Registration and session establishment methods, apparatuses, communication systems, and storage media

Abstract

The application provides a registration and session establishment method and device, a communication system and a storage medium, and 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 core network elements, so that the total interaction times of the two processes are effectively reduced, and the interaction delay and service waiting time of the terminal device and the core network device are reduced. The SMF-NT decodes and preprocesses the PDU session establishment request, which can effectively avoid DoS attacks and reduce the ground response time in the session management process to a certain extent.

Description

TECHNICAL FIELD

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

[0002] In the user registration process and the protocol data unit (PDU) session establishment process specified by 3GPP, the PDU session establishment process is usually performed after the user registration process is completed. From the terminal device initiates a registration request or a PDU session establishment request, a series of complex interactions need to be performed by a plurality of network elements, and the terminal device and the core network also need to perform multiple rounds of interactions. The interval between the two processes is relatively long, which increases the interaction delay of the terminal device and the core network and the service waiting time. SUMMARY

[0003] The present application provides a registration and session establishment method and device, a communication system and a 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-mentioned purpose, the present application adopts the following technical solutions:

[0005] In a first aspect, the present application provides a registration and session establishment method. The method can be executed by a terminal device, or by a component (such as a circuit, a chip or a chip system, etc.) configured in the terminal device, or by a logic module or software capable of realizing all or part of the functions of the terminal device. Hereinafter, the terminal device is taken as an example for description.

[0006] The method can include: the terminal device sends a registration request message to a non-ground device; the terminal device sends a PDU session establishment request message to the non-ground device, the PDU session establishment request message can include a first information identifier, the first information identifier can be used to instruct the non-ground device to pre-process and store the PDU session establishment request message; the terminal device receives a registration and PDU session establishment acceptance message from the non-ground device. The registration and PDU session establishment acceptance message is used to indicate that the registration process and the PDU session establishment process are successful.

[0007] In the foregoing scheme, by fusing the PDU session establishment process into the registration process, the total number of interactions of the two processes is effectively reduced, the interaction delay and service waiting time of the terminal device and the core network device are reduced, and the service experience is improved. In addition, by adding the first information identifier in the PDU session establishment request message, the non-terrestrial device can be instructed to preprocess 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-terrestrial device directly forwards the preprocessed PDU session establishment request message to the ground device, thereby reducing the ground response time in the session management process to a certain extent.

[0008] In a possible implementation, the non-terrestrial device can include an SMF-NT. The first information identifier can be used to instruct the SMF-NT to preprocess and store the PDU session establishment request message. In the related art, there is no SMF deployed on the satellite, and the satellite does not have the decoding and preprocessing capability of the PDU session establishment request message. In the foregoing scheme, by deploying the SMF-NT on the satellite, the SMF-NT can preprocess the PDU session establishment request based on the first information identifier, thereby reducing the ground response time in the session management process to a certain extent.

[0009] In a possible implementation, the non-terrestrial device can further include an AMF-NT. The security mode response message can further include a second information identifier, and the second information identifier can be 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 arranged on the satellite does not have the decoding and preprocessing capability of the PDU session establishment request message. In the foregoing scheme, by adding the second information identifier, the AMF-NT arranged on the satellite can be caused to forward the PDU session establishment request message to the SMF-NT arranged on the ground, thereby not only reducing the storage pressure of the AMF-NT, but also realizing preprocessing of the PDU session establishment request.

[0010] In a possible implementation, before the terminal device sends the PDU session establishment request message to the non-ground device, the method further includes: receiving a security mode command from the non-ground device. As an example, the terminal device can enable the security context in response to the security mode command, and send a security mode response message to the non-ground device, the security mode response message including the PDU session establishment request message. It can be understood that the terminal device returns the security mode response message, and considers that the NAS security context establishment is completed, and the PDU session establishment request message carried in the security mode response message can be protected by security. As another example, the terminal device can also send the security mode response message to the non-ground device first, and then send the 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.

[0011] In a possible implementation, before the terminal device receives the security mode command from the non-ground device, the method further includes: the terminal device receives an authentication request message from the non-ground device; and the terminal device sends an authentication response message to the non-ground device. In the above scheme, after the terminal device sends the registration request message to the non-ground device, the core network starts to perform a user authentication process, and returns the authentication request message to the terminal device to complete the user authentication.

[0012] In a possible implementation, the method further includes: in a case where the registration and the PDU session establishment fail, receiving a registration and PDU session establishment rejection message from the non-ground device, the registration and PDU session establishment rejection message being used to indicate that the registration and the PDU session establishment fail. Alternatively, in a case where the registration establishment succeeds and the PDU session establishment fails, receiving a registration accept message from the non-ground device, the registration accept message including first indication information, the first indication information being used to indicate that the PDU session establishment fails. In the above scheme, when the registration and the PDU session establishment both succeed, or when the registration succeeds and the PDU session establishment fails, or when the registration and the PDU session establishment both fail, one message is returned by merging, which can reduce the interaction times between the terminal device and the network side device, and reduce the signaling overhead. In addition, the corresponding information is returned to the terminal device regardless of whether the registration and the PDU session establishment succeed or not, which can improve the perception of the network by the terminal device and indicate the user behavior.

[0013] In a second aspect, the present application provides a registration and session establishment method. The method can be executed by a non-ground device, or can be executed by a component (such as a circuit, a chip or a chip system, etc.) configured in the non-ground device, and can also be implemented by a logic module or software capable of implementing all or part of the terminal device function. Hereinafter, the non-ground device is taken as an example for description.

[0014] The method can comprise: receiving, by the non-terrestrial device, a registration request message from the terminal device; receiving, by the non-terrestrial device, a PDU session establishment request message from the terminal device, the PDU session establishment request message can comprise a first information identifier; pre-processing and storing, by the non-terrestrial device, the PDU session establishment request message based on the first information identifier; sending, by the non-terrestrial device, a security mode response message and the pre-processed PDU session establishment request message to the ground device, the security mode response message sent to the ground device can not comprise the PDU session establishment request message; receiving, by the non-terrestrial device, a registration and PDU session establishment accept message from the ground device; and sending, by the non-terrestrial device, the registration and PDU session establishment accept message to the terminal device, the registration and PDU session establishment accept message is used to indicate that the registration and the PDU session establishment are successful.

[0015] In the above scheme, by fusing the PDU session establishment process into the registration process, the total number of interactions of the two processes is effectively reduced, the interaction delay and service waiting time of the terminal device and the core network device are reduced, and the service experience is improved. In addition, by adding the first information identifier in the PDU session establishment request message, the non-terrestrial 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-terrestrial device directly forwards the pre-processed PDU session establishment request message to the ground device, thereby reducing the ground response time in the session management process to some extent.

[0016] It should be noted that for non-stationary orbit devices such as low-orbit satellites, the coverage range of the satellite varies at different times. In the process of revolving around the earth, the terminal device will intermittently obtain satellite services from a satellite. The above non-terrestrial device is not limited to a satellite that provides services to the terminal device, that is, the non-terrestrial device can comprise 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.

[0017] In a possible implementation manner, the non-terrestrial device can comprise a first non-terrestrial device, and the first non-terrestrial device can comprise an SMF-NT. The pre-processing and storing, by the non-terrestrial device, the PDU session establishment request message based on the first information identifier can comprise: decoding, by the SMF-NT, the PDU session establishment request message to obtain the first information identifier, and pre-processing and storing, by the SMF-NT, the PDU session establishment request message based on the first information identifier.

[0018] In a possible implementation, the first non-ground device can further include the AMF-NT. Receiving the PDU session establishment request message from the terminal device can include: the AMF-NT sending a security mode command to the terminal device; the AMF-NT receiving a security mode response message from the terminal device, the security mode response message including the second information identifier and the PDU session establishment request message; the AMF-NT decoding the security 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 can be understood that the terminal device returns the security mode response message, and considers that the NAS security context establishment is completed, and carries the PDU session establishment request message in the security mode response message, so that the PDU session establishment request message is protected by security. In addition, by adding the second information identifier, the AMF-NT arranged on the satellite can forward the PDU session establishment request message to the SMF-NT arranged on the ground, so as to not only reduce the storage pressure of the AMF-NT, but also realize preprocessing of the PDU session establishment request.

[0019] In a possible implementation, the ground device can include the AMF-T and the SMF-T. The non-ground device sending the preprocessed PDU session establishment request message to the ground device can include: the AMF-NT sending a security mode response message to the AMF-T and the SMF-NT sending the preprocessed PDU session establishment request message to the SMF-T, in a case that the power feeding link is available. 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 power feeding power is not available, the AMF-NT and the SMF-NT temporarily store the message; when the power feeding power is available, the AMF-NT and the 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.

[0020] In a possible implementation, the non-ground device can include a second non-ground device. The non-ground device receiving the registration and PDU session establishment accept message from the ground device can include: the second non-ground device receiving the registration and PDU session establishment accept message from the AMF-T. The non-ground device sending the registration and PDU session establishment accept message to the terminal device can include: the second non-ground device sending the registration and PDU session establishment accept message to the terminal device.

[0021] In a possible implementation, the method can further include: in a case where the registration and the PDU session establishment fail, the second non-ground device receiving a registration and PDU session establishment rejection message from the ground device, and sending the registration and PDU session establishment rejection message to the terminal device, the registration and PDU session establishment rejection message being used to indicate that the registration and the PDU session establishment fail. Alternatively, in a case where the registration establishment succeeds and the PDU session establishment fails, the second non-ground device receiving a registration accept message from the ground device, and sending the registration accept message to the terminal device, the registration accept message including first indication information, the first indication information being used to indicate that the PDU session establishment fails.

[0022] In a possible implementation, the non-ground device can include a third non-ground device. The ground device receiving the registration request message from the terminal device can 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.

[0023] In a possible implementation, the non-ground device can include a fourth non-ground device. After the third non-ground device sends the registration request message to the ground device, the method can further include: the fourth non-ground device receiving an authentication request message from the ground device; the fourth non-ground device sending the 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 the authentication response message to the ground device.

[0024] The second aspect is a non-ground device side implementation corresponding to the first aspect, and the explanations, supplements, and beneficial effects described with respect to the first aspect also apply to the second aspect, and will not be described again.

[0025] The third aspect, the present application provides a registration and session establishment method. The method can be executed by a ground device, or can also be executed by a component (such as a circuit, a chip, or a chip system, etc.) configured in the ground device, and can also be implemented by a logic module or software that can implement all or part of the terminal device function. The following is described taking the ground device as an example.

[0026] The method can include: the ground device receiving a registration request message from a non-ground device; the ground device receiving a preprocessed PDU session establishment request message from the non-ground device, and storing the PDU session establishment request message; the ground device performing a registration process in response to a security mode response message; after the registration succeeds, the ground device performing a PDU session establishment process based on the stored PDU session establishment request message; and after the PDU session establishment process succeeds, the ground device sending a registration and PDU session establishment accept message to the non-ground device, the registration and PDU session establishment accept message being used to indicate that the registration and the PDU session establishment succeed.

[0027] In the above scheme, by fusing the PDU session establishment process into the registration process, the total number of interactions of the two processes is effectively reduced, the interaction delay and service waiting time of the terminal device and the core network device are reduced, and the service experience is improved. In addition, the non-terrestrial device pre-processes and stores the PDU session establishment request message when the feeder circuit is unavailable, so that when the feeder circuit is restored, the non-terrestrial device directly forwards the pre-processed PDU session establishment request message to the ground device, thereby reducing the ground response time in the session management process to a certain extent.

[0028] In a possible implementation, the ground 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 the pre-processed PDU session establishment request message from the non-terrestrial device includes that the SMF-T receives the pre-processed PDU session establishment request message from the SMF-NT.

[0029] In a possible implementation, the ground device further includes an AMF-T. The first non-terrestrial device further includes an AMF-NT. Performing the registration process includes that the AMF-T sends a security mode command to the AMF-NT and receives a security mode response message from the AMF-NT, and performs the registration process in response to the security mode response message. After the registration is successful, performing the PDU session establishment process based on the stored PDU session establishment request message includes that after the registration is successful, the AMF-T sends a notification message to the SMF-T, the notification message being used to indicate that the registration is successful; and the SMF-T performs the PDU session establishment process based on the stored PDU session establishment request message.

