Communication method, and apparatus, device and storage medium

Abstract

The present application belongs to the technical field of communications. Disclosed are a communication method, and an apparatus, a device and a storage medium. The communication method in the embodiments of the present application comprises: when determining that a satellite for a first user equipment changes, a first network-side apparatus executing a first operation, which comprises at least one of the following: sending a first message to a second network-side apparatus on a target satellite for the first user equipment, wherein the first message is used for requesting the second network-side apparatus to allocate a first address to the first user equipment; sending a second message to the first user equipment, wherein the second message is used for instructing the first user equipment to initiate SIP re-negotiation or SDP re-negotiation; and sending a third message to the first user equipment, wherein the third message is used for SIP re-negotiation or SDP re-negotiation with the first user equipment.

Description

Communication method, device, equipment and storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on February 7, 2024, with application number 202410174986.8 and titled “Communication Method, Apparatus, Device and Storage Medium,” the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application belongs to the field of communication technology, and specifically relates to a communication method, apparatus, device and storage medium. Background Art

[0004] In the 5G satellite NR non-terrestrial network (NTN) scenario, since the satellite is far away from the ground, a possible communication path for a call between two terminals is: terminal 1-satellite-ground station-core network equipment (such as user plane function (UPF))-satellite-terminal 2. This communication path is long and the call delay is large, affecting the user experience.

[0005] One solution is to place the UPF on the satellite to achieve user equipment-satellite-user equipment (UE-satellite-UE, USU) communication, shortening the communication path between the two terminals, reducing call delays, and providing a better user experience.

[0006] However, due to the rapid movement of satellites, the terminal needs to constantly switch satellites, causing the terminal's satellite to change. In this case, it is necessary to use the UPF on the satellite before and after the change to forward data at the same time, wasting satellite resources. Summary of the Invention

[0007] The embodiments of the present application provide a communication method, apparatus, device, and storage medium that can solve the problem of wasting satellite resources.

[0008] In a first aspect, a communication method is provided, comprising:

[0009] The first network-side device performs a first operation when determining that the satellite of the first user equipment has changed;

[0010] The first operation includes at least one of the following:

[0011] Sending a first message to a second network-side device on a target satellite of the first user equipment, where the first message is used to request the second network-side device to allocate a first address to the first user equipment, and the target satellite is a changed satellite of the first user equipment;

[0012] Sending a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0013] A third message is sent to the first user equipment, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0014] In a second aspect, a communication method is provided, comprising:

[0015] When determining that the satellite of the first user equipment has changed, the first user equipment sends an eighth message to the first network side device, where the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0016] Alternatively, the first user equipment sends a fourth message to the first network side apparatus when receiving the second message from the first network side apparatus, where the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0017] Alternatively, the first user equipment receives a third message from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

[0018] A third aspect provides a communication method, comprising:

[0019] The fourth network-side device receives the third information or the fourth information from the first network-side device;

[0020] The fourth network-side device sends a second message to the first network-side device according to the third information, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0021] Alternatively, the fourth network-side apparatus sends a third message to the first network-side apparatus according to the fourth information, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0022] In a fourth aspect, a communication method is provided, comprising:

[0023] The fifth network-side device receives the fifth information;

[0024] The fifth network-side device performs a second operation according to the fifth information;

[0025] The second operation includes at least one of the following:

[0026] Release the connection between the source upstream split and the target upstream split;

[0027] Release the tunnel between the source upstream split and the target upstream split;

[0028] Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

[0029] In a fifth aspect, a communication device is provided, including:

[0030] A first execution module is configured to execute a first operation when it is determined that a satellite of the first user equipment changes;

[0031] The first operation includes at least one of the following:

[0032] Sending a first message to a second network-side device on a target satellite of the first user equipment, where the first message is used to request the second network-side device to allocate a first address to the first user equipment, and the target satellite is a changed satellite of the first user equipment;

[0033] Sending a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0034] A third message is sent to the first user equipment, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0035] In a sixth aspect, a communication device is provided, including:

[0036] The first sending module is configured to send an eighth message to the first network-side device when it is determined that the satellite of the first user equipment has changed, wherein the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0037] The second sending module is configured to send a fourth message to the first network side device when receiving the second message from the first network side device, wherein the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0038] The first receiving module is configured to receive a third message from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

[0039] In a seventh aspect, a communication device is provided, comprising:

[0040] a fourth receiving module, configured to receive third information or fourth information from the first network-side device;

[0041] A third sending module is configured to send a second message to the first network-side device according to the third information, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0042] Alternatively, a third message is sent to the first network-side apparatus according to the fourth information, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0043] In an eighth aspect, a communication apparatus is provided, including:

[0044] a fifth receiving module, configured to receive fifth information;

[0045] a second execution module, configured to execute a second operation according to the fifth information;

[0046] The second operation includes at least one of the following:

[0047] Release the connection between the source upstream split and the target upstream split;

[0048] Release the tunnel between the source upstream split and the target upstream split;

[0049] Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

[0050] In a ninth aspect, a user device is provided, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the second aspect are implemented.

[0051] In the tenth aspect, a user device is provided, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method described in the second aspect.

[0052] In the eleventh aspect, a network side device is provided, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the first aspect, the third aspect, or the fourth aspect are implemented.

[0053] In the twelfth aspect, a network side device is provided, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method described in the first aspect, the third aspect, or the fourth aspect.

[0054] In the thirteenth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect, the second aspect, the third aspect, or the fourth aspect are implemented.

[0055] In the fourteenth aspect, a wireless communication system is provided, including: a first user equipment, a first network side device, a fourth network side device, and a fifth network side device, wherein the first user equipment can be used to execute the steps of the method described in the second aspect, the first network side device can be used to execute the steps of the method described in the first aspect, the fourth network side device can be used to execute the steps of the method described in the third aspect, and the fifth network side device can be used to execute the steps of the method described in the fourth aspect.

[0056] In the fifteenth aspect, a chip is provided, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the steps of the method described in the first aspect, the second aspect, the third aspect, or the fourth aspect.

[0057] In the sixteenth aspect, a computer program / program product is provided, which is stored in a storage medium and executed by at least one processor to implement the steps of the method described in the first aspect, the second aspect, the third aspect, or the fourth aspect.

[0058] In an embodiment of the present application, when the first network-side device determines that the satellite of the first user device has changed, it sends a first message to the second network-side device on the target satellite of the first user device to request the second network-side device to assign a first address to the first user device, or sends a second message to the first user device to instruct the first user device to initiate SIP renegotiation or SDP renegotiation, or sends a third message to the first user device to perform SIP renegotiation or SDP renegotiation with the first user device. Through the above process, the second network-side device on the target satellite can be added to the communication path, so that when USU communication is performed between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG1 is a block diagram of a wireless communication system applicable to embodiments of the present application;

[0060] FIG2 is a schematic diagram of a terminal switching satellite in the related art;

[0061] FIG3 is another schematic diagram of a terminal switching satellite in the related art;

[0062] FIG4 is a schematic diagram of a data packet uplink split in the related art;

[0063] FIG5 is a schematic diagram of a UL CL switching process in the related art;

[0064] FIG6 is a schematic diagram of communication before and after a terminal switches satellites in the related art;

[0065] FIG7 is a flowchart of an implementation method of the first communication in an embodiment of the present application;

[0066] FIG8 is a schematic diagram of a communication path after the terminal performs re-negotiation in an embodiment of the present application;

[0067] FIG9 is a schematic diagram of a flow chart of Example 1 in an embodiment of the present application;

[0068] FIG10 is a schematic diagram of a flow chart of Example 2 in an embodiment of the present application;

[0069] FIG11 is a schematic diagram of a message sending process in an embodiment of the present application;

[0070] FIG12 is a schematic diagram of a flow chart of Example 3 in the embodiment of the present application;

[0071] FIG13 is a schematic diagram of another message sending process in an embodiment of the present application;

[0072] FIG14 is another flow chart of Example 3 in the embodiment of the present application;

[0073] FIG15 is a flowchart of an implementation method of the second communication in an embodiment of the present application;

[0074] FIG16 is a flowchart of an implementation method of the third communication method in an embodiment of the present application;

[0075] FIG17 is a flowchart of an implementation method of the fourth communication method in an embodiment of the present application;

[0076] FIG18 is a schematic structural diagram of a communication device corresponding to FIG7 in an embodiment of the present application;

[0077] FIG19 is a schematic structural diagram of a communication device corresponding to FIG15 in an embodiment of the present application;

[0078] FIG20 is a schematic structural diagram of a communication device corresponding to FIG16 in an embodiment of the present application;

[0079] FIG21 is a schematic structural diagram of a communication device corresponding to FIG17 in an embodiment of the present application;

[0080] FIG22 is a schematic structural diagram of a communication device according to an embodiment of the present application;

[0081] FIG23 is a schematic diagram of the structure of a user equipment according to an embodiment of the present application;

[0082] Figure 24 is a structural diagram of a network-side device in an embodiment of the present application. Specific embodiments

[0083] The following will be combined with the accompanying drawings in the embodiments of this application to clearly describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0084] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects, for example, the first object can be one or more. In addition, "or" in this application represents at least one of the connected objects. For example, "A or B" covers three options, namely, Option 1: including A but not including B; Option 2: including B but not including A; Option 3: including both A and B. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0085] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). A direct indication can be understood as the sender explicitly informing the receiver of specific information, the operation to be performed, or the requested result, etc. in the instruction sent; an indirect indication can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the operation to be performed or the requested result, etc. based on the judgment result.

[0086] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the technology described can be used for the systems and radio technologies mentioned above, as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for illustrative purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) systems. th Generation, 6G) communication system.

[0087] FIG1 is a block diagram of a wireless communication system applicable to an embodiment of the present application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 may be a mobile phone, a tablet computer, a laptop computer, a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device, an aircraft, a vehicle user equipment (VUE), a ship-borne device, a pedestrian user equipment (PUE), a smart home (a household appliance with wireless communication capabilities, such as a refrigerator, a television, a washing machine, or furniture), a game console, a personal computer (PC), a teller machine, or a self-service machine, or other terminal-side device. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle-mounted device can also be called a vehicle-mounted terminal, a vehicle-mounted controller, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip or a vehicle-mounted unit, etc. In addition to the above-mentioned terminal devices, it can also be a chip in the terminal, such as a modem chip, a system-on-chip (SoC). It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network side device 12 may include an access network device or a core network device, wherein the access network device may also be called a radio access network (RAN) device, a radio access network function or a radio access network unit. The access network device may include a base station, a wireless local area network (WLAN) access point (AP) or a wireless fidelity (WiFi) node, etc.Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the next generation Node B (gNB), New Radio Node B (NR Node B), access point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B (home evolved Node B), Transmission Reception Point (TRP) or other appropriate terms in the relevant field. As long as the same technical effect is achieved, the base station is not limited to specific technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is used as an example for introduction, and the specific type of the base station is not limited.

[0088] The core network equipment may include but is not limited to at least one of the following: core network node, core network function, mobility management entity (MME), access mobility management function (AMF), session management function (SMF), user plane function, policy control function (PCF), policy and charging rules function unit (PCRF), edge application server discovery function (EASDF), unified data management (UDM), unified data repository (UDR), home subscriber server (HSS), centralized network configuration (CNC), network storage function (NRF), network exposure function (NEF), local NEF (L-NEF), binding support function (BSF), application function (AF), location management function (Location Management Function, AF), etc. Function, LMF), Gateway Mobile Location Centre (GMLC), Network Data Analytics Function (NWDAF), etc. It should be noted that in the embodiment of the present application, only the core network equipment in the NR system is introduced as an example, and the specific type of the core network equipment is not limited.

[0089] To facilitate understanding, the relevant technologies and concepts involved in the embodiments of this application are first introduced.

[0090] 1. USU Communications

[0091] USU communication has the following two scenarios:

[0092] Scenario 1: Two terminals are in the same satellite;

[0093] Scenario 2: Two terminals are in different satellites, and the two satellites communicate through an Inter Satellite Link (ISL).

[0094] In related technologies, terminals need to constantly switch satellites due to the rapid movement of satellites. As shown in Figure 2, Terminal 1 and Terminal 2 are initially on the same satellite (SAT-1), and then Terminal 2 switches to SAT-2. Alternatively, as shown in Figure 3, Terminal 1 is initially on SAT-1 and Terminal 2 is on SAT-2, and then Terminal 2 switches to SAT-3.

[0095] Among them, FIG3 can be considered as a subsequent scene of FIG2, or a scene independent of FIG2.

[0096] Two terminals being in the same satellite may be understood as two terminals being connected to the same satellite, two terminals being stationed in the same satellite, or two terminals accessing a network via the same satellite.

[0097] The two terminals being in different satellites may be understood as the two terminals being connected to different satellites, or the two terminals being stationed in different satellites, or the two terminals accessing the network via different satellites.

[0098] 2. Protocol Data Unit (PDU) Session in Satellite Scenario

[0099] In order to reduce the impact of satellite movement on PDU sessions, when the terminal initially establishes a PDU session, the SMF selects the first PDU session anchor (PSA) (PSA-1) on the ground. The advantage of this selection is that the IP address can be maintained unchanged when the terminal switches between satellites.

[0100] When the terminal initiates a voice call and the SMF determines that USU communication can be used, the SMF adds the satellite's UPF as an uplink classifier (UL CL) and PSA2 (also called a local PSA or additional PSA) to the communication path. As shown in Figure 4, the satellite is deployed with gNB1, UPF2, and an access gateway (AGW). UL CL and PSA2 are two logical functional modules of the satellite's UPF (UPF2). The UL CL is used to offload uplink data packets received from the terminal. For example, in the USU scenario, when the UL CL receives a voice data packet sent by the terminal, it sends the data packet to the satellite's PSA2; when the UL CL receives a data packet for a non-voice service sent by the terminal, it sends the data packet to the ground-based PSA1.

[0101] 3. UL CL switching process

[0102] As shown in Figure 3, the terminal establishes a PDU session with the source UL CL, source PSA2, and PSA1, and the source UL CL, source PSA2, PSA1, (R)AN, terminal, etc. perform uplink and downlink data transmission. The UL CL switching process is as follows:

[0103] 1. At some point, the SMF decides to change PSA2 and UL CL due to handover;

[0104] 2.SMF selects a local target PSA2 and uses N4 to establish the local target PSA2 for the PDU session;

[0105] 3. The SMF selects a UPF and uses N4 to establish a target UL CL for the PDU session. The SMF also uses N4 to establish an N9 forwarding tunnel between the source UL CL and the target UL CL.

[0106] It should be noted that if the target UL CL and the target PSA2 are located in the same UPF, steps 2 and 3 can be combined;

[0107] 4.SMF updates PSA1 via N4 to provide PDU session CN tunnel information for downlink services;

[0108] 5.SMF updates the target PSA2 via N4 to provide CN tunnel information for downlink services;

[0109] It should be noted that if the target UL CL and the target PSA2 are located in the same UPF, step 5 is not required;

[0110] 6.SMF updates the target (R)AN for uplink services;

[0111] 7. During the time interval provided by the SMF for the User Plane inactivity report, a check is performed to detect no active traffic on the N9 forwarding tunnel in order to release the N9 forwarding channel. The detection can be done by the source UL CL, which notifies the SMF of no active traffic via the N9 forwarding tunnel.

[0112] 8.SMF releases source PSA2 through N4;

[0113] 9.SMF release source UL CL.

[0114] In step 3, a tunnel between the source UL CL and the target UL CL is established to forward uplink and downlink data of the terminal.

[0115] In step 7, when the source UL CL detects that there is no data to send, it notifies the SMF, and the SMF releases the source UL CL and the source PSA2.

[0116] 4. Terminal switching process between satellites

[0117] To implement USU communication, base stations, UPFs, and AGWs must all be deployed on satellites. Figure 6 shows the communication diagram before and after a terminal switches satellites in this scenario. Initially, terminal 1 is in SAT-1 and terminal 2 is in SAT-2. The communication path between terminal 1 and terminal 2 is: terminal 1-gNB1-UPF1-AGW1-AGW2-UPF2-gNB2-terminal 2. Afterward, terminal 2 switches to the base station in SAT-3. The communication path between terminal 1 and terminal 2 is: terminal 1-gNB1-UPF1-AGW1-AGW2-UPF2-UPF3-gNB3-terminal 2.

[0118] As shown in Figure 6, after Terminal 2 switches satellites, it must use the UPFs of both the satellites before and after the switch to forward packets, wasting satellite resources. If Terminal 2 continues to switch satellites, such as to SAT-4, UPF-3 will be unable to forward packets to UPF4 on SAT-4, resulting in communication interruption and a poor user experience.

[0119] The above introduces the relevant technologies and concepts involved in the embodiments of the present application. Now, in conjunction with the accompanying drawings, the communication method provided by the embodiments of the present application is described in detail through some embodiments and their application scenarios.

[0120] 7 is a flowchart of an implementation method of a communication method provided in an embodiment of the present application. The method includes the following steps:

[0121] S710: The first network-side device performs a first operation when determining that a satellite of the first user equipment has changed.

[0122] The first operation includes at least one of the following:

[0123] Sending a first message to a second network-side device on a target satellite of the first user equipment, where the first message is used to request the second network-side device to allocate a first address to the first user equipment, and the target satellite is the changed satellite of the first user equipment;

[0124] Sending a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0125] A third message is sent to the first user equipment, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0126] It should be noted that the SIP renegotiation or SDP renegotiation is used to add the second network-side device to the communication path of the first user equipment.

[0127] SIP renegotiation can be understood as performing SIP renegotiation through SIP messages (such as SIP re-Invite messages) and response messages.

[0128] SDP renegotiation can be understood as performing SDP renegotiation through an SDP offer and an SDP answer.

[0129] By applying the method provided in the embodiment of the present application, when the first network-side device determines that the satellite of the first user device has changed, the first network-side device sends a first message to the second network-side device on the target satellite of the first user device, requesting the second network-side device to assign a first address to the first user device, or sends a second message to the first user device to instruct the first user device to initiate SIP renegotiation or SDP renegotiation, or sends a third message to the first user device for performing SIP renegotiation or SDP renegotiation with the first user device. Through the above process, the second network-side device on the target satellite can be added to the communication path of the first user device, so that when USU communication is performed between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0130] In an embodiment of the present application, the first network-side device may include a Proxy-Call Session Control Function (P-CSCF), and the second network-side device may include an access gateway (AGW), wherein the second network-side device is deployed in a satellite.

[0131] Initially, the first user device can establish a PDU session. The PDU session of the first user device uses the first UPF on the ground as PSA1. The first user device can conduct a USU voice call with the second user device. Afterwards, the satellite of the first user device may change, such as switching from other satellites to the target satellite, and the SMF can use the target UPF of the target satellite as the target UL CL and target PSA2, and add the target UL CL and target PSA2 to the PDU session.

[0132] The satellite of the first user equipment can be understood as: a satellite providing services for the first user equipment, or a satellite to which the first user equipment is connected, or a satellite used by the first user equipment, or a satellite on which the first user equipment resides, or a satellite used by the first user equipment to access a network. If the satellite of the first user equipment changes, the changed satellite is the target satellite of the first user equipment, and the satellite before the change is the source satellite of the first user equipment.

[0133] If the first network device determines that the satellite of the first user device has changed, it can send a first message to the second network device on the target satellite of the first user device. This first message is used to request the second network device to assign a first address to the first user device. The first address is the destination address of the data packet when the first user device sends the data packet. It can be understood that the first address is used by the first user device to send the data packet to the second user device. In this way, when the first user device sends a data packet to the second user device, it can use the first address as the destination address. In this way, the second network device on the target satellite of the first user device can receive the data packet of the first user device. The second network device processes the data packet and sends it to the second user device. Through this process, the second network device can be added to the communication path of the first user device, so that the USU communication between the first user device and other user devices is no longer forwarded through the UPF on the satellite before the change of the first user device, which helps to save satellite resources and improve the stability of USU communication.

[0134] The first address may be an IP address, an IP address + a port number, or a transport address.

[0135] It should be noted that after the second network-side device receives a data packet with the first address as the destination address, it replaces the first address with the IP address of the second user device side and sends it to the second user device side. The second user device side can be the second user device, or the second user device side network device, such as an access gateway serving the second user device. The IP address of the second user device side can be the IP address of the second user device or the IP address assigned to the second user device by the second user device side network device, such as the IP address assigned to the second user device by the access gateway serving the second user device. The subsequent steps are the same and will not be repeated here.

[0136] The first message may include a re-invite message.

[0137] When the first network-side device determines that the satellite of the first user equipment has changed, it can send a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initialization Protocol (SIP) or Session Description Protocol (SDP) renegotiation. After receiving the second message, the first user equipment can initiate a SIP renegotiation or an SDP renegotiation. Through this process, the second network-side device on the target satellite of the first user equipment can be added to the communication path of the first user equipment, so that the first user equipment communicates with the USU of other user equipment, and no longer forwards through the UPF on the satellite before the change of the first user equipment, which helps to save satellite resources and improve the stability of USU communication.

[0138] The second message may include a Notify message, a re-Invite message, or an Information message.

[0139] In the embodiment of the present application, the indication may also be understood or replaced by a trigger.

[0140] When the first network-side device determines that the satellite of the first user device has changed, it can send a third message to the first user device, and the third message is used to perform SIP renegotiation or SDP renegotiation with the first user device. It can be understood that the SIP renegotiation or SDP renegotiation is initiated by the first network-side device. Through this process, the second network-side device on the target satellite of the first user device can be added to the communication path of the first user device, so that the first user device communicates with the USU of other user devices, and no longer forwards through the UPF on the satellite before the change of the first user device, which helps to save satellite resources and improve the stability of USU communication.

[0141] The third message may include a re-Invite message.

[0142] In some embodiments of the present application, the method may further include the following steps:

[0143] Step 1: The first network-side device receives first information from the first user equipment;

[0144] Step 2: The first network-side device determines, based on the first information, that the satellite of the first user equipment has changed.

[0145] For the convenience of description, the above two steps are combined for explanation.

[0146] In an embodiment of the present application, upon determining that the satellite of the first user equipment has changed, the first user equipment may send first information to the first network-side apparatus. Optionally, the first user equipment may send a re-Invite message to the first network-side apparatus, wherein the re-Invite message carries the first information and the SDP includes the IP address of the first user equipment.

[0147] Optionally, the first information may include at least one of the following:

[0148] 1) The first satellite ID of the target satellite;

[0149] The first satellite identifier may identify the changed satellite of the first user equipment.

[0150] 2) The first Cell Global Identifier (CGI) of the target satellite;

[0151] The first global cell identifier may identify a cell where the first user equipment resides, and the cell corresponds to the changed satellite.

[0152] CGI is the globally unique identifier of the cell. When the cell is a 5G cell, it is the New Radio Global Identifier (NCGI). When the cell is a 4G cell, it is the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Global Cell Identifier (ECGI).

[0153] 3) Information indicating changes in satellites;

[0154] The information may indicate that the satellite of the first user equipment has changed, such as the first user equipment has changed from one satellite to another satellite. The first user equipment may change from one satellite to another satellite in a connected state, or change from one satellite to another satellite in an idle state.

[0155] 4) Information indicating that a satellite switch has occurred;

[0156] The information may indicate that the satellite of the first user equipment has been switched, such as the first user equipment has been switched from one satellite to another. The satellite switching of the first user equipment may be understood as a change in the satellite of the first user equipment in a connected state.

[0157] 5) Information indicating the updated media path (mediapath);

[0158] This information may indicate that a media path needs to be updated. A media path may be understood as a communication path.

[0159] 6) Information used to indicate update of access gateway;

[0160] This information may indicate that the access gateway needs to be updated.

[0161] After receiving the first information from the first user equipment, the first network-side device can accurately determine, based on the first information, that the satellite of the first user equipment has changed.

[0162] In some embodiments of the present application, when the first information includes the first satellite identifier or the first global cell identifier, the first network-side apparatus determines, based on the first information, that the satellite of the first user equipment has changed, which may include the following steps:

[0163] When the first satellite identifier is different from the satellite identifier associated with the first user equipment stored by the first network side device, the first network side device determines that the satellite of the first user equipment has changed;

[0164] Alternatively, when the first global cell identifier is different from the global cell identifier associated with the first user equipment stored in the first network side device, the first network side device determines that the satellite of the first user equipment has changed.

[0165] In an embodiment of the present application, the first network-side device may store a satellite identifier or a global cell identifier associated with the first user equipment. The satellite identifier or global cell identifier associated with the first user equipment stored by the first network-side device may be understood as the satellite identifier or global cell identifier of the satellite of the first user equipment before the satellite of the first user equipment changes.

[0166] After the first network side device receives the first information, if the first information includes the first satellite identifier of the target satellite of the first user equipment, the first network side device can compare the first satellite identifier with the satellite identifier associated with the first user equipment stored in itself. If the two are different, it can accurately determine that the satellite of the first user equipment has changed.

[0167] Alternatively, if the first information includes the first global cell identification code of the target satellite of the first user equipment, the first network side device can compare the first global cell identification code with the global cell identification code associated with the first user equipment stored in itself. If the two are different, it can be accurately determined that the satellite of the first user equipment has changed.

[0168] After the first network-side device determines that the satellite of the first user equipment has changed, it may use the first satellite identifier or the first global cell identifier to update the satellite identifier or the global cell identifier associated with the first user equipment stored in itself.

[0169] If the first information includes information for indicating a satellite change, or information for indicating a satellite switch, or information for indicating an update of a media path, or information for indicating an update of an access gateway, the first network side device can determine that the satellite of the first user equipment has changed based on the specific indication information.

[0170] In some embodiments of the present application, the method may further include the following steps:

[0171] First step: the first network side device receives information of the first user equipment from the third network side device, where the information of the first user equipment includes a second satellite identifier or a second global cell identifier;

[0172] The second step: when the second satellite identifier is different from the satellite identifier associated with the first user equipment stored in the first network side device, the first network side device determines that the satellite of the first user equipment has changed;

[0173] Alternatively, when the second global cell identifier is different from the global cell identifier associated with the first user equipment stored in the first network side device, the first network side device determines that the satellite of the first user equipment has changed.

[0174] For the convenience of description, the above two steps are combined for explanation.

[0175] In the embodiment of the present application, the third network-side device may include a PCF.

[0176] The first network side device can receive information of the first user equipment from the third network side device, where the information of the first user equipment includes a second satellite identifier or a second global cell identifier, where the second satellite identifier or the second global cell identifier is the satellite identifier or the global cell identifier of the latest satellite of the first user equipment.

[0177] Optionally, the first network side device can subscribe to the information of the first user equipment from the third network side device, and the third network side device can send the information of the first user equipment to the first network side device at a set time interval or when the information of the first user equipment changes.

[0178] It should be noted that the information of the first user equipment can be understood or replaced by the access network information (Access Network Information) of the first user equipment, and the subsequent related parts will not be repeated.

[0179] Optionally, the first network side device may request the information of the first user equipment from the third network side device according to actual needs. After receiving the request from the first network side device, the third network side device sends the information of the first user equipment to the first network side device.

[0180] After receiving the first user equipment information from the third network device, the first network device may compare the first user equipment information with the satellite identifier or global cell identifier stored by the first network device and associated with the first user equipment. If the second satellite identifier differs from the satellite identifier stored by the first network device and associated with the first user equipment, the first network device may determine that the satellite of the first user equipment has changed. Alternatively, if the second global cell identifier differs from the global cell identifier stored by the first network device and associated with the first user equipment, the first network device may determine that the satellite of the first user equipment has changed.

[0181] After the first network-side device determines that the satellite of the first user equipment has changed, it can use the information of the first user equipment to update the satellite identifier or global cell identifier associated with the first user equipment stored in itself.

[0182] The first network-side device can obtain the latest satellite identifier or global cell identifier associated with the first user equipment through the third network-side device, so as to accurately determine, through comparison, whether the satellite of the first user equipment has changed.

[0183] In some embodiments of the present application, the method may further include the following steps:

[0184] Step 1: The first network-side device receives a fourth message from the first user equipment, where the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0185] Step 2: The first network-side device sends a fifth message to the third network-side device, where the fifth message is used to obtain information about the first user equipment.

[0186] For the convenience of description, the above two steps are combined for explanation.

[0187] In an embodiment of the present application, the first user equipment may send a fourth message to the first network-side apparatus, where the fourth message is used to perform SIP re-negotiation or SDP re-negotiation. The fourth message may include a re-Invite message.

[0188] If the fourth message does not carry the first information, or the first network side device determines that the information of the first user equipment needs to be obtained, the first network side device can determine by itself that the satellite of the first user equipment has changed.

[0189] After receiving the fourth message from the first user equipment, the first network-side apparatus may send a fifth message to the third network-side apparatus, where the fifth message is used to obtain information about the first user equipment.

[0190] After receiving the information of the first user equipment from the third network side device, the first network side device can determine that the satellite of the first user equipment has changed by comparing the information of the first user equipment with the satellite identifier or global cell identification code associated with the first user equipment stored in itself.

[0191] After receiving the fourth message from the first user device, the first network device may determine that SIP renegotiation or SDP renegotiation is currently required. In this case, it sends a fifth message to the third network device to obtain information about the first user device. Obtaining information only when needed helps conserve communication resources and improves the stability of USU communication.

[0192] In some embodiments of the present application, when determining that a satellite of the first user equipment has changed, the first network-side device performs a first operation, including:

[0193] The first network-side device performs a first operation when it is determined that the satellite of the first user equipment has changed and the first user equipment and the second user equipment can perform user equipment-satellite-user equipment (USU) communication.

[0194] In the embodiment of the present application, the first network-side device may determine whether the first user equipment and the second user equipment can perform USU communication or not.

[0195] It should be noted that the first network side device determines whether the first user equipment and the second user equipment can perform USU communication or not, which can also be understood as the first network side device determining whether the first user equipment and the second user equipment can perform USU communication.

[0196] Optionally, the first network side device may determine whether the first user equipment and the second user equipment can perform USU communication or not based on the satellite identifier or global cell identifier associated with the first user equipment and the satellite identifier or global cell identifier associated with the second user equipment.

[0197] The satellite identifier or global cell identification code associated with the first user equipment can be understood as the satellite identifier or global cell identification code of the target satellite of the first user equipment. The satellite identifier or global cell identification code associated with the second user equipment can be stored by the first network side device, or obtained by the first network side device from a third network side device, or obtained by the first network side device from a request message or response message sent by the second user equipment, or obtained by the first network side device from a request message or response message sent by the network side device corresponding to the second user equipment, such as a P-CSCF or a Serving-Call Session Control Function (S-CSCF).

[0198] The first network-side device can determine whether the satellite of the first user equipment and the satellite of the second user equipment are the same satellite or different satellites with an ISL connection based on the satellite identifier or global cell identifier associated with the first user equipment and the satellite identifier or global cell identifier associated with the second user equipment. If they are the same satellite or different satellites with an ISL connection, it can be determined that USU communication is possible between the first user equipment and the second user equipment; otherwise, it can be determined that USU communication is not possible between the first user equipment and the second user equipment.

[0199] It should be noted that the first network-side device may also determine whether the first user equipment and the second user equipment can perform USU communication based on other conditions, such as whether the satellite of the first user equipment and the satellite of the second user equipment are deployed with an access gateway. When the satellite of the first user equipment and the satellite of the second user equipment are the same and the satellite is deployed with an access gateway, the first user equipment and the second user equipment can perform USU communication. Alternatively, when the satellite of the first user equipment and the satellite of the second user equipment are on different satellites with an ISL connection and both satellites are deployed with an access gateway, USU communication can be performed.

[0200] The first network side device performs a first operation when it is determined that the satellite of the first user equipment has changed and the first user equipment and the second user equipment can perform USU communication. Before performing the first operation, it is first determined whether the first user equipment and the second user equipment can perform USU communication. If USU communication is not possible, the first network side device may not perform the first operation to save communication resources.

[0201] In some embodiments of the present application, the first network-side device sending the first message to the second network-side device on the target satellite of the first user equipment may include the following steps:

[0202] The first step: the first network side device determines the second network side device according to the satellite identifier or global cell identifier of the target satellite;

[0203] Second step: the first network side device sends a first message to the second network side device.

[0204] For the convenience of description, the above two steps are combined for explanation.

[0205] In an embodiment of the present application, the first network device can obtain the satellite identifier or global cell identifier of the target satellite of the first user equipment through the first information received from the first user equipment, or the information of the first user equipment received from the third network device. Based on the satellite identifier or global cell identifier of the target satellite, the address of the target satellite or the second network device on the target satellite can be determined, and the first message can be sent to the second network device.

[0206] The first network-side device can accurately determine the second network-side device on the target satellite according to the satellite identifier or global cell identifier of the target satellite.

[0207] In some embodiments of the present application, when the first operation includes sending a first message to a second network-side device on a target satellite of the first user equipment, the method may further include the following steps:

[0208] Step 1: The first network-side device receives a first address from the second network-side device;

[0209] Step 2: The first network-side device sends the first address to the first user equipment.

[0210] For the convenience of description, the above two steps are combined for explanation.

[0211] In an embodiment of the present application, when the first network-side device determines that the satellite of the first user equipment has changed, it sends a first message to the second network-side device on the target satellite of the first user equipment, requesting the second network-side device to assign a first address to the first user equipment. After receiving the first address from the second network-side device, the first network-side device sends the first address to the first user equipment. The first user equipment can receive the first address from the first network-side device. The first user equipment uses the first address as the destination address of the first data packet and sends the first data packet to the second network-side device. In this way, when the first user equipment sends a data packet to the second user equipment, when the second network-side device on the target satellite of the first user equipment receives the data packet with the first address as the destination address, it processes it and sends it to the second user equipment, and no longer forwards it through the UPF or access gateway on the satellite before the change of the first user equipment, which helps to save communication resources and improve the stability of USU communication.

[0212] In some embodiments of the present application, the method may further include the following steps:

[0213] Step 1: The first network side apparatus sends a sixth message to the second network side apparatus, where the sixth message is used to request the second network side apparatus to allocate a second address to the first user equipment;

[0214] Second step: the first network-side device receives the second address from the second network-side device, and sends the second address to the second user equipment.

[0215] For the convenience of description, the above two steps are combined for explanation.

[0216] It should be noted that the second address is used by the second user equipment or a network device on the second user equipment side, such as an access gateway serving the second user equipment, to send a data packet to the first user equipment.

[0217] The second address may be an IP address, an IP address + a port number, or a transport address.

[0218] In an embodiment of the present application, when the first network side device determines that the satellite of the first user equipment has changed, it can send a sixth message to the second network side device on the target satellite of the first user equipment, requesting the second network side device to assign a second address to the first user equipment.

[0219] After receiving the second address from the second network device, the first network device can send the second address to the second user device. In this way, when the second user device sends a data packet to the first user device, the second network device on the first user device's target satellite receives the data packet with the second address as the destination address, processes it and sends it to the first user device. This eliminates the need for forwarding through the UPF or access gateway on the satellite before the first user device's change, thereby saving communication resources.

[0220] It should be noted that the second user equipment may also be a second user equipment side network device, such as an AGW serving the second user equipment.

[0221] In some embodiments of the present application, the method may further include the following steps:

[0222] The first network side device sends second information to the third network side device;

[0223] The second information includes at least one of the following:

[0224] Information indicating that the access gateway update is complete;

[0225] Information used to indicate the release of the connection between upstream splits;

[0226] Information used to instruct the release of the tunnel between upstream splits;

[0227] Information indicating the update of voice bearer.

[0228] It should be noted that a voice bearer is a bearer or data channel used to transmit voice services. The corresponding concept in 5G communication systems is a Quality of Service (QoS) flow, and the corresponding concept in 4G communication systems is an Evolved Packet System (EPS) bearer. The QoS level corresponding to voice bearers is 1. The relevant sections will not be repeated here.

[0229] It should be noted that the connection between uplink splits can be understood as the connection between the UL CL of the source satellite and the UL CL of the target satellite;

[0230] The tunnel between uplink splits can be understood as a tunnel between the UL CL of the source satellite and the UL CL of the target satellite.

[0231] In an embodiment of the present application, after the first network device sends the first address to the first user equipment or sends the second address to the second user equipment, it can send a message to the third network device, the message carrying media information and second information. The media information may include caller and caller information, QoS information, latency information, etc.

[0232] The second information may include information indicating that the access gateway update is completed, or information indicating that the connection between uplink branches is released, or information indicating that the tunnel between uplink branches is released, or information indicating that the voice bearer is updated.

[0233] The third network side device may send a session management (SM) related policy modification to the fifth network side device, carrying the media information and the fifth information. The fifth network side device may include an AMF.

[0234] The fifth information may include at least one of the following:

[0235] Information indicating that the access gateway update is complete;

[0236] Information used to indicate the release of the connection between upstream splits;

[0237] Information used to instruct the release of the tunnel between upstream splits;

[0238] Information indicating the update of voice bearer.

[0239] It should be noted that the fifth information and the second information may be the same or different.

[0240] After receiving the fifth information, the fifth network-side device may perform a second operation according to the fifth information. The second operation may include at least one of the following:

[0241] Release the connection between the source upstream split and the target upstream split;

[0242] Release the tunnel between the source upstream split and the target upstream split;

[0243] Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

[0244] The sixth network-side device may include a UPF.

[0245] Optionally, the fifth network side device can send an uplink diversion rule to the uplink diversion function of the sixth network side device on the target satellite of the first user device, and the uplink diversion rule is used to instruct the sixth network side device to send the received data packet of the first user device to the PDU session anchor point PSA of the sixth network side device.

[0246] After the fifth network side device updates the uplink offload function of the sixth network side device on the target satellite of the first user equipment, the uplink offload function of the sixth network side device can send the received data packet of the first user equipment to the PSA of the sixth network side device, which is different from sending it to the source UL CL in the related technology.

[0247] The fifth network-side device releases the connection or tunnel between the source uplink offload and the target uplink offload, which can be understood as a transmission channel (tunnel). The source uplink offload is the uplink offload serving the first user equipment before the satellite of the first user equipment changes, or is called the uplink offload function.

[0248] After the fifth network-side device performs the second operation, it may send an SMF association modification message to the third network-side device to notify the third network-side device that the processing is successful.

[0249] Furthermore, the third network-side device sends a notification message to the first network-side device to notify the first network-side device that the processing is successful.

[0250] Furthermore, the first network-side apparatus may send a response message to the first user equipment.

[0251] In some embodiments of the present application, the first network-side device sending the second message to the first user equipment may include the following steps:

[0252] First step: the first network side device receives a second message from the fourth network side device;

[0253] Second step: the first network-side device sends a second message to the first user equipment.

[0254] For the convenience of description, the above two steps are combined for explanation.

[0255] In the embodiment of the present application, the fourth network-side device may include an S-CSCF or an application server (AS).

[0256] The first network side device sends the second message to the first user equipment. The first network side device may generate the second message and send it to the first user equipment, or the first network side device may receive the second message from the fourth network side device and send it to the first user equipment.

[0257] The first network side device receives the second message from the fourth network side device and forwards it to the first user equipment. The fourth network side device takes the lead in sending the second message, which is closer to the process in the related art.

[0258] In some embodiments of the present application, the method may further include the following steps:

[0259] The first network-side device sends third information to the fourth network-side device, where the third information includes at least one of the following:

[0260] an identifier of the first user equipment;

[0261] Information used to indicate sending a second message;

[0262] a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user equipment;

[0263] The first global cell identifier of the target satellite;

[0264] Information indicating changes in satellites;

[0265] Information indicating that a satellite switch has occurred;

[0266] Information indicating an updated media path;

[0267] Used to indicate the update of access gateway information.

[0268] In this embodiment of the present application, the first network device can send third information to the fourth network device. After receiving the third information, the fourth network device generates a second message based on the third information and sends it to the first network device, which then forwards it to the first user equipment. This helps improve the effectiveness of the second message.

[0269] In some embodiments of the present application, the first network-side apparatus sending the third message to the first user equipment may include the following steps:

[0270] Step 1: The first network-side device receives a third message from the fourth network-side device;

[0271] Step 2: The first network-side device sends a third message to the first user equipment.

[0272] For the convenience of description, the above two steps are combined for explanation.

[0273] The first network side device sends the third message to the first user equipment. The first network side device may generate the third message and send it to the first user equipment, or the first network side device may receive the third message from the fourth network side device and send it to the first user equipment.

[0274] The first network side device receives the third message from the fourth network side device and forwards it to the first user equipment. The fourth network side device takes the lead in sending the third message, which is closer to the process in the related art.

[0275] In some embodiments of the present application, the method may further include the following steps:

[0276] The first network-side device sends fourth information to the fourth network-side device, where the fourth information includes at least one of the following:

[0277] an identifier of the first user equipment;

[0278] First address;

[0279] Information for instructing to send a third message;

[0280] a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user equipment;

[0281] The first global cell identifier of the target satellite;

[0282] Information indicating changes in satellites;

[0283] Information indicating that a satellite switch has occurred;

[0284] Information indicating an updated media path;

[0285] Used to indicate the update of access gateway information.

[0286] In this embodiment of the present application, the first network device may send fourth information to the fourth network device. After receiving the fourth information, the fourth network device generates a third message based on the fourth information and sends it to the first network device, which then forwards it to the first user equipment. This helps improve the effectiveness of the third message.

[0287] In some embodiments of the present application, when the first operation includes sending a third message to the first user equipment, the method may further include the following steps:

[0288] The first network-side device sends a seventh message to the second user equipment, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

[0289] The satellite of the second user device may also change. The first network side device sends the seventh message to the second user device and performs SIP re-negotiation or SDP re-negotiation with the second user device, so that the access gateway of the satellite after the change of the second user device can be added to the communication path. The UPF or access gateway of the satellite before the change of the second user device is not required to forward, which helps to save satellite resources.

[0290] Optionally, the first network side device may first send the seventh message to the second user device, perform SIP re-negotiation or SDP re-negotiation with the second user device, and then send the third message to the first user device, perform SIP re-negotiation or SDP re-negotiation with the first user device; or, the first network side device may first send the third message to the first user device, perform SIP re-negotiation or SDP re-negotiation with the first user device, and then send the seventh message to the second user device, perform SIP re-negotiation or SDP re-negotiation with the second user device.

[0291] The first network-side device successively performs SIP re-negotiation or SDP re-negotiation with different user equipments, which helps to improve the processing success rate.

[0292] Optionally, the fourth network side device can send a seventh message to the first network side device for SIP renegotiation or SDP renegotiation with the second user equipment. After receiving the seventh message from the fourth network side device, the first network side device forwards the seventh message to the second user equipment.

[0293] In some embodiments of the present application, the first user device may send an eighth message to the first network side device when it is determined that the satellite of the first user device has changed. The eighth message is used to initiate SIP renegotiation or SDP renegotiation. The SIP renegotiation or SDP renegotiation is used to add the second network side device on the target satellite of the first user device to the communication path of the first user device, so that the first user device communicates with the USU of other user devices, and no longer forwards through the UPF on the satellite before the change of the first user device, which helps to save satellite resources.

[0294] The eighth message may include a re-Invite message.

[0295] In some embodiments of the present application, the first user equipment may determine that the satellite of the first user equipment has changed according to a change in a received satellite identifier or a global cell identification code.

[0296] If the satellite identifier received by the first user equipment changes, it can be determined that the satellite of the first user equipment has changed. Alternatively, if the global cell identification code received by the first user equipment changes, it can be determined that the satellite of the first user equipment has changed.

[0297] In some embodiments of the present application, the eighth message may carry the first information. The content included in the first information has been described above and will not be repeated here.

[0298] The first user equipment sends an eighth message to the first network side apparatus. The eighth message carries the first information, which helps the first network side apparatus determine that the satellite of the first user equipment has changed based on the first information.

[0299] As can be seen from the above description of the technical solutions provided in the embodiments of the present application, the core concept of the embodiments of the present application is to add the AGW and UPF of the target satellite to the communication path of the first user equipment after the first user equipment completes the satellite handover. As shown in Figure 8, the first user equipment is represented by Terminal 2. After Terminal 2 switches from SAT-2 to SAT-3 (the target satellite of Terminal 2), if IP Multimedia Subsystem (IMS) renegotiation is performed, UPF-3 and AGW-3 of SAT-3 are added to the communication path of Terminal 2, and data is no longer forwarded through UPF-2 of SAT-2. This helps to save satellite resources and improve the stability of USU communication.

[0300] IMS renegotiation can be understood as SIP renegotiation or SDP renegotiation.

[0301] For ease of understanding, the embodiments of the present application are described below with reference to specific examples.

[0302] It should be noted that the first user equipment in this example corresponds to terminal 2 in Figures 2, 6, and 8, the target satellite corresponds to SAT-3 in Figures 6 and 8, the P-CSCF corresponds to the first network side device, the target satellite is deployed with a target gNB, a target UPF, and a target AGW, the target AGW on the target satellite corresponds to the second network side device, the PCF corresponds to the third network side device, the S-CSCF or AS corresponds to the fourth network side device, the AMF corresponds to the fifth network side device, and the target UPF on the target satellite corresponds to the sixth network side device.

[0303] Example 1: After the first user equipment completes the handover, it actively initiates the IMS renegotiation process

[0304] As shown in Figure 9, the process is as follows:

[0305] 0. The first user equipment establishes a PDU session. The PDU session of the first user equipment uses the first UPF on the ground as PSA1. The first user equipment currently conducts a USU voice call with the second user equipment. The first user equipment completes the process of switching from other satellites to the target satellite, and the SMF adds the target UPF of the target satellite as the target UL CL and target PSA2 to the PDU session. It can be understood that the process of Figure 5 is completed.

[0306] 1. When the first user equipment determines that the satellite has changed, it sends a re-invite message. Optionally, the re-invite message carries first information, and the SDP includes the IP address of the first user equipment, such as IP-1.

[0307] The first information includes at least one of the following:

[0308] Satellite ID / CGI of the target satellite;

[0309] Information indicating changes in satellites;

[0310] Information indicating that a satellite switch has occurred;

[0311] Information indicating an updated media path;

[0312] Information indicating that the AGW should be updated.

[0313] The first user equipment may determine whether the satellite has changed according to the received CGI or satellite ID.

[0314] Satellite ID is the unique identifier of the satellite;

[0315] CGI is a globally unique identifier of the cell where the user equipment resides. When the cell is a 5G cell, it is NCGI, and when the cell is a 4G cell, it is ECGI.

[0316] 2. The P-CSCF determines that the satellite of the first user equipment has changed. There are two ways to determine:

[0317] Mode 1: The P-CSCF determines based on the first information sent by the first user equipment:

[0318] Method 1.1: When the first information includes a satellite ID / CGI, the P-CSCF performs a comparison between the stored satellite ID / CGI and the satellite ID / CGI sent by the first user equipment. If the two values ​​are different, it is determined that the satellite of the first user equipment has changed.

[0319] Method 1.2: When the first information includes other information, the P-CSCF directly determines, based on the first information, that the satellite of the first user equipment has changed.

[0320] Optionally, the P-CSCF may further make a judgment according to method 2.

[0321] Method 2: The P-CSCF makes the judgment itself (without the need for the first user equipment to send the first information):

[0322] After receiving the re-Invite message from the first user equipment, the P-CSCF requests the PCF for information about the first user equipment. The information about the first user equipment includes the latest satellite ID / CGI. The P-CSCF compares the saved satellite ID / CGI with the satellite ID / CGI sent by the PCF. When the two values ​​are different, it is determined that the satellite of the first user equipment has changed.

[0323] Optionally, the P-CSCF may further determine whether the first user equipment and the second user equipment can perform USU communication. The P-CSCF may make this determination based on the stored satellite ID / CGI of the second user equipment and the satellite ID / CGI of the first user equipment. When the two satellites are the same satellite or different satellites connected by an ISL, the P-CSCF determines that the first user equipment and the second user equipment can perform USU communication.

[0324] 3. When the P-CSCF determines that the satellite of the first user equipment has changed, it sends an allocation request to the target AGW on the target satellite, requesting the target AGW to allocate a second address to the first user equipment. The second address can be understood as the transport address corresponding to IP-1.

[0325] Optionally, the P-CSCF performs step 3 when it is determined that the first user equipment and the second user equipment can perform USU communication.

[0326] Optionally, the P-CSCF may determine the address of the target AGW on the target satellite according to the satellite ID / CGI of the first user equipment.

[0327] 4. The target AGW allocates a second address: Tr_IP-1 to the first user equipment.

[0328] It should be noted that the second user equipment sends a data packet to the first user equipment, and when the target AGW receives the data packet with Tr_IP-1 as the destination address, it sends the data packet to the first user equipment.

[0329] It should be noted that, after the target access gateway modifies the destination IP address of the data packet from Tr_IP-1 to IP-1, it sends the modified data packet to the first user equipment.

[0330] 5. After the P-CSCF modifies the address of the SDP offer of the first user equipment to Tr_IP-1, it sends a re-invite message to the second user equipment.

[0331] The second user equipment side may include the second user equipment or a network side device corresponding to the second user equipment.

[0332] 6. The second user equipment returns a response message, which includes an SDP answer. The SDP answer includes the IP address of the second user equipment, such as IP-2.

[0333] Optionally, the response message includes the satellite ID / CGI of the second user equipment.

[0334] Optionally, the response message may be a 183 message or a 200OK message.

[0335] 7. Optionally, the P-CSCF determines whether the first user equipment and the second user equipment can perform USU communication based on the response message from the second user equipment side. This is because the satellite of the second user equipment may also change.

[0336] 8-9. The P-CSCF sends an allocation request to the target AGW on the target satellite, requesting the target AGW to allocate a first address to the first user equipment. The first address can be understood as the transport address corresponding to IP-2. The target AGW allocates the first address: Tr_IP-2 to the first user equipment.

[0337] Optionally, the P-CSCF performs steps 8-9 when it is determined that the first user equipment and the second user equipment can perform USU communication.

[0338] It should be noted that when the first user equipment sends a data packet to the second user equipment, the destination address of the data packet is Tr_IP-2. When the target AGW receives the data packet with Tr_IP-2 as the destination address, it modifies its destination IP address to IP-2 and sends it to the second user equipment.

[0339] 10. The P-CSCF sends a request message to the PCF, such as an HTTP POST request message, carrying the media information and the second information.

[0340] The second information includes at least one of the following:

[0341] Information used to indicate that the AGW update is complete;

[0342] Information used to indicate the release of the UL inter-CL connection / tunnel;

[0343] Information indicating the update of voice bearer.

[0344] 11. PCF sends SM-related policy modifications to SMF, carrying media information and the fifth information.

[0345] The fifth information includes at least one of the following:

[0346] Information indicating that the AGW update is complete;

[0347] Information used to indicate the release of the UL inter-CL connection / tunnel;

[0348] Information indicating the update of voice bearer.

[0349] The fifth information is the same as or different from the second information.

[0350] 12. The SMF updates the UL CL function of the target UPF to send the received data packet of the first user equipment to the target PSA on the target satellite through the target UL CL, which is different from sending it to the source UL CL in the related art.

[0351] 13. The SMF releases the transmission channel (tunnel) between the target UL CL and the source UL CL of the target UPF.

[0352] The source UL CL is the UL CL that serves the first user equipment before the first user equipment switches to the satellite.

[0353] 14.SMF sends an SMF association modification message to PCF to notify PCF of successful processing;

[0354] 15. The PCF sends a notification message to the P-CSCF to inform the P-CSCF of successful processing.

[0355] 16. The P-CSCF sