Network device access method and communication apparatus

Abstract

The embodiments of the present application relate to the technical field of communications. Disclosed are a network device access method and a communication apparatus, by means of which method and apparatus a terminal device determines, on the basis of an operating mode of a network device, to access the network device, thereby improving the data transmission efficiency of the terminal device. The method comprises: receiving system information, wherein the system information is used for indicating an operating mode of a first network device, and the operating mode is a store-and-forward mode; and accessing the first network device. The embodiments of the present application are used for the process of a terminal device choosing to access a network device.

Description

Network device access method and communication device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on March 6, 2024, with application number 202410258315.X and application name “A network equipment access method and communication device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a method for accessing a network device and a communication device. Background Art

[0003] In satellite communication systems, store-and-forward (S&F) satellite operations are proposed to provide latency-tolerant services. S&F satellites operate over the area where terminal devices are located for a specific period of time, providing services to these devices. For example, an S&F satellite stores signaling or data sent by a terminal device. When the S&F satellite passes over a ground gateway, it transmits the stored signaling or data to the gateway, which then transmits it to the core network or server.

[0004] Terminal devices may be served by either S&F satellites or non-S&F satellites (e.g., directly connected satellites). When both S&F and non-S&F satellites are in non-geosynchronous orbit (NGSO) satellites, NGSO satellites can only serve terminal devices in the same area for a limited period of time. Therefore, how terminal devices choose to access these two types of satellites is an urgent issue. Summary of the Invention

[0005] The embodiments of the present application provide a network device access method and a communication device, which enable a terminal device to determine an access network device according to the working mode of the network device, so as to improve the data transmission efficiency of the terminal device.

[0006] In a first aspect, a method for accessing a network device is provided. Optionally, the method may be performed by a terminal device, a component or device (such as a processor, chip, or chip system) applied to the terminal device, or a logic module or software capable of implementing all or part of the terminal device's functions. The method includes: receiving system information indicating an operating mode of a first network device, the operating mode being a store-and-forward mode; and accessing the first network device.

[0007] Therefore, in this application, the first network device can send system information to the terminal device in the cell, and the system information can be used to indicate the working mode of the first network device, which is the storage and forwarding mode, that is, the S&F mode. The first network device can also be called an S&F satellite. The S&F satellite flies over the area where the system information is located within a certain period of time to provide services, such as storing the signaling or data sent by the system information. When the S&F satellite flies over the ground gateway station, the stored signaling or data of the terminal device is handed over to the gateway station for transmission to the core network or even the server for processing. In the case where the first network device is a satellite, the working mode of the first network device can also be understood as the type of satellite or the working mode of the satellite, etc.

[0008] This can help the terminal device determine that the network device's working mode is S&F mode and then access the first network device for data transmission. Compared to the existing scenario where a terminal is within the coverage of a network device working in store and forward mode and network devices with different working modes coexist, and the terminal is unsure whether to access the network device covering the terminal or wait for the network device in the neighboring area to cover the terminal, the present application can broadcast system information through the network device, so that the terminal determines whether to access the network device based on the system information, thereby improving the data transmission efficiency of the terminal device.

[0009] In one possible design, the system information includes a first regional service period, which indicates the shortest time interval during which the first network device serves the same region. Thus, a terminal device can determine access to the first network device based on the operating mode of the first network device and the first regional service period. In scenarios where network devices operating in different modes coexist, the terminal device can determine access to the first network device based on the system information, thereby improving data transmission efficiency for the terminal device.

[0010] In one possible design, the first regional service period is less than or equal to the second regional service period, where the second regional service period is the regional service period of a second network device serving the same area, and the second network device is a neighboring network device of the first network device. In this way, when the first regional service period is less than or equal to the second regional service period, accessing the first network device in store-and-forward mode can improve data transmission efficiency for terminal devices.

[0011] In one possible design, the system information also includes a first-area service period, which includes the start time and / or end time of the first network device serving the area where the terminal device is located. That is, when the first network device operates in store-and-forward mode, the terminal device can determine access to the first network device based on the first-area service period and the first-area service period included in the system information. This addresses the issue of the terminal device being unsure of which network device to access in scenarios where network devices operate in multiple modes.

[0012] In one possible design, the first time is less than or equal to the second time. The first time is the time it takes for the terminal device to connect to the first network device and complete transmission of the remaining data on the terminal device. The second time is the time it takes for the terminal device to wait for the connection with the second network device to be restored and complete transmission of the remaining data on the terminal device. In this way, if the terminal device connects to the first network device when the first time is less than or equal to the second time, the data transmission efficiency of the terminal device when connected to the first network device in store and forward mode can be improved.

[0013] In one possible design, the first time is determined based on the first regional service cycle, and the second time is determined based on the second regional service cycle; or, the first time is determined based on the first regional service cycle and the first regional service time, and the second time is determined based on the second regional service cycle and the second regional service time, and the second regional service time includes the start time and / or end time of the area where the second network device serves the terminal device. If the first time and the second time are only related to the regional service cycle, it can be considered that the first network device and the second network device are running on different tracks. For the terminal device, in a scenario where network devices with different working modes coexist, if the first network device currently covering the terminal device is in storage and forwarding mode, the terminal device can determine access to the first network device based on the regional service cycle, or the terminal device can determine the transmission time of the remaining data based on the regional service cycle and the regional service time, so as to determine whether to access the first network device based on the transmission time of the remaining data.

[0014] In one possible design, the system information includes a first-area service time, which includes the start time and / or end time of the first network device serving the area where the terminal device is located. That is, if the system information indicates that the first network device operates in store-and-forward mode, the terminal device may determine to access the first network device based on the first-area service time, thereby resolving the issue of how the terminal device selects a network device to access in scenarios where network devices operating in multiple modes coexist.

[0015] In one possible design, the first time is less than or equal to the second time, the first time is the time when the terminal device accesses the first network device and transmits the remaining data of the terminal device, and the second time is the time when the terminal device waits to restore the connection with the second network device and transmit the remaining data of the terminal device; wherein the first time is determined based on the first area service time, and the second time is determined based on the second area service time, and the second area service time includes the start time and / or end time of the area where the second network device serves the terminal device. In this case, the first network device and the second network device can be running on the same track, and the regional service cycles of the two are the same, and the first time and the second time can be determined based on the regional service time. In this way, when the terminal device determines to access the first network device based on the size of the first time and the second time, the efficiency of the terminal device in transmitting data can be improved.

[0016] In one possible design, the first regional service period of the first network device meets the QoS requirements of the current service. That is, if the first network device currently covering the terminal device is in store-and-forward mode, the terminal device may determine to access the first network device if the first regional service period meets the QoS requirements of the current service, thereby ensuring the QoS requirements of the current service. This method of determining whether the first regional service period meets the QoS requirements can also be combined with the aforementioned condition that the first regional service period is less than or equal to the second regional service period, or with the aforementioned condition that the first time is less than or equal to the second time.

[0017] In one possible design, the system information includes information about neighboring network devices of the first network device. The neighboring network device information includes at least one of the following: an operating mode of the neighboring network device; a regional service period during which the neighboring network device serves the same area; and a regional service time during which the neighboring network device serves the area where the terminal device resides. In this way, the terminal device can combine the system information of the first network device currently covering the terminal device and the information about the neighboring network devices to determine whether to access the first network device or wait to access the neighboring network device, thereby improving data transmission efficiency when the terminal device determines whether to access the first network device or the neighboring network device.

[0018] In one possible design, the method further includes: receiving indication information, the indication information being used to release the connection between the first network device and the terminal device, the indication information including a reason value for releasing the connection; wherein the reason value is used to indicate that the first network device is overloaded with uplink data cached by the terminal device, or the reason value is used to indicate that the first network device no longer sends downlink data to the terminal device. In this way, for the first network device in store and forward mode, terminal device access and data transmission management can be performed based on the load information of the first network device and whether there is downlink data to be sent.

[0019] In one possible design, the first network device and the second network device are satellites. Thus, in a scenario where satellites with multiple operating modes coexist, if the first network device covering the terminal device is in store-and-forward mode, compared to existing scenarios where a terminal is within the coverage of a satellite operating in store-and-forward mode and satellites with different operating modes coexist, and the terminal is unsure whether to access the satellite covering the terminal or wait for a satellite in a neighboring area to cover the terminal, the present application can broadcast system information via the satellite, allowing the terminal to determine whether to access the satellite currently covering the terminal based on the system information, thereby improving the data transmission efficiency of the terminal device.

[0020] In a second aspect, a method for accessing a network device is provided. Optionally, the method may be performed by a first network device, a component or device (such as a processor, a chip, or a chip system) applied to the first network device, or a logic module or software capable of implementing all or part of the functions of the first network device. The first network device includes: sending system information indicating an operating mode of the first network device, the operating mode being a store and forward mode; and establishing a connection with a terminal device.

