Registration and session establishment method and device, communication system and storage medium

Abstract

The invention provides a registration and session establishment method and device, a communication system and a storage medium. The method can be applied to the technical field of wireless communication. In the scheme, non-ground access AMF-NT and SMF-NT are deployed on a satellite, AMF-T and SMF-T are deployed on the ground, and the registration process and the session establishment process are fused by using the network elements of the core network, so that the total interaction times of the two processes are effectively reduced, and the interaction time delay and the service waiting duration of the terminal equipment and the core network equipment are reduced. The SMF-NT decodes and preprocesses the PDU session establishment request, so that DoS attacks can be effectively avoided, and the ground response duration in the session management process is reduced to a certain extent.

Description

Technical Field

[0001] The present application relates to the field of wireless communications, and in particular to a registration and session establishment method, device, communication system, and storage medium. Background Art

[0002] In the user registration process and protocol data unit (PDU) session establishment process specified by 3GPP, the PDU session establishment process typically occurs after the user registration process is completed. From the time the terminal device initiates a registration request or PDU session establishment request, a series of complex interactions between multiple network elements are required, and the terminal device and the core network also undergo multiple rounds of interaction. The long interval between these two processes increases the interaction latency between the terminal device and the core network and service wait time. Summary of the Invention

[0003] The present application provides a registration and session establishment method, device, communication system and storage medium, which solves the problem of interaction delay in the overall process of user registration and PDU session establishment.

[0004] To achieve the above objectives, this application adopts the following technical solutions: In a first aspect, the present application provides a registration and session establishment method. This method can be executed, for example, by a terminal device, or by a component configured in the terminal device (such as a circuit, chip, or chip system), or by a logic module or software that implements all or part of the terminal device's functions. The following description uses a terminal device as an example.

[0005] The method may include: a terminal device sending a registration request message to a non-terrestrial device; the terminal device sending a PDU session establishment request message to the non-terrestrial device, where the PDU session establishment request message may include a first information identifier, and the first information identifier may be used to instruct the non-terrestrial device to pre-process and store the PDU session establishment request message; and the terminal device receiving a registration and PDU session establishment accept message from the non-terrestrial device. The registration and PDU session establishment accept message is used to indicate that the registration process and the PDU session establishment process are successful.

[0006] In the above solution, by integrating the PDU session establishment process into the registration process, the total number of interactions between the two processes is effectively reduced, the interaction delay between the terminal device and the core network device and the service waiting time are reduced, and the service experience is improved. In addition, by adding a first information identifier to the PDU session establishment request message, the non-ground device can be instructed to pre-process and store the PDU session establishment request message when the feeder circuit is unavailable. In this way, when the feeder circuit is restored, the non-ground device directly forwards the pre-processed PDU session establishment request message to the ground device, thereby reducing the ground response time during the session management process to a certain extent.

[0007] In one possible implementation, the non-ground device may include an SMF-NT. The first information identifier may be used to instruct the SMF-NT to pre-process and store the PDU session establishment request message. In related technologies, the SMF is not deployed onboard the satellite and lacks the ability to decode and pre-process the PDU session establishment request message. In the above solution, by deploying the SMF-NT onboard the satellite, the SMF-NT can pre-process the PDU session establishment request based on the first information identifier, thereby reducing the ground response time during the session management process to a certain extent.

[0008] In one possible implementation, the non-ground device may further include an AMF-NT. The security mode response message may further include a second information identifier, and the second information identifier is used to instruct the AMF-NT to forward the PDU session establishment request message to the SMF-NT. In the related art, the AMF-NT set up on the satellite does not have the ability to decode and pre-process the PDU session establishment request message. In the above scheme, by adding the second information identifier, the AMF-NT set up on the satellite can forward the PDU session establishment request message to the SMF-NT set up on the ground, thereby not only reducing the storage pressure of the AMF-NT, but also realizing the pre-processing of the PDU session establishment request.

[0009] In one possible implementation, before the terminal device sends a PDU session establishment request message to the non-ground device, the method may further include: receiving a security mode command from the non-ground device. As an example, the terminal device may enable a security context in response to the security mode command, and send a security mode response message to the non-ground device, where the security mode response message includes the PDU session establishment request message. It can be understood that the terminal device returns a security mode response message, which is deemed to be the completion of the NAS security context establishment. Carrying the PDU session establishment request message in the security mode response message can ensure that the PDU session establishment request message is securely protected. As another example, the terminal device may first send a security mode response message to the non-ground device, and then send a PDU session establishment request message to the non-ground device, that is, the security mode response message does not carry the PDU session establishment request message.

[0010] In one possible implementation, before the terminal device receives the security mode command from the non-terrestrial device, the method may further include: the terminal device receiving an authentication request message from the non-terrestrial device; and the terminal device sending an authentication response message to the non-terrestrial device. In the above solution, after the terminal device sends the registration request message to the non-terrestrial device, the core network begins the user authentication process and returns an authentication request message to the terminal device to complete user authentication.

[0011] In one possible implementation, the method may further include: in the case where registration and PDU session establishment fail, receiving a registration and PDU session establishment rejection message from a non-ground device, the registration and PDU session establishment rejection message being used to indicate that registration and PDU session establishment failed. Alternatively, in the case where registration establishment is successful but PDU session establishment fails, receiving a registration acceptance message from a non-ground device, the registration acceptance message including first indication information being used to indicate that PDU session establishment failed. In the above scheme, when both registration and PDU session establishment are successful, or when registration is successful and PDU session establishment fails, or when both registration and PDU session establishment fail, by merging and returning one message, the number of interactions between the terminal device and the network side device can be reduced, and signaling overhead can be reduced. In addition, regardless of whether registration and PDU session establishment are successful, corresponding information is returned to the terminal device, which can improve the terminal device's perception of the network and indicate user behavior.

[0012] In a second aspect, the present application provides a registration and session establishment method. This method can be performed, for example, by a non-terrestrial device, or by a component configured within the non-terrestrial device (such as a circuit, chip, or chip system). It can also be implemented by a logic module or software that implements all or part of the terminal device's functionality. The following description uses a non-terrestrial device as an example.

[0013] The method may include: a non-ground device receives a registration request message from a terminal device; the non-ground device receives a PDU session establishment request message from the terminal device, and the PDU session establishment request message may include a first information identifier; the non-ground device pre-processes and stores the PDU session establishment request message based on the first information identifier; the non-ground device sends a safety mode response message and a pre-processed PDU session establishment request message to the ground device, and the safety mode response message sent to the ground device may not include the PDU session establishment request message; the non-ground device receives a registration and PDU session establishment acceptance message from the ground device; the non-ground device sends a registration and PDU session establishment acceptance message to the terminal device, and the registration and PDU session establishment acceptance message is used to indicate that the registration and PDU session establishment are successful.

[0014] In the above solution, by integrating the PDU session establishment process into the registration process, the total number of interactions between the two processes is effectively reduced, the interaction delay between the terminal device and the core network device and the service waiting time are reduced, and the service experience is improved. In addition, by adding a first information identifier to the PDU session establishment request message, the non-ground device can pre-process and store the PDU session establishment request message when the feeder circuit is unavailable. In this way, when the feeder circuit is restored, the non-ground device directly forwards the pre-processed PDU session establishment request message to the ground device, thereby reducing the ground response time during the session management process to a certain extent.

[0015] It should be noted that for non-geostationary orbit devices such as low-orbit satellites, the satellite's coverage varies at different times. As the terminal device orbits the Earth, it will intermittently receive service from a particular satellite. The aforementioned non-terrestrial devices are not limited to a single satellite providing service to the terminal device; that is, the non-terrestrial devices may include multiple non-terrestrial devices, such as a first non-terrestrial device, a second non-terrestrial device, a third non-terrestrial device, and a fourth non-terrestrial device.

[0016] In one possible implementation, the non-terrestrial device may include a first non-terrestrial device, and the first non-terrestrial device may include an SMF-NT. The non-terrestrial device pre-processing and storing the PDU session establishment request message based on the first information identifier may include: the SMF-NT decoding the PDU session establishment request message to obtain the first information identifier, and pre-processing and storing the PDU session establishment request message based on the first information identifier.

[0017] In one possible implementation, the first non-terrestrial device may further include an AMF-NT. Receiving a PDU session establishment request message from a terminal device may include: the AMF-NT sending a secure mode command to the terminal device; the AMF-NT receiving a secure mode response message from the terminal device, the secure mode response message including a second information identifier and the PDU session establishment request message; the AMF-NT decoding the secure mode response message to obtain the second information identifier and the PDU session establishment request message, and forwarding the PDU session establishment request message to the SMF-NT based on the second information identifier. It is understood that the terminal device's return of the secure mode response message is considered to complete the establishment of the NAS security context. Carrying the PDU session establishment request message within the secure mode response message can ensure that the PDU session establishment request message is securely protected. Furthermore, by adding the second information identifier, the onboard AMF-NT can forward the PDU session establishment request message to the terrestrial SMF-NT, thereby reducing the storage pressure on the AMF-NT and enabling pre-processing of the PDU session establishment request.

[0018] In one possible implementation, the ground device may include AMF-T and SMF-T. The non-ground device sends a pre-processed PDU session establishment request message to the ground device, which may include: when the feeder link is available, AMF-NT sends a security mode response message to AMF-T, and SMF-NT sends a pre-processed PDU session establishment request message to SMF-T. Among them, the security mode response message sent to the ground device does not include the PDU session establishment request message. In the above scheme, when the feeding power is unavailable, AMF-NT and SMF-NT temporarily store the message; when the feeding power is available, AMF-NT and SMF-NT send the stored message to the ground device. For delay-tolerant services such as SMS, MTC and CIoT, the store-and-forward mode improves communication reliability and flexibility.

[0019] In one possible implementation, the non-terrestrial device may include a second non-terrestrial device. The non-terrestrial device receiving a registration and PDU session establishment accept message from the terrestrial device may include: the second non-terrestrial device receiving a registration and PDU session establishment accept message from the AMF-T. The non-terrestrial device sending a registration and PDU session establishment accept message to the terminal device may include: the second non-terrestrial device sending a registration and PDU session establishment accept message to the terminal device.

[0020] In one possible implementation, the method may further include: in the event that registration and PDU session establishment fail, the second non-ground device receives a registration and PDU session establishment rejection message from the ground device, and sends a registration and PDU session establishment rejection message to the terminal device, where the registration and PDU session establishment rejection message is used to indicate that registration and PDU session establishment failed. Alternatively, in the event that registration establishment succeeds but PDU session establishment fails, the second non-ground device receives a registration acceptance message from the ground device, and sends a registration acceptance message to the terminal device, where the registration acceptance message includes first indication information, where the first indication information is used to indicate that PDU session establishment failed.

[0021] In one possible implementation, the non-ground device may include a third non-ground device. The ground device receiving the registration request message from the terminal device may include: the third non-ground device receiving the registration request message from the terminal device; and the third non-ground device sending the registration request message to the ground device.

[0022] In one possible implementation, the non-ground device may include a fourth non-ground device. After the third non-ground device sends a registration request message to the ground device, the method may further include: the fourth non-ground device receiving an authentication request message from the ground device; the fourth non-ground device sending an authentication request message to the terminal device; the fourth non-ground device receiving an authentication response message from the terminal device; and the fourth non-ground device sending an authentication response message to the ground device.

[0023] The second aspect is the implementation on the non-ground equipment side corresponding to the first aspect. The explanation, supplement and description of the beneficial effects of the first aspect are also applicable to the second aspect and will not be repeated here.

[0024] In a third aspect, the present application provides a registration and session establishment method. This method can be executed, for example, by ground equipment, or by components configured within the ground equipment (such as circuits, chips, or chip systems), or by a logic module or software that implements all or part of the terminal device's functionality. The following description uses ground equipment as an example.

[0025] The method may include: the ground device receives a registration request message from a non-ground device; the ground device receives a pre-processed PDU session establishment request message from the non-ground device and stores the PDU session establishment request message; the ground device executes a registration process in response to a security mode response message; after the registration is successful, the ground device executes a PDU session establishment process based on the stored PDU session establishment request message; after the PDU session establishment process is successful, the ground device sends a registration and PDU session establishment acceptance message to the non-ground device, and the registration and PDU session establishment acceptance message is used to indicate that the registration and PDU session establishment are successful.

