption and integrity protection.

12. The method according to claim 10 or 11, characterized in that, The method further includes: The second access network device broadcasts fourth indication information, and the fourth indication information indicates that the first RRC connection is supported to be resumed at the second access network device, wherein the first RRC connection includes an RRC connection suspended at any one of N access network devices, and the N access network devices at least include the first access network device, and N is a positive integer.

13. The method of claim 12, wherein, The fourth indication information includes an identifier of each of the N access network devices and / or an identifier of a satellite to which each of the N access network devices belongs.

14. The method of claim 10 or 11, wherein, The method further includes: In response to the link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the second access network device receives a first paging message for paging the first terminal device from the mobility management network element; In response to the second access network device storing resume information of the first terminal device and the link between the satellite to which the second access network device belongs and the first terminal device being in communication, the second access network device sends a second paging message to the first terminal device, and the second paging message includes fifth indication information, and the fifth indication information indicates that the first terminal device sends the resume request.

15. The method according to any one of claims 10 to 14, characterized in that, The method further includes: In response to the first terminal device passing the verification, the second access network device sends an RRC connection resume message to the first terminal device; In response to the link between the satellite to which the second access network device belongs and the mobility management network element being in communication, the second access network device sends sixth indication information to the mobility management network element, and the sixth indication information indicates that a third access network device storing the resume information releases the resume information or indicates that the RRC connection resume is completed at the second access network device.

16. The method of claim 11, wherein, The first parameter includes a short resume medium access control identifier or a resume medium access control identifier.

17. A radio resource control (RRC) connection resume method, comprising: The method includes: In response to the link between the first terminal device and a satellite to which the second access network device belongs being connected, the first terminal device sends a resume request to the second access network device, wherein the second access network device stores resume information used to resume the RRC connection of the first terminal device suspended under the first access network device, and the resume request is used to request to resume the RRC connection of the first terminal device.

18. The method of claim 17, wherein, The resume information includes one or more of a first resume identifier, a first parameter of a token used for authentication, a context of the first terminal device, an identifier of a satellite to which the first access network device belongs, an identifier of the first access network device, an identifier of a historical cell accessed by the first terminal device recently, a next hop parameter NH used for post-connection encryption and integrity protection, and a next hop link number NCC used for post-connection encryption and integrity protection.

19. The method of claim 17 or 18, wherein, The method further includes: In response to the link between the first terminal device and a satellite to which the first access network device belongs being connected, the first terminal device receives first indication information from the first access network device, and the first indication information indicates one or more of support for a store-and-forward mode and support for resuming the RRC connection of the first terminal device at M access network devices, wherein the M access network devices at least include the second access network device, and M is a positive integer.

20. The method of claim 19, wherein, The first indication information further indicates one or more of: an identifier of each of the M access network devices; an identifier of a satellite to which each of the M access network devices belongs; a first time period corresponding to each of the M access network devices, wherein the RRC connection of the first terminal device is supported to be resumed at the access network device in the first time period corresponding to the access network device; a start time of the first time period corresponding to each of the M access network devices.

21. The method according to any one of claims 17-20, characterized in that, The method further includes: The first terminal device receives fourth indication information broadcast by the second access network device, and the fourth indication information at least includes one of an indication of support for a store-and-forward mode and an indication of resuming the first RRC connection at the second access network device, wherein the first RRC connection includes an RRC connection suspended under any one of N access network devices, and the N access network devices at least include the first access network device, and N is a positive integer.

22. The method of claim 21, wherein, The fourth indication information includes an identifier of each of the N access network devices and / or an identifier of a satellite to which each of the N access network devices belongs.

23. The method according to any one of claims 17-20, characterized by, The method further includes: In response to the link between the first terminal device and a satellite to which the second access network device belongs being connected, the first terminal device receives a second paging message from the second access network device, the second paging message includes fifth indication information, and the second paging message is sent in a case where the second access network device stores resume information of the first terminal device, and the fifth indication information indicates that the first terminal device sends the resume request.

24. The method of claim 18, wherein, The first parameter comprises a short resume medium access control identifier or a resume medium access control identifier.

25. A communications device, characterized by The apparatus comprises means for performing the method of any one of claims 1-9; or, the apparatus comprises means for performing the method of any one of claims 10-16; or, the apparatus comprises means for performing the method of any one of claims 17-24.

26. A communications device, characterized by The apparatus comprises a processor configured to execute a computer program or instructions in a memory, which when executed by the processor, cause the apparatus to perform the method of any one of claims 1-9, or the method of any one of claims 10-16, or the method of any one of claims 17-24.

27. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program or computer instructions, which when executed by a processor, cause a first access network device to perform the method of any one of claims 1-9, or cause a second access network device to perform the method of any one of claims 10-16, or cause a terminal device to perform the method of any one of claims 17-24.

28. A communication system, characterized by The apparatus comprises a first access network device, a second access network device and a terminal device, wherein the first access network device is configured to perform the method of any one of claims 1-9, the second access network device is configured to perform the method of any one of claims 10-16, and the terminal device is configured to perform the method of any one of claims 17-24.

29. A chip system, characterized by The apparatus comprises at least one processor, at least one memory, and interface circuitry, the at least one memory, the interface circuitry, and the at least one processor are connected through lines, and the at least one memory stores instructions; the instructions are executed by the processor, and cause a first access network device to perform the method of any one of claims 1-9, or cause a second access network device to perform the method of any one of claims 10-16, or cause a terminal device to perform the method of any one of claims 17-24.

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