[0021] The beneficial effects of the second aspect can be found in the description of the first aspect.

[0022] In one possible design, the system information includes a first area service period, where the first area service period is used to indicate the shortest time interval for the first network device to serve the same area.

[0023] In a possible design, the system information includes the first area service time, and the first area service time includes the start time and / or end time of the first network device serving the area where the terminal device is located.

[0024] In one possible design, the system information includes information of a neighboring network device of the first network device, and the information of the neighboring network device includes at least one of the following information: an operating mode of the neighboring network device; a regional service period of the neighboring network device serving the same area; and a regional service time of the neighboring network device serving the area where the terminal device is located.

[0025] In one possible design, the method also includes: sending a notification message, where the notification message is used to instruct the second network device to delete or update the context of the terminal device, and the second network device is a neighboring network device of the first network device.

[0026] In one possible design, the method also includes: sending an indication message, the indication message being used to release the connection between the first network device and the terminal device, the indication message including a reason value for releasing the connection; wherein the reason value is used to indicate that the first network device is overloaded with uplink data cached by the terminal device, or the reason value is used to indicate that the first network device no longer sends downlink data to the terminal device.

[0027] In a third aspect, a communication device is provided. Optionally, the communication device may be a terminal device, a component or device (such as a processor, chip, or chip system) used in the terminal device, or a logic module or software capable of implementing all or part of the terminal device's functions. The communication device includes: a receiving unit for receiving system information indicating an operating mode of a first network device, the operating mode being a store-and-forward mode; and a processing unit for accessing the first network device.

[0028] In one possible design, the first area service period is less than or equal to the second area service period, wherein the second area service period is the area service period of the second network device serving the same area, and the second network device is a neighboring area network device of the first network device.

[0029] In one possible design, the first time is less than or equal to the second time, the first time is the time it takes for the terminal device to access the first network device and transmit the remaining data of the terminal device, and the second time is the time it takes for the terminal device to wait for the connection with the second network device to be restored and transmit the remaining data of the terminal device.

[0030] In one possible design, the first time is determined based on the first area service cycle, and the second time is determined based on the second area service cycle; or, the first time is determined based on the first area service cycle and the first area service time, and the second time is determined based on the second area service cycle and the second area service time, and the second area service time includes the start time and / or end time of the area where the second network device serves the terminal device.

[0031] In one possible design, the first time is less than or equal to the second time, the first time is the time when the terminal device accesses the first network device and transmits the remaining data of the terminal device, and the second time is the time when the terminal device waits to restore the connection with the second network device and transmit the remaining data of the terminal device; wherein, the first time is determined based on the first area service time, and the second time is determined based on the second area service time, and the second area service time includes the start time and / or end time of the area where the second network device serves the terminal device.

[0032] In one possible design, the first area service period of the first network device meets the service quality requirements of the current business.

[0033] In one possible design, the receiving unit is also used to receive indication information, where the indication information is used to release the connection between the first network device and the terminal device, and the indication information includes a reason value for releasing the connection; wherein the reason value is used to indicate that the first network device is overloaded with uplink data cached by the terminal device, or the reason value is used to indicate that the first network device no longer sends downlink data to the terminal device.

[0034] In a fourth aspect, a communication device is provided. The communication device may be a first network device, a component or device (e.g., a processor, chip, or chip system) applied to the first network device, or a logic module or software capable of implementing all or part of the functions of the first network device. The communication device includes: a sending unit for sending system information indicating an operating mode of the first network device, wherein the operating mode is a store and forward mode; and a processing unit for establishing a connection with a terminal device.

[0035] In one possible design, the sending unit is also used to send indication information, where the indication information is used to release the connection between the first network device and the terminal device, and the indication information includes a reason value for releasing the connection; wherein the reason value is used to indicate that the first network device is overloaded with uplink data cached by the terminal device, or the reason value is used to indicate that the first network device no longer sends downlink data to the terminal device.

[0036] In the third and fourth aspects:

[0037] In one possible design, the system information includes a first area service period, where the first area service period is used to indicate the shortest time interval for the first network device to serve the same area.

[0038] In a possible design, the system information also includes a first area service time, and the first area service time includes a start time and / or an end time of the area where the first network device serves the terminal device.

[0039] In a possible design, the system information includes the first area service time, and the first area service time includes the start time and / or end time of the first network device serving the area where the terminal device is located.

[0040] In one possible design, the system information includes information of a neighboring network device of the first network device, where the information of the neighboring network device includes at least one of the following information:

[0041] The working mode of the neighboring network equipment; the regional service period of the neighboring network equipment serving the same area; the regional service time of the neighboring network equipment serving the area where the terminal equipment is located.

[0042] In one possible design, the first network device and the second network device are satellites.

[0043] In a fifth aspect, a communication device is provided, comprising at least one processor, wherein the at least one processor is connected to a memory and a transceiver, the transceiver being used to receive system information, the system information being used to indicate a working mode of a first network device, the working mode being a storage and forwarding mode; and the processor being used to access the first network device.

[0044] In a sixth aspect, a communication device is provided, comprising at least one processor, wherein the at least one processor is connected to a memory and a transceiver, the transceiver being used to send system information, the system information being used to indicate a working mode of a first network device, the working mode being a storage and forwarding mode; and the processor being used to establish a connection with a terminal device.

[0045] In the seventh aspect, a communication system is provided, comprising a first communication device and a second communication device, wherein the first communication device is used to execute the method as described in the first aspect and any possible design of the first aspect, and the second communication device is used to execute the method as described in the second aspect and any possible design of the second aspect.

[0046] In an eighth aspect, a computer-readable storage medium is provided, comprising computer instructions, which, when the computer instructions are executed on a communication device, cause the communication device to execute the method of the first aspect and any possible design of the first aspect, and / or the second aspect and any possible design of the second aspect.

[0047] In the ninth aspect, a computer program product is provided, which, when running on a computer or processor, enables the computer or processor to execute the method of the above-mentioned first aspect and any possible design of the first aspect, and / or the second aspect and any possible design of the second aspect.

[0048] In the tenth aspect, a chip is provided, which is coupled to a memory and is used to read and execute program instructions stored in the memory to implement the method of the first aspect and any possible design of the first aspect, and / or the second aspect and any possible design of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0050] FIG2 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0051] FIG3 is a schematic diagram of an NTN architecture in which a transparent architecture and a regenerative architecture are provided in an embodiment of the present application;

[0052] FIG4 is a schematic diagram of a scenario in which two modes of satellites coexist, provided in an embodiment of the present application;

[0053] FIG5 is a schematic diagram of a flow chart of a method for accessing a network device provided in an embodiment of the present application;

[0054] FIG6 is a schematic diagram of a process flow of a UE initial access process provided by an embodiment of the present application;

[0055] FIG7 is a schematic diagram of a process for establishing a UE context according to an embodiment of the present application;

[0056] FIG8 is a schematic diagram of a flow chart of a method for accessing a network device according to an embodiment of the present application;

[0057] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0058] FIG10 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] For ease of understanding, some examples of concepts related to the embodiments of the present application are provided for reference as follows.

[0060] Non-geosynchronous orbit (NGSO): An Earth-centered orbit whose orbital period does not match Earth's rotation. NGSOs include low Earth orbit (LEO) and medium Earth orbit (MEO). For example, LEOs operate at altitudes between 300 and 1,500 kilometers, while MEOs operate at altitudes between approximately 7,000 and 25,000 kilometers.

[0061] Geosynchronous orbit: An orbit centered on the Earth, approximately 35,786 kilometers above the Earth's surface, synchronized with the Earth's rotation. A geostationary orbit is a non-inclined geosynchronous orbit, meaning it lies in the plane of the Earth's equator.

[0062] In the embodiments of this application, unless otherwise specified, " / " represents "or". For example, A / B can represent A or B. "And / or" in this document is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A exists simultaneously, and using NGSO satellites, the gNB can provide a quasi-geo-fixed service link or a geo-mobile service link. If using GSO satellites, the operating gNB can provide a geo-fixed service link.

[0063] The following describes the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. In the description of the embodiments of the present application, B exists alone in three cases. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two.

[0064] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

[0065] Figure 1 is a schematic diagram of the architecture of a communication system 1000 used in an embodiment of the present application. As shown in Figure 1 , the communication system includes a radio access network (RAN) 100 and a core network (CN) 200. RAN 100 includes at least one RAN node (e.g., 110a and 110b in Figure 1 , collectively referred to as 110) and at least one terminal (e.g., 120a-120j in Figure 1 , collectively referred to as 120). RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment (not shown in Figure 1 ). Terminal 120 is wirelessly connected to RAN node 110. RAN node 110 is wirelessly or wiredly connected to core network 200. The core network equipment in core network 200 and RAN node 110 in RAN 100 may be separate physical devices, or they may be a single physical device that integrates core network logical functions and radio access network logical functions. Communication system 1000 may also include the Internet 300.

[0066] The RAN 100 may be a cellular system related to the Third Generation Partnership Project (3GPP), such as a 4G or 5G mobile communication system, or a future-oriented evolutionary system (such as a 6G mobile communication system). The RAN 100 may also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. The RAN 100 may also be a communication system that integrates two or more of the above systems.

[0067] The RAN node 110, also known as a radio access network device, a RAN entity, or an access node, is used to help terminals access the communication system wirelessly. In one application scenario, the RAN node 110 can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a fifth-generation (5G) mobile communication system, a next-generation base station in a sixth-generation (6G) mobile communication system, or a base station in a future mobile communication system. The RAN node 110 can be a macro base station (such as 110a in Figure 1), a micro base station or an indoor station (such as 110b in Figure 1), a relay node, or a donor node. Optionally, the RAN node can also be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle-to-everything (V2X) technology can be a road side unit (RSU).

[0068] In another application scenario, the collaboration of multiple RAN nodes 110 can be used to help terminals achieve wireless access, with different RAN nodes 110 respectively implementing part of the functions of the base station. For example, the RAN node 110 can be a centralized unit (CU), a distributed unit (DU), or a radio unit (RU). The CU here implements the functions of the radio resource control protocol and the packet data convergence protocol (PDCP) of the base station, and can also implement the function of the service data adaptation protocol (SDAP); the DU implements the functions of the radio link control layer and the medium access control (MAC) layer of the base station, and can also implement part or all of the physical layer functions. For detailed descriptions of the above-mentioned protocol layers, please refer to the relevant technical specifications of 3GPP. The RU can be used to implement the transmission and reception functions of radio frequency signals. The CU and DU can be two independent RAN nodes, or they can be integrated into the same RAN node 110, for example, integrated into the baseband unit (BBU). The RU may be included in a radio frequency device, such as a remote radio unit (RRU) or an active antenna unit (AAU). The CU may be further divided into two types of RAN nodes: the CU-control plane and the CU-user plane.

[0069] In different systems, the RAN node 110 may have different names. For example, in an O-RAN system, the CU may be called an open CU (O-CU), the DU may be called an open DU (O-DU), and the RU may be called an open RU (O-RU). The RAN node 110 in the embodiments of the present application may be implemented using a software module, a hardware module, or a combination of software and hardware modules. For example, the RAN node 110 may be a server loaded with the corresponding software module. The embodiments of the present application do not limit the specific technology and specific device form used by the RAN node 110. For ease of description, the following description uses a base station as an example of a RAN node.

[0070] The communication between the RAN 100 and the terminal 120 follows a certain protocol layer structure. The protocol layer may include a control plane protocol layer and a user plane protocol layer. The control plane protocol layer may include at least one of the following: a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer, or a physical (PHY) layer. The user plane protocol layer may include at least one of the following: a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, or a physical layer.

[0071] For the correspondence between the network elements in the ORAN system and their achievable protocol layer functions, please refer to Table 1 below.

[0072] Table 1

[0073] FIG2 is a schematic diagram of the architecture of a communication system 1000, where Nx in FIG2 represents an interface. The terminal 120 is shown as a user equipment (UE), and the core network 200 mainly includes: an access and mobility management function (AMF) network element, a session management function (SMF) network element, a user plane function (UPF) network element, a policy control function (PCF) network element, a unified data management (UDM) network element, and an application function (AF) network element. The AMF network element is mainly responsible for mobility management, access authentication / authorization, and other functions in the mobile network, including management of user registration, reachability detection, selection of SMF network elements, and mobility state transition management. In addition, it is also responsible for transmitting user policies between the UE and the PCF network element. The SMF network element is primarily responsible for session management in the mobile network (including session establishment, modification, and deletion), execution of control policies issued by the PCF network element, selection of the UPF network element, and allocation of UE Internet Protocol (IP) addresses. The PCF network element is responsible for providing policies such as QoS and slice selection to the AMF and SMF. The UDM network element is used to store user data such as subscription information and authentication / authorization information. The AF network element is responsible for providing services to the 3GPP network, such as influencing service routing and interacting with the PCF network element for policy control.

[0074] As the interface with the data network, the UPF network element is mainly responsible for data packet routing and forwarding, mobility anchor point, uplink classifier to support routing service flows to the data network, branch point to support multi-homed PDU sessions, etc.

[0075] A data network (DN) refers to an operator network that provides data transmission services to users, such as IP multi-media service (IMS) and the Internet (e.g., Internet 300). A UE can access a DN by establishing a packet data unit (PDU) session (PDU session) from the UE to the RAN to the UPF to the DN.

[0076] In this application, terminal devices may be, for example, UE, mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, for example, device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. The terminal may be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of this application do not limit the specific technology and specific device form adopted by the terminal.

[0077] In some scenarios, in a non-terrestrial network (NTN), RAN 100 may be a next-generation radio access network (NG-RAN) composed of base stations (gNodeBs and gNBs). NTN refers to a network or network segment that uses radio frequency resources on satellites (or high altitude platform stations). The base station may provide non-terrestrial new radio (NR) access to the UE via an NTN payload and an NTN gateway on an airborne or satellite-based NTN carrier.

[0078] The NTN Gateway, which can be understood as a ground station located on the Earth's surface, provides connectivity to the NTN payload using feeder links. The NTN Gateway is a transport network layer (TNL) node.

[0079] The NTN payload can be understood as a network node carried on a satellite or high-altitude platform station, providing connectivity between the service link / business link and the feeder link. In some scenarios, the NTN payload is a TNL node. The feeder link is the wireless link between the NTN gateway and the NTN payload. The business link is the wireless link between the NTN payload and the terminal.

[0080] Exemplarily, the NTN payload can support three types of service links:

[0081] 1) Earth fixed service links: provided by beams that always continuously cover the same geographical area (e.g. in the case of geosynchronous satellites);

[0082] 2) Quasi-Earth Fixed Service links: provided by beam(s) that cover one geographical area for a limited time and a different geographical area for another time (e.g. in the case of NGSO satellites generating steerable beams);

[0083] 3) Earth mobile service links: provided by beams whose coverage area slides over the surface of the Earth (e.g., in the case of NGSO satellites producing fixed or non-steerable beams).

[0084] If NGSO satellites are used to provide some or all of the base station functions, the base station can provide quasi-geo-fixed service links or geo-mobile service links, while base stations operating using GSO satellites can provide geo-fixed service links.

[0085] When NTN is used for satellite communications, it can also be called a satellite mobile communications system, which can perform satellite mobile communications. When NTN is used for satellite navigation, it can be called a satellite navigation system.

[0086] Compared to traditional terrestrial cellular networks, the NTN network architecture differs slightly from traditional terrestrial cellular access networks. However, overall, the NTN network architecture is similar to that of 5G systems, consisting of two components: the 5G core network (5GC) and the Next-Generation Radio Access Network (NGRAN). The 5GC includes, for example, the Advanced Mobile Module (AMF) and User Plane Function (UPF) network elements, while the 5G RAN includes the Next-Generation Radio Access Network (NGRAN). During the standardization process, two models for the NG-RAN architecture were discussed: a transparent architecture and a regenerative architecture.

[0087] Figure 3(a) shows an architecture diagram of a transparent NTN architecture 30. This transparent architecture 30 includes NG-RAN 303, 5GC 304, and terminal equipment 305. NG-RAN 303 includes NTN payload 301, NTN gateway 302, and gNB 306. NTN payload 301 and NTN gateway 302 can be understood as RRUs in NR. NTN payload 301 functions as a radio frequency relay, performing frequency conversion and radio frequency amplification in both the uplink and downlink directions. Both the service link and feeder link of NTN payload 301 utilize the 5G NR Uu interface. NTN gateway 302 can be a gateway or ground station. The transmission type of this transparent architecture 30 is called transparent transmission, meaning that the signal undergoes frequency conversion and amplification on the NTN payload / satellite. Transmission latency is the transmission delay from NTN gateway 302 through NTN payload 301 to terminal equipment 305.

[0088] Figure 3(b) shows an architecture diagram of an NTN regenerative architecture 31. This regenerative architecture 31 includes NG-RAN 312, 5GC 314, and terminal equipment 315. NG-RAN 312 includes NTN payload 311 and NTN gateway 313. NTN payload 311 can be understood as a gNB (gNB) onboard satellite. The service link can utilize the NR Uu interface, and the feeder link can utilize the satellite private radio interface (SRI). Different gNBs can communicate with each other via the Xn interface, and the gNBs and terminal equipment 315 can communicate via the NR Uu interface. The transmission type of this regenerative architecture 31 is also referred to as non-transparent transmission. NTN payload 311 has some or all base station functions and needs to support some or all transmission protocols. Transmission latency is from NTN payload 311 to terminal equipment 315.