[0026] In the above solution, by integrating the PDU session establishment process into the registration process, the total number of interactions between the two processes is effectively reduced, reducing the interaction delay and service waiting time between terminal devices and core network devices, and improving the service experience. In addition, when the feeder circuit is unavailable, the non-ground device pre-processes and stores the PDU session establishment request message. When the feeder circuit is restored, the non-ground device directly forwards the pre-processed PDU session establishment request message to the ground device, thereby reducing the ground response time during the session management process to a certain extent.

[0027] In one possible implementation, the terrestrial device includes an SMF-T. The non-terrestrial device includes a first non-terrestrial device. The first non-terrestrial device includes an SMF-NT. Receiving a pre-processed PDU session establishment request message from the non-terrestrial device includes: the SMF-T receiving the pre-processed PDU session establishment request message from the SMF-NT.

[0028] In one possible implementation, the ground device further includes an AMF-T. The first non-ground device further includes an AMF-NT. Executing a registration process includes: the AMF-T sending a security mode command to the AMF-NT, receiving a security mode response message from the AMF-NT, and executing the registration process in response to the security mode response message. After successful registration, based on the stored PDU session establishment request message, executing a PDU session establishment process includes: after successful registration, the AMF-T sending a notification message to the SMF-T, the notification message being used to indicate successful registration; and the SMF-T executing the PDU session establishment process based on the stored PDU session establishment request message.

[0029] In one possible implementation, the non-terrestrial device may include a second non-terrestrial device. The terrestrial device sending a registration and PDU session establishment accept message to the non-terrestrial device may include: if the registration and PDU session establishment are successful, the terrestrial device sending the registration and PDU session establishment accept message to the second non-terrestrial device, where the second non-terrestrial device is the next non-terrestrial device covering the terminal device.

[0030] In one possible implementation, the method may further include: in the event that registration and PDU session establishment fail, sending a registration and PDU session establishment rejection message to the second non-ground device, where the registration and PDU session establishment rejection message is used to indicate that registration and PDU session establishment failed; or, in the event that registration establishment is successful but PDU session establishment fails, sending a registration acceptance message to the second non-ground device, where the registration acceptance message includes first indication information, where the first indication information is used to indicate that PDU session establishment failed.

[0031] In one possible implementation, the non-terrestrial device includes a third non-terrestrial device. Receiving a registration request message from the non-terrestrial device includes: the terrestrial device receiving the registration request message from the third non-terrestrial device; and performing a user authentication process in response to the registration request message.

[0032] In one possible implementation, the non-terrestrial device further includes a fourth non-terrestrial device. After performing the user authentication process, the method may further include: the terrestrial device sending an authentication request message to the fourth non-terrestrial device; and receiving an authentication response message from the fourth non-terrestrial device.

[0033] The third aspect is the implementation of the non-ground equipment side corresponding to the first aspect. The explanations, supplements and descriptions of the beneficial effects of the first and second aspects are also applicable to the third aspect and will not be repeated here.

[0034] In a fourth aspect, an electronic device is provided, comprising a communication module. The communication module can be configured to: send a registration request message to a non-terrestrial device; receive a secure mode command from the non-terrestrial device; send a secure mode response message to the non-terrestrial device, wherein the secure mode response message may include a PDU session establishment request message, wherein the PDU session establishment request message may include a first information identifier, and wherein the first information identifier may be used to instruct the non-terrestrial device to pre-process and store the PDU session establishment request message; and receive a registration and PDU session establishment accept message from the non-terrestrial device.

[0035] In a fifth aspect, an electronic device is provided, which includes a communication module and a processing module. The communication module can be used to: receive a registration request message from a terminal device; send a safe mode command to the terminal device; receive a safe mode response message from the terminal device, the safe mode response message may include a PDU session establishment request message, and the PDU session establishment request message may include a first information identifier. The processing module can be used to: pre-process and store the PDU session establishment request message based on the first information identifier. The communication module can also be used to: send a safe mode response message and a pre-processed PDU session establishment request message to a ground device, the safe mode response message sent to the ground device cannot include a PDU session establishment request message; receive a registration and PDU session establishment acceptance message from the ground device; and send a registration and PDU session establishment acceptance message to the terminal device.

[0036] In a sixth aspect, an electronic device is provided, comprising a communication module and a processing module. The communication module may be configured to receive a safety mode response message and a pre-processed PDU session establishment request message from a non-terrestrial device, and store the PDU session establishment request message. The processing module may be configured to execute a registration process in response to the safety mode response message; and after successful registration, execute a PDU session establishment process based on the stored PDU session establishment request message. The communication module may also be configured to send a registration and PDU session establishment acceptance message to the non-terrestrial device after the PDU session establishment process is successful.

[0037] The fourth, fifth and sixth aspects are the device-side implementations corresponding to the first, second and third aspects. The explanations, supplements and descriptions of the beneficial effects of the first, second and third aspects also apply to the fourth, fifth and sixth aspects and will not be repeated here.

[0038] In a seventh aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and can be configured to execute instructions or data in the memory to implement the method of any possible implementation of the first aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

[0039] In an eighth aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and can be configured to execute instructions or data in the memory to implement the method of any possible implementation of the second aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

[0040] In a ninth aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and can be configured to execute instructions or data in the memory to implement the method of any possible implementation of the third aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

[0041] In a tenth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method in any possible implementation of any aspect.

[0042] In a specific implementation, the processor may be one or more chips, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter. The input circuit and the output circuit may be the same circuit, which functions as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation of the processor and various circuits.

[0043] In the eleventh aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instructions), which, when executed, enables a computer to execute a method in any possible implementation of any of the above aspects.

[0044] In a twelfth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program (also referred to as code or instructions). When the computer-readable storage medium is executed, the computer executes the method in any possible implementation of any of the above aspects.

[0045] In a thirteenth aspect, an embodiment of the present application provides a chip system, which includes one or more processors for calling and running instructions stored in the memory from a memory, so that the method in any of the above aspects or any possible implementation of each aspect is executed. The chip system can be composed of a chip, or it can include a chip and other discrete devices. Among them, the chip system may include an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

[0046] In the fourteenth aspect, a communication system is provided, comprising a terminal device, a non-terrestrial device and a terrestrial device. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a satellite communication system provided in an embodiment of the present application; Figure 2 A schematic diagram of a scenario in which a low-orbit satellite in store-and-forward mode is provided in an embodiment of the present application; Figure 3 A schematic diagram of a UPF-based satellite architecture provided in an embodiment of the present application; Figure 4 A flow chart of a method for merging user registration and PDU session establishment processes provided in an embodiment of the present application; Figure 5A schematic diagram of a satellite-ground separation architecture based on AMF and SMF provided in an embodiment of the present application; Figure 6 A schematic diagram of a registration and session establishment method in store-and-forward mode provided in an embodiment of the present application; Figure 7 A flowchart of a PDU session establishment method provided in an embodiment of the present application; Figure 8 A schematic diagram of another registration and session establishment method provided in an embodiment of the present application; Figure 9 A schematic diagram of another registration and session establishment method provided in an embodiment of the present application; Figures 10A-10K The embodiments of this application provide Figure 9 Schematic diagram of the scenario corresponding to the method shown; Figure 11 A schematic diagram of another registration and session establishment method provided in an embodiment of the present application; Figure 12 A schematic diagram of another registration and session establishment method provided in an embodiment of the present application; Figure 13 A schematic diagram of another registration and session establishment method provided in an embodiment of the present application; Figure 14 A schematic diagram of an electronic device provided in an embodiment of the present application; Figure 15 A schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The terms "first" and "second" in the specification and drawings of this application are used to distinguish different objects, or to distinguish different processing of the same object, rather than to describe a specific order of objects. In addition, the terms "including" and "having" and any variations thereof mentioned in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices. In the embodiments of the present application, "multiple" includes two or more. In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. In addition, the network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation of the technical solutions provided in the embodiments of the present application. It will be appreciated by those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are equally applicable to similar technical problems.

[0049] The technical solutions in the embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0050] Because traditional terrestrial network (TN) communications cannot provide seamless coverage, especially in areas where base stations cannot be deployed, such as oceans, mountains, deserts, and the air, non-terrestrial network (NTN) communications are considered an important aspect of future wireless communication technology development. NTN communications refer to new radio (NR) communications implemented via satellites or high altitude platform systems (HAPS). NTN communications can cover remote areas that TN communications cannot reach. Currently, NTN communications are mainly targeted at low earth orbit (LEO), medium earth orbit (MEO), geostationary satellites (GEO), and unmanned aircraft systems (UAS).

[0051] Satellite communication, a form of NTN communication, refers to communications conducted by ground-based radio communication equipment using satellites as relays. Typically, a satellite communication system consists of two components: satellites and ground stations. Satellite communication offers advantages such as long communication distances, wide coverage areas, high reliability, and a wide frequency bandwidth.

[0052] As a supplement to cellular communication systems, satellite communications have the following advantages: Extended coverage: For areas where cellular communication systems cannot cover or the coverage cost is high, such as oceans, deserts, and remote mountainous areas, satellite communication can be used to solve communication problems.

[0053] Emergency communications: In extreme situations such as disasters and earthquakes, when the cellular communication system infrastructure is unavailable, satellite communications can be used to quickly establish communication connections.

[0054] Providing industry applications: For delay-sensitive services transmitted over long distances, satellite communications can be used to reduce service transmission delays.

[0055] Currently, NTN communication systems have two typical network architectures: transparent payload and regenerative payload. In transparent forwarding mode, also known as transparent transmission, satellites or UAS platforms forward signals, performing RF filtering, frequency conversion, and amplification, while maintaining the payload's repeating waveform. In regenerative mode, satellites or UAS platforms perform all or part of the functions of a base station (such as a gNB), including RF filtering, frequency conversion, and amplification, as well as demodulation / decoding, switching and / or routing, and encoding or modulation.

[0056] For example, Figure 1 A schematic diagram of a satellite communication system provided in an embodiment of the present application.

[0057] like Figure 1 As shown, a satellite communication system may include at least one terminal device, a satellite, and a ground station. The terminal device and the satellite are connected via a service link, which is implemented by NR. The satellite and the ground station are connected via a feeder link, which can be a 3GPP-defined radio interface or a non-3GPP radio interface. As an example, an access point (RP) may also be included between the satellite and the ground station. As another example, the ground station may also be connected to a data center (DN) via a base station (such as a gNB) or a next-generation core (NGC).

[0058] Satellites orbiting the Earth achieve wide-area coverage through independent or intersatellite collaboration. In regenerative mode, for example, a terminal device sends data or signaling to a satellite. The satellite, acting as a base station, forwards the data or signaling to a ground station. The ground station then transmits the data or signaling to a data center via routing equipment, base stations (such as gNBs), and / or NGCs.

[0059] In the embodiments of the present application, a terminal device is a device with wireless transceiver capabilities. The terminal device can be a mobile terminal device or a non-mobile terminal device. For example, the terminal device can be a wireless terminal device capable of receiving scheduling and instruction information from a network device. A wireless terminal device can be a device that provides voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing device connected to a wireless modem. A terminal device can also be referred to as a terminal, user equipment (UE), subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, access terminal, user terminal, wireless communication device, user agent, or user device. The terminal device can be widely used in various scenarios, such as vehicle-to-everything (V2X) communication, machine-type communication (MTC), ultra-reliable low-latency communication (URLLC), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, etc. The terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a flying robot, a robotic arm or a smart home device, etc. The embodiments of the present application do not limit the form of the terminal device.

[0060] In 3GPP, the store and forward (S&F) model aims to provide communication services for terminal devices within satellite coverage. Its core concept is to improve communication reliability and flexibility by storing data packets on the satellite before forwarding them to the next node or destination, addressing intermittent or temporary satellite connections (for example, when the satellite is not connected to the terrestrial network via a feeder link or inter-switch link (ISL)). This model is suitable for delay-tolerant services such as SMS, machine-to-machine communication (MTC), and the Cloud-based Internet of Things (CIoT).

[0061] Take non-geostationary orbit (NGSO) low-orbit satellites as an example. Figure 2A schematic diagram of a scenario of a low-orbit satellite in store-and-forward mode provided in an embodiment of the present application.