[0030] In a possible implementation, the non-terrestrial device can include a second non-terrestrial device. The ground device sending the registration and PDU session establishment acceptance message to the non-terrestrial device can include that in the case that the registration and the PDU session establishment are successful, the ground device sends the registration and PDU session establishment acceptance message to the second non-terrestrial device, the second non-terrestrial device being a non-terrestrial device for a next covered terminal device.

[0031] In a possible implementation, the method can further include that in the case that the registration and the PDU session establishment fail, sending a registration and PDU session establishment rejection message to a second non-terrestrial device, the registration and PDU session establishment rejection message being used to indicate that the registration and the PDU session establishment fail; or in the case that the registration establishment is successful and the PDU session establishment fails, sending a registration acceptance message to the second non-terrestrial device, the registration acceptance message including first indication information, the first indication information being used to indicate that the PDU session establishment fails.

[0032] In a possible implementation, the non-ground device includes a third non-ground device. The receiving the registration request message from the non-ground device includes that the ground device receives the registration request message from the third non-ground device; and the performing the user authentication procedure includes that the ground device performs the user authentication procedure in response to the registration request message.

[0033] In a possible implementation, the non-ground device includes a fourth non-ground device. After the performing the user authentication procedure, the method further includes that the ground device sends an authentication request message to the fourth non-ground device; and the receiving the authentication response message from the fourth non-ground device.

[0034] The third aspect is a non-ground device side implementation corresponding to the first aspect. The explanations, supplements and beneficial effects of the first aspect and the second aspect are also applicable to the third aspect, and will not be repeated.

[0035] The fourth aspect provides an electronic device including a communication module. The communication module can be configured to: send a registration request message to a non-ground device; receive a security mode command from the non-ground device; send a security mode response message to the non-ground device, the security mode response message can include a PDU session establishment request message, the PDU session establishment request message can include a first information identifier, the first information identifier can be used to instruct the non-ground device to preprocess the PDU session establishment request message and store; and receive a registration and PDU session establishment acceptance message from the non-ground device.

[0036] The fifth aspect provides an electronic device including a communication module and a processing module. The communication module can be configured to: receive a registration request message from a terminal device; send a security mode command to the terminal device; and receive a security mode response message from the terminal device, the security mode response message can include a PDU session establishment request message, the PDU session establishment request message can include a first information identifier. The processing module can be configured to: preprocess and store the PDU session establishment request message based on the first information identifier. The communication module can be further configured to: send the security mode response message and the preprocessed PDU session establishment request message to a ground device, the security mode response message sent to the ground device can not include the PDU session establishment request message; 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.

[0037] In a sixth aspect, an electronic device is provided, which includes a communication module and a processing module. The communication module can be configured to receive a security mode response message and a pre-processed PDU session establishment request message from a non-ground device, and store the PDU session establishment request message. The processing module can be configured to perform a registration procedure in response to the security mode response message, and perform a PDU session establishment procedure based on the stored PDU session establishment request message after the registration is successful. The communication module can be further configured to send a registration and PDU session establishment accept message to the non-ground device after the PDU session establishment procedure is successful.

[0038] The fourth aspect, the fifth aspect and the sixth aspect are corresponding device-side implementations of the first aspect, the second aspect and the third aspect. The explanations, supplements and beneficial effects of the first aspect, the second aspect and the third aspect are also applicable to the fourth aspect, the fifth aspect and the sixth aspect, and will not be repeated.

[0039] In a seventh aspect, a communication device is provided, which includes a processor. The processor is coupled with a memory, and is configured to execute instructions or data in the memory to implement the method in any possible implementation of the first aspect. Optionally, the communication device further includes the memory. Optionally, the communication device further includes a communication interface, and the processor is coupled with the communication interface.

[0040] In an eighth aspect, a communication device is provided, which includes a processor. The processor is coupled with a memory, and is configured to execute instructions or data in the memory to implement the method in any possible implementation of the second aspect. Optionally, the communication device further includes the memory. Optionally, the communication device further includes a communication interface, and the processor is coupled with the communication interface.

[0041] In a ninth aspect, a communication device is provided, which includes a processor. The processor is coupled with a memory, and is configured to execute instructions or data in the memory to implement the method in any possible implementation of the third aspect. Optionally, the communication device further includes the memory. Optionally, the communication device further includes a communication interface, and the processor is coupled with the communication interface.

[0042] In a tenth aspect, a processor is provided, which includes 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.

[0043] In the implementation process, the processor can be one or more chips, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a flip-flop, various logic circuits, etc. The input signal received by the input circuit can be received and input by, for example but not limited to, a receiver, the output signal output by the output circuit can be output to and transmitted by, for example but not limited to, a transmitter, and the input circuit and the output circuit can be the same circuit which is used as the input circuit and the output circuit at different times. The embodiments of the present application do not limit the specific implementation of the processor and various circuits.

[0044] In a eleventh aspect, a computer program product is provided, which includes a computer program (also referred to as code or instructions). When the computer program is run, the computer program causes a computer to execute the method in any possible implementation manner of any aspect described above.

[0045] In a twelfth aspect, a computer readable storage medium is provided, which stores a computer program (also referred to as code or instructions). When the computer program is run on a computer, the computer program causes the computer to execute the method in any possible implementation manner of any aspect described above.

[0046] In a thirteenth aspect, the embodiments of the present application provide a chip system, which includes one or more processors for calling and running instructions stored in a memory, so that the method in each aspect or any possible implementation manner of each aspect is executed. The chip system can be composed of a chip, or can include a chip and other discrete devices. The chip system can include an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

[0047] In a fourteenth aspect, a communication system is provided, which includes a terminal device, a non-ground device and a ground device. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 A schematic diagram of a satellite communication system provided by the embodiments of the present application is shown;

[0049] Figure 2 A scenario schematic diagram of a low-orbit satellite in a store-and-forward mode provided by the embodiments of the present application is shown;

[0050] Figure 3 A schematic diagram of a UPF-based satellite architecture provided by the embodiments of the present application is shown;

[0051] Figure 4 A method flowchart for merging user registration and PDU session establishment processes provided by the embodiments of the present application is shown;

[0052] Figure 5 A schematic diagram of a star-ground separation architecture based on AMF and SMF provided for an embodiment of the present application;

[0053] Figure 6 A schematic diagram of a registration and session establishment method in a store-and-forward mode provided for an embodiment of the present application;

[0054] Figure 7 A flowchart of a PDU session establishment method provided for an embodiment of the present application;

[0055] Figure 8 A schematic diagram of another registration and session establishment method provided for an embodiment of the present application;

[0056] Figure 9 A schematic diagram of another registration and session establishment method provided for an embodiment of the present application;

[0057] Figures 10A-10K A schematic diagram of another registration and session establishment method provided for an embodiment of the present application; Figure 9 A schematic diagram of a scenario corresponding to the method shown in the present application;

[0058] Figure 11 A schematic diagram of another registration and session establishment method provided for an embodiment of the present application;

[0059] Figure 12 A schematic diagram of another registration and session establishment method provided for an embodiment of the present application;

[0060] Figure 13 A schematic diagram of another registration and session establishment method provided for an embodiment of the present application;

[0061] Figure 14 A schematic diagram of an electronic device provided for an embodiment of the present application;

[0062] Figure 15 A schematic diagram of a communication device provided for an embodiment of the present application. DETAILED DESCRIPTION

[0063] The terms "first" and "second" and the like in the description and in the claims of the present application are used for distinguishing between similar objects having a same name and not necessarily for describing a specific order. Also, the terms "comprises", "comprising", "includes", "including" and the like in the description and the claims of the present application are used in the sense of "including but not limited to". The term "coupled" as used in the description and the claims of the present application means that the entities staved to be coupled can or can not be in direct physical or electrical contact, and they can or can not be fixed to each other. The term "coupled" as used in the description and the claims of the present application means that the entities staved to be coupled can or can not be in direct physical or electrical contact, and they can or can not be fixed to each other. The term "plurality" in the description and the claims of the present application means two or more than two. The terms "exemplary" and "for example" are used to introduce examples or examples of the present application. In addition, the network architecture and business scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that with the evolution of network architecture and the appearance of new business scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0064] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0065] Since the traditional terrestrial network (TN) communication cannot provide seamless coverage, especially in places where base stations cannot be deployed, such as the sea, mountains, deserts, and the air. Non-terrestrial network (NTN) communication is considered an important aspect of future wireless communication technology development. NTN communication refers to new radio (NR) communication through satellites or high altitude platform systems (HAPS). NTN communication can cover remote areas that TN communication cannot cover. Currently, NTN communication is mainly for low earth orbit (LEO), medium earth orbit (MEO), geostationary earth orbiting (GEO), and unmanned aircraft system (UAS).

[0066] As an implementation of NTN communication, satellite communication refers to communication between radio communication devices on the ground using satellites as relays. Generally, a satellite communication system consists of two parts: satellites and ground stations. Satellite communication has the characteristics of long communication distance, large coverage area, high reliability, and wide communication frequency band.

[0067] In addition to cellular communication systems, satellite communication has the following advantages:

[0068] Extended coverage: For areas that cannot be covered by cellular communication systems or where coverage is costly, such as oceans, deserts, and remote mountainous areas, satellite communication can be used to solve communication problems.

[0069] Emergency communication: In the event of a disaster such as an earthquake, which can cause the infrastructure of a cellular communication system to be unavailable, satellite communication can be used to quickly establish a communication connection.

[0070] Providing industry applications: For long-distance transmission of time-sensitive services, satellite communication can be used to reduce the transmission delay of services.

[0071] Currently, there are two typical network architectures for NTN communication systems, namely transparent payload and regenerative payload. In the transparent mode, also known as transparent forwarding mode, the satellite or UAS platform can forward the signal, with the functions of radio frequency filtering, frequency conversion, and amplification, and the effective payload waveform signal remains unchanged. In the regenerative mode, the satellite or UAS platform has all or part of the functions of a base station (such as gNB), with the functions of radio frequency filtering, frequency conversion, and amplification, as well as demodulation / decoding, switching and / or routing, encoding or modulation.

[0072] Exemplarily, Figure 1 A schematic diagram of a satellite communication system is provided for embodiments of the present application.

[0073] As Figure 1 shown, the satellite communication system can include at least one terminal device, a satellite, and a ground station. The terminal device and the satellite are connected through a service link, which is implemented by NR. The satellite and the ground station are connected through a feeder link, which can be a wireless interface defined by 3GPP or a non-3GPP wireless interface. As an example, the satellite and the ground station can also include an access point (RP) and the like. As another example, the ground station can also be connected to a data center (DN) through a base station (such as gNB), a next-generation core network (NGC), and the like.

[0074] Satellites working normally around the earth achieve wide-area coverage through independent or inter-satellite cooperation. Taking the regenerative mode as an example, the terminal device sends data or signaling to the satellite, the satellite acts as a base station to forward the data or signaling to the ground station, and the ground station transmits the data or signaling to the data center through a routing device, a base station (such as a gNB) and / or an NGC, etc.

[0075] In the embodiments of the present application, the terminal device is a device with wireless transceiving function. 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 network device scheduling and indication information. The wireless terminal device can be a device that provides voice and / or data connectivity to a user, or a handheld device with wireless connection function, or other processing devices connected to a wireless modem. The terminal device can also be referred to as a terminal, a user equipment (UE), a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, an access terminal, a user terminal, a wireless communication device, a user agent or a user apparatus, etc. 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, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiving function, a wearable device, a vehicle, a robot, a mechanical arm or a smart home device, etc. The embodiments of the present application do not limit the form of the terminal device.

[0076] In 3GPP, the store and forward (S&F) mode aims to provide communication services for terminal devices under satellite coverage. The core idea is to store data packets by the satellite before forwarding them to the next node or destination, in order to improve communication reliability and flexibility for terminal devices with intermittent or temporary satellite connections (for example, when the satellite is not connected to the ground network through a feeder link or an inter-switch link (ISL)). The store and forward mode is suitable for delay-tolerant services such as SMS, MTC and CIoT, etc.