[0089] In Release 19, store and forward (S&F) satellite operations are proposed for latency-tolerant services, such as those supporting IoT-NTN data transmission. The S&F satellite can be understood as the NTN payload 311 in the regeneration architecture 31. The S&F satellite operates in store and forward mode. Figure 4 shows a schematic diagram of a scenario where satellites in both modes coexist. Assuming that SAT-RAN1 is an S&F satellite, SAT-RAN1 operates over the area where the UE is located within a certain period of time to provide services to the UE. For example, SAT-RAN1 can store signaling or data sent by the UE. When SAT-RAN1 orbits over the ground gateway 401, SAT-RAN1 can send the stored UE signaling or data to the gateway 401, which then transmits the signaling or data to the core network 5GC or even the server.

[0090] Referring to Figure 4 , when a UE is served by either an S&F satellite, such as SAT-RAN1, or a satellite directly connected to the UE in a transparent architecture (a satellite capable of transparently transmitting signaling / data), such as SAT-RAN2, SAT-RAN2 can directly communicate with gateway 402, for example, to receive and send UE-related signaling or data. Assuming that both SAT-RAN1 and SAT-RAN2 are NGSO satellites, each can only serve UEs in that area for a period of time. The service duration and period are related to the satellite orbit and the Earth's rotation.

[0091] Therefore, if a UE is accessing SAT-RAN1 or transmitting data after accessing SAT-RAN1 and SAT-RAN1 is in S&F mode, and SAT-RAN1 leaves the UE's area and no longer provides service, while the UE is within the coverage of SAT-RAN2 (e.g., a directly connected satellite), how will the UE determine whether to continue waiting for SAT-RAN1 to return to the UE's area and be served by SAT-RAN1, or to access SAT-RAN2? This is an urgent issue to be resolved. In other words, there is currently no discussion on how to select satellite access when S&F satellites and directly connected satellites coexist.

[0092] Therefore, in this application, the network device can send system information to the terminal in the cell, and the system information can be used to indicate the working mode of the network device, and the working mode is the storage and forwarding mode, that is, the S&F mode. This can help the terminal determine whether to access the network device for data transmission, so as to access the network device when it is determined to access. Compared with the existing terminal, when it is within the coverage of the network device whose working mode is the storage and forwarding mode and there are network devices with different working modes coexisting, the terminal is not sure whether to access the network device covering the terminal or wait for the network device in the neighboring area to cover the terminal access, this application can broadcast system information through the network device, so that the terminal determines whether to access the network device based on the system information, so as to improve the data transmission efficiency of the terminal device.

[0093] Based on the above network architecture, the embodiments of the present application are introduced below.

[0094] FIG5 is a flow chart of a method for accessing a network device provided in an embodiment of the present application, and the method includes the following process.

[0095] 501. A terminal device receives system information, where the system information is used to indicate a working mode of a first network device, which is a store and forward mode.

[0096] Accordingly, the first network device sends the system information. The first network device may be a satellite, such as the NTN payload 311 described above.

[0097] In some embodiments, the system message may be understood as a broadcast message, which is used to indicate the operating mode of the first network device. When the cell of the first network device, such as an S&F satellite, covers a terminal device, the S&F satellite may broadcast its operating mode to the terminal devices within the coverage area via a broadcast message.

[0098] In some embodiments, the system information includes a first regional service period, which indicates the shortest time interval during which the first network device serves the same region. Thus, the terminal device can determine whether to access the first network device based on the operating mode of the first network device and the first regional service period.

[0099] In some embodiments, the system information includes a first area service time, which includes the start time and / or end time of the first network device serving the area where the terminal device is located. Thus, the terminal device can determine whether to access the first network device based on the operating mode of the first network device and the first area service time.

[0100] In some embodiments, the system information further includes the first area service time. Thus, for the terminal device, access to the first network device can be determined based on the working mode of the first network device, the first area service time, and the first area service time.

[0101] 502. The terminal device accesses the first network device.

[0102] Accordingly, the first network device establishes a connection with the terminal device.

[0103] In some embodiments, when the system information indicates that the operating mode of the first network device is the S&F mode, and the system information includes a first regional service period, the terminal device accesses the first network device when the first regional service period is less than or equal to a second regional service period. The second regional service period is a regional service period of the second network device serving the same area, and the second network device is a neighboring network device of the first network device.

[0104] For example, the first network device and the second network device are satellites operating in different orbits, and the operating mode of the second network device is S&F mode or non-S&F mode. Non-S&F mode is, for example, transparent transmission mode / direct connection mode. That is, when a terminal device is within the cell range of the first network device in S&F mode, the terminal device can select the first network device with a shorter regional service period than the regional service period of the neighboring network device to access. In this way, for the terminal device, the transmission efficiency of signaling / data is higher.

[0105] In some embodiments, when the system information indicates that the operating mode of the first network device is the S&F mode, and the system information includes a first area service period and a first area service time, the terminal device accesses the first network device when the first time is less than or equal to a second time. The first time is the time it takes for the terminal device to access the first network device and complete transmission of the remaining data of the terminal device, and the second time is the time it takes for the terminal device to wait for the connection with the second network device to be restored and complete transmission of the remaining data of the terminal device.

[0106] The first time is determined based on the first area service cycle, and the second time is determined based on the second area service cycle. Alternatively, the first time is determined based on the first area service cycle and the first area service time, and the second time is determined based on the second area service cycle and the second area service time, where the second area service time includes the start time and / or end time of the area where the second network device serves the terminal device.

[0107] If the determination of the first time and the second time is related to the regional service period of the network device, the first network device and the second network device may be operated in different orbits or different regional service periods.

[0108] In this way, the terminal device can select the first network device that takes the shortest time to transmit the remaining data for access, so as to improve data transmission efficiency.

[0109] In some embodiments, if the system information includes a first area service time, the first network device is accessed when the first time is less than or equal to a second time. The first time is determined based on the first area service time, and the second time is determined based on the second area service time. The second area service time includes the start time and / or end time of the second network device serving the area where the terminal device is located.

[0110] If the determination of the first time and the second time is related to the regional service time of the network device, the first network device and the second network device may be of the same period, or on the same track, or the regional service periods of the two network devices are the same.

[0111] In some embodiments, the first regional service period of the first network device satisfies the quality of service (QoS) requirement of the current service. That is, when the operating mode of the first network device is the S&F mode and the first regional service period satisfies the QoS requirement of the current service, the terminal device accesses the first network device to improve the service quality of the terminal device.

[0112] The condition that the first area service period meets the QoS requirement of the current service may also be superimposed on at least one of the two conditions that the first area service period is less than or equal to the second area service period and the first time is less than or equal to the second time.

[0113] In some embodiments, the system information includes information of a neighboring network device of the first network device, and the information of the neighboring network device includes at least one of the following information: the working mode of the neighboring network device; the regional service period of the neighboring network device serving the same area; and the regional service time of the neighboring network device serving the area where the terminal device is located.

[0114] The term "neighboring network device" can also be understood as a network device adjacent to the first network device. When the first network device leaves and its cell no longer covers the terminal device, the terminal device's next cell may be that of the neighboring network device. Of course, the number of neighboring network devices here can be one or more. If there are multiple neighboring network devices, it can be understood that the system information broadcast by the first network device carries information about multiple neighboring network devices.

[0115] In this way, the terminal device can make a judgment based on the information of the first network device and the information of the second network device broadcast in the system information, and determine whether to access the first network device or the second network device, so as to improve the data transmission efficiency of the terminal device by selecting a network device with higher transmission efficiency.

[0116] In some embodiments, a terminal device receives an indication message for releasing a connection between a first network device and the terminal device, the indication message including a reason value for releasing the connection. The reason value indicates that the first network device is overloaded with the terminal device's uplink data buffer, or indicates that the first network device will no longer send downlink data to the terminal device. In other words, the first network device, or the S&F satellite, can manage terminal device access and data transmission based on the satellite's own load information, thereby improving the terminal device's transmission performance.

[0117] In some embodiments, a first network device may send a notification message instructing a second network device to delete or update the context of a terminal device. The second network device is a neighboring network device of the first network device. This can be understood as the second network device being the previous serving network device of the terminal device, and the first network device being the next serving network device of the terminal device. When a terminal device accesses the first network device, the second network device may be notified to delete the terminal device's context to reduce storage space usage on the second network device.

[0118] Therefore, in the present application, compared with the existing scenario where a terminal is within the coverage of a network device operating in a storage and forwarding mode and network devices with different working modes coexist, and the terminal is not sure whether to access the network device covering the terminal or wait for the network device in the neighboring area to cover the terminal for access, the present application can broadcast system information through the network device, so that the terminal determines whether to access the network device based on the system information, thereby improving the data transmission efficiency of the terminal device.

[0119] In order to facilitate understanding of the process of the embodiment of the present application, the initial access process of the terminal device is first introduced below.