[0062] like Figure 2 As shown, a low-orbit satellite orbits the Earth along the dotted orbit. Its coverage varies at different times (e.g., times a1, a2, a3, and a4). Compared to medium-orbit and geosynchronous satellites, low-orbit satellites have shorter orbital periods, orbiting the Earth approximately every 90 to 120 minutes. This means that terminal devices will receive intermittent satellite service. Furthermore, the coverage area of ​​a single low-orbit satellite is relatively small, making it prone to intermittent coverage and unstable ground station connections. In store-and-forward mode, satellites have a certain data buffering capability, temporarily storing user data when the communication link is unavailable or interrupted, and forwarding it when the link is restored or the destination node is reachable. For example, at time a1, a terminal device is within the coverage area of ​​an low-orbit satellite. The serving link is available, but the feeder link is unavailable. The terminal device can send data packets to the low-orbit satellite via the serving link, and the low-orbit satellite buffers the data packets. At time a2, the ground station is within the coverage area of ​​the low-orbit satellite. The serving link is unavailable, but the feeder link is. The low-orbit satellite forwards the data packets to the ground station via the feeder link. In this way, problems such as intermittent satellite coverage and unstable ground station connections are effectively solved, and the reliability and resource utilization of delay-tolerant and interruption-tolerant business data transmission are improved.

[0063] In the user registration process and protocol data unit (PDU) session establishment process specified by 3GPP, from the moment a terminal device initiates a registration request or PDU session establishment request, a series of complex interactions between various network elements are required, and multiple rounds of interaction between the terminal device and the core network are also required. Furthermore, the PDU session establishment process is typically performed after the user registration process is complete. That is, the terminal device can only send a PDU session establishment request message after user registration is complete.

[0064] In TN communications, propagation delays between terminal devices and base stations are typically minimal. However, in NTN communications, the distances between terminal devices, ground stations, and satellites are vast, and it takes longer for radio waves sent by satellites to reach the terminal devices or ground stations, typically ranging from a few milliseconds to hundreds of milliseconds. In low-orbit satellite scenarios, the continued use of the process of sending a PDU session establishment request message after user registration is complete can easily lead to increased latency, especially in store-and-forward mode. If registration and PDU session establishment are still performed according to the traditional standard process, the gap between the two processes may be long, thereby increasing interaction latency between terminal devices and the core network and service wait times.

[0065] To address the above issues, this application provides a solution that merges the user registration and PDU session establishment processes. In this solution, the user plane function (UPF) or the UPF and some control plane functions (SMF) are deployed on the satellite payload. By integrating key network elements onboard, most 5G core network (5GC) services, as well as store-and-forward services, can be directly implemented on the satellite.

[0066] For example, Figure 3 A schematic diagram of a UPF-based satellite architecture provided in an embodiment of the present application.

[0067] like Figure 3 As shown, onboard network elements may include at least one of a radio access network (RAN), an UPF, a PDU session anchor UPF (PSA-UPF), and an edge application server (EAS). The RAN is an access network device or access node that implements base station functions, including but not limited to a base station, an evolved NodeB (eNodeB), a transmit / receive point (TRP), a NR Node B (gNB) in a 5G mobile communication system, a next-generation evolved eNodeB (ng-eNB) in a 5G mobile communication system, and an access network device or access network device module in an open access network (ORAN) system. The RAN can communicate with terminal devices using access technologies such as NR or through relay stations. The UPF is a key component in the 5GC, responsible for forwarding, routing, and processing data flows, such as routing data packets from terminal devices to the DN. The PSA-UPF serves as the anchor point for PDU sessions and manages the routing and forwarding of user-plane data. Edge application servers are deployed in mobile edge computing (MEC) environments and work closely with the PSA-UPF, operating at edge nodes close to users to reduce latency in data transmission back to the core network or cloud.

[0068] In such Figure 3In the UPF-based satellite architecture shown, the RAN provides store-and-forward functionality during the registration and session establishment phases. After activating the onboard UPF, the onboard UPF can also be used to forward cached uplink data.

[0069] For example, based on Figure 3 The UPF satellite architecture shown, Figure 4 Schematic diagram of the method flow for merging the user registration and PDU session establishment processes provided in the embodiment of the present application. Figure 4 As shown, the execution subjects of the method may include terminal equipment, satellite network elements and ground network elements. Among them, satellite network elements refer to network elements deployed on satellites (such as low-orbit satellites), such as RAN and UPF, etc.; ground network elements refer to network elements deployed on land, such as access and mobility management function (AMF), session management function (SMF), policy control function (PCF), unified data management entity (UDM) and DN, etc. It can be understood that, Figure 4 The satellite-borne network elements and ground-based network elements shown are merely exemplary. In actual implementation, other possible network elements may also be included.

[0070] like Figure 4 As shown in the figure, the interaction process between the terminal equipment, satellite network elements and ground network elements is as follows: The terminal device sends a registration and PDU session establishment request message to the RAN.

[0071] In the case that the feeder link is unavailable, the RAN stores the registration and PDU session establishment request message and sends a store-and-forward registration notification to the terminal device.

[0072] When the feeder link is available, the UPF forwards the stored registration and PDU session establishment request messages to the ground network element.

[0073] The ground network element performs the registration and PDU session establishment process.

[0074] After the ground network element completes the registration and PDU session establishment process, the ground network element sends a registration and PDU session establishment reception message to the UPF, and the UPF forwards the registration and PDU session establishment reception message to the RAN.

[0075] If the service link is available, the RAN forwards the registration and PDU session establishment reception message to the terminal device.

[0076] The terminal device sends an N2 PDU session response message to the RAN.

[0077] The terminal device sends an uplink data storage N2 PDU session response message to the UPF.

[0078] In the satellite architecture provided in the above embodiment, the RAN is responsible for storing registration and PDU session establishment request messages. This architecture may have the following issues: The satellite-based network elements only provide store-and-forward functionality and must wait until the feeder link is restored before forwarding messages to the ground. This places significant storage pressure on the RAN when multiple terminal devices send registration and PDU session establishment request messages to the RAN. The RAN lacks the ability to process registration and PDU session establishment request messages. These messages are forwarded to the ground network elements via the UPF, which then processes the messages. This can result in a long response time for ground processing after the data is forwarded to the ground if data processing is not timely. The satellite-based network elements lack decoding capabilities, making it difficult to effectively prevent denial of service (DoS) attacks when processing integrity-protected messages from terminal devices. Furthermore, when sending the combined registration and PDU session establishment request messages, the network attached storage (NAS) security context and security mode are not established, potentially allowing NAS messages sent by users to be eavesdropped, tampered with, or forged.

[0079] In view of the above-mentioned problems of the UPF-based satellite architecture, this application also provides a satellite-ground separation architecture based on AMF and SMF. In this architecture, network elements such as non-terrestrial access and mobility management function (AMF-NT) and non-terrestrial session management function (SMF-NT) are deployed on the satellite, and network elements such as terrestrial access and mobility management function (AMF-T) and terrestrial session management function (SMF-T) are deployed on the ground.

[0080] For example, Figure 5 A schematic diagram of a satellite-ground separation architecture based on AMF and SMF provided in an embodiment of the present application.

[0081] like Figure 5As shown, the onboard network elements may include the RAN, AMF-NT, and SMF-NT. The RAN is an access network device or access node that can implement base station functions. For example, the RAN is responsible for receiving registration request messages and PDU session establishment request messages from terminal devices. In addition to providing store-and-forward functionality, the AMF-NT can also decode messages from terminal devices (such as NAS messages carrying PDU session establishment request messages) and forward the PDU session establishment request messages carried in the decoded messages to the SMF-NT. In addition to providing store-and-forward functionality, the SMF-NT can also pre-process the PDU session establishment request messages to reduce the ground processing response time after the data is forwarded to the ground.

[0082] Ground network elements may include AMF-T and SMF-T. AMF-T can be used to initiate user authentication and send registration and reception messages. SMF-T can be used to cache PDU session establishment request messages from SMF-NT and execute the PDU session establishment process. In addition, ground network elements may also include authentication server function (AUSF), UDM, UPF, policy control function (PCF), short message service function (SMSF), and DN. The AUSF is used to verify the legitimacy of user, device, or system identities, ensuring that only authorized entities can access specific resources or perform operations. UDM is a centralized, standardized data governance architecture designed to achieve unified management, modeling, storage, and distribution of heterogeneous data sources. The UPF is responsible for forwarding, routing, and processing data flows, such as routing data packets from terminal devices to the DN. The PCF supports a unified policy framework and manages network behavior, providing policy rules to network entities and accessing subscription information in the unified data repository (UDR). SMSF refers to the Short Message Service Function, which supports NSA-based SMS services, including SMS management, subscription data inspection, and corresponding SMS delivery. DN refers to the data network, such as operator services, Internet access, and third-party services.

[0083] In the satellite-ground separation architecture provided in the above embodiment, deploying SMF-NT and SMF-T can improve the collaboration between the AMF and SMF, reducing the AMF's store-and-forward pressure. In addition, SMF-NT can pre-process information such as PDU session establishment requests, which can reduce the ground response time during the session management process to a certain extent.

[0084] It is understandable that Figure 5The various network elements shown are only exemplary. In actual implementation, the satellite-ground separation architecture may also include other possible network elements, which can be adjusted according to usage requirements and are not limited in the embodiments of this application.

[0085] The scheme provided by the embodiment of the present application is described in detail below in conjunction with the corresponding flow chart. It can be understood that the schematic flow chart provided in the embodiment of the present application mainly uses different devices (such as terminal devices, non-ground devices and ground devices) as examples of the execution subjects of the interaction diagram to illustrate the method, but the present application does not limit the execution subjects of the interaction diagram. For example, the device (such as terminal devices, non-ground devices and ground devices) in the schematic flow chart can also be a chip, chip system, or processor that supports the device to implement the method, or a logic module or software that can implement all or part of the functions of the device. In addition, in the interaction process of the embodiment of the present application, the message or signaling interaction involved can adopt the message or signaling in the standard, or it can be a newly introduced message or signaling, and the embodiment of the present application does not make specific limitations on this.

[0086] Here, for unified explanation, non-terrestrial equipment refers to equipment set up in the air in NTN communication, such as satellites. Terrestrial equipment refers to equipment set up on the ground in NTN communication, such as ground stations. Non-terrestrial equipment can include one or more satellite-borne network elements, such as Figure 5 The RAN, AMF-NT and SMF-NT shown in Figure 1. The ground equipment may include one or more ground network elements, such as Figure 5 AMF-T, SMF-T, UPF, PCF, SMSF, AUSF and UDM shown.

[0087] For example, Figure 6 The embodiment of the present application provides a registration and session establishment method in a store-and-forward mode, in which the registration process and the session establishment process are integrated.

[0088] It should be noted that this method is implemented by terminal equipment, non-terrestrial onboard network elements (such as RAN, AMF-NT, and SMF-NT), and terrestrial network elements (such as AMF-T, SMF-T, UPF, UDM, and AUSF) of terrestrial equipment. Among them, AMF-NT and SMF-NT are onboard core network elements, while AMF-T, SMF-T, UPF, UDM, and AUSF are terrestrial core network elements.

[0089] like Figure 6 As shown, the method may include the following S101 to S108.

[0090] S101. The terminal device sends a registration request message to the onboard network element.

[0091] In some embodiments, the registration request message may include at least one of the following: a registration type, a subscription concealed identifier (SUCI), a 5G globally unique temporary identifier (5G-GUTI), and a permanent equipment identifier (PEI).

[0092] For example, a terminal device can send a registration request message to the RAN, which forwards the message to an onboard core network element (e.g., AMF-NT). If the feeder link is unavailable at this moment, the onboard core network element stores the message and forwards it to the terrestrial core network element when the feeder link is restored.

[0093] In some embodiments, the terminal device may also send AN / RAN parameters to the onboard network element.

[0094] S102. After receiving the registration request message, the ground core network element initiates the authentication process for the terminal device.

[0095] For example, after AMF-T receives the registration request message forwarded by the onboard core network element, AMF-T sends an authentication request to AUSF. AUSF performs the authentication process, selects a UDM and obtains authentication data.