[0077] Taking a non-geostationary orbit (NGSO) low earth orbit satellite as an example. Figure 2This is a schematic diagram of a low-orbit satellite in store-and-forward mode, as provided in an embodiment of this application.

[0078] like Figure 2 As shown, low-Earth orbit (LEO) satellites orbit the Earth along the dotted lines. The coverage area of ​​LEO satellites varies at different times (e.g., times a1, a2, a3, a4). Compared to medium-Earth orbit (MEO) and geostationary satellites, LEO satellites have shorter orbital periods, completing one revolution around the Earth approximately every 90 to 120 minutes, resulting in intermittent satellite service for terminal devices. Furthermore, the coverage area of ​​a single LEO satellite is relatively small, making it prone to intermittent coverage and unstable ground station connections. In store-and-forward mode, the satellite has a certain data caching capability, allowing it to temporarily store user data when the communication link is unavailable or interrupted, and then forward it when the link is restored or the target node is reachable. For example, at time a1, the terminal device is within the coverage area of ​​the LEO satellite. At this moment, the service link is available, but the feeder link is unavailable. The terminal device can send data packets to the LEO satellite through the service link, and the LEO satellite caches the data packets. At time a2, the ground station is within the coverage area of ​​the LEO satellite. At this moment, the service link is unavailable, but the feeder link is available. The LEO satellite forwards the data packets to the ground station through the feeder link. This effectively solves problems such as intermittent satellite coverage and unstable ground station connections, and improves the reliability and resource utilization of data transmission in delay-tolerant and interruption-tolerant services.

[0079] In the user registration process and Protocol Data Unit (PDU) session establishment process specified by 3GPP, numerous network elements need to perform a series of complex interactions from the moment the terminal device initiates a registration request or PDU session establishment request. The terminal device also needs to engage in multiple rounds of interaction with the core network. Furthermore, the PDU session establishment process typically occurs after the user registration process is completed; that is, the terminal device can only send the PDU session establishment request information after user registration is finished.

[0080] In TN communication, the propagation delay between terminal devices and base stations is typically small. However, in NTN communication, the distance between terminal devices, ground stations, and satellites is vast, and it takes a considerable amount of time for radio waves transmitted by the satellite to reach the terminal devices or ground stations, typically ranging from a few milliseconds to hundreds of milliseconds. In low-Earth orbit satellite scenarios, continuing to use the process of sending PDU session establishment request information only after user registration is completed can easily lead to increased latency, especially in store-and-forward mode. If the traditional standard process of registration and PDU session establishment is still followed, the interval between the two processes may be long, thereby increasing the interaction latency between the terminal device and the core network and the service waiting time.

[0081] To solve the above problems, the application provides a scheme of combining user registration and PDU session establishment process. In the scheme, the user plane function (UPF) or the UPF and part of the control plane function (session management function, SMF) are deployed on the satellite payload. By integrating key network elements on the satellite, most 5G core network (5G core network, 5GC) services and store-and-forward services can be directly completed at the satellite end.

[0082] Exemplarily, Figure 3 A schematic diagram of a UPF satellite architecture is provided for the embodiments of the application.

[0083] As Figure 3 shown, the satellite network element can include at least one of a radio access network (RAN), a UPF, a PDU session anchor UPF (PSA-UPF), and an edge application server (EAS). Among them, the RAN is an access network device or an access node, which can realize the function of the base station, such as including but not limited to the base station (base station), evolved NodeB (eNodeB), transmit / receive point (transmit / receive point, TRP), NR node (NR Node B, gNB) in 5G mobile communication system, next generation evolved NodeB (next generation eNodeB, ng-eNB) in 5G mobile communication system, access network device or module of access network device in open access network (open RAN, ORAN) system, etc. The RAN can communicate with the terminal device through access technology such as NR, or communicate with the terminal device through a relay station. The UPF is a key component in the 5GC, responsible for data flow forwarding, routing and processing, such as routing the data packet of the terminal device to the DN. The PSA-UPF is responsible for serving as the anchor point of the PDU session, managing the routing and forwarding of user plane data. The edge application server is an application server deployed in the mobile edge computing (mobile edge computing, MEC) environment, which closely cooperates with the PSA-UPF and runs on the edge node close to the user, reducing the delay of data backhaul to the core network or cloud.

[0084] As Figure 3In the UPF-based on-board satellite architecture shown, the storage and forwarding function is provided by the RAN in the registration and session establishment phase. After the on-board satellite UPF is selected and activated, the on-board satellite UPF can also be used to forward the buffered uplink data.

[0085] Exemplarily, based on the UPF-based on-board satellite architecture shown, Figure 3 Figure 4 The method flow diagram provided by the embodiments of the present application combines the user registration and PDU session establishment procedures. As shown in Figure 4 The execution subject of the method can include a terminal device, an on-board satellite network element, and a ground network element. The on-board satellite network element refers to a network element deployed on a satellite (such as a low-orbit satellite), such as a RAN and a UPF, etc. The ground network element refers to a network element deployed on land, such as an access and mobility management function (AMF), a session management function (SMF), a policy control function (PCF), a unified data management (UDM), and a DN, etc. It can be understood that the on-board satellite network element and the ground network element shown are only exemplary, and other possible network elements can also be included in actual implementation. Figure 4

[0086] As shown in Figure 4 The interaction flow of the terminal device, the on-board satellite network element, and the ground network element is as follows:

[0087] The terminal device sends a registration and PDU session establishment request message to the RAN.

[0088] In the case where the feeder link is unavailable, the RAN stores the registration and PDU session establishment request message and sends a storage and forwarding registration notification to the terminal device.

[0089] In the case where the feeder link is available, the UPF forwards the stored registration and PDU session establishment request message to the ground network element.

[0090] The ground network element performs the registration and PDU session establishment procedure.

[0091] After the ground network element completes the registration and PDU session establishment procedure, 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.

[0092] In the case where the service link is available, the RAN forwards the registration and PDU session establishment reception message to the terminal device.

[0093] ​​The terminal device sends an N2 PDU session response message to the RAN.

[0094] The terminal device sends an uplink data storage N2 PDU session response message to the UPF.

[0095] In the uplink architecture provided in the above embodiments, the RAN is responsible for storing the registration and PDU session establishment request messages. The architecture may have the following problems: the network element deployed on the satellite only provides a store-and-forward function and needs to wait for the feeder link to recover before forwarding to the ground, the storage pressure of the RAN is large when multiple terminal devices send registration and PDU session establishment request messages to the RAN; the RAN does not have the processing capability for the registration and PDU session establishment request messages, the messages are forwarded to the ground network element through the UPF, and the ground network element processes the messages, which may result in a long ground processing response time when the data processing is not timely; the on-board network element does not have a decoding function, and when processing the integrity protection message from the terminal device, it cannot effectively avoid denial of service attacks (DoS); when the registration and PDU session establishment request messages are combined, the network attached storage (NAS) security context and security mode are not established, and the NAS message sent by the user may be eavesdropped, tampered with, or forged.

[0096] In view of the above problems of the UPF-based uplink architecture, the present application also provides an AMF and SMF-based star-ground separation architecture. In this architecture, network elements such as access and mobility management function-non-terrestrial (AMF-NT) and session management function-non-terrestrial (SMF-NT) are deployed on the satellite, and network elements such as access and mobility management function-terrestrial (AMF-T) and session management function-terrestrial (SMF-T) are deployed on the ground.

[0097] Exemplarily, Figure 5 A schematic diagram of an AMF and SMF-based star-ground separation architecture provided by an embodiment of the present application.

[0098] As Figure 5As shown, the spaceborne network element can include a RAN, an AMF-NT and an SMF-NT. The RAN is an access network device or an access node, which can implement the function of a base station, for example, the RAN is responsible for receiving a registration request message and a PDU session establishment request message from a terminal device. The AMF-NT can not only provide a store-and-forward function, but also decode a message (such as a NAS message carrying a PDU session establishment request message) from a terminal device, and forward the PDU session establishment request message carried in the decoded message to the SMF-NT. The SMF-NT can not only provide a store-and-forward function, but also pre-process a PDU session establishment request message to reduce the ground processing response time after the data is forwarded to the ground.

[0099] The ground network element can include an AMF-T and an SMF-T. The AMF-T can be used to initiate a user authentication process, and issue a registration reception message, etc. The SMF-T can be used to buffer a PDU session establishment request message from the SMF-NT, and perform a PDU session establishment process. In addition, the ground network element can also include an authentication server function (AUSF), a UDM, a UPF, a policy control function (PCF), a short message service function (SMSF) and a DN, etc. The AUSF is used to verify the legitimacy of the identity of a user, a device or a system, and to ensure that only authorized entities can access specific resources or perform operations. The UDM is a centralized and standardized data governance architecture, which aims to achieve unified management, modeling, storage and distribution of heterogeneous data sources. The UPF is responsible for forwarding, routing and processing data streams, for example, routing data packets of a terminal device to a DN. The PCF supports a unified policy framework and manages network behavior, provides policy rules to network entities, and accesses subscription information in a unified data repository (UDR). The SMSF refers to a short message service function, which supports NSA-based short message service, including short message management subscription data checking and corresponding short message transmission, etc. The DN refers to a data network, such as operator services, Internet access and third-party services, etc.

[0100] In the space-ground separation architecture provided in the above embodiment, the deployment of the SMF-NT and the SMF-T can improve the cooperation capability between the AMF and the SMF, and reduce the store-and-forward pressure of the AMF. In addition, the SMF-NT can pre-process the PDU session establishment request and other information, which can reduce the ground response time in the session management process to a certain extent.

[0101] It can be understood that, as Figure 5The various network elements shown are only illustrative, and in actual implementation, other possible network elements can also be included, which can be adjusted according to use requirements, and embodiments of the application are not limited.

[0102] The scheme provided by the embodiments of the application will be described in detail below in combination with corresponding flowcharts. It can be understood that the devices (such as terminal devices, non-ground devices and ground devices) in the illustrative flowcharts are taken as examples of the execution subjects of the interaction scheme, but the application is not limited to the execution subjects of the interaction scheme. For example, the devices (such as terminal devices, non-ground devices and ground devices) in the illustrative flowcharts can also be chips, chip systems or processors supporting the devices to implement the method, and can also be logical modules or software capable of implementing all or part of the functions of the devices. In addition, the messages or signaling interactions involved in the interaction flow of the embodiments of the application can adopt messages or signaling in standards or newly introduced messages or signaling, and the embodiments of the application are not limited in this regard.

[0103] Here, it is uniformly stated that the non-ground device refers to a device arranged in the air in NTN communication, such as a satellite. The ground device refers to a device arranged on the ground in NTN communication, such as a ground station. The non-ground device can include one or more satellite-borne network elements, such as Figure 5 the RAN, AMF-NT and SMF-NT shown. The ground device can include one or more ground network elements, such as Figure 5 the AMF-T, SMF-T, UPF, PCF, SMSF, AUSF and UDM shown.

[0104] Illustratively, Figure 6 A registration and session establishment method in a store-and-forward mode is provided for the embodiments of the application. In the method, the registration process and the session establishment process are fused.

[0105] It should be noted that the method takes the terminal device, the satellite-borne network element (such as the RAN, AMF-NT and SMF-NT) of the non-ground device and the ground network element (such as the AMF-T, SMF-T, UPF, UDM and AUSF) of the ground device as the execution subject. Among them, the AMF-NT and SMF-NT belong to the satellite-borne core network element, and the AMF-T, SMF-T, UPF, UDM and AUSF belong to the ground core network element.

[0106] As Figure 6 shown, the method can include the following S101 to S108.

[0107] S101. The terminal device sends a registration request message to the satellite-borne network element.

[0108] In some embodiments, the registration request message can comprise at least one of the following: registration type, subscription concealed identifier (SUCI), 5G globally unique temporary identifier (5G-GUTI), permanent equipment identifier (PEI).