[0120] Taking the terminal device as UE, the network device as gNB, and the core network as 5GC as an example, Figure 6 is a flow chart of a UE initial access process.

[0121] When a UE needs to search for a serving network to access the network, it undergoes a cell search and selection process, as well as a random access (RA) process. These two processes are fundamental to the interaction between the UE and the gNB. Without them, the UE cannot access the network, and wireless communication cannot be achieved. As shown in Figure 6, taking the initial UE access in a standalone (SA) network as an example, a 5G UE accesses an NR cell through cell search and selection, and random access. The specific process may include the following.

[0122] 1) Cell search and selection: The process by which the UE and the NR cell achieve downlink synchronization and select the NR cell with the best signal to reside in.

[0123] 2) Random access: This is the necessary process for establishing a radio link between the UE and the network. The UE establishes uplink synchronization with the NR cell through the random access process and obtains uplink resources.

[0124] 3) RRC connection establishment: The process of establishing a radio signaling bearer (SRB1) between the UE and the gNB.

[0125] 4) Initial Context Establishment: The gNB needs to know the UE context information when making various event decisions or executing various algorithms to make the most appropriate decisions. After the initial context establishment is completed, the gNB can obtain all the UE context it needs.

[0126] 5) (Optional) PDU session establishment: PDU session is used to provide PDU connectivity service between UE and data network DN, that is, to support PDU exchange between UE and data network. Therefore, the PDU session establishment process is only involved when the UE initiates data service.

[0127] Due to the particularity of S&F satellites, the UE may need to complete steps 1), 2), and 3) with the satellite, and then wait for a while until the S&F satellite and 5GC complete the necessary signaling interaction. Only when the satellite moves to the UE area again can the UE proceed to subsequent steps, such as steps 4) and 5).

[0128] Figure 7 is a flow chart of establishing a UE context. The S&F satellite may require multiple flight cycles to complete interaction with the UE and 5GC. For example, after completing step 11), the S&F satellite needs to fly to the gateway station and interact with the 5GC network element to complete step 12. If non-access stratum (NAS) messages need to be exchanged, the S&F satellite needs to fly back to the area where the UE is located to complete the transmission of NAS messages over the air interface with the UE. Steps 4) and 5) above may specifically include the following processes.

[0129] 11) After RRC is successfully established, the UE sends an RRCSetupComplete message to the gNB. The RRCSetupComplete message carries the selected PLMN-Identity, the registered AMF, the slice information (s-nssai-list), and the NAS.

[0130] 12) The gNB allocates a dedicated RAN-UE-NGAP-ID for the UE. The gNB selects the AMF network element based on the selectedPLMN-Identity, registeredAMF, and s-nssai-list, and then sends the NAS carried in the RRCSetupComplete message to the AMF network element through the Initial UE Message (INITIAL UE MESSAGE), triggering the establishment of the NG control plane (NG-C) connection.

[0131] 13) The gNB transparently transmits NAS direct messages between the UE and the AMF network element to complete identity query, authentication, NAS security mode and registration processes.

[0132] 14) The AMF network element sends an Initial Context Setup Request (INITIAL CONTEXT SETUP REQUEST) message to the gNB to start the initial context establishment process.

[0133] If the INITIAL CONTEXT SETUP REQUEST message does not carry the UE Radio Capability IE, the gNB will send a UECapabilityEnquiry message to the UE to initiate the UE Capability Enquiry process (steps 17) to 19) after the security mode process is completed. Otherwise, steps 17) to 19) are skipped.

[0134] If the INITIAL CONTEXT SETUP REQUEST message carries the PDU Session Resource Setup Request List IE, the gNB sends an encrypted and integrity-protected RRC Reconfiguration message to the UE after the UE capability query process is complete, instructing the UE to establish signaling radio bearer (SRB) 2 and data radio bearer (DRB), corresponding to steps 10 and 11. Otherwise, steps 10 and 11 are skipped.

[0135] 15) The gNB sends a SecurityModeCommand message to the UE, instructing the UE to start integrity protection and ciphering. Downlink ciphering is then initiated.

[0136] 16) The UE derives the key based on the integrity protection and encryption algorithms indicated in the SecurityModeCommand message, and then responds with a SecurityModeComplete message to the gNB. Uplink encryption is then initiated.

[0137] 17) The gNB sends a UECapabilityEnquiry message to the UE to initiate the UE capability query process.

[0138] 18) The UE replies to the gNB with a UECapabilityInformation message carrying the UE capability information.

[0139] 19) The gNB sends a UE RADIO CAPABILITY INFO INDICATION message to the AMF network element, transparently transmitting the UE capabilities.

[0140] 20) The gNB sends an RRC reconfiguration message to the UE, instructing it to establish SRB2 and DRB.

[0141] After the encryption and integrity protection are performed during the dedicated NG-C connection establishment process, the gNB sends an RRCReconfiguration message carrying the SRB Add Modification List (srb-ToAddModList) information element and the DRB Add Modification List (drb-ToAddModList) information element to the UE, instructing the UE to establish SRB2 and DRB.

[0142] 21) After receiving the RRCReconfiguration message, the UE starts to establish SRB2 and DRB. According to the message instructions:

[0143] Establish the corresponding PDCP entity and configure relevant security parameters.

[0144] Establish and configure the RLC entity.

[0145] Establish and configure a dedicated control channel (DCCH) logical channel.

[0146] Establish and configure a dedicated transmission channel (DTCH) logical channel.

[0147] After SRB2 and DRB are successfully established, the UE responds with an RRC reconfiguration complete message to the gNB.

[0148] 22) The gNB responds with an INITIAL CONTEXT SETUP RESPONSE message to the AMF network element.

[0149] FIG8 is a flow chart of a method for accessing a network device provided in an embodiment of the present application, and the method includes the following process.

[0150] 801. When the UE has completed the initial access process, the UE accesses SAT-RAN1 for data transmission.

[0151] Exemplarily, here the UE has completed the initial access process, for example, it may be that SAT-RAN1 covers the area where the UE is located for the first time, and SAT-RAN1 and the UE complete step 3) in the process shown in Figure 6, that is, the RRC connection establishment is completed. Alternatively, it may be that after SAT-RAN1 flies away, it performs steps 12) to 14) shown in Figure 7 with the core network, and then flies back to the area where the UE is located again, and completes steps 15) to 16) with the UE. Alternatively, it may be that SAT-RAN1 and the UE complete the UE capability interaction process of steps 17) to 18). Alternatively, it may be that SAT-RAN1 exchanges the UE capability information with the AMF network element of the core network, that is, after executing step 19), it flies back to the area where the UE is located for the third time, performs RRC reconfiguration with the UE, and the UE starts to establish SRB2 and DRB, etc.

[0152] In some embodiments, when the UE performs cell search and selection in step 1 above and selects SAT-RAN1 for camping, SAT-RAN1 may broadcast system information before the UE accesses the cell. The system information indicates the operating mode of SAT-RAN1 and includes at least one of a second regional service time and a second regional service period for SAT-RAN1. The second regional service time includes the start time and / or end time of the second network device serving the area where the UE is located. The second regional service period is the regional service period during which the second network device serves the same area.

[0153] Exemplarily, the system information is a system information block (SIB). If applied in LTE, the system information may be SIB31, and if applied in NR, the system information may be SIB19. Alternatively, the system information may be other newly defined SIBs.

[0154] The operating mode of SAT-RAN1 can be, for example, the S&F mode, i.e., SAT-RAN1. Alternatively, the operating mode of SAT-RAN1 can be the non-S&F mode. The non-S&F mode can be, for example, the direct connection mode, i.e., the transparent transmission mode in the NTN transparent transmission architecture, which can directly send and receive UE-related signaling or data.

[0155] Optionally, SAT-RAN1 may also broadcast information about SAT-RAN1's ​​neighboring satellites via system information, including at least one of an operating mode, a regional service time, and a regional service period. This allows the UE to perform an access determination before accessing SAT-RAN1 to determine whether to access SAT-RAN1 or wait to access SAT-RAN1's ​​neighboring satellites. For details on the determination method, refer to the implementation described in step 805.

[0156] In some embodiments, the information of the neighboring satellites may be configured to SAT-RAN1 by a management network device, that is, an operations, administration, and management (OAM) network element that manages the satellites.

[0157] 802. SAT-RAN1 performs data buffering. When the second area service time of SAT-RAN1 ends, SAT-RAN1 stops serving the current UE and releases the UE.

[0158] For example, if the operating mode of SAT-RAN1 is S&F mode, while SAT-RAN1 is serving the UE, for example, the second area service time of the area where SAT-RAN1 serves the UE is from T1 to T2, that is, the start time of SAT-RAN1 serving the area where the UE is located is T1 and the end time is T2. During the time period from T1 to T2, SAT-RAN1 can send downlink data / signaling to the UE and can also receive and buffer uplink signaling or data sent by the UE. When time T2 is reached, SAT-RAN1 stops serving the current UE.