[0096] In the solution provided in the above embodiment that combines the user registration and PDU session establishment processes, when the registration and PDU session establishment request messages are sent together, the NAS security context and security mode are not established, and the NAS messages sent by the user may be eavesdropped, tampered with, or forged. To solve this problem, as an optional method, such as Figure 6 The method shown may include the following S103. It is understood that, as another optional method, after identity authentication is completed, the terminal device may also directly send a PDU session establishment request message to the onboard core network element via the RAN.

[0097] S103. After identity authentication is completed, the ground core network element sends a NAS security start instruction to the onboard core network element, and the onboard core network element sends a NAS security mode command to the terminal device to establish security mode.

[0098] S104. The terminal device returns a Security Mode Response message to the RAN. This completes the NAS security context establishment, and NAS messages are now protected. After activating the 5G NAS security context generated by the Security Mode Control process, the entire PDU Session Establishment Request message can be included in a NAS message container, which in turn can be included in a Security Mode Response message. The PDU Session Establishment Request message can contain both plaintext information elements (IEs) and non-plaintext IEs.

[0099] S105. The onboard core network element pre-processes the PDU session establishment request message and temporarily stores the pre-processed PDU session establishment request message.

[0100] In the solution provided in the above embodiment for merging the user registration and PDU session establishment processes, the onboard network element only provides a storage and forwarding function and does not have the ability to process registration and PDU session establishment request messages. The message can only be forwarded to the ground network element through the UPF when the feeder link is restored, and the ground network element then processes the message. Untimely data processing may result in a longer ground processing response time after the data is forwarded to the ground. In order to solve this problem, after the onboard core network element receives the PDU session establishment request message, the onboard core network element can execute some of the functions of the ground core network element and pre-process the message in advance, such as calculating the sending priority of the PDU session establishment request message. It can be understood that the onboard core network element can also perform other pre-processing operations on the PDU session establishment request message, which can be determined according to usage requirements and is not limited in this application.

[0101] S106. After the feeder link is available, the onboard core network element forwards the PDU session establishment request message to the ground core network element. The ground core network element and the onboard core network element continue the registration process to complete the registration.

[0102] S107. After registration is completed, the ground core network element and the onboard core network element execute the PDU session establishment process.

[0103] S108. After the registration and PDU session establishment processes are completed, the onboard core network element returns a registration and PDU session establishment accept message to the terminal device. This message indicates that both the registration and PDU session establishment processes were successful.

[0104] In the method provided in the above embodiment, by integrating the PDU session establishment process into the registration process, the total number of interactions between the two processes is effectively reduced, reducing the interaction latency and service wait time between terminal devices and core network equipment, and improving the terminal service experience. In addition, the core network elements deployed onboard pre-process the PDU session establishment request, which to a certain extent reduces the ground response time during the session management process.

[0105] The above embodiments are combined Figure 6 This article introduces the method of integrating the registration process with the session establishment process. Figure 6 Based on the provided flowchart, the PDU session establishment process is illustrated in more detail with examples, combining core network elements such as AMF-NT and SMF-NT deployed on board, and AMF-T and SMF-T deployed on the ground.

[0106] For example, Figure 7 A flowchart of a PDU session establishment method provided in an embodiment of the present application.

[0107] It should be noted that this method is implemented by terminal equipment, satellite A's onboard network elements (such as RAN-A, AMF-NT-A, and SMF-NT), satellite B's onboard network elements (such as RAN-B and AMF-NT-B), and ground core network elements (such as AMF-T, UPF, and SMF-T). Among them, AMF-NT-A, SMF-NT, and AMF-NT-B are onboard core network elements.

[0108] like Figure 7 As shown, the method may include the following S201 to S210.

[0109] S201. When the service link between the terminal device and satellite A is available, the terminal device sends a PDU Session Establishment Request message to RAN-A, which forwards the message to AMF-NT-A.

[0110] In some embodiments, the terminal device sends a security mode response message to RAN-A, where the security mode response message includes a NAS message, where the NAS message includes a PDU session establishment request message. RAN-A forwards the NAS message to AMF-NT-A.

[0111] S202. AMF-NT-A forwards the PDU session establishment request message to SMF-NT.

[0112] In some embodiments, the security mode response message may include an information identifier (which may be referred to as a second information identifier), which may be used to instruct the AMF-NT-A to forward the PDU session establishment request message to the SMF-NT. The AMF-NT-A decodes the security mode response message, obtains the information identifier and the PDU session establishment request message, and forwards the PDU session establishment request message to the SMF-NT based on the information identifier.

[0113] S203. After the SMF-NT receives the PDU session establishment request message forwarded by the AMF-NT-A, the SMF-NT pre-processes the PDU session establishment request message and temporarily stores the pre-processed PDU session establishment request message.

[0114] In some embodiments, the PDU Session Establishment Request message may also include an information identifier (referred to as a first information identifier), which may be used to instruct the SMF-NT to pre-process and store the PDU Session Establishment Request message. The SMF-NT decodes the PDU Session Establishment Request message, obtains the information identifier, and pre-processes and temporarily stores the PDU Session Establishment Request message based on the information identifier.

[0115] In some embodiments, the information identifier may be in TLV (Type-Length-Value) format. The TLV format is flexible and scalable, and is compatible with existing 3GPP IE encoding specifications. For example, the information identifier is one bit long and has two states: if encoded as 0, it indicates immediate forwarding; if encoded as 1, it indicates preprocessing and temporary storage. As an example, the information identifier is encoded together with other information; this application does not specifically limit the encoding format.

[0116] S204. When the feeder link between Satellite A and the ground core network element is available, the SMF-NT and SMF-T synchronize information. For example, the SMF-NT forwards the PDU Session Establishment Request message to the SMF-T, and the SMF-T can also upload other messages to the SMF-NT.

[0117] In some embodiments, after SMF-NT forwards the PDU session establishment request message to SMF-T, SMF-NT can start a timer. When the timer reaches a preset duration, the information stored in SMF-NT is cleared to release the storage space of SMF-NT in time to facilitate the storage of PDU session establishment request messages from other terminal devices.

[0118] In some embodiments, after the SMF-NT forwards the PDU session establishment request message to the SMF-T, the SMF-T may also temporarily store the PDU session establishment request message.

[0119] For example, Table 1 below shows the context fields established by the SMF-T for a terminal device. Since the terminal device is currently in a state where registration and PDU session establishment are not yet complete, an additional storage space can be added to the SMF-T to store the terminal device context information during this state. After registration and PDU session establishment are complete, the SMF-T performs session management for the user and stores user context information normally, clearing the additional storage space for the corresponding terminal device.

[0120]

[0121] S205. The SMF-T starts executing the session establishment process.

[0122] Exemplarily, the SMF-T may execute a session establishment process based on temporarily stored PDU session establishment request information.

[0123] S206. The SMF-T sends an N4 session establishment request to the selected UPF.

[0124] An N4 session typically refers to the session control function managed by the N4 interface in a 5GC or cloud-native network architecture. This primarily involves interactions between the UPF and the SMF. The N4 interface utilizes the Packet Forwarding Control Protocol (PFCP). The SMF can issue session rules, such as session establishment requests, to the UPF via the N4 interface. These rules can include packet detection rules (PDRs), forwarding action rules (FARs), and QoS enforcement rules (QERs).

[0125] S207. UPF returns an N4 session establishment response to SMF-T.

[0126] S208. The SMF-T sends a PDU session establishment accept message to the AMF-T.

[0127] Exemplarily, SMF-T may send a Namf_Communication_N1N2MessageTransfer message to AMF-T. The message may include an N1 session management (SM) container and N2 SM information. The N1 SM container may include a PDU session establishment accept message. The N2 SM information may include CN Tunnel Info, QoS flow identifier (QFI), quality of service (QoS) configuration, aingle network slice selection assistance information (S-NSSAI), aggregate maximum bit rate (AMBR), PDU type, user plane security information, integrity protection maximum rate, redundancy sequence number (RSN), etc.

[0128] As described in the above embodiments, the coverage of a non-geostationary satellite can change as it orbits the Earth. After establishing a PDU session, the next satellite covering the terminal device may change, for example, switching from Satellite A to Satellite B. Alternatively, the next satellite covering the terminal device may remain unchanged, for example, returning to cover the terminal device after orbiting the Earth once more. The following explanation assumes that the next satellite covering the terminal device is Satellite B.

[0129] S209. When the feeder link between satellite B and the ground core network element is available, AMF-T sends a PDU session establishment accept message to AMF-NT-B.

[0130] In some embodiments, if the service link between satellite B and the terminal device is unavailable at this moment, AMF-NT-B temporarily stores the PDU session establishment acceptance message and forwards it to the terminal device when the service link is available.

[0131] S210. When the service link between satellite B and the terminal device is available, AMF-NT-B sends a PDU session establishment accept message to the terminal device via RAN-B.

[0132] In related technologies, there is no SMF deployed onboard, and the satellite does not have the ability to decode and pre-process PDU session establishment request messages. However, in the above-mentioned method provided in the embodiment of the present application, by deploying AMF-NT and SMF-NT onboard, and deploying AMF-T and SMF-T and other core network elements on the ground, the collaboration capability of AMF and SMF is improved, and the storage and forwarding pressure of AMF-NT is reduced. SMF-NT decodes the PDU session establishment request, which can effectively avoid DoS attacks. In addition, SMF-NT pre-processes the PDU session establishment request, which reduces the ground response time during the session management process to a certain extent.

[0133] The above embodiments are combined Figure 6 The method flow for integrating the registration process with the session establishment process is introduced. In the description of S107 and S108 of the method, after the registration is completed, the ground core network element and the satellite core network element execute the PDU session establishment process. If the registration and PDU session establishment processes are successfully executed, a registration and PDU session establishment acceptance message is returned to the terminal device. In actual implementation, there may be two other scenarios: one scenario is that both the registration and PDU session establishment processes fail; the other scenario is that the registration is successfully executed, but the PDU session establishment fails. Based on this, Figure 6 On the basis of Figure 8 As shown, the method for integrating the registration process with the session establishment process provided in the embodiment of the present application may also include the following steps: AMF-NT determines whether the registration and PDU session are successfully established based on the message returned by the ground core network element.

[0134] If both the registration and PDU session establishment processes are successful, then the following S108 is executed.

[0135] If both the registration and PDU session establishment processes fail, then the following S109 is executed.

[0136] If the registration is successfully performed but the PDU session establishment fails, the following S110 is executed.

[0137] S108. The AMF-NT returns a combined registration and PDU session establishment accept message to the terminal device via the RAN. This message may be used to indicate that both the registration process and the PDU session establishment process are successful.

[0138] S109. The AMF-NT returns a combined registration and PDU session establishment reject message to the terminal device via the RAN. This message may be used to indicate that both the registration process and the PDU session establishment process have failed.

[0139] S110. The AMF-NT returns a registration accept message to the terminal device via the RAN. The message may carry indication information (referred to as first indication information), which is used to indicate that the PDU session establishment has failed.

[0140] In some embodiments, the above-mentioned indication information may include at least one of the following: the reason for the failure to establish the PDU session, the information processing status, and whether to instruct the terminal device to resend the PDU session establishment request.

[0141] In the above method provided in the embodiment of the present application, when both registration and PDU session establishment are successful, or when registration is successful but PDU session establishment fails, a combined message is returned. This can reduce the number of interactions between the terminal device and the network device and reduce signaling overhead. In addition, regardless of whether the PDU session establishment is successful, the corresponding information is returned to the terminal device, which can improve the terminal device's perception of the network and indicate user behavior.

[0142] The following takes low-orbit satellite as an example, combined with Figure 9 、 Figures 10A-10K The overall process of the registration and session establishment method proposed based on the initial registration process is described.

[0143] For example, Figure 9 A schematic diagram of the overall process of the registration and session establishment method in store-and-forward mode provided in an embodiment of the present application. Figures 10A-10K For Figure 9 Schematic diagram of the scenario corresponding to the method shown.

[0144] It should be noted that Figure 9 The method shown is performed by terminal equipment, satellite-borne network elements of satellite 1 (such as RAN-1, AMF-NT-1), satellite-borne network elements of satellite 2 (such as RAN-2, AMF-NT-2), satellite-borne network elements of satellite 3 (such as RAN-3, AMF-NT-3 and SMF-NT), satellite-borne network elements of satellite 4 (such as RAN-4, AMF-NT-4), and ground core network elements of ground equipment (such as AMF-T, AUSF, UDM, UPF and SMF-T).