[0109] Exemplarily, the terminal device can send a registration request message to the RAN, and the RAN forwards the message to the spaceborne core network element (such as AMF-NT). If the feeder link is unavailable at this moment, the spaceborne core network element stores the message, and waits for the feeder link to recover, and then forwards the message to the ground core network element.

[0110] In some embodiments, the terminal device can also send the AN / RAN parameters to the spaceborne network element.

[0111] S102. After the ground core network element receives the registration request message, an authentication process for the terminal device is initiated.

[0112] Exemplarily, after the AMF-T receives the registration request message forwarded by the spaceborne core network element, the AMF-T sends an authentication request to the AUSF. The AUSF performs the authentication process, selects a UDM, and obtains authentication data.

[0113] In the scheme provided by the above embodiments for combining the user registration and PDU session establishment processes, when the registration and PDU session establishment request messages are combined and sent, the NAS security context and security mode are not established, and the NAS message sent by the user can be eavesdropped, tampered with, or forged. In order to solve this problem, as an optional way, the method shown in Figure 6 may comprise the following S103. It can be understood that, as another optional way, after the identity authentication is completed, the terminal device can also directly send a PDU session establishment request message to the spaceborne core network element through the RAN.

[0114] S103. After the identity authentication is completed, the ground core network element sends a NAS security start instruction to the spaceborne core network element, and the spaceborne core network element sends a NAS security mode command to the terminal device to establish a security mode.

[0115] S104. The terminal device returns a security mode response message to the RAN, at which time the establishment of the NAS security context is considered complete, and the NAS message will be protected by security. After activating the 5G NAS security context generated by the security mode control procedure, the entire PDU session establishment request message can be included in the NAS message container, and the NAS message container is included in the security mode response message. Among them, the PDU session establishment request message can include a clear text information element (IE) and a non-clear text IE.

[0116] S105. The satellite core network element preprocesses the PDU session establishment request message and temporarily stores the preprocessed PDU session establishment request message.

[0117] In the scheme provided by the above embodiment of combining the user registration and PDU session establishment process, the satellite network element only provides a storage forwarding function and does not have the processing capability of the registration and PDU session establishment request message. When the feeder link is restored, the message can be forwarded to the ground network element through the UPF, and then the ground network element processes the message. If the data processing is not timely, the ground processing response time after the data is forwarded to the ground may be long. In order to solve this problem, after the satellite core network element receives the PDU session establishment request message, the satellite core network element can perform part of the functions of the ground core network element, and preprocess the message in advance, such as calculating the sending priority of the PDU session establishment request message. It can be understood that the satellite core network element can also perform other preprocessing operations on the PDU session establishment request message, which can be determined according to the use requirement, and the present application is not limited.

[0118] S106. After the feeder link is available, the satellite core network element forwards the PDU session establishment request message to the ground core network element, and the ground core network element and the satellite core network element continue the registration process and complete the registration.

[0119] S107. After the registration is completed, the ground core network element and the satellite core network element perform the PDU session establishment process.

[0120] S108. After the registration and PDU session establishment processes are completed, the satellite core network element returns a registration and PDU session establishment accept message to the terminal device. The message is used to indicate that the registration process and the PDU session establishment process are both successful.

[0121] In the method provided in the above embodiment, by fusing the PDU session establishment process into the registration process, the total number of interactions of the two processes is effectively reduced, the interaction delay and service waiting time of the terminal device and the core network device are reduced, and the terminal service experience is improved. In addition, the core network element deployed on the satellite pre-processes the PDU session establishment request, which to some extent reduces the ground response time in the session management process.

[0122] The above embodiment combines Figure 6 The method process of fusing the registration process and the session establishment process is introduced. Next, based on the flowchart provided, the PDU session establishment process is more specifically illustrated in combination with the AMF-NT and SMF-NT deployed on the satellite, and the AMF-T and SMF-T deployed on the ground, and other core network elements. Figure 6

[0123] Exemplarily, Figure 7 A flowchart of a PDU session establishment method provided by an embodiment of the present application.

[0124] It should be noted that the method takes the terminal device, the satellite A on-board network element (such as RAN-A, AMF-NT-A and SMF-NT), the satellite B on-board network element (such as RAN-B and AMF-NT-B), and the ground core network element (such as AMF-T, UPF and SMF-T) of the ground device as the execution subject. Among them, the AMF-NT-A, the SMF-NT, and the AMF-NT-B belong to the on-board core network element.

[0125] As Figure 7 indicated, the method can include the following S201 to S210.

[0126] S201. In the case that the service link between the terminal device and the satellite A is available, the terminal device sends a PDU session establishment request message to the RAN-A, and the RAN-A forwards the message to the AMF-NT-A.

[0127] In some embodiments, the terminal device sends a security mode response message to the RAN-A, and the security mode response message contains a NAS message, and the NAS message contains the PDU session establishment request message. The RAN-A forwards the NAS message to the AMF-NT-A.

[0128] S202. The AMF-NT-A forwards the PDU session establishment request message to the SMF-NT.

[0129] ​In some embodiments, the above-mentioned security mode response message can comprise an information identifier (which can be referred to as a second information identifier) which can be used to indicate that the AMF-NT-A forwards the PDU session establishment request message to the SMF-NT. The AMF-NT-A decodes the security mode response message to obtain 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.

[0130] 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.

[0131] In some embodiments, the PDU session establishment request message can also comprise an information identifier (which can be referred to as a first information identifier) which can be used to indicate that the SMF-NT pre-processes and stores the PDU session establishment request message. The SMF-NT decodes the PDU session establishment request message to obtain the information identifier, and pre-processes and temporarily stores the PDU session establishment request message based on the information identifier.

[0132] In some embodiments, the above-mentioned information identifier can be in the format of TLV (Type-length-value). The TLV format has strong flexibility and strong compatibility with the existing IE coding specification of 3GPP. For example, the length of the information identifier is 1 bit, which contains two states: if coded as 0, it indicates immediate forwarding; if coded as 1, it indicates pre-processing and temporary storage. As an example, the information identifier is coded together with other information, and the coding form is not limited in the present application.

[0133] S204. In the case that the feeder link between the satellite A and the ground core network element is available, the SMF-NT synchronizes information with the SMF-T. 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.

[0134] In some embodiments, after the SMF-NT forwards the PDU session establishment request message to the SMF-T, the SMF-NT can start a timer, and when the timing duration of the timer reaches a preset duration, the SMF-NT clears the information stored in the SMF-NT, so as to release the storage space of the SMF-NT in time and facilitate the storage of PDU session establishment request messages of other terminal devices.

[0135] In some embodiments, after the SMF-NT forwards the PDU session establishment request message to the SMF-T, the SMF-T can also temporarily store the PDU session establishment request message.

[0136] For example, Table 1 below is a context field established by the SMF-T for a terminal device. The terminal device is in a state where the registration and PDU session establishment have not been completed, and an additional storage space can be added in the SMF-T to store the context information of the terminal device in the state where the registration and PDU session establishment have not been completed. After the registration and PDU session establishment are completed, the SMF-T performs session management for the user and normally stores the context information of the user, and cleans up the additional storage space corresponding to the terminal device.

[0137]

[0138] S205. The SMF-T starts to perform a session establishment procedure.

[0139] For example, the SMF-T can perform the session establishment procedure based on the temporarily stored PDU session establishment request information.

[0140] S206. The SMF-T sends an N4 session establishment request to the selected UPF.

[0141] N4 session generally refers to a session control function managed by an N4 interface in a 5GC or a cloud native network architecture, mainly involving the interaction between a UPF and an SMF. The N4 interface adopts a packet forwarding control protocol (PFCP). The SMF can issue a session rule, such as a session establishment request, to the UPF through the N4 interface, which can specifically include a packet detection rule (PDR), a forwarding action rule (FAR), a QoS enforcement rule (QER), and the like.

[0142] S207. The UPF returns an N4 session establishment response to the SMF-T.

[0143] S208. The SMF-T sends a PDU session establishment accept message to the AMF-T.

[0144] Exemplarily, the SMF-T can send a Namf_Communication_N1N2MessageTransfer message to the AMF-T. The message can contain an N1 Session Management (SM) container, N2 SM information. The N1 SM container can include a PDU session establishment accept message. The N2 SM information can include CN Tunnel Info, QoS flow identifier (QFI), Quality of service (QoS) configuration, single 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.

[0145] With reference to the description of the above embodiments, the coverage range of the non-geostationary satellite changes during the orbiting around the earth. After the PDU session is established, the next satellite covering the terminal device can change, such as switching from satellite A to satellite B; or the next satellite covering the terminal device can not change, such as covering the terminal device again after one orbit around the earth. The next satellite covering the terminal device is taken as satellite B for illustration.

[0146] S209. In the case that the feeder link between satellite B and the ground core network element is available, the AMF-T sends a PDU session establishment accept message to the AMF-NT-B.

[0147] In some embodiments, if the service link between satellite B and the terminal device is not available at this moment, the AMF-NT-B temporarily stores the PDU session establishment accept message and forwards it to the terminal device when the service link is available.

[0148] S210. In the case that the service link between satellite B and the terminal device is available, the AMF-NT-B sends the PDU session establishment accept message to the terminal device through the RAN-B.

[0149] In the related art, no SMF is deployed on the satellite, and no decoding and preprocessing capability of the PDU session establishment request message is provided. In the above method provided by the embodiments of the present application, the AMF-NT and SMF-NT deployed on the satellite and the AMF-T and SMF-T deployed on the ground improve the cooperation capability of the AMF and SMF, and reduce the storage and forwarding pressure of the AMF-NT. The SMF-NT decodes the PDU session establishment request, which can effectively avoid the DoS attack. In addition, the SMF-NT preprocesses the PDU session establishment request, which reduces the ground response time in the session management process to a certain extent.

[0150] The above embodiments are combined with Figure 6 The method of fusing the registration process and the session establishment process is introduced. In the description of S107 and S108 in the method, after the registration is completed, the ground core network element and the satellite core network element perform the PDU session establishment process. If the registration and the PDU session establishment process are successfully performed, the registration and PDU session establishment accept message is returned to the terminal device. In actual implementation, there may be another two scenarios: one scenario is that the registration and the PDU session establishment process both fail; the other scenario is that the registration is successfully performed, but the PDU session establishment fails. Based on this, in Figure 6 the method of fusing the registration process and the session establishment process provided by the embodiments of the present application can further include the following steps: Figure 8

[0151] The AMF-NT judges whether the registration and the PDU session are successfully established based on the message returned by the ground core network element.

[0152] If the registration and the PDU session establishment process are both successful, the following S108 is performed.

[0153] If the registration and the PDU session establishment process both fail, the following S109 is performed.

[0154] If the registration is successfully performed, but the PDU session establishment fails, the following S110 is performed.

[0155] S108. The AMF-NT returns the registration and PDU session establishment accept message to the terminal device through the RAN, which can be used to indicate that the registration process and the PDU session establishment process are both successful.

[0156] ​S109. The AMF-NT returns a registration and PDU session establishment reject message to the terminal device through the RAN, which can be used to indicate that both the registration process and the PDU session establishment process fail.

[0157] S110. The AMF-NT returns a registration accept message to the terminal device through the RAN, which can carry indication information (referred to as first indication information), indicating that the PDU session establishment fails.

[0158] In some embodiments, the above-mentioned indication information can include at least one of the following: PDU session establishment failure reason, information processing status, and information indicating whether the terminal device retransmits the PDU session establishment request.

[0159] In the above-mentioned method provided by the embodiments of the present application, when both the registration and the PDU session establishment are successful, or when the registration is successful and the PDU session establishment fails, a message is returned by merging, which can reduce the number of interactions between the terminal device and the network side device and reduce the signaling overhead. In addition, the corresponding information is returned to the terminal device regardless of whether the PDU session establishment is successful, which can improve the perception of the network by the terminal device and indicate the user behavior.

[0160] The following takes a low-orbit satellite as an example, and the overall process of the registration and session establishment method based on the initial registration process is described in combination with Figure 9 、 Figures 10A-10K .

[0161] Exemplarily, Figure 9 the overall flowchart of the registration and session establishment method provided by the embodiments of the present application in the store-and-forward mode is shown. Figures 10A-10K The scenario diagram corresponding to the method shown in Figure 9 .