[0159] If the working mode of SAT-RAN1 is Non-S&F mode, for example, direct connection mode, step 802 is not executed, and SAT-RAN1 directly sends and receives UE-associated signaling / data, that is, SAT-RAN1 does not perform data / signaling buffering.

[0160] In some embodiments, releasing the UE here may be that SAT-RAN1 sends a release connection message to the UE to actively release the UE, or the UE sends a release connection request message to SAT-RAN1 at a time before T2, the end time of the second area service time broadcast in the system information, to request to release the connection.

[0161] Here, when the UE releases the connection with SAT-RAN1, the UE may enter the activated state (inactive) from the connected state, or another connected state, or an enhancement of the existing state, or a new RRC state, etc., which is not limited in this application. The other connection state here is different from the connection state established between the UE and SAT-RAN1. In the other connection state, the UE does not perform data transmission, and the connection between SAT-RAN1 and the core network is not always in the connected state, or the core network element believes that the UE is periodically reachable (the UE can send and receive signaling / data). Within the specified time range (the above-mentioned service time), the UE is reachable, and the UE is unreachable at other times. Correspondingly, the signaling sent to the UE during this period needs to be suspended or canceled, the data needs to be cached, and the associated timers, such as the mobility management timer and the session management timer, also need to be suspended or stopped.

[0162] Moreover, when SAT-RAN1 releases the UE, SAT-RAN1 can retain all or part of the UE context, so that the UE can quickly access SAT-RAN1 the next time it accesses SAT-RAN1, reducing signaling interaction delay overhead.

[0163] 803. SAT-RAN1 transmits the cached UE data back to the ground gateway and core network.

[0164] For example, when SAT-RAN1 is in S&F mode, SAT-RAN1 continues to operate in orbit and, when it reaches the gateway at, for example, time T5, SAT-RAN1 transmits the buffered data / signaling back to the gateway, so that the gateway transmits the data / signaling to the core network for processing. Time T5 is related to SAT-RAN1's ​​orbit and the second-area service period.

[0165] The core network's processing of data may be the processing of data transparently transmitted by the gateway by the UPF network element in the core network, or the processing of signaling transparently transmitted by the gateway by the AMF network element in the core network. That is, the gateway may not store data / signaling.

[0166] 804. SAT-RAN2 covers the area where the UE is located. SAT-RAN2 broadcasts system information, where the system information is used to indicate a working mode of SAT-RAN2, including at least one of a first area service time and a first area service period of SAT-RAN2.

[0167] For example, when SAT-RAN1 no longer covers the area where the UE is located and the next satellite covering the area where the UE is located is SAT-RAN2, if the UE selects SAT-RAN2 to reside in during cell search and selection, the UE can receive system information broadcast by SAT-RAN1, and the system information can be used by the UE to determine whether to access SAT-RAN2.

[0168] In some embodiments, the system information broadcast by SAT-RAN2 may carry an indication of whether the operating mode of SAT-RAN2 is the S&F mode. This indication may be explicit or implicit. If the indication is explicit, it is equivalent to the system information broadcast by SAT-RAN2 including the indication of the operating mode of SAT-RAN2. If the indication is implicit, the operating mode of SAT-RAN2 may be indicated by, for example, the presence of certain information in the system information. For example, when certain information is present, the system information indicates that the operating mode of SAT-RAN2 is the S&F mode; when certain information is absent, the system information indicates that the operating mode of SAT-RAN2 is the non-S&F mode / direct connection mode (transparent transmission mode).

[0169] In some embodiments, the system information broadcast by SAT-RAN2 includes a first regional service period, which indicates the minimum time interval between SAT-RAN2 services for the same area. Alternatively, it can be understood as the minimum time interval / minimum period between two SAT-RAN2 services for the area. The first regional service period can be used by the UE to determine when SAT-RAN2 will next serve the UE. Exemplarily, the first regional service period includes the time interval between the start time / end time of SAT-RAN2 service to the UE and the start time / end time of the next SAT-RAN2 service to the UE.

[0170] In some embodiments, the system information broadcast by SAT-RAN2 includes the first area service time, or the system information broadcast by SAT-RAN2 includes not only the first area service period but also the first area service time. The first area service time includes the start time and / or end time of the area where the SAT-RAN2 serves the UE.

[0171] In some embodiments, the system information broadcast by SAT-RAN2 may not carry the first area service time, and the first area service time may be inferred based on other information of SAT-RAN2. For example, the first area service time may be inferred by the UE based on the ephemeris information and coverage information of SAT-RAN2 and the UE's own location information. For example, the UE may obtain the satellite movement trajectory of SAT-RAN2 through the ephemeris information of SAT-RAN2, and infer the first area service time based on the satellite movement trajectory, the coverage information of SAT-RAN2, and the UE's own location information.

[0172] In some embodiments, the system information broadcast by SAT-RAN2 includes information about SAT-RAN2's neighboring satellites. The neighboring satellite information includes at least one of the following: the operating mode of the neighboring satellite; the regional service period for the neighboring satellite serving the same area; and the regional service time for the neighboring satellite serving the area where the UE is located. The neighboring satellite may be the next satellite available to provide service to the UE after SAT-RAN2 releases the UE. The neighboring satellite may also be referred to as a neighboring satellite of SAT-RAN2.

[0173] 805. The UE determines to access SAT-RAN2 according to the system information.

[0174] In some embodiments, the UE may first determine the operating mode of SAT-RAN2 based on the system information broadcast by SAT-RAN2. If the operating mode of SAT-RAN2 is Non-S&F mode, such as direct connection mode, and the UE has uplink data arriving or needs to send, it determines to access SAT-RAN2. This ensures the UE's uplink data transmission efficiency.

[0175] If SAT-RAN2 is operating in S&F mode, the UE can further determine whether the first service period of SAT-RAN2 is less than the second service period of the neighboring satellite, namely SAT-RAN1. If the first service period is less than or equal to the second service period, the UE determines to access SAT-RAN2. This improves data transmission efficiency when the UE accesses SAT-RAN2.

[0176] If SAT-RAN2 is operating in S&F mode, the UE can further determine whether the first time corresponding to SAT-RAN2 is less than the second time corresponding to the neighboring satellite SAT-RAN1. The first time is the time it takes for the UE to access SAT-RAN2 and complete the transmission of its remaining data, while the second time is the time it takes for the UE to wait for the connection with SAT-RAN1 to be restored and complete the transmission of its remaining data. If the first time is less than or equal to the second time, the UE determines to access SAT-RAN2. This improves the UE's data transmission efficiency when accessing SAT-RAN2.

[0177] The first time may be determined by the UE based on the first-area service cycle, and the second time may be determined by the UE based on the second-area service cycle. Alternatively, when the system information broadcast by SAT-RAN2 includes the first-area service cycle and the first-area service time, the first time may be determined by the UE based on the first-area service cycle and the first-area service time. Similarly, the second time may be determined by the UE based on the second-area service cycle and the first-area service time, and the second-area service time may include the start time and / or end time of the area where the SAT-RAN1 serves the UE.

[0178] Among them, if the first time can be determined by the UE according to the first area service cycle, and the second time is determined by the UE according to the second area service cycle, SAT-RAN2 and SAT-RAN1 can be understood as the same area service time, so the size of the first time and the second time can be determined by the area service cycle.

[0179] In some embodiments, the system information broadcast by SAT-RAN2 includes a first regional service time. If SAT-RAN2 operates in S&F mode, the UE may further determine whether the first time corresponding to SAT-RAN2 is less than the second time corresponding to the neighboring satellite SAT-RAN1. If the first time is less than or equal to the second time, the UE determines to access SAT-RAN2. The first time is the time it takes for the UE to access SAT-RAN2 and complete transmission of the remaining UE data, and the second time is the time it takes for the UE to wait for reestablishment of connection with SAT-RAN1 and complete transmission of the remaining UE data. The first time is determined based on the first regional service time, and the second time is determined based on the second regional time. This method of determining the data transmission time based on the regional service time can be used when SAT-RAN2 and SAT-RAN1 operate in the same orbit and have the same regional service cycles for the two satellites.

[0180] Here, by comparing the first time and the second time, the UE determines whether to access SAT-RAN2. It can be assumed that the UE also considers the time spent previously accessing SAT-RAN1 when making this determination. For example, if the first-area service period of SAT-RAN2 is shorter than the second-area service period of SAT-RAN1, the time required for the UE to wait for SAT-RAN1 to complete the transmission of the remaining data (the sum of the time from SAT-RAN1 time T5 to time T1 and the time between T1 and T2) is longer. However, if SAT-RAN2 is determined to be accessed, the time required to re-complete the initial access to SAT-RAN2 and transmit the remaining data is shorter. The UE can then select SAT-RAN2, and the UE's data transmission efficiency is also higher.

[0181] In some embodiments, the UE may also determine to access SAT-RAN2 when it is determined that the first area service period is less than or equal to the second area service period and the first time is less than or equal to the second time, that is, when both conditions are met. If one of the conditions is not met, the UE determines to wait to access SAT-RAN1 again.

[0182] In some embodiments, if the operating mode of SAT-RAN2 is S&F mode, the UE may further determine whether the first regional service cycle of SAT-RAN2 meets the QoS requirements of the current service. If the first regional service cycle of SAT-RAN2 meets the QoS requirements of the current service, and the second regional service cycle of SAT-RAN1 does not, the UE determines to access SAT-RAN2. If the first regional service cycle of SAT-RAN2 meets the QoS requirements of the current service, and the second regional service cycle of SAT-RAN1 also meets the QoS requirements of the current service, the UE determines to access SAT-RAN1. This is because the UE has previously performed an access procedure with SAT-RAN1 and SAT-RAN1 still stores all or part of the UE's context. If the regional service cycles of both satellites meet the QoS requirements, the UE can improve the efficiency of remaining data transmission when accessing SAT-RAN1.

[0183] For example, the UE may determine, based on the second regional service period, that SAT-RAN1 is far away from the UE when serving the UE. Considering that the UE's transmit power is effective, this may result in a low transmission rate, high latency, poor jitter, etc. when SAT-RAN1 is serving the UE. The UE may determine that SAT-RAN1 does not meet the QoS requirements of the current service. Conversely, if the UE may determine, based on the first regional service period, that SAT-RAN2 is close to the UE when serving the UE, the UE may determine that SAT-RAN2 meets the QoS requirements of the current service.

[0184] In some embodiments, the conditions for determining whether the satellite meets the QoS requirements of the current business through the regional service cycle can also be used for access judgment at the same time as the above-mentioned conditions related to the first regional service cycle, or can also be used for access judgment at the same time as the above-mentioned conditions related to the first regional service time, or can also be used for access judgment at the same time as the above-mentioned conditions related to the first regional service cycle and the above-mentioned conditions related to the first regional service time.

[0185] 806. The UE completes RACH with SAT-RAN2 and performs data transmission.

[0186] That is, when the UE determines to access SAT-RAN2, for example, when the UE receives the RRCSetupComplete message sent by SAT-RAN2, the UE and SAT-RAN2 perform data / signaling transmission, including the UE continuing to send the remaining data to SAT-RAN2, and SAT-RAN2 completing the uplink and downlink data transmission with the core network device, and the core network and even the server perform application (App) layer data merging.

[0187] 807. SAT-RAN2 notifies SAT-RAN1 to delete the UE context.

[0188] In some embodiments, after the UE accesses SAT-RAN2, when SAT-RAN2 operates over a gateway, SAT-RAN2 may send a notification message, where the notification message is used to instruct SAT-RAN1 to delete or update the context of the UE.

[0189] For example, when SAT-RAN2 is operating over a gateway station, SAT-RAN2 can notify the core network element through a notification message and the gateway station that the UE has completed the re-establishment of the context. The core network element then notifies SAT-RAN1 to delete the UE context to reduce the storage space occupied by SAT-RAN1.

[0190] 808. SAT-RAN2 sends indication information to the UE, where the indication information is used to release the connection between the first network device and the terminal device, and the indication information includes a reason value for releasing the connection.

[0191] If the buffer space allocated by SAT-RAN2 to the UE is about to reach the buffer threshold and SAT-RAN2 will have no more space to buffer the UE's data / signaling, SAT-RAN2 may release the connected UE through an indication message. The carried cause value is used to indicate that the uplink data buffered by SAT-RAN2 for the UE is overloaded, and non-connected UEs are prohibited from accessing SAT-RAN2.

[0192] For example, when the UE attempts to access SAT-RAN2, SAT-RAN2 may prohibit the UE from accessing SAT-RAN2 through an RRC Reject message or by broadcasting a message to the entire cell. For example, SAT-RAN2 prohibits the UE from accessing SAT-RAN2 by broadcasting system information or a paging message. Accordingly, the UE suspends data transmission to SAT-RAN2 or suspends access to SAT-RAN2. The UE may wait for service from the next satellite or continue to wait for the next service from SAT-RAN2 (if the UE determines to access SAT-RAN2).

[0193] Alternatively, if SAT-RAN2 no longer sends downlink data to the UE after sending the downlink data, SAT-RAN2 may also send an indication message to the UE to release the UE. The cause value in the indication message is used to indicate that SAT-RAN2 no longer sends downlink data to the UE. The indication message is, for example, an RRC Release (RRCRelease) message. A newly defined cause value may also be carried in the RRCRelease message to indicate that the UE has no downlink data to send.

[0194] Alternatively, if the buffer space allocated by SAT-RAN2 to the UE is about to reach the buffer threshold and SAT-RAN2 has finished sending downlink data, SAT-RAN2 sends an indication message to the UE to release the UE, and the indication message includes the above two cause values.

[0195] In this way, the S&F satellite can manage UE access and data transmission based on its own load information or downlink data transmission status.

[0196] In this application, if applied under the ORAN architecture, the above-mentioned SAT-RAN2 and SAT-RAN1 can also be replaced by a functional module of the satellite, such as CU-CP.

[0197] Therefore, in this application, in a scenario where satellites with different working modes coexist, the UE is not sure whether to access the satellite covering the terminal or wait for the satellite in the neighboring area to cover the UE for access. This application can broadcast system information through the satellite, so that the UE can determine whether to access the satellite in the currently covered area based on the system information, thereby improving the data transmission efficiency of the UE.

[0198] It is understood that in order to implement the functions in the above embodiments, the network devices and terminal devices include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily appreciate that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0199] FIG9 is a schematic diagram of the structure of a possible communication device provided by an embodiment of the present application. These communication devices can be used to implement the functions of the terminal device or network device in the above-mentioned method embodiment, and thus can also achieve the beneficial effects possessed by the above-mentioned method embodiment. In an embodiment of the present application, the communication device can be a terminal 120 as shown in FIG1 , or a RAN node 110 as shown in FIG1 , or a module (such as a chip) applied to a terminal or a RAN node. Among them, the RAN node may include a satellite, such as a satellite whose working mode in the present application is the S&F mode. The satellite can implement some or all of the functions of a RAN node, such as a base station.

[0200] As shown in Figure 9, the communication device 900 includes a processing unit 910 and a transceiver unit 920. The communication device 900 is used to implement the functions of the terminal device or the first network device in the method embodiments shown in Figures 5 and 8 above.

[0201] When the communication device 900 is used to implement the function of the terminal device in the method embodiment shown in Figure 5: the transceiver unit 920 is used to receive system information, the system information is used to indicate the working mode of the first network device, and the working mode is a storage and forwarding mode; the processing unit 910 is used to access the first network device.

[0202] When the communication device 900 is used to implement the functions of the UE in the method embodiment shown in Figure 8: the transceiver unit 920 is used to receive the system information broadcast by SAT-RAN2; complete the RACH with SAT-RAN2 and perform data transmission; the processing unit 910 is used to complete the initial access process, and the UE accesses SAT-RAN1 for data transmission; and determines to access SAT-RAN2 based on the system information.

[0203] When the communication apparatus 900 is used to implement the function of the first network device in the method embodiment shown in FIG5 : the transceiver unit 920 is used to send system information, and the system information is used to indicate the working mode of the first network device, and the working mode is the store and forward mode.

[0204] When the communication device 900 is used to implement the functions of SAT-RAN1 / SAT-RAN2 in the method embodiment shown in Figure 8: the processing unit 910 is used to cache data; release the UE; the transceiver unit 920 is used to: transmit the cached UE data back to the ground gateway and the core network; broadcast system information, where the system information is used to indicate the working mode of SAT-RAN2, which includes at least one of the first area service time and the first area service period of SAT-RAN2; notify SAT-RAN1 to delete the UE context; and send indication information to the UE, where the indication information is used to release the connection between the first network device and the terminal device, and the indication information includes a reason value for releasing the connection.

[0205] For a more detailed description of the processing unit 910 and the transceiver unit 920 , reference may be made to the relevant descriptions in the method embodiments shown in FIG. 5 and FIG. 8 .

[0206] Figure 10 shows a schematic diagram of the structure of a possible communication device. It is understood that the communication device 10000 includes necessary means such as modules, units, elements, circuits, or interfaces, which are appropriately configured together to implement the present solution. The communication device 10000 can be the RAN node, terminal, core network device, or other network device shown in Figure 1, such as the NTN payload shown in Figure 3, or a component (e.g., a chip) in these devices, used to implement the methods described in the following method embodiments. The communication device 10000 includes one or more processors 111. The processor 111 can be a general-purpose processor or a dedicated processor. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device (e.g., RAN node, NTN payload, terminal, or chip), execute software programs, and process software program data.