[0145] like Figure 9 As shown, the method may include the following S301 to S325.

[0146] S301. When a service link between the terminal device and satellite 1 (also known as the third non-terrestrial device) is available, the terminal device sends a registration request message to RAN-1, which forwards the message to AMF-NT-1.

[0147] The availability of the service link between the terminal device and the satellite means that the terminal device is within the coverage of the satellite, and the terminal device can send data to the satellite through the service link, and the satellite can also send data to the terminal device through the service link.

[0148] like Figure 10A As shown in the figure, satellite 1, which includes RAN-1 and AMF-NT-1, rotates around the Earth. When satellite 1 rotates over the terminal device, the terminal device is within the coverage area of ​​satellite 1. At this moment, the service link between the terminal device and satellite 1 is available. If the terminal device needs to register and transmit delay-tolerant services, the terminal device can send a registration request message to RAN-1, and RAN-1 forwards the registration request message to AMF-NT-1.

[0149] In some embodiments, the registration request message may include at least one of the following: registration type, SUCI, 5G-GUTI, PEI. The registration request message may also include S-NSSAI request information, where the request information is used to request configuration of the S-NSSAI.

[0150] S302. AMF-NT-1 returns a downlink NAS transport message to the terminal device via RAN-1. The message includes a temporary identifier (interim GUTI) allocated for the terminal device.

[0151] Assuming that the AMF-NT on each satellite in the constellation has a unique AMF ID, the terminal device can store the temporary identifier (Interim GUTI) for subsequent interactions, and the AMF-NT-1 can also provide a validity period for this identifier. It can be understood that by assigning a temporary identifier to the terminal device, GUTI conflicts can be avoided. Among them, the GUTI includes one or more of the public land mobile network (PLMN) identifier, AMF region identifier, AMF set identifier, AMF identifier and temporary mobile subscription identifier (TMSI).

[0152] S303. When the feeder link between satellite 1 and the ground core network element is available, AMF-NT-1 forwards the stored registration request message and the temporary identifier (interim GUTI) to AMF-T.

[0153] like Figure 10B As shown in the figure, satellite 1 containing RAN-1 and AMF-NT-1 continues to rotate around the earth, and satellite 1 leaves the coverage area of ​​the terminal device. When satellite 1 rotates over the ground station, the ground station is within the coverage area of ​​satellite 1. At this moment, the service link between satellite 1 and the ground station is available, so AMF-NT-1 can forward the stored registration request message and temporary identifier (interim GUTI) to AMF-T.

[0154] S304. AMF-T initiates the user authentication process.

[0155] AMF-T can select AUSF based on the subscription permanent identifier (SUPI) or subscription concealed identifier (SUCI) and send an authentication request to the selected AUSF. If authentication is required, AMF-T sends a request to AUSF, and AUSF performs the authentication process. AUSF selects a UDM and obtains the authentication data. AMF-T associates and stores the authentication data with the temporary identifier (interimGUTI) received from AMF-NT-1 of satellite 1. In addition, AMF-T can also determine the next satellite that may cover the terminal device, such as satellite 2.

[0156] S305. When the feeder link between Satellite 2 (which may be referred to as the fourth non-terrestrial device) and the terrestrial core network element is available, AMF-T sends an authentication request message to AMF-NT-2.

[0157] like Figure 10C As shown in the figure, satellite 1 leaves the coverage area of ​​the ground station. When satellite 2, which includes RAN-2 and AMF-NT-2, rotates over the ground station, the ground station is within the coverage area of ​​satellite 2. At this time, the service link between satellite 2 and the ground station is available, so AMF-T can send a Namf_N1N2MessageTransfer message to AMF-NT-2. The message carries the authentication request message and the temporary identifier (interim GUTI) allocated to the terminal device. In addition, the message can also carry the location information of the terminal device. Since the terminal device is not within the coverage area of ​​satellite 2 at this time, the service link between satellite 2 and the terminal device is unavailable, so satellite 2 can temporarily store the authentication request message.

[0158] S306. When the service link between satellite 2 and the terminal device is available, AMF-NT-2 sends an authentication request message to the terminal device via RAN-2.

[0159] S307. The terminal device returns an authentication response message to AMF-NT-2 via RAN-2.

[0160] like Figure 10D As shown in the figure, when satellite 2 rotates over the terminal device, the terminal device is within the coverage area of ​​satellite 2. RAN-2 of satellite 2 sends an authentication request message to the terminal device via the service link. The terminal device then returns an authentication response message to RAN-2 of satellite 2 via the service link. Since the ground core network element is not within the coverage area of ​​satellite 2 at this time, the service link between satellite 2 and the ground core network element is unavailable, and the authentication response message can be temporarily stored.

[0161] S308. When the feeder link between Satellite 2 and the ground core network element is available, AMF-NT-2 sends an authentication response message to AMF-T.

[0162] like Figure 10E As shown, when satellite 2 rotates over the ground station again, the ground station is within the coverage of satellite 2. At this moment, the service link between satellite 2 and the ground station is available, so AMF-NT-2 sends an authentication response message to AMF-T.

[0163] S309. The AUSF sends an authentication response message to the AMF-T. This message contains the key security anchor function (KSEAF) key.

[0164] In 5G Authentication and Key Agreement (AKA), the KSEAF is the security foundation of the authentication process. During 5G AKA (Authentication and Key Agreement), the terminal device and AUSF collaborate to complete bidirectional authentication.

[0165] S310: When the feeder link between satellite 3 (which may be referred to as the first non-terrestrial device) and the terrestrial core network element is available, the AMF-T sends a security mode command to the AMF-NT-3.

[0166] like Figure 10FAs shown in the figure, satellite 2 leaves the coverage area of ​​the ground station. When satellite 3, which includes RAN-3, AMF-NT-3 and SMF-NT, rotates over the ground station, the ground station is within the coverage of satellite 3. At this moment, the service link between satellite 3 and the ground station is available, so AMF-T can send a Namf_N1N2MessageTransfer message to AMF-NT-3. The message carries the NAS security mode command, the received registration request message, the temporary identifier (interim GUTI) allocated to the terminal device, and the NAS key for decoding. Since the terminal device is not within the coverage of satellite 3 at this moment, the service link between satellite 3 and the terminal device is unavailable, so satellite 3 can temporarily store the message.

[0167] In some embodiments, the security mode command may also include multiple S-NSSAIs configured by the ground core network device, where the multiple S-NSSAIs are configured in response to the S-NSSAI request information in the above S301.

[0168] S311. When the service link between satellite 3 and the terminal device is available, AMF-NT-3 sends a security mode command to the terminal device via RAN-3.

[0169] The above-mentioned security mode command can be used by the terminal device to enable and confirm the security context. As an example, the security mode command can include the registration request message received by the AMF-T, the Interim GUTI, and the NAS key used for decoding. The security mode command can also include multiple S-NSSAIs configured by the ground core network device.

[0170] In some embodiments, the AMF-NT-3 initiates paging or receives a connection request from a terminal device. The AMF-NT-3 uses a temporary identifier (interim GUTI) allocated to the terminal device for paging, or the terminal device proactively establishes a radio resource control (RRC) connection. The AMF-NT-3 sends a NAS security mode command to the terminal device.

[0171] S312. The terminal device sends a Security Mode Response message to AMF-NT-3 via RAN-3. The Security Mode Response message includes a NAS message, which may include a PDU Session Establishment Request message based on an S-NSSAI. This S-NSSAI is selected by the terminal device from multiple S-NSSAIs configured in the terrestrial core network equipment and is used for the PDU session of the serving PLMN.

[0172] In some embodiments, the NAS message may further include a registration request message encrypted using a NAS key and information such as an Interim GUTI.

[0173] like Figure 10G As shown in the figure, when satellite 3 rotates over the terminal device, the terminal device is located in the coverage area of ​​satellite 3. At this moment, the service link between satellite 3 and the terminal device is available, so AMF-NT-3 sends a security mode command to the terminal device through RAN-3, and then the terminal device sends a security mode response message to AMF-NT-3 through RAN-3.

[0174] S313. AMF-NT-3 forwards the PDU session establishment request message to SMF-NT.

[0175] In some embodiments, the security mode response message may include an information identifier (which may be referred to as a second information identifier), which may be used to instruct the AMF-NT-3 to forward the PDU session establishment request message to the SMF-NT. The AMF-NT-3 decodes the security mode response message, obtains the information identifier and the PDU session establishment request message, and forwards the PDU session establishment request message to the SMF-NT based on the information identifier.

[0176] S314. After the SMF-NT receives the PDU session establishment request message forwarded by the AMF-NT-3, the SMF-NT pre-processes the PDU session establishment request message and temporarily stores the pre-processed PDU session establishment request message.

[0177] In some embodiments, the PDU Session Establishment Request message may also include an information identifier (referred to as a first information identifier), which may be used to instruct the SMF-NT to pre-process and store the PDU Session Establishment Request message. The SMF-NT decodes the PDU Session Establishment Request message, obtains the information identifier, and pre-processes the PDU Session Establishment Request message (e.g., calculates a transmission priority of the PDU Session Establishment Request message) and temporarily stores the message based on the information identifier.

[0178] S315. When the feeder link between Satellite 3 and the ground core network element is available, SMF-NT and SMF-T synchronize information. For example, SMF-NT forwards the PDU Session Establishment Request message to SMF-T.

[0179] In some embodiments, after SMF-NT forwards the PDU session establishment request message to SMF-T, SMF-NT can start a timer. When the timer reaches a preset duration, the information stored in SMF-NT is cleared to release the storage space of SMF-NT in time to facilitate the storage of PDU session establishment request messages from other terminal devices.

[0180] S316. After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0181] S317. After receiving the Safe Mode Response message, the AMF-NT-3 stores it temporarily until it reconnects to the ground station and forwards it to the AMF-T.

[0182] The security mode response message may include the registration request message encrypted using the NAS key and information such as the Interim GUTI.

[0183] S318. AMF-T continues the registration process.

[0184] As an example, the above registration process can refer to steps 13-15 of Section 4.2.2.2.2 (5G core network registration process) in the 3GPP TS 23.502 protocol: AUSF requests the user's authentication vector (AV) from UDM; UDM sends an authentication response to AUSF (Nudm_UEAuthentication_Get); The AUSF processes the authentication vector, such as storing the KSEAF as an anchor point for subsequent session key distribution.

[0185] S319. If the registration is successful, the AMF-T prepares to send a Registration Acceptance Request message. Since the feeder link is currently unavailable, the AMF-T can wait until the feeder link is restored before sending the message. Additionally, the AMF-T can send a Notification message to the SMF-T, notifying the SMF-T of the successful registration.

[0186] S320: SMF-T executes the session establishment process.

[0187] like Figure 10H As shown, when the feeder link between satellite 3 and the ground station is available, SMF-T performs the session establishment process.

[0188] As an example, the above session establishment process can refer to steps 4-9 of Section 4.3.2 (Service Request Process) in the 3GPP TS 23.502 protocol: The AMF-T sends an Nsmf_PDUSession_UpdateSMContext request message to the SMF-T to notify the terminal device of the activity state change (for example, switching from idle state to connected state); SMF-T sends an N4 session establishment request message to the selected UPF, and the UPF returns an N4 session establishment response message; SMF-T sends Nsmf_PDUSession_UpdateSMContext response message to AMF to notify AMF that the session is ready, which specifically includes UPF's N3 / N9 interface tunnel information for establishing a data channel between the satellite and UPF; The AMF-T sends an NGAP Initial Context Setup Request message to the satellite to trigger the satellite to establish a context; The satellite sends an RRC connection reconfiguration to the terminal device; The satellite sends an NGAP Initial Context Setup Response message to the AMF-T, which contains the data radio bearer (DRB) configuration result and user plane tunnel information (UL TEID).

[0189] S321. AMF-T sends a PDU session establishment accept message to SMF-T.

[0190] For example, the SMF-T may send a Namf_Communication_N1N2MessageTransfer message to the AMF-T. This message may include an N1 SM container and N2 SM information. The N1 SM container may include a PDU session establishment accept message. The N2 SM information may include CN Tunnel Info, QoS flow identifier, QoS configuration, S-NSSAI, AMBR, PDU type, user plane security information, integrity protection maximum rate, RSN, etc.