[0162] It should be noted that Figure 9 the method shown in the figure takes the terminal device, the satellite 1 on-board network element (such as RAN-1, AMF-NT-1), the satellite 2 on-board network element (such as RAN-2, AMF-NT-2), the satellite 3 on-board network element (such as RAN-3, AMF-NT-3 and SMF-NT), the satellite 4 on-board network element (such as RAN-4, AMF-NT-4), the ground device ground core network element (such as AMF-T, AUSF, UDM, UPF and SMF-T) as the execution subject.

[0163] As shown in Figure 9 , the method can include the following S301-S325.

[0164] S301. When the service link between the terminal device and satellite 1 (which may be referred to as the third non-terrestrial device) is available, the terminal device sends a registration request message to RAN-1, and RAN-1 forwards the message to AMF-NT-1.

[0165] The availability of a service link between a terminal device and a satellite means that the terminal device is within the satellite's coverage area, and the terminal device can send data to the satellite through the service link, while the satellite can also send data to the terminal device through the service link.

[0166] like Figure 10A As shown, satellite 1, which includes RAN-1 and AMF-NT-1, orbits the Earth. When satellite 1 rotates above the terminal device, the terminal device is within the coverage area of ​​satellite 1, and the service link between the terminal device and satellite 1 is available at this moment. If the terminal device needs to register and transmit latency-tolerant services, the terminal device can send a registration request message to RAN-1, and RAN-1 will forward the registration request message to AMF-NT-1.

[0167] 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, which is used to request configuration of S-NSSAI.

[0168] S302. AMF-NT-1 returns a downlink NAS transport (DL NAS transport) message to the terminal device via RAN-1, which includes a temporary identifier (interim GUTI) assigned to the terminal device.

[0169] Assuming each AMF-NT on a satellite in the constellation has a unique AMF ID, the terminal device can store this temporary identifier (Interim GUTI) for subsequent interactions, and the AMF-NT-1 can also provide an expiration date for this identifier. It is understood that assigning a temporary identifier to the terminal device can avoid GUTI conflicts. The GUTI includes one or more of the following: Public Land Mobile Network (PLMN) identifier, AMF region identifier, AMF set identifier, AMF identifier, and Temporary Mobile Subscription Identifier (TMSI).

[0170] S303. In case the feeder link between satellite 1 and the terrestrial core network element is available, the AMF-NT-1 forwards the stored registration request message and the interim identifier (interim GUTI) to the AMF-T.

[0171] As shown in FIG. 3B, satellite 1, including RAN-1 and AMF-NT-1, continues to rotate around the earth, and satellite 1 moves out of the coverage area of the terminal device. When satellite 1 rotates to above the ground station, the ground station is located in the coverage of satellite 1, and at this moment the service link between satellite 1 and the ground station is available, so that the AMF-NT-1 can forward the stored registration request message and the interim identifier (interim GUTI) to the AMF-T. Figure 10B

[0172] S304. The AMF-T initiates a user authentication procedure.

[0173] The AMF-T can select an AUSF based on a subscription permanent identifier (SUPI) or a subscription concealed identifier (SUCI), and send an authentication request to the selected AUSF. If authentication is required, the AMF-T sends a request to the AUSF, and the AUSF performs an authentication procedure. The AUSF selects a UDM and obtains authentication data. The AMF-T stores the authentication data in association with the interim identifier (interim GUTI) received from the AMF-NT-1 of satellite 1. In addition, the AMF-T can also determine the next satellite that can cover the terminal device, such as satellite 2.

[0174] S305. In case the feeder link between satellite 2 (which can be referred to as a fourth non-terrestrial device) and the terrestrial core network element is available, the AMF-T sends an authentication request message to the AMF-NT-2.

[0175] As shown in FIG. 3C, satellite 1 moves out of the coverage area of the ground station, and satellite 2, including RAN-2 and AMF-NT-2, rotates to above the ground station, and at this moment the service link between satellite 2 and the ground station is available, so that the AMF-T can send a Namf_N1N2MessageTransfer message to the AMF-NT-2, which carries the authentication request message and the interim identifier (interim GUTI) allocated for the terminal device. In addition, the message can also carry the location information of the terminal device. Since the terminal device is not located in the coverage of satellite 2 at this moment, the service link between satellite 2 and the terminal device is not available, so satellite 2 can temporarily store the authentication request message. Figure 10C

[0176] ​​S306. When the service link between satellite 2 and the terminal equipment is available, AMF-NT-2 sends an authentication request message to the terminal equipment through RAN-2.

[0177] S307. The terminal device returns an authentication response message to AMF-NT-2 via RAN-2.

[0178] like Figure 10D As shown, when satellite 2 rotates above 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. Subsequently, the terminal device returns an authentication response message to RAN-2 of satellite 2 via the service link. Since the ground core network element is not currently within the coverage area of ​​satellite 2, the service link between satellite 2 and the ground core network element is unavailable, and the authentication response message can be temporarily stored.

[0179] S308. When the power supply link between satellite 2 and the ground core network element is available, AMF-NT-2 sends an authentication response message to AMF-T.

[0180] like Figure 10E As shown, when satellite 2 rotates back over the ground station, the ground station is within the coverage area 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.

[0181] S309. AUSF sends an authentication response message to AMF-T. This message contains the key security anchor function (KSEAF) key.

[0182] In 5GC, KSEAF is the security foundation of the authentication process. During 5G AKA (Authentication and Key Agreement), the terminal device and AUSF work together to complete two-way authentication.

[0183] S310. When the power supply link between satellite 3 (which may be referred to as the first non-ground equipment) and the ground core network element is available, AMF-T sends a security mode command to AMF-NT-3.

[0184] like Figure 10FAs shown, satellite 2 is out of the coverage area of the ground station, satellite 3 containing RAN-3, AMF-NT-3 and SMF-NT rotates to the space above the ground station, the ground station is located in the coverage of satellite 3 at this moment, the service link between satellite 3 and the ground station is available at this moment, so that AMF-T can send Namf_N1N2MessageTransfer message to AMF-NT-3, the message carries the NAS security mode command, the received registration request message, the interim GUTI allocated for the terminal device, and the NAS key for decoding. Since the terminal device is not located in the coverage of satellite 3 at this moment, the service link between satellite 3 and the terminal device is not available, so satellite 3 can temporarily store the message.

[0185] In some embodiments, the security mode command can further include a plurality of S-NSSAIs configured by the ground core network device, the plurality of S-NSSAIs being configured in response to the request information of the S-NSSAI in S301.

[0186] S311. In the case that the service link between satellite 3 and the terminal device is available, AMF-NT-3 sends a security mode command to the terminal device through RAN-3.

[0187] The security mode command described above can be used for the terminal device to enable a security context and confirmation. As an example, the security mode command can include the registration request message received by AMF-T, the interim GUTI, and the NAS key for decoding. The security mode command can further include a plurality of S-NSSAIs configured by the ground core network device.

[0188] In some embodiments, AMF-NT-3 initiates paging or receives a connection establishment request of the terminal device. AMF-NT-3 pages using the interim GUTI allocated for the terminal device, or the terminal device actively establishes a radio resource control (RRC) connection. AMF-NT-3 sends a NAS security mode command to the terminal device.

[0189] S312. The terminal device sends a security mode response message to AMF-NT-3 through RAN-3, the security mode response message containing a NAS message, which can include a PDU session establishment request message based on one S-NSSAI. This S-NSSAI is one S-NSSAI selected by the terminal device from the plurality of S-NSSAIs configured by the ground core network device, for a PDU session of the serving PLMN.

[0190] In some embodiments, the NAS message can also include a registration request message and an Interim GUTI encrypted using the NAS key, etc.

[0191] As shown in FIG. 3, when the satellite 3 rotates to above the terminal device, the terminal device is located in the coverage of the satellite 3, at this moment, the service link between the satellite 3 and the terminal device is available, so the AMF-NT-3 sends a security mode command to the terminal device through the RAN-3, and then the terminal device sends a security mode response message to the AMF-NT-3 through the RAN-3. Figure 10G

[0192] S313. The AMF-NT-3 forwards the PDU session establishment request message to the SMF-NT.

[0193] In some embodiments, the security mode response message described above can include an information identifier (which can be referred to as a second information identifier), which can be used to indicate that the AMF-NT-3 forwards the PDU session establishment request message to the SMF-NT. The AMF-NT-3 decodes the security mode response message to obtain 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.

[0194] 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.

[0195] In some embodiments, the PDU session establishment request message can also include an information identifier (which can be referred to as a first information identifier), which can be used to indicate that the SMF-NT pre-processes and stores the PDU session establishment request message. The SMF-NT decodes the PDU session establishment request message to obtain the information identifier, and pre-processes (such as calculating the sending priority of the PDU session establishment request message) and temporarily stores the PDU session establishment request message based on the information identifier.

[0196] S315. In the case that the feeder link between the satellite 3 and the ground core network element is available, the SMF-NT synchronizes information with the SMF-T. For example, the SMF-NT forwards the PDU session establishment request message to the SMF-T.

[0197] ​In some embodiments, after the SMF-NT forwards the PDU session establishment request message to the SMF-T, the SMF-NT can start a timer. When the timer reaches a preset duration, the information stored in the SMF-NT is cleared to release the storage space of the SMF-NT in a timely manner, so as to facilitate the storage of PDU session establishment request messages of other terminal devices.

[0198] S316. After receiving the PDU session establishment request message, SMF-T temporarily stores the message.

[0199] S317. After AMF-NT-3 receives the safety mode response message, it temporarily stores the message until it reconnects to the ground station and then forwards the message to AMF-T.

[0200] The security mode response message may include a registration request message encrypted with the NAS key and information such as Interim GUTI.

[0201] S318. AMF-T continues the registration process.

[0202] As an example, the above registration process can be referenced from steps 13-15 of Section 4.2.2.2.2 (5G Core Network Registration Process) of 3GPP TS 23.502:

[0203] AUSF requests the user's authentication vector (AV) from UDM.

[0204] UDM sends an authentication response (Nudm_UEAuthentication_Get) to AUSF.

[0205] AUSF processes authentication vectors, such as storing KSEAF as an anchor point for subsequent session key distribution.

[0206] S319. If registration is successful, the AMF-T prepares to send a registration receive request message. Since the power supply link is unavailable at this time, the AMF-T can wait until the power supply link is restored before sending the message. Additionally, the AMF-T can also send a notification message to the SMF-T to inform it of the successful registration.

[0207] S320. SMF-T executes the session establishment process.

[0208] like Figure 10H As shown, when the power supply link between satellite 3 and the ground station is available, SMF-T executes the session establishment procedure.

[0209] As an example, the above session establishment procedure can refer to 3GPP TS 23.502 protocol, section 4.3.2 (Service Request procedure), steps 4-9:

[0210] The AMF-T sends an Nsmf_PDUSession_UpdateSMContext request message to the SMF-T to inform the active state change of the terminal device (e.g., from idle state to connected state);

[0211] The SMF-T sends an N4 session establishment request message to the selected UPF, and the UPF returns an N4 session establishment response message;

[0212] The SMF-T sends an Nsmf_PDUSession_UpdateSMContext response message to the AMF to inform the AMF that the session is ready, which specifically includes the N3 / N9 interface tunnel information of the UPF, for the satellite to establish a data channel with the UPF;

[0213] The AMF-T sends an NGAP Initial Context Setup Request message to the satellite to trigger the satellite to establish a context;

[0214] The satellite sends an RRC connection reconfiguration to the terminal device;

[0215] The satellite sends an NGAP Initial Context Setup Response message to the AMF-T, which includes data radio bearer (DRB) configuration results and user plane tunnel information (UL TEID).

[0216] S321. The AMF-T sends a PDU session establishment accept message to the SMF-T.

[0217] Illustratively, the SMF-T can send a Namf_Communication_N1N2MessageTransfer message to the AMF-T. The message can include an N1 SM container and N2 SM information. The N1 SM container can include a PDU session establishment accept message. The N2 SM information can include CN Tunnel Info, QoS flow identity, QoS configuration, S-NSSAI, AMBR, PDU type, user plane security information, integrity protection maximum rate, RSN, etc.

[0218] The above S321 is described by taking the PDU session establishment success as an example. In other embodiments, if the PDU session establishment fails, the AMF-T sends a PDU session establishment reject message to the SMF-T.

[0219] S322. In the case that the feeder link between satellite 4 (may be referred to as the second non-terrestrial equipment) and the ground core network element is available, the AMF-T sends the registration and PDU session establishment accept message to the AMF-NT-4.

[0220] As shown in FIG. 6, when the feeder link between satellite 4 and the ground station is available, the AMF-T sends the registration and PDU session establishment accept message to the AMF-NT-4. Figure 10I

[0221] S323. In the case that the service link between satellite 4 and the terminal equipment is available, the AMF-NT-4 sends the registration and PDU session establishment accept message to the terminal equipment through the RAN-4.

[0222] S324. The terminal equipment returns the registration and PDU session establishment accept message to the AMF-NT-4 through the RAN-4.

[0223] As shown in FIG. 7, when satellite 4 rotates to above the terminal equipment, the terminal equipment is located in the coverage of satellite 4, at this moment, the service link between satellite 4 and the terminal equipment is available, so the AMF-NT-4 sends the registration and PDU session establishment accept message to the terminal equipment through the RAN-4, and then the terminal equipment returns the registration and PDU session establishment accept message to the AMF-NT-4 through the RAN-4. Figure 10J

[0224] S325. In the case that the feeder link between satellite 4 and the ground core network element is available, the AMF-NT-4 sends the registration and PDU session establishment accept message to the AMF-T.

[0225] As shown in FIG. 8, when the feeder link between satellite 4 and the ground station is available again, the AMF-NT-4 sends the registration and PDU session establishment accept message to the AMF-T. Figure 10K

[0226] It should be noted that the above embodiments are described by taking the cases that satellite 1, satellite 2, satellite 3 and satellite 4 intermittently provide services for the terminal equipment at different time or time periods as examples, which do not limit the present application. In other embodiments, some of the satellites may be the same satellite, for example, satellite 1 of S301-S303 and satellite 3 of S310-S321 may be the same satellite.

[0227] ​​​In the method provided in the above embodiment, by fusing the PDU session establishment process into the initial registration process, the total number of interactions of the two processes is effectively reduced, the interaction delay and service waiting time of 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, AMF-T and SMF-T on the ground, the cooperation capability of AMF and SMF is improved, and the storage and forwarding pressure of AMF-NT is reduced. The SMF-NT decodes the PDU session establishment request, which can effectively avoid DoS attack. In addition, the SMF-NT preprocesses the PDU session establishment request, which reduces the ground response time in the session management process to a certain extent.

[0228] The above embodiment introduces a specific implementation method of fusing the PDU session establishment process in the initial registration process. The embodiment of the present application also provides another implementation scenario. When the terminal is in a deregistered state, the terminal device and the AMF (including AMT-NT deployed on the satellite and AMF-T deployed on the ground) may store the NAS security context. If the user re-registers, the registration process and the PDU session establishment process can be combined and enhanced. However, in the storage and forwarding (S&F) scenario, the service satellites may be different, and it is difficult to synchronize the information between the satellites after the user deregisters. To this end, as shown in Figure 11 , the present application also provides another registration and session establishment method in the storage and forwarding mode.

[0229] It should be noted that, Figure 11 The method shown in the method takes the terminal device, the satellite 5 on-board network element (such as RAN-5, AMF-NT-5), the satellite 6 on-board network element (such as RAN-6, AMF-NT-6 and SMF-NT), the satellite 7 on-board network element (such as RAN-7, AMF-NT-7), and the ground core network element (such as AMF-T, AUSF, UDM, UPF and SMF-T) of the ground device as the execution subject.

[0230] As shown in Figure 11 , the method can include the following S401 to S419.

[0231] S401. In the case that the service link between the terminal device and the satellite 5 is available, the terminal device sends a registration request message to the RAN-5, and the RAN-5 forwards the message to the AMF-NT-5.

[0232] S402. The AMF-NT-5 returns a downlink NAS transport (DL NAS transport) message to the terminal device through the RAN-5, and the message includes an interim identifier (interim GUTI) allocated for the terminal device.

[0233] S403. In case the feeder link between satellite 5 and the ground core network element is available, the AMF-NT-5 forwards the stored registration request message and an interim identifier (interim GUTI) to the AMF-T.

[0234] For implementation of S401-S403, reference can be made to the description of S301-S303 in the above embodiments, which will not be repeated here.

[0235] S404. In case the feeder link between satellite 6 and the ground core network element is available, the AMF-T sends a security mode command to the AMF-NT-6.

[0236] S405. In case the service link between satellite 6 and the terminal device is available, the AMF-NT-6 sends a security mode command to the terminal device through RAN-6.

[0237] S406. The terminal device sends a security mode response message to the AMF-NT-6 through RAN-6, the security mode response message containing a NAS message, and the NAS message containing a PDU session establishment request message.

[0238] S407. The AMF-NT-6 forwards the PDU session establishment request message to the SMF-NT.

[0239] In some embodiments, the above security mode response message can include an information identifier, which can be used to indicate that the AMF-NT-6 forwards the PDU session establishment request message to the SMF-NT.

[0240] 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.

[0241] In some embodiments, the PDU session establishment request message can also include an information identifier, which can be used to indicate that the SMF-NT pre-processes and stores the PDU session establishment request message.

[0242] S409. In case the feeder link between satellite 6 and the ground core network element is available, the SMF-NT synchronizes information with the SMF-T. For example, the SMF-NT forwards the PDU session establishment request message to the SMF-T.

[0243] In some embodiments, after the SMF-NT forwards the PDU session establishment request message to the SMF-T, the SMF-NT can start a timer, and when the timer reaches a preset time length, the SMF-NT clears the information stored in the SMF-NT.

[0244] S410. After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0245] S411. After the AMF-NT-6 receives the security mode response message, the message is temporarily stored until the AMF-NT-6 forwards the message to the AMF-T after connecting to the ground station again.

[0246] S412. The AMF-T continues to perform the registration procedure.

[0247] S413. The AMF-T prepares to send a registration reception request message. Since the feeder link is not available at this moment, the AMF-T can wait until the feeder link is restored for sending. In addition, the AMF-T can also notify the SMF-T of the registration success.

[0248] S414. The SMF-T performs the session establishment procedure.

[0249] S415. The AMF-T sends a PDU session establishment accept message to the SMF-T.

[0250] S416. In the case that the feeder link between the satellite 7 and the ground core network element is available, the AMF-T sends a registration and PDU session establishment accept message to the AMF-NT-7.

[0251] S417. In the case that the service link between the satellite 7 and the terminal device is available, the AMF-NT-7 sends a registration and PDU session establishment accept message to the terminal device through the RAN-7.

[0252] S418. The terminal device returns a registration and PDU session establishment accept message to the AMF-NT-7 through the RAN-7.

[0253] S419. In the case that the feeder link between the satellite 7 and the ground core network element is available, the AMF-NT-7 sends a registration and PDU session establishment accept message to the AMF-T.

[0254] For the implementation of S404-S419, refer to the description of S310-S325 in the above embodiments, which will not be repeated here.

[0255] In the method provided in the embodiments of the present application, when the terminal device is in the logged-out state, the NAS security context can be stored in the terminal device and the AMF, so that the user authentication process of S310-S325 can be skipped, the NAS security context is directly established, and the PDU session establishment request message is sent based on the NAS security context.

[0256] The above embodiments are combined with Figure 9The overall process of successful registration and PDU session establishment is introduced. The following introduces the overall process of failed registration and PDU session establishment. Figure 12 The overall process of failed registration and PDU session establishment is introduced.

[0257] It should be noted that, Figure 12 The method shown still takes the terminal device, the satellite 1 satellite network element (such as RAN-1, AMF-NT-1), the satellite 2 satellite network element (such as RAN-2, AMF-NT-2), the satellite 3 satellite network element (such as RAN-3, AMF-NT-3 and SMF-NT), the satellite 4 satellite network element (such as RAN-4, AMF-NT-4), the ground device ground core network element (such as AMF-T, AUSF, UDM, UPF and SMF-T) as the execution subject.

[0258] As Figure 12 The method can include the following S501-S521.

[0259] S501. In the case that the service link between the terminal device and the satellite 1 (which can be referred to as the third non-terrestrial device) is available, the terminal device sends a registration request message to the RAN-1, and the RAN-1 forwards the message to the AMF-NT-1.

[0260] S502. The AMF-NT-1 returns a downlink NAS transport (DL NAS transport) message to the terminal device through the RAN-1, and the message includes an interim identifier (interim GUTI) allocated for the terminal device.

[0261] S503. In the case that the feeder link between the satellite 1 and the ground core network element is available, the AMF-NT-1 forwards the stored registration request message and the interim identifier (interim GUTI) to the AMF-T.

[0262] S504. The AMF-T initiates a user authentication process.

[0263] S505. In the case that the feeder link between the satellite 2 (which can be referred to as the fourth non-terrestrial device) and the ground core network element is available, the AMF-T sends an authentication request message to the AMF-NT-2.

[0264] S506. In the case that the service link between the satellite 2 and the terminal device is available, the AMF-NT-2 sends an authentication request message to the terminal device through the RAN-2.

[0265] S507. The terminal device returns an authentication response message to the AMF-NT-2 through the RAN-2.

[0266] S508. In case the feeder link between satellite 2 and the ground core network element is available, the AMF-NT-2 sends an authentication response message to the AMF-T.

[0267] S509. The AUSF sends an authentication response message to the AMF-T. The message contains a key security anchor function (KSEAF) key.

[0268] S510. In case the feeder link between satellite 3 (may be referred to as the first non-terrestrial equipment) and the ground core network element is available, the AMF-T sends a security mode command to the AMF-NT-3.

[0269] S511. In case the service link between satellite 3 and the terminal equipment is available, the AMF-NT-3 sends a security mode command to the terminal equipment through the RAN-3.

[0270] S512. The terminal equipment sends a security mode response message to the AMF-NT-3 through the RAN-3, the security mode response message contains a NAS message, and the NAS message contains a PDU session establishment request message.

[0271] S513. The AMF-NT-3 forwards the PDU session establishment request message to the SMF-NT.

[0272] 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.

[0273] For the implementation of S501-S514, refer to the description of S301-S314 in the above embodiment, which will not be repeated here.

[0274] S515. In case the feeder link between satellite 3 and the ground core network element is available, the SMF-NT synchronizes information with the SMF-T. For example, the SMF-NT forwards the PDU session establishment request message to the SMF-T.

[0275] In some embodiments, after the SMF-NT forwards the PDU session establishment request message to the SMF-T, the SMF-NT can start a timer, and when the timer reaches a preset time length, clean up the information stored in the SMF-NT, and release the storage space of the SMF-NT in time.

[0276] S516. After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0277] S517. After AMF-NT-3 receives the security mode response message, it temporarily stores the message until it forwards the message to AMF-T after re-connecting to the ground station.

[0278] S518. AMF-T continues to perform the registration procedure.

[0279] S519. If the registration fails, AMF-T sends a notification message to SMF-T, which is used to inform SMF-T that the registration fails.

[0280] The registration can fail for certain reasons, which can include user authentication failure, security context establishment failure, or failure due to policy, access type mismatch, etc. after the second half of the registration. The PDU session establishment request carried in the security mode response message, if it is due to user authentication failure, security context establishment failure, then the terminal device can perform a re-registration procedure. If it is due to policy, access type mismatch, etc. after the second half of the registration, since the PDU session establishment request has been sent in advance at this time, AMF-NT and SMF-NT can have forwarded or processed the message, based on the intermittence of the link in the store-and-forward scenario, after confirming the registration failure, AMF-T can notify SMF-T of the registration failure. SMF-T can immediately release the stored PDU session establishment request information and possibly allocated resources, which can include session ID, policy and charging related information, etc.

[0281] S520. In the case that the feeder link between satellite 4 (which can be referred to as a second non-terrestrial device) and the ground core network element is available, 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 fails.

[0282] S521. In the case that 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 through RAN-4.

[0283] In some embodiments, the registration and PDU session establishment reject message can contain at least one of the following: a reason for registration failure, a monitoring list of S&F, a wait time of S&F. These information can be used to guide the user to re-initiate registration.

[0284] In the method provided in the embodiments of the present application, if the registration and PDU session establishment fails due to policy, access type mismatch, or the like in the second half of the registration, the terminal device can be informed of the registration and PDU session establishment failure and whether to reinitiate the registration by returning a registration and PDU session establishment rejection message to the terminal device.

[0285] In Figure 9 In the above embodiments, the registration request message can include request information for requesting configuration of S-NSSAI, the security mode command can include multiple S-NSSAIs configured by the ground core network device, and the security mode response message can include a PDU session establishment request corresponding to one S-NSSAI. By carrying S-NSSAI in the security mode command and carrying the PDU session establishment request in the security mode response message, the signaling overhead can be reduced, but the DoS attack can be faced. Based on this, as Figure 13 shown in the method for registering and session establishment in the store-and-forward mode is further provided.

[0286] It should be noted that Figure 13 the method shown still takes the terminal device, the satellite-borne network element (such as RAN-1, AMF-NT-1) of satellite 1, the satellite-borne network element (such as RAN-2, AMF-NT-2) of satellite 2, the satellite-borne network element (such as RAN-3, AMF-NT-3 and SMF-NT) of satellite 3, the satellite-borne network element (such as RAN-4, AMF-NT-4) of satellite 4, and the ground core network element (such as AMF-T, AUSF, UDM, UPF and SMF-T) of the ground device as the execution subject.

[0287] As Figure 13 shown, the method can include the following S601 to S627.

[0288] S601. In the case that the service link between the terminal device and satellite 1 (which can be referred to as a third non-ground device) is available, the terminal device sends a registration request message to RAN-1, and RAN-1 forwards the message to AMF-NT-1.

[0289] In some embodiments, the registration request message can include a registration type, SUCI, 5G-GUTI, PEI, and request information of S-NSSAI. The request information is used to request the network side device to configure S-NSSAI.

[0290] S602. AMF-NT-1 returns a downlink NAS transport (DL NAS transport) message to the terminal device through RAN-1, and the message includes an interim GUTI allocated for the terminal device.

[0291] S603. The AMF-NT-1 forwards the stored registration request message and interim GUTI to the AMF-T in case the feeder link between satellite 1 and the terrestrial core network element is available.

[0292] S604. The AMF-T initiates a user authentication procedure.

[0293] S605. The AMF-T sends an authentication request message to the AMF-NT-2 in case the feeder link between satellite 2 (may be referred to as fourth non-terrestrial equipment) and the terrestrial core network element is available.

[0294] S606. The AMF-NT-2 sends an authentication request message to the terminal equipment through RAN-2 in case the service link between satellite 2 and the terminal equipment is available.

[0295] S607. The terminal equipment returns an authentication response message to the AMF-NT-2 through RAN-2.

[0296] S608. The AMF-NT-2 sends an authentication response message to the AMF-T in case the feeder link between satellite 2 and the terrestrial core network element is available.

[0297] S609. The AUSF sends an authentication response message to the AMF-T. The message contains a key security anchor function (KSEAF) key.

[0298] S610. The AMF-T sends a security mode command to the AMF-NT-3 in case the feeder link between satellite 3 (may be referred to as first non-terrestrial equipment) and the terrestrial core network element is available.

[0299] For implementation of S601-S610, reference can be made to the description of S301-S310 in the above embodiment, which will not be repeated here.

[0300] S611. The AMF-NT-3 sends a security mode command to the terminal equipment through RAN-3 in case the service link between satellite 3 and the terminal equipment is available.

[0301] The difference from the security mode command in S311 described above is that the security mode command in S611 does not contain the plurality of S-NSSAIs configured by the terrestrial core network equipment, but is implemented through S613.

[0302] S612. The terminal equipment sends a security mode response message to the AMF-NT-3 through RAN-3.

[0303] The difference between the security mode response message in S312 and S612 is that the security mode response message in S612 does not contain the PDU session establishment request message, but is implemented through S614.

[0304] S613. The AMF-NT-3 sends multiple S-NSSAIs to the terminal device through the RAN-3, wherein the multiple S-NSSAIs are configured for the ground core network device.

[0305] S614. The terminal device sends a PDU session establishment request message based on one S-NSSAI to the AMF-NT-3 through the RAN-3, wherein the S-NSSAI is selected by the terminal device from the multiple S-NSSAIs.

[0306] S615. The AMF-NT-3 forwards the PDU session establishment request message to the SMF-NT.

[0307] S616. After the SMF-NT receives the PDU session establishment request message forwarded by the AMF-NT-3, the SMF-NT preprocesses the PDU session establishment request message and temporarily stores the preprocessed PDU session establishment request message.

[0308] For the implementation of S601-S614, refer to the description of S301-S314 in the above embodiment, which will not be repeated here.

[0309] S617. In the case that the feeder link between the satellite 3 and the ground core network element is available, the SMF-NT synchronizes information with the SMF-T. For example, the SMF-NT forwards the PDU session establishment request message to the SMF-T.

[0310] S618. After receiving the PDU session establishment request message, the SMF-T temporarily stores the message.

[0311] S619. After the AMF-NT-3 receives the security mode response message, the message is temporarily stored until the AMF-NT-3 forwards the message to the AMF-T after connecting to the ground station again.

[0312] S620. The AMF-T continues to perform the registration process.

[0313] S621. The AMF-T prepares to issue a registration accept request message. Since the feeder link is not available at this moment, the AMF-T can wait until the feeder link is restored for sending. In addition, the AMF-T can also notify the SMF-T of the successful registration.

[0314] S622. The SMF-T performs the session establishment process.

[0315] S623. AMF-T sends a PDU session establishment accept message to SMF-T.

[0316] S624. When the power supply link between satellite 4 and the ground core network element is available, AMF-T sends a registration and PDU session establishment acceptance message to AMF-NT-4.

[0317] S625. When the service link between satellite 4 and the terminal equipment is available, AMF-NT-4 sends a registration and PDU session establishment acceptance message to the terminal equipment through RAN-4.

[0318] S626. The terminal equipment returns a registration and PDU session establishment acceptance message to AMF-NT-4 via RAN-4.

[0319] S627. When the power supply link between satellite 4 and the ground core network element is available, AMF-NT-4 sends a registration and PDU session establishment acceptance message to AMF-T.

[0320] The implementation of S615-S627 can be described with reference to the above embodiments for S313-S325, and will not be repeated here.

[0321] In the method provided in this application embodiment, the security mode command and security mode response message do not carry S-NSSAI. First, a security context is established through the security mode command and security mode response message. Then, the non-terrestrial device sends multiple S-NSSAIs configured by the terrestrial core network device to the terminal device. The terminal device can select one S-NSSAI and send a PDU session establishment and acceptance message based on that S-NSSAI. This avoids network attacks on the S-NSSAI and more effectively ensures its security.

[0322] It should be understood that Figures 1-13 The flowcharts or scene diagrams shown are for illustrative purposes only and are not intended to limit the embodiments of this application to the examples illustrated. In fact, those skilled in the art can interpret the embodiments based on... Figures 1-13 The examples in the document can be transformed into equivalent ways to obtain more implementations.

[0323] The above text combined Figures 1-13 This paper describes in detail the handover decision determination method provided in the embodiments of this application. The following will combine... Figures 14-15 The device embodiments of this application are described in detail below. It should be understood that the communication device of this application embodiment can execute the various handover decision determination methods described in the foregoing embodiments of this application. That is, the specific working processes of the various products below can be referred to the corresponding processes in the foregoing method embodiments.

[0324] In the embodiments above, the terminal device, the non-ground device and the ground device can perform some or all of the steps in the embodiments. These steps or operations are only 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 different orders as presented in the embodiments, and it is possible that not all operations in the embodiments of the present application are performed. Moreover, the magnitude of the serial number of each step does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0325] Figure 14 is a schematic block diagram of an electronic device provided by the embodiments of the present application. The electronic device can be a communication device. As shown in Figure 14 The electronic device 140 can include a communication module 141 and a processing module 142. The processing module 142 can implement corresponding processing functions. The communication module 141 can implement corresponding communication functions, which can be internal communication functions of the electronic device 140, or communication functions of the electronic device 140 and other devices. Alternatively, the communication module 141 can also be referred to as a communication interface or a communication module.

[0326] 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 foregoing method embodiments.

[0327] In a possible implementation, the electronic device 140 can correspond to the terminal device in the foregoing method embodiments, or a component (such as a circuit, a chip or a chip system, etc.) configured in the terminal device. The electronic device 140 can be used to perform the steps or processes performed by the terminal device in any of the foregoing method embodiments.

[0328] For example, the communication module 141 can be used to: send a registration request message to a non-ground device; receive a security mode command from the non-ground device; send a security mode response message to the non-ground device, the security mode response message can include a PDU session establishment request message, the PDU session establishment request message can include a first information identifier, the first information identifier can be used to indicate that the non-ground device pre-processes the PDU session establishment request message and stores it; receive a registration and PDU session establishment acceptance message from the non-ground device.

[0329] The above is only an example, and the detailed steps or processes can refer to the description of the foregoing embodiments.

[0330] In another possible implementation, the electronic device 140 can correspond to a non-ground device in the above method embodiments, or a component (such as a circuit, a chip, or a chip system, etc.) configured in the non-ground device. The electronic device 140 can be used to perform the steps or procedures performed by the non-ground device in any of the above method embodiments.

[0331] Exemplarily, the communication module 141 can be configured to receive a registration request message from a terminal device, send a security mode command to the terminal device, and receive a security mode response message from the terminal device, which can include a PDU session establishment request message including a first information identifier. The processing module 142 can be configured to pre-process and store the PDU session establishment request message based on the first information identifier. The communication module 141 can be further configured to send the security mode response message and the pre-processed PDU session establishment request message to a ground device, send a registration and PDU session establishment accept message to the terminal device, and send the registration and PDU session establishment accept message to the terminal device.

[0332] The above is only an example, and detailed steps or procedures can be referred to the descriptions of the foregoing embodiments.

[0333] In another possible implementation, the electronic device 140 can correspond to a ground device in the above method embodiments, or a component (such as a circuit, a chip, or a chip system, etc.) configured in the ground device. The electronic device 140 can be used to perform the steps or procedures performed by the ground device in any of the above method embodiments.

[0334] Exemplarily, the communication module 141 can be configured to receive a security mode response message and a pre-processed PDU session establishment request message from a non-ground device, and store the PDU session establishment request message. The processing module 142 can be configured to perform a registration procedure in response to the security mode response message, and perform a PDU session establishment procedure based on the stored PDU session establishment request message after the registration is successful. The communication module 141 can be further configured to send a registration and PDU session establishment accept message to the non-ground device after the PDU session establishment procedure is successful.

[0335] The above is only an example, and detailed steps or procedures can be referred to the descriptions of the foregoing embodiments.

[0336] Figure 15is a schematic block diagram of a communication apparatus 150 provided by an embodiment of the present application. The communication apparatus 150 can be a chip, a chip system, or a processor, etc. of a terminal device, a non-ground device, and a ground device implementing the above method. The communication apparatus 150 can be used to implement the method described in the above method embodiments, which can be referred to the description in the above method embodiments.

[0337] As shown in Figure 15 , the communication apparatus 150 can include one or more processors 151, which can also be referred to as processing units or processing modules, and can implement certain control functions. The processor 151 can be a general purpose processor or a special purpose processor, etc., for example, can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication apparatus 150 (such as a base station, a baseband chip, a user, and a user chip), execute software programs, and process data of the software programs.

[0338] In a possible implementation, the processor 151 can also store instructions and / or data, which can be executed by the processor 151, so that the communication apparatus 150 performs the method described in the above method embodiments.

[0339] In another possible implementation, the communication apparatus 150 can include a communication interface 152 for implementing receiving and sending functions. For example, the communication interface 152 can be a transceiver circuit, an interface, an interface circuit, or a transceiver, etc. The transceiver circuit, the interface, the interface circuit, or the transceiver for implementing the receiving and sending functions can be separate or integrated together. The above transceiver circuit, interface, interface circuit, or transceiver can be used for reading and writing of codes / data, or the above transceiver circuit, interface, interface circuit, or transceiver can be used for transmission or transfer of signals.

[0340] Optionally, the communication apparatus 150 can include one or more memories 153, which can store instructions that can be executed on the processor 151, so that the communication apparatus 150 performs the method described in the above method embodiments. Optionally, the memory 153 can also store data. Optionally, the processor 151 can also store instructions and / or data. The processor 151 and the memory 153 can be separately arranged or integrated together.

[0341] It should be understood that, in a possible implementation, each step in the method embodiments provided in the present application can be completed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor. The software modules can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, register, etc. The storage medium is located in the memory, and the processor reads the information in the memory, and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0342] In an implementation, the communication apparatus 150 can correspond to the terminal device in the above method embodiments, and can be used to execute each step and / or process executed by the terminal device in the above method embodiments. The processor 151 can be used to execute the 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 each step and / or process of the above method embodiments corresponding to the terminal device.

[0343] In another implementation, the communication apparatus 150 can correspond to the non-ground device in the above method embodiments, and can be used to execute each step and / or process executed by the non-ground device in the above method embodiments. The processor 151 can be used to execute the 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 each step and / or process of the above method embodiments corresponding to the non-ground device.

[0344] In another implementation, the communication apparatus 150 can correspond to the ground device in the above method embodiments, and can be used to execute each step and / or process executed by the ground device in the above method embodiments. The processor 151 can be used to execute the 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 each step and / or process of the above method embodiments corresponding to the ground device.

[0345] It should be understood that the above-mentioned processing device can be one or more chips. For example, the processing device can be a field programmable gate array (FPGA), can be an application specific integrated circuit (ASIC), can also be a system on chip (SoC), can also be a central processor unit (CPU), can also be a network processor (NP), can also be a digital signal processor (DSP), can also be a micro controller unit (MCU), can also be a programmable logic device (PLD) or other integrated chip.

[0346] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM) and direct rambus RAM (DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0347] According to the method provided in the embodiments of the present application, the present application further provides a chip system, which comprises one or more processors, and is configured to call and run instructions stored in a memory, so that the method provided in the embodiments of the present application is executed. The chip system can be composed of a chip, or can comprise a chip and other discrete devices.

[0348] The chip system can comprise an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

[0349] According to the method provided in the embodiments of the present application, the present application further provides a communication system, which comprises the terminal device, the non-ground device and the ground device.

[0350] According to the method provided in the embodiments of the present application, the present application further provides a computer program product, which comprises computer program codes, and when the computer program codes are executed on a computer, the computer is caused to execute each step or flow of the LMF and the access network device in any of the preceding method embodiments.

[0351] According to the method provided in the embodiments of the present application, the present application further provides a computer readable storage medium, which stores program codes, and when the program codes are executed on a computer, the computer is caused to execute each step or flow of the terminal device, the non-ground device or the ground device in any of the preceding method embodiments.

[0352] The computer readable storage medium can be the volatile memory or the non-volatile memory, or can comprise the volatile memory and the non-volatile memory.

[0353] In the embodiments of the present application, each term and English abbreviation is an exemplary example given for convenience of description, and should not constitute any limitation on the present application. The present application does not exclude the possibility of defining other terms capable of achieving the same or similar functions in the existing or future protocols.

[0354] In the above embodiments, all or part of the embodiments can be realized by software, hardware, firmware or any combination thereof. When realized by software, all or part of the embodiments can be realized in the form of a computer program product. The computer program product comprises one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated.

[0355] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the division of the units is only a logical function division, and there can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0356] It should be understood that, in various embodiments of the present application, the sequence of the processes does not mean the execution sequence, and the execution sequence of the processes should be determined according to the functions and the inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0357] In summary, the above is only a preferred embodiment of the technical scheme of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of registration and session establishment, characterized by, The method is applied to a terminal device, and the method comprises: sending a registration request message to a non-ground device; in a registration process, performing: after user authentication is completed, sending a protocol data unit (PDU) session establishment request message to the non-ground device; wherein the PDU session establishment request message comprises a first information identifier, and the first information identifier is used to instruct the non-ground device to pre-process and store the PDU session establishment request message; receiving a registration and PDU session establishment acceptance message from the non-ground device, the registration and PDU session establishment acceptance message being used to indicate that registration and PDU session establishment are successful.

2. The method of claim 1, wherein, The non-ground device comprises a non-ground session management function (SMF-NT); and 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 of claim 2, wherein, The non-ground device further comprises a non-ground access and mobility management function (AMF-NT); and the PDU session establishment request message is carried in a security mode response message, and the security mode response message further comprises 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.

4. The method of claim 1, wherein, After user authentication is completed, the PDU session establishment request message is sent to the non-ground device, comprising: after sending an authentication response message to the non-ground device, the PDU session establishment request message is sent separately, and no security mode command is received from the non-ground device in a registration process; or after sending an authentication response message to the non-ground device, a security mode command is received from the non-ground device; in response to the security mode command, a security context is enabled, and a security mode response message is sent to the non-ground device, the security mode response message comprising the PDU session establishment request message; or after sending an authentication response message to the non-ground device, a security mode command is received from the non-ground device; in response to the security mode command, a security context is enabled, and a security mode response message is sent to the non-ground device; after the security mode response message is sent to the non-ground device, the PDU session establishment request message is sent separately.

5. The method according to any one of claims 1 to 4, characterized in that, Before the PDU session establishment request message is sent to the non-ground device, the method further comprises: receiving an authentication request message from the non-ground device; sending an authentication response message to the non-ground device.

6. The method according to any one of claims 1 to 4, characterized in that, The method further comprises: in a case where registration and PDU session establishment fail, receiving a registration and PDU session establishment rejection message from the non-ground device, the registration and PDU session establishment rejection message being used to indicate that registration and PDU session establishment fail; or in a case where registration establishment succeeds and PDU session establishment fails, receiving a registration acceptance message from the non-ground device, the registration acceptance message comprising first indication information, and the first indication information being used to indicate that PDU session establishment fails.

7. A method of registration and session establishment, characterized by The method is applied to a non-ground device, and the method comprises: receiving a registration request message from a terminal device; in a registration procedure, performing: receiving a PDU session establishment request message from the terminal device after user authentication is completed, the PDU session establishment request message comprising a first information identifier; based on the first information identifier, pre-processing and storing the PDU session establishment request message; sending the pre-processed PDU session establishment request message to a ground device; receiving a registration and PDU session establishment accept message from the ground device, and sending the registration and PDU session establishment accept message to the terminal device, the registration and PDU session establishment accept message being used to indicate that registration and PDU session establishment are successful.

8. The method of claim 7, wherein, The non-ground device comprises a first non-ground device, and the first non-ground device comprises an SMF-NT. The pre-processing and storing of the PDU session establishment request message based on the first information identifier comprises: 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 of claim 8, wherein, The first non-ground device further comprises an AMF-NT. The receiving of the PDU session establishment request message from the terminal device comprises: 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, the security mode response message comprising 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 forwards the PDU session establishment request message to the SMF-NT based on the second information identifier.

10. The method of claim 9, wherein, The ground device comprises a ground access and mobility management function AMF-T and a ground session management function SMF-T; The sending of the pre-processed PDU session establishment request message to a ground device comprises: In a case where a 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 comprise the PDU session establishment request message.

11. The method of claim 10, wherein, The non-ground device comprises a second non-ground device; The receiving of the registration and PDU session establishment accept message from the ground device comprises: The second non-ground device receives the registration and PDU session establishment accept message from the AMF-T; The sending of the registration and PDU session establishment accept message to the terminal device comprises: The second non-ground device sends the registration and PDU session establishment accept message to the terminal device.

12. The method of claim 11, wherein, The method further comprises: In a case that the registration and the PDU session establishment fail, the second non-ground device receives a registration and PDU session establishment rejection message from the ground device, and sends the registration and PDU session establishment rejection message to the terminal device, the registration and PDU session establishment rejection message being used to indicate that the registration and the PDU session establishment fail; or In a case that the registration establishment succeeds and the PDU session establishment fails, 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 including first indication information, the first indication information being used to indicate that the PDU session establishment fails.

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

14. The method of claim 13, wherein, The non-ground device includes a fourth non-ground device; After the third non-ground device sends the registration request message to the ground device, the method further includes: The fourth non-ground device receives an authentication request message from the ground device; The fourth non-ground device sends the authentication request message to the terminal device; The fourth non-ground device receives an authentication response message from the terminal device; The fourth non-ground device sends the authentication response message to the ground device.

15. A method of registration and session establishment, characterized by, The method is applied to a ground device, and the method includes: Receiving a registration request message from a non-ground device; During a registration process, performing: receiving a preprocessed PDU session establishment request message from the non-ground device after user authentication is completed, and storing the PDU session establishment request message; performing a registration procedure; after the registration succeeds, performing a PDU session establishment procedure based on the stored PDU session establishment request message; After the PDU session establishment procedure succeeds, sending a registration and PDU session establishment acceptance message to the non-ground device, the registration and PDU session establishment acceptance message being used to indicate that the registration and the PDU session establishment succeed.

16. The method of claim 15, wherein, The ground device includes an SMF-T, and the non-ground device includes a first non-ground device, the first non-ground device including an SMF-NT; The receiving the preprocessed PDU session establishment request message from the non-ground device includes: The SMF-T receives the preprocessed PDU session establishment request message from the SMF-NT.

17. The method of claim 16, wherein, The ground device further includes an AMF-T, and the first non-ground device further includes an AMF-NT; The performing the registration procedure 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 the registration procedure in response to the security mode response message; The performing the PDU session establishment procedure based on the stored PDU session establishment request message after the registration succeeds includes: After the registration is successful, the AMF-T sends a notification message to the SMF-T, the notification message being used to indicate that the registration is successful; and the SMF-T performs a PDU session establishment procedure based on the stored PDU session establishment request message.

18. The method of claim 15, wherein, The non-ground device includes a second non-ground device; The sending of the registration and PDU session establishment acceptance message to the non-ground device includes: In a case where the registration and the PDU session establishment are successful, the registration and PDU session establishment acceptance message is sent to the second non-ground device, the second non-ground device being a non-ground device of a next coverage terminal device.

19. The method of claim 18, wherein, The method further includes: In a case where the registration and the PDU session establishment are unsuccessful, a registration and PDU session establishment rejection message is sent to the second non-ground device, the registration and PDU session establishment rejection message being used to indicate that the registration and the PDU session establishment are unsuccessful; or In a case where the registration is successful and the PDU session establishment is unsuccessful, a registration acceptance message is sent to the second non-ground device, the registration acceptance message including first indication information, the first indication information being used to indicate that the PDU session establishment is unsuccessful.

20. The method of any one of claims 15-19, wherein, The non-ground device includes a third non-ground device; The receiving of the registration request message from the non-ground device includes: The registration request message is received from the third non-ground device; In response to the registration request message, a user authentication procedure is performed.

21. The method of claim 20, wherein, The non-ground device further includes a fourth non-ground device; After the user authentication procedure is performed, the method further includes: An authentication request message is sent to the fourth non-ground device; An authentication response message is received from the fourth non-ground device.

22. A communications device, characterized by The communication device includes at least one processor coupled with a memory, the memory storing a program or instructions, the processor executing the program or instructions to cause the device to perform the method of any one of claims 1 to 21.

23. A communication system, characterized by The communication system includes a terminal device, a non-ground device, and a ground device; wherein the terminal device is configured to perform the method of any one of claims 1 to 6, the non-ground device is configured to perform the method of any one of claims 7 to 14, and the ground device is configured to perform the method of 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, the computer program or instructions being executed to cause a computer to perform the method of any one of claims 1 to 21.

Images