[0207] Optionally, in one design, the processor 111 may include a program 113 (sometimes also referred to as code or instruction), which may be executed on the processor 111 to enable the communication apparatus 10000 to perform the method described in the above embodiment. In another possible design, the communication apparatus 10000 includes a circuit (not shown in FIG. 10 ), which is configured to implement the functions of the terminal device / first network device / UE / SAT-RAN1 / SAT-RAN2 in the above embodiment.

[0208] Optionally, the communication device 10000 may include one or more memories 112, on which a program 114 (sometimes also referred to as code or instructions) is stored. The program 114 can be run on the processor 111, so that the communication device 10000 performs the method described in the following method embodiment.

[0209] Optionally, the processor 111 and / or the memory 112 may include artificial intelligence (AI) modules 117 and 118, which are used to implement AI-related functions. The AI ​​module may be implemented through software, hardware, or a combination of software and hardware. For example, the AI ​​module may include a radio access network intelligent controller (RAN intelligent controller, RIC) module. For example, the AI ​​module may be a near real-time RIC or a non-real-time RIC.

[0210] Optionally, data may be stored in the processor 111 and / or the memory 112. The processor and the memory may be provided separately or integrated together.

[0211] Optionally, the communication device 10000 may further include a transceiver 115 and / or an antenna 116. The processor 111 may also be referred to as a processing unit, and controls the communication device (e.g., a RAN node or terminal). The transceiver 115 may also be referred to as a transceiver unit, a transceiver, a transceiver circuit, or a transceiver, and is configured to implement the transceiver functions of the communication device through the antenna 116.

[0212] When the communication device 10000 is used to implement the method shown in FIG. 5 or FIG. 8 , the processor 111 is used to implement the functions of the processing unit 910 , and the transceiver 115 is used to implement the functions of the transceiver unit 920 .

[0213] When the above-mentioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above-mentioned method embodiment. When the terminal chip receives information from the base station, it can be understood that the information is first received by other modules in the terminal (such as a radio frequency module or antenna) and then sent to the terminal chip by these modules. When the terminal chip sends information to the base station, it can be understood that the information is first sent to other modules in the terminal (such as a radio frequency module or antenna) and then sent to the base station by these modules.

[0214] When the above-mentioned communication device is a chip applied to a base station, the base station chip implements the functions of the base station in the above-mentioned method embodiment. When the base station chip receives information from the terminal, it can be understood that the information is first received by other modules in the base station (such as a radio frequency module or antenna) and then sent to the base station chip by these modules. When the base station chip sends information to the terminal, it can be understood that the information is sent to other modules in the base station (such as a radio frequency module or antenna) and then sent to the terminal by these modules.

[0215] In this application, when entity A sends information to entity B, it can be done directly from A to B or indirectly through another entity. Similarly, when entity B receives information from entity A, it can be done directly from entity B or indirectly through another entity. Entities A and B herein can be RAN nodes or terminals, or modules within a RAN node or terminal. The sending and receiving of information can be information exchange between a RAN node and a terminal, for example, between a base station and a terminal; the sending and receiving of information can also be information exchange between two RAN nodes, for example, between a CU and a DU; the sending and receiving of information can also be information exchange between different modules within a device, for example, between a terminal chip and other modules in the terminal, or between a base station chip and other modules within the base station.

[0216] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0217] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and storage medium can also exist in a base station or a terminal as discrete components.

[0218] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0219] In the various embodiments of the present application, unless otherwise specified or there is any logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0220] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0221] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

Claims

1. A method for accessing a network device, characterized in that: include: receiving system information, where the system information is used to indicate an operating mode of the first network device, where the operating mode is a store and forward mode; Access the first network device.

2. The method according to claim 1, characterized in that The system information includes a first area service period, where the first area service period is used to indicate a shortest time interval for the first network device to serve the same area.

3. The method according to claim 2, characterized in that The first area service period is less than or equal to a second area service period, wherein the second area service period is an area service period of a second network device serving the same area, and the second network device is a neighboring area network device of the first network device.

4. The method according to claim 2 or 3, characterized in that The system information further includes a first area service time, where the first area service time includes a start time and / or an end time when the first network device serves an area where the terminal device is located.

5. The method according to claim 4, characterized in that The first time is less than or equal to the second time. The first time is the time it takes for the terminal device to access the first network device and transmit the remaining data of the terminal device. The second time is the time it takes for the terminal device to wait for the connection with the second network device to be restored and transmit the remaining data of the terminal device.

6. The method according to claim 5, characterized in that The first time is determined according to the first area service cycle, and the second time is determined according to the second area service cycle; Alternatively, the first time is determined based on the first area service cycle and the first area service time, the second time is determined based on the second area service cycle and the second area service time, and the second area service time includes the start time and / or end time of the second network device serving the area where the terminal device is located.

7. The method according to claim 1, characterized in that The system information includes a first area service time, and the first area service time includes a start time and / or an end time when the first network device serves an area where the terminal device is located.

8. The method according to claim 7, characterized in that The first time is less than or equal to the second time, the first time is the time it takes for the terminal device to access the first network device and complete the transmission of the remaining data of the terminal device, and the second time is the time it takes for the terminal device to wait for the connection with the second network device to be restored and complete the transmission of the remaining data of the terminal device; The first time is determined based on the first area service time, the second time is determined based on the second area service time, and the second area service time includes the start time and / or end time of the second network device serving the area where the terminal device is located.

9. The method according to any one of claims 1 to 8, characterized in that The first area service period of the first network device meets the service quality requirement of the current service.

10. The method according to any one of claims 1 to 9, characterized in that The system information includes information about a neighboring network device of the first network device, and the information about the neighboring network device includes at least one of the following information: The working mode of the neighboring area network device; the regional service period of the neighboring area network device serving the same area; and the regional service time of the neighboring area network device serving the area where the terminal device is located.

11. The method according to any one of claims 1 to 10, characterized in that The method further comprises: receiving indication information, where the indication information is used to release the connection between the first network device and the terminal device, and the indication information includes a reason value for releasing the connection; The cause value is used to indicate that the first network device is overloaded with uplink data cached by the terminal device, or the cause value is used to indicate that the first network device no longer sends downlink data to the terminal device.

12. The method according to any one of claims 3 to 11, characterized in that: The first network device and the second network device are satellites.

13. A method for accessing a network device, characterized in that: include: Sending system information, where the system information is used to indicate an operating mode of the first network device, where the operating mode is a store and forward mode; Establish a connection with the terminal device.

14. The method according to claim 13, characterized in that The system information includes a first area service period, where the first area service period is used to indicate a shortest time interval for the first network device to serve the same area.

15. The method according to claim 13 or 14, characterized in that The system information includes a first area service time, and the first area service time includes a start time and / or an end time when the first network device serves the area where the terminal device is located.

16. The method according to any one of claims 13 to 15, characterized in that: The system information includes information about a neighboring network device of the first network device, and the information about the neighboring network device includes at least one of the following information: The working mode of the neighboring area network device; the regional service period of the neighboring area network device serving the same area; and the regional service time of the neighboring area network device serving the area where the terminal device is located.

17. The method according to any one of claims 13 to 16, characterized in that: The method further comprises: Send a notification message, where the notification message is used to instruct a second network device to delete or update the context of the terminal device, where the second network device is a neighboring network device of the first network device.

18. The method according to any one of claims 13 to 17, characterized in that: The method further comprises: Sending instruction information, where the instruction information is used to release the connection between the first network device and the terminal device, and the instruction information includes a reason value for releasing the connection; The cause value is used to indicate that the first network device is overloaded with uplink data cached by the terminal device, or the cause value is used to indicate that the first network device no longer sends downlink data to the terminal device.

19. A communication device, characterized in that: include: a receiving unit, configured to receive system information, wherein the system information is used to indicate an operating mode of the first network device, wherein the operating mode is a store and forward mode; A processing unit is used to access the first network device.

20. A communication device, characterized in that: include: a sending unit, configured to send system information, wherein the system information is used to indicate an operating mode of the first network device, wherein the operating mode is a store and forward mode; A processing unit is used to establish a connection with a terminal device.

21. A communication device, characterized in that: The communication device comprises at least one processor connected to a memory, and the at least one processor is configured to read and execute a program stored in the memory, so that the communication device executes the method according to any one of claims 1 to 18.

22. A communication system, characterized in that: The method comprises a first communication device and a second communication device, wherein the first communication device is used to execute the method according to any one of claims 1 to 12, and the second communication device is used to execute the method according to any one of claims 13 to 18.

23. A computer-readable storage medium, characterized in that The method comprises computer instructions, which, when executed on a communication device, enable the method according to any one of claims 1 to 18 to be performed.

24. A chip, characterized in that: The chip is coupled to a memory and is configured to read and execute program instructions stored in the memory to implement the method according to any one of claims 1 to 18.

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