[0191] The above S321 is explained by taking the successful establishment of the PDU session as an example. In other embodiments, if the PDU session establishment fails, the AMF-T sends a PDU session establishment rejection message to the SMF-T.

[0192] S322. When the feeder link between satellite 4 (which may be referred to as the second non-terrestrial device) and the terrestrial core network element is available, the AMF-T sends a registration and PDU session establishment accept message to the AMF-NT-4.

[0193] like Figure 10IAs shown, when the feeder link between satellite 4 and the ground station is available, AMF-T sends a registration and PDU session establishment acceptance message to AMF-NT-4.

[0194] S323. When the service link between satellite 4 and the terminal device is available, AMF-NT-4 sends a registration and PDU session establishment accept message to the terminal device via RAN-4.

[0195] S324. The terminal device returns a registration and PDU session establishment acceptance message to AMF-NT-4 via RAN-4.

[0196] like Figure 10J As shown in the figure, when satellite 4 rotates over the terminal device, the terminal device is located in the coverage area of ​​satellite 4. At this moment, the service link between satellite 4 and the terminal device is available, so AMF-NT-4 sends a registration and PDU session establishment acceptance message to the terminal device through RAN-4, and then the terminal device returns the registration and PDU session establishment acceptance message to AMF-NT-4 through RAN-4.

[0197] S325. When the feeder link between satellite 4 and the ground core network element is available, AMF-NT-4 sends a registration and PDU session establishment accept message to AMF-T.

[0198] like Figure 10K As shown, when the feeder link between satellite 4 and the ground station is available again, AMF-NT-4 sends a registration and PDU session establishment acceptance message to AMF-T.

[0199] It should be noted that the above embodiment is described by taking satellite 1, satellite 2, satellite 3, and satellite 4 as examples of intermittently providing services to a terminal device at different times or time periods, and does not limit the present application. In other embodiments, some of these satellites may be the same satellite, for example, satellite 1 in S301-S303 and satellite 3 in S310-S321 may be the same satellite.

[0200] In the method provided in the above embodiment, by integrating the PDU session establishment process into the initial registration process, the total number of interactions between the two processes is effectively reduced, the interaction delay and service waiting time between the terminal device and the core network device are reduced, and the terminal service experience is improved. By deploying AMF-NT and SMF-NT on the satellite, and core network elements such as AMF-T and SMF-T on the ground, the collaboration ability of AMF and SMF is improved, and the storage and forwarding pressure of AMF-NT is reduced. SMF-NT decodes the PDU session establishment request, which can effectively avoid DoS attacks. In addition, SMF-NT pre-processes the PDU session establishment request, which reduces the ground response time in the session management process to a certain extent.

[0201] The above embodiment introduces the specific implementation method of integrating the PDU session establishment process into the initial registration process. The embodiment of the present application also provides another implementation scenario. When the terminal is in the deregistered state, the NAS security context may be stored in the terminal device and AMF (including AMT-NT deployed on the satellite and AMF-T deployed on the ground). If the user re-registers, the registration process and the PDU session establishment process can be combined and enhanced. However, in the store-and-forward (S&F) scenario, the service satellites may be different, and it is difficult to synchronize the information between satellites after the user deregisters. In this regard, Figure 11 As shown, the present application also provides another registration and session establishment method in the store-and-forward mode.

[0202] It should be noted that Figure 11 The method shown is executed by the terminal equipment, the onboard network elements of satellite 5 (such as RAN-5, AMF-NT-5), the onboard network elements of satellite 6 (such as RAN-6, AMF-NT-6 and SMF-NT), the onboard network elements of satellite 7 (such as RAN-7, AMF-NT-7), and the ground core network elements of the ground equipment (such as AMF-T, AUSF, UDM, UPF and SMF-T).

[0203] like Figure 11 As shown, the method may include the following S401 to S419.

[0204] S401. When the service link between the terminal device and satellite 5 is available, the terminal device sends a registration request message to RAN-5, which forwards the message to AMF-NT-5.

[0205] S402. The AMF-NT-5 returns a downlink NAS transport message to the terminal device via the RAN-5. The message includes a temporary identifier (interim GUTI) allocated to the terminal device.

[0206] S403. When the feeder link between the satellite 5 and the ground core network element is available, the AMF-NT-5 forwards the stored registration request message and the temporary identifier (interim GUTI) to the AMF-T.

[0207] For the implementation of S401-S403, reference may be made to the description of S301-S303 in the above embodiment, which will not be repeated here.

[0208] S404. When the feeder link between satellite 6 and the ground core network element is available, AMF-T sends a security mode command to AMF-NT-6.

[0209] S405: When the service link between satellite 6 and the terminal device is available, AMF-NT-6 sends a security mode command to the terminal device via RAN-6.

[0210] S406. The terminal device sends a security mode response message to AMF-NT-6 via RAN-6. The security mode response message includes a NAS message, which includes a PDU session establishment request message.

[0211] S407. AMF-NT-6 forwards the PDU session establishment request message to SMF-NT.

[0212] In some embodiments, the above-mentioned security mode response message may include an information identifier, which can be used to instruct AMF-NT-6 to forward the PDU session establishment request message to SMF-NT.

[0213] S408. After the SMF-NT receives the PDU session establishment request message forwarded by the AMF-NT-6, the SMF-NT pre-processes the PDU session establishment request message and temporarily stores the pre-processed PDU session establishment request message.

[0214] In some embodiments, the PDU session establishment request message may also include an information identifier, which may be used to instruct the SMF-NT to pre-process and store the PDU session establishment request message.

[0215] S409. When the feeder link between satellite 6 and the ground core network element is available, SMF-NT and SMF-T perform information synchronization. For example, SMF-NT forwards the PDU session establishment request message to SMF-T.

[0216] In some embodiments, after SMF-NT forwards the PDU session establishment request message to SMF-T, SMF-NT may start a timer, and when the timer reaches a preset time, clear the information stored in SMF-NT.

[0217] S410: After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0218] S411. After receiving the Safe Mode Response message, the AMF-NT-6 temporarily stores the message until it reconnects to the ground station and forwards the message to the AMF-T.

[0219] S412. AMF-T continues the registration process.

[0220] S413. The AMF-T prepares to send a Registration Receive Request message. Since the feeder link is currently unavailable, the AMF-T can wait until the feeder link is restored before sending the message. Additionally, the AMF-T can notify the SMF-T of the successful registration.

[0221] S414. SMF-T executes the session establishment process.

[0222] S415. AMF-T sends a PDU session establishment accept message to SMF-T.

[0223] S416. When the feeder link between satellite 7 and the ground core network element is available, AMF-T sends a registration and PDU session establishment accept message to AMF-NT-7.

[0224] S417. When the service link between satellite 7 and the terminal device is available, AMF-NT-7 sends a registration and PDU session establishment accept message to the terminal device via RAN-7.

[0225] S418. The terminal device returns a registration and PDU session establishment acceptance message to AMF-NT-7 via RAN-7.

[0226] S419. When the feeder link between satellite 7 and the ground core network element is available, AMF-NT-7 sends a registration and PDU session establishment accept message to AMF-T.

[0227] For the implementation of S404-S419, reference may be made to the description of S310-S325 in the above embodiment, which will not be repeated here.

[0228] In the method provided in the embodiment of the present application, when the terminal device is in the deregistered state, the NAS security context may be stored in the terminal device and the AMF, so the user authentication process of S310-S325 can be skipped, the NAS security context can be directly established, and a PDU session establishment request message can be sent based on the NAS security context.

[0229] The above embodiments are combined Figure 9 This describes the overall process of successful registration and PDU session establishment. Figure 12 This section describes the overall process when both the registration and PDU session establishment processes fail.

[0230] It should be noted that Figure 12The method shown still uses the terminal equipment, satellite 1's onboard network elements (such as RAN-1, AMF-NT-1), satellite 2's onboard network elements (such as RAN-2, AMF-NT-2), satellite 3's onboard network elements (such as RAN-3, AMF-NT-3 and SMF-NT), satellite 4's onboard network elements (such as RAN-4, AMF-NT-4), and ground core network elements of ground equipment (such as AMF-T, AUSF, UDM, UPF and SMF-T) as the execution entities.

[0231] like Figure 12 As shown, the method may include the following S501 to S521.

[0232] S501. When a service link between the terminal device and satellite 1 (also known as the third non-terrestrial device) is available, the terminal device sends a registration request message to RAN-1, which forwards the message to AMF-NT-1.

[0233] S502. AMF-NT-1 returns a downlink NAS transport message to the terminal device via RAN-1. The message includes a temporary identifier (interim GUTI) allocated to the terminal device.

[0234] S503. When the feeder link between satellite 1 and the ground core network element is available, AMF-NT-1 forwards the stored registration request message and the temporary identifier (interim GUTI) to AMF-T.

[0235] S504: AMF-T initiates the user authentication process.

[0236] S505: When the feeder link between satellite 2 (which may be referred to as the fourth non-terrestrial device) and the terrestrial core network element is available, AMF-T sends an authentication request message to AMF-NT-2.

[0237] S506: When the service link between satellite 2 and the terminal device is available, AMF-NT-2 sends an authentication request message to the terminal device via RAN-2.

[0238] S507. The terminal device returns an authentication response message to AMF-NT-2 via RAN-2.

[0239] S508: When the feeder link between satellite 2 and the ground core network element is available, AMF-NT-2 sends an authentication response message to AMF-T.

[0240] S509. The AUSF sends an authentication response message to the AMF-T. The message contains the key security anchor function (KSEAF) key.

[0241] S510: When the feeder link between satellite 3 (which may be referred to as the first non-terrestrial device) and the terrestrial core network element is available, the AMF-T sends a security mode command to the AMF-NT-3.

[0242] S511. When the service link between satellite 3 and the terminal device is available, AMF-NT-3 sends a security mode command to the terminal device via RAN-3.

[0243] S512. The terminal device sends a security mode response message to AMF-NT-3 via RAN-3. The security mode response message includes a NAS message, which includes a PDU session establishment request message.

[0244] S513. AMF-NT-3 forwards the PDU session establishment request message to SMF-NT.

[0245] S514. After the SMF-NT receives the PDU session establishment request message forwarded by the AMF-NT-3, the SMF-NT pre-processes the PDU session establishment request message and temporarily stores the pre-processed PDU session establishment request message.

[0246] For the implementation of S501-S514, reference may be made to the description of S301-S314 in the above embodiment, which will not be repeated here.

[0247] S515. When the feeder link between satellite 3 and the ground core network element is available, SMF-NT and SMF-T perform information synchronization. For example, SMF-NT forwards the PDU session establishment request message to SMF-T.

[0248] In some embodiments, after SMF-NT forwards the PDU session establishment request message to SMF-T, SMF-NT can start a timer. When the timer reaches a preset duration, the information stored in SMF-NT is cleared to release the storage space of SMF-NT in time.

[0249] S516. After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0250] S517. After receiving the Safe Mode Response message, the AMF-NT-3 temporarily stores the message until it reconnects to the ground station and forwards the message to the AMF-T.

[0251] S518. AMF-T continues the registration process.

[0252] S519. If the registration fails, the AMF-T sends a notification message to the SMF-T, which is used to notify the SMF-T of the registration failure.

[0253] Registration may fail for certain reasons, which may include user authentication failure, security context establishment failure, or failure in the second half of registration due to policy or access type mismatch. The PDU session establishment request is carried in the security mode response message. If it is due to user authentication failure or security context establishment failure, the terminal device can perform a re-registration process. If the registration fails in the second half due to policy or access type mismatch, the PDU session establishment request has been sent in advance at this time, and the AMF-NT and SMF-NT may have forwarded or processed the message. Based on the intermittent nature of the link in the store-and-forward scenario, after confirming the registration failure, the AMF-T can notify the SMF-T of the registration failure. SMF-T can immediately release the stored PDU session establishment request information and any allocated resources, which may include session ID, policy and billing related information, etc.

[0254] S520. If the feeder link between satellite 4 (which may be referred to as the second non-terrestrial device) and the terrestrial core network element is available, the AMF-T sends a Registration and PDU Session Establishment Reject message to AMF-NT-4. The Registration and PDU Session Establishment Reject message is used to indicate that the Registration and PDU Session Establishment failed.

[0255] S521. If the service link between satellite 4 and the terminal device is available, AMF-NT-4 forwards the registration and PDU session establishment reject message to the terminal device via RAN-4.

[0256] In some embodiments, the registration and PDU session establishment rejection message may include at least one of the following: the reason for the registration failure, the S&F monitoring list, and the S&F wait time. This information can be used to guide the user to re-initiate registration.

[0257] In the method provided in the embodiment of the present application, if the registration fails in the second half due to policy, access type mismatch, etc., by returning a registration and PDU session establishment rejection message to the terminal device, the terminal device can be informed of the failure of the registration and PDU session establishment and decide whether to re-initiate registration.

[0258] exist Figure 9In the corresponding above embodiment, the registration request message may include request information for requesting the configuration of S-NSSAI, the security mode command may include multiple S-NSSAIs configured by the ground core network device, and the security mode response message may include a PDU session establishment request corresponding to one S-NSSAI. Using the security mode command to carry S-NSSAI and using the security mode response message to carry the PDU session establishment request can reduce signaling overhead, but may face DoS attacks. Based on this, Figure 13 As shown, the present application also provides another registration and session establishment method in the store-and-forward mode.

[0259] It should be noted that Figure 13 The method shown still uses the terminal equipment, satellite 1's onboard network elements (such as RAN-1, AMF-NT-1), satellite 2's onboard network elements (such as RAN-2, AMF-NT-2), satellite 3's onboard network elements (such as RAN-3, AMF-NT-3 and SMF-NT), satellite 4's onboard network elements (such as RAN-4, AMF-NT-4), and ground core network elements of ground equipment (such as AMF-T, AUSF, UDM, UPF and SMF-T) as the execution entities.

[0260] like Figure 13 As shown, the method may include the following S601 to S627.

[0261] S601. When a service link between the terminal device and satellite 1 (also known as the third non-terrestrial device) is available, the terminal device sends a registration request message to RAN-1, which forwards the message to AMF-NT-1.

[0262] In some embodiments, the registration request message may include: registration type, SUCI, 5G-GUTI, PEI, and S-NSSAI request information. This request information is used to request the network-side device to configure S-NSSAI.

[0263] S602. AMF-NT-1 returns a downlink NAS transport message to the terminal device via RAN-1. The message includes a temporary identifier (interim GUTI) allocated to the terminal device.

[0264] S603. When the feeder link between satellite 1 and the ground core network element is available, AMF-NT-1 forwards the stored registration request message and the temporary identifier (interim GUTI) to AMF-T.

[0265] S604: AMF-T initiates user authentication process.

[0266] S605: When the feeder link between satellite 2 (which may be referred to as the fourth non-terrestrial device) and the terrestrial core network element is available, AMF-T sends an authentication request message to AMF-NT-2.

[0267] S606: When the service link between satellite 2 and the terminal device is available, AMF-NT-2 sends an authentication request message to the terminal device via RAN-2.

[0268] S607. The terminal device returns an authentication response message to AMF-NT-2 via RAN-2.

[0269] S608: When the feeder link between Satellite 2 and the ground core network element is available, AMF-NT-2 sends an authentication response message to AMF-T.

[0270] S609. The AUSF sends an authentication response message to the AMF-T. The message contains the key security anchor function (KSEAF) key.

[0271] S610: When the feeder link between satellite 3 (which may be referred to as the first non-terrestrial device) and the terrestrial core network element is available, the AMF-T sends a security mode command to the AMF-NT-3.

[0272] For the implementation of S601-S610, reference may be made to the description of S301-S310 in the above embodiment, which will not be repeated here.

[0273] S611. When the service link between satellite 3 and the terminal device is available, AMF-NT-3 sends a security mode command to the terminal device via RAN-3.

[0274] The difference from the security mode command in S311 above is that the security mode command in S611 does not include multiple S-NSSAIs configured by the ground core network equipment, but is implemented through S613.

[0275] S612. The terminal device sends a security mode response message to AMF-NT-3 via RAN-3.

[0276] The difference from the security mode response message in S312 is that the security mode response message in S612 does not include a PDU session establishment request message, but is implemented through S614.

[0277] S613. AMF-NT-3 sends multiple S-NSSAIs to the terminal device via RAN-3. These multiple S-NSSAIs are configured for the terrestrial core network device.

[0278] S614. The terminal device sends a PDU session establishment request message based on an S-NSSAI to AMF-NT-3 via RAN-3. This S-NSSAI is selected by the terminal device from multiple S-NSSAIs.

[0279] S615. AMF-NT-3 forwards the PDU session establishment request message to SMF-NT.

[0280] S616. After the SMF-NT receives the PDU session establishment request message forwarded by the AMF-NT-3, the SMF-NT pre-processes the PDU session establishment request message and temporarily stores the pre-processed PDU session establishment request message.

[0281] For the implementation of S601-S614, reference may be made to the description of S301-S314 in the above embodiment, which will not be repeated here.

[0282] S617. When the feeder link between Satellite 3 and the ground core network element is available, SMF-NT and SMF-T perform information synchronization. For example, SMF-NT forwards the PDU Session Establishment Request message to SMF-T.

[0283] S618. After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0284] S619. After receiving the Safe Mode Response message, the AMF-NT-3 stores it temporarily until it reconnects to the ground station and forwards it to the AMF-T.

[0285] S620. AMF-T continues the registration process.

[0286] S621. The AMF-T prepares to send a Registration Receive Request message. Since the feeder link is currently unavailable, the AMF-T can wait until the feeder link is restored before sending the message. Additionally, the AMF-T can notify the SMF-T of the successful registration.

[0287] S622. SMF-T executes the session establishment process.

[0288] S623. AMF-T sends a PDU session establishment accept message to SMF-T.

[0289] S624. When the feeder link between satellite 4 and the ground core network element is available, AMF-T sends a registration and PDU session establishment accept message to AMF-NT-4.

[0290] S625. When the service link between satellite 4 and the terminal device is available, AMF-NT-4 sends a registration and PDU session establishment accept message to the terminal device via RAN-4.

[0291] S626. The terminal device returns a registration and PDU session establishment acceptance message to AMF-NT-4 via RAN-4.

[0292] S627. When the feeder link between satellite 4 and the ground core network element is available, AMF-NT-4 sends a registration and PDU session establishment accept message to AMF-T.

[0293] For the implementation of S615-S627, reference may be made to the description of S313-S325 in the above embodiment, which will not be repeated here.

[0294] In the method provided in the embodiments of the present application, the security mode command and security mode response messages do not carry the S-NSSAI. A security context is first established through the security mode command and security mode response messages. The non-terrestrial device then sends multiple S-NSSAIs configured by the terrestrial core network device to the terminal device. The terminal device then selects one S-NSSAI and sends a PDU session establishment accept message based on this S-NSSAI. This protects the S-NSSAI from network attacks and more effectively ensures the security of the S-NSSAI.

[0295] It should be understood that Figures 1 to 13 The flowcharts or scenario diagrams shown are only for ease of understanding and are not intended to limit the embodiments of the present application to the examples shown in the diagrams. In fact, those skilled in the art will Figures 1 to 13 The examples in can be equivalently transformed to obtain more implementation methods.

[0296] Combined with the above Figures 1 to 13 , describes in detail the handover decision determination method provided by the embodiment of the present application. Figures 14 and 15 It should be understood that the communication device of the present invention can execute the various handover decision determination methods of the above embodiments of the present invention, that is, the specific working processes of the following various products can refer to the corresponding processes in the above method embodiments.

[0297] In the above embodiments, the terminal device, the non-terrestrial device, and the terrestrial device can perform some or all of the steps in the embodiments. These steps or operations are merely examples, and the embodiments of the present application can also perform other operations or variations of various operations. In addition, the various steps can be performed in the different orders presented in the embodiments, and it is possible that not all operations in the embodiments of the present application need to be performed. Moreover, the size of the sequence number of each step does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0298] Figure 14 is a schematic block diagram of an electronic device provided in an embodiment of the present application. The electronic device may be a communication device. Figure 14 As shown, the electronic device 140 may include a communication module 141 and a processing module 142. The processing module 142 may implement corresponding processing functions. The communication module 141 may implement corresponding communication functions, which may be internal communication functions of the electronic device 140 or communication functions between the electronic device 140 and other devices. Optionally, the communication module 141 may also be referred to as a communication interface or a communication module.

[0299] Optionally, the electronic device 140 further includes a storage module, which can be used to store instructions and / or data; the processing module 142 can read the instructions and / or data in the storage module, so that the electronic device 140 implements the aforementioned method embodiment.

[0300] In one possible implementation, the electronic device 140 may correspond to the terminal device in the above method embodiments, or a component configured in the terminal device (such as a circuit, chip, or chip system). The electronic device 140 can be used to execute the steps or processes executed by the terminal device in any of the above method embodiments.

[0301] Exemplarily, the communication module 141 can be used to: send a registration request message to a non-ground device; receive a safety mode command from the non-ground device; send a safety mode response message to the non-ground device, the safety mode response message may include a PDU session establishment request message, the PDU session establishment request message may include a first information identifier, the first information identifier may be used to instruct the non-ground device to pre-process and store the PDU session establishment request message; receive a registration and PDU session establishment acceptance message from the non-ground device.

[0302] The above is only an example, and for detailed steps or processes, please refer to the description of the aforementioned embodiments.

[0303] In another possible implementation, the electronic device 140 may correspond to the non-terrestrial device in the above method embodiments, or a component (such as a circuit, chip, or chip system) configured in the non-terrestrial device. The electronic device 140 can be used to execute the steps or processes performed by the non-terrestrial device in any of the above method embodiments.

[0304] Exemplarily, the communication module 141 can be used to: receive a registration request message from a terminal device; send a safe mode command to the terminal device; receive a safe mode response message from the terminal device, the safe mode response message may include a PDU session establishment request message, and the PDU session establishment request message may include a first information identifier. The processing module 142 can be used to: pre-process and store the PDU session establishment request message based on the first information identifier. The communication module 141 can also be used to: send a safe mode response message and a pre-processed PDU session establishment request message to a ground device, the safe mode response message sent to the ground device may not include a PDU session establishment request message; receive a registration and PDU session establishment acceptance message from the ground device; and send a registration and PDU session establishment acceptance message to the terminal device.

[0305] The above is only an example, and for detailed steps or processes, please refer to the description of the aforementioned embodiments.

[0306] In another possible implementation, the electronic device 140 may correspond to the ground equipment in the above method embodiments, or a component configured in the ground equipment (such as a circuit, chip, or chip system). The electronic device 140 can be used to execute the steps or processes performed by the ground equipment in any of the above method embodiments.

[0307] Exemplarily, communication module 141 is configured to receive a secure mode response message and a pre-processed PDU session establishment request message from a non-terrestrial device, and store the PDU session establishment request message. Processing module 142 may be configured to execute a registration process in response to the secure mode response message; upon successful registration, execute a PDU session establishment process based on the stored PDU session establishment request message. Communication module 141 may also be configured to send a registration and PDU session establishment acceptance message to the non-terrestrial device upon successful PDU session establishment.

[0308] The above is only an example, and for detailed steps or processes, please refer to the description of the aforementioned embodiments.

[0309] Figure 15This is a schematic block diagram of a communication device 150 provided in an embodiment of the present application. This communication device 150 can be a terminal device, a non-terrestrial device, or a chip, a chip system, or a processor that implements the above-described method. This communication device 150 can be used to implement the method described in the above-described method embodiment. For details, please refer to the description of the above-described method embodiment.

[0310] like Figure 15 As shown, the communication device 150 may include one or more processors 151, which may also be referred to as processing units or processing modules, and may implement certain control functions. Processor 151 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor may be used to process communication protocols and communication data, while the central processing unit may be used to control the communication device 150 (e.g., base station, baseband chip, user, user chip), execute software programs, and process software program data.

[0311] In one possible implementation, the processor 151 may also store instructions and / or data, and the instructions and / or data may be executed by the processor 151 so that the communication device 150 executes the method described in the above method embodiment.

[0312] In another possible implementation, the communication device 150 may include a communication interface 152 for implementing receiving and transmitting functions. For example, the communication interface 152 may be a transceiver circuit, an interface, an interface circuit, or a transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing the receiving and transmitting functions may be separate or integrated. The transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or may be used for transmitting or delivering signals.

[0313] Optionally, the communication device 150 may include one or more memories 153, which may store instructions that can be executed on the processor 151, causing the communication device 150 to perform the methods described in the above method embodiments. Optionally, the memories 153 may also store data. Optionally, the processor 151 may also store instructions and / or data. The processor 151 and memory 153 may be provided separately or integrated together.

[0314] It should be understood that, in one possible implementation, each step in the method embodiment provided in the present application can be completed by an integrated logic circuit of hardware in a processor or by instructions in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0315] In one implementation, the communication device 150 may correspond to the terminal device in the above-mentioned method embodiment and may be used to execute the various steps and / or processes performed by the terminal device in the above-mentioned method embodiment. The processor 151 may be used to execute instructions stored in the memory 153, and when the processor 151 executes the instructions stored in the memory, the processor 151 is used to execute the various steps and / or processes of the above-mentioned method embodiment corresponding to the terminal device.

[0316] In another implementation, the communication device 150 may correspond to the non-terrestrial device in the above-mentioned method embodiment and may be configured to execute the various steps and / or processes performed by the non-terrestrial device in the above-mentioned method embodiment. The processor 151 may be configured to execute instructions stored in the memory 153. When the processor 151 executes the instructions stored in the memory, the processor 151 is configured to execute the various steps and / or processes of the above-mentioned method embodiment corresponding to the non-terrestrial device.

[0317] In another implementation, the communication device 150 may correspond to the ground equipment in the above-mentioned method embodiment and may be used to execute the various steps and / or processes performed by the ground equipment in the above-mentioned method embodiment. The processor 151 may be used to execute instructions stored in the memory 153, and when the processor 151 executes the instructions stored in the memory, the processor 151 is used to execute the various steps and / or processes of the above-mentioned method embodiment corresponding to the ground equipment.

[0318] It should be understood that the processing device may be one or more chips. For example, the processing device may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0319] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0320] Based on the methods provided in the embodiments of the present application, the present application also provides a chip system, which includes one or more processors configured to retrieve and execute instructions stored in a memory, thereby executing the methods of the embodiments of the present application. The chip system can be composed of a chip or can include a chip and other discrete devices.

[0321] Among them, the chip system may include an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

[0322] According to the method provided in the embodiment of the present application, the present application also provides a communication system, which includes the aforementioned terminal equipment, non-terrestrial equipment and terrestrial equipment.

[0323] According to the method provided in the embodiments of the present application, the present application also provides a computer program product, which includes: computer program code, which, when the computer program code runs on a computer, enables the computer to execute the various steps or processes performed by the LMF and access network device in any of the aforementioned method embodiments.

[0324] According to the method provided in the embodiments of the present application, the present application also provides a computer-readable storage medium, which stores program code. When the program code runs on a computer, the computer executes the various steps or processes performed by the terminal device, non-ground device or ground device in any of the aforementioned method embodiments.

[0325] The computer-readable storage medium may be the aforementioned volatile memory or non-volatile memory, or may include both volatile memory and non-volatile memory.

[0326] In the embodiments of this application, each term and English abbreviation is provided for convenience of description and shall not constitute any limitation to this application. This application does not exclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0327] 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. A computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the processes or functions according to the embodiments of the present application are generated in whole or in part.

[0328] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0329] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0330] In short, the above is only a preferred embodiment of the technical solution of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A registration and session establishment method, characterized in that: The method is applied to a terminal device, and the method includes: Sending a registration request message to a non-ground device; Sending a protocol data unit (PDU) session establishment request message to the non-terrestrial device, where the PDU session establishment request message includes a first information identifier, where the first information identifier is used to instruct the non-terrestrial device to pre-process and store the PDU session establishment request message; A registration and PDU session establishment accept message is received from the non-terrestrial device, where the registration and PDU session establishment accept message is used to indicate that the registration and PDU session establishment are successful.

2. The method according to claim 1, characterized in that The non-terrestrial device includes a non-terrestrial session management function SMF-NT; the first information identifier is used to instruct the SMF-NT to pre-process and store the PDU session establishment request message.

3. The method according to claim 2, characterized in that The non-terrestrial device also includes a non-terrestrial access and mobility management function AMF-NT; the PDU session establishment request message is carried in a security mode response message, and the security mode response message also includes a second information identifier, which is used to instruct the AMF-NT to forward the PDU session establishment request message to the SMF-NT.

4. The method according to claim 1, wherein The method further comprises: receiving a safe mode command from the non-ground device; Sending the PDU session establishment request message to the non-terrestrial device includes: In response to the security mode command, a security context is enabled, and a security mode response message is sent to the non-terrestrial device, where the security mode response message includes the PDU session establishment request message.

5. The method according to claim 4, characterized in that Before receiving the safety mode command from the non-ground device, the method further includes: receiving an authentication request message from the non-ground device; An authentication response message is sent to the non-terrestrial device.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: In the case where the registration and PDU session establishment fails, receiving a registration and PDU session establishment rejection message from the non-terrestrial device, wherein the registration and PDU session establishment rejection message is used to indicate that the registration and PDU session establishment fails; or In the case where the registration establishment is successful but the PDU session establishment fails, a registration acceptance message is received from the non-terrestrial device, where the registration acceptance message includes first indication information, and the first indication information is used to indicate that the PDU session establishment fails.

7. A registration and session establishment method, characterized in that: The method is applied to non-ground equipment, and the method includes: Receiving a registration request message from a terminal device; receiving a PDU session establishment request message from the terminal device, where the PDU session establishment request message includes a first information identifier; Preprocessing and storing the PDU session establishment request message based on the first information identifier; Sending the pre-processed PDU session establishment request message to the ground device; Receive a registration and PDU session establishment acceptance message from the ground device, and send the registration and PDU session establishment acceptance message to the terminal device, where the registration and PDU session establishment acceptance message is used to indicate that the registration and PDU session establishment are successful.

8. The method according to claim 7, characterized in that The non-terrestrial device includes a first non-terrestrial device, and the first non-terrestrial device includes an SMF-NT; The preprocessing and storing the PDU session establishment request message based on the first information identifier includes: The SMF-NT decodes the PDU session establishment request message to obtain the first information identifier, and pre-processes and stores the PDU session establishment request message based on the first information identifier.

9. The method according to claim 8, characterized in that The first non-terrestrial equipment further includes AMF-NT; The receiving a PDU session establishment request message from the terminal device includes: The AMF-NT sends a security mode command to the terminal device; The AMF-NT receives a security mode response message from the terminal device, where the security mode response message includes a second information identifier and the PDU session establishment request message; The AMF-NT decodes the security mode response message to obtain the second information identifier and the PDU session establishment request message, and based on the second information identifier, forwards the PDU session establishment request message to the SMF-NT.

10. The method according to claim 9, characterized in that The ground equipment includes a ground access and mobility management function AMF-T and a ground session management function SMF-T; The sending the pre-processed PDU session establishment request message to the ground device includes: When the feeder link is available, the AMF-NT sends the security mode response message to the AMF-T, and the SMF-NT sends the pre-processed PDU session establishment request message to the SMF-T, wherein the security mode response message sent to the AMF-T does not include the PDU session establishment request message.

11. The method according to claim 10, characterized in that The non-terrestrial device includes a second non-terrestrial device; The receiving a registration and PDU session establishment acceptance message from the ground device includes: The second non-terrestrial device receives the registration and PDU session establishment accept message from the AMF-T; The sending the registration and PDU session establishment acceptance message to the terminal device includes: The second non-terrestrial device sends the registration and PDU session establishment acceptance message to the terminal device.

12. The method according to claim 11, characterized in that The method further comprises: In the case where the registration and PDU session establishment fails, the second non-terrestrial device receives a registration and PDU session establishment rejection message from the terrestrial device and sends the registration and PDU session establishment rejection message to the terminal device, where the registration and PDU session establishment rejection message is used to indicate that the registration and PDU session establishment failed; or When the registration is successfully established but the PDU session fails to be established, the second non-ground device receives a registration acceptance message from the ground device and sends the registration acceptance message to the terminal device. The registration acceptance message includes first indication information, and the first indication information is used to indicate that the PDU session fails to be established.

13. The method according to any one of claims 7 to 12, characterized in that The non-terrestrial device includes a third non-terrestrial device; The receiving a registration request message from the terminal device includes: The third non-terrestrial device receives a registration request message from the terminal device; The third non-terrestrial device sends the registration request message to the terrestrial device.

14. The method according to claim 13, characterized in that The non-terrestrial device includes a fourth non-terrestrial device; After the third non-terrestrial device sends the registration request message to the terrestrial device, the method further includes: The fourth non-ground device receives the authentication request message from the ground device; The fourth non-terrestrial device sends the authentication request message to the terminal device; The fourth non-terrestrial device receives the authentication response message from the terminal device; The fourth non-ground device sends the authentication response message to the ground device.

15. A registration and session establishment method, characterized in that: The method is applied to ground equipment, and the method includes: receiving a registration request message from a non-ground device; receiving a pre-processed PDU session establishment request message from the non-ground device, and storing the PDU session establishment request message; Execute the registration process; After successful registration, executing the PDU session establishment process based on the stored PDU session establishment request message; After the PDU session establishment process is successful, a registration and PDU session establishment accept message is sent to the non-terrestrial device, where the registration and PDU session establishment accept message is used to indicate that the registration and PDU session establishment are successful.

16. The method according to claim 15, characterized in that The ground equipment includes SMF-T; the non-ground equipment includes a first non-ground equipment, and the first non-ground equipment includes SMF-NT; The receiving the pre-processed PDU session establishment request message from the non-terrestrial device includes: The SMF-T receives the pre-processed PDU session establishment request message from the SMF-NT.

17. The method according to claim 16, characterized in that The ground equipment further includes AMF-T; the first non-ground equipment further includes AMF-NT; The execution registration process includes: The AMF-T sends a security mode command to the AMF-NT, receives a security mode response message from the AMF-NT, and performs a registration process in response to the security mode response message; After the registration is successful, the PDU session establishment process is executed based on the stored PDU session establishment request message, including: After successful registration, the AMF-T sends a notification message to the SMF-T, where the notification message is used to indicate that the registration is successful; the SMF-T executes the PDU session establishment process based on the stored PDU session establishment request message.

18. The method according to claim 15, characterized in that The non-terrestrial device includes a second non-terrestrial device; The sending a registration and PDU session establishment acceptance message to the non-terrestrial device includes: When the registration and PDU session establishment are successful, the registration and PDU session establishment acceptance message is sent to the second non-terrestrial device, which is the next non-terrestrial device covering the terminal device.

19. The method according to claim 18, characterized in that The method further comprises: In the case where the registration and PDU session establishment fails, sending a registration and PDU session establishment rejection message to the second non-terrestrial device, where the registration and PDU session establishment rejection message is used to indicate that the registration and PDU session establishment fails; or In the case where the registration establishment is successful but the PDU session establishment fails, a registration acceptance message is sent to the second non-terrestrial device, where the registration acceptance message includes first indication information, and the first indication information is used to indicate that the PDU session establishment fails.

20. The method according to any one of claims 15 to 19, characterized in that The non-terrestrial device includes a third non-terrestrial device; The receiving a registration request message from the non-ground device includes: receiving a registration request message from the third non-terrestrial device; In response to the registration request message, a user authentication process is performed.

21. The method according to claim 20, characterized in that The non-terrestrial equipment further includes a fourth non-terrestrial equipment; After performing the user authentication process, the method further includes: Sending an authentication request message to the fourth non-terrestrial device; An authentication response message is received from the fourth non-terrestrial device.

22. A communication device, characterized in that: The communication device includes at least one processor coupled to a memory, wherein the memory stores a program or instruction. The processor executes the program or instruction so that the device is configured to perform the method according to any one of claims 1 to 21.

23. A communication system, characterized in that: The communication system includes a terminal device, a non-ground device and a ground device; wherein the terminal device is used to execute the method as described in any one of claims 1 to 6, the non-ground device is used to execute the method as described in any one of claims 7 to 14, and the ground device is used to execute the method as described in any one of claims 15 to 21.

24. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or instructions, which, when executed, causes a computer to perform the method according to any one of claims 1 to 21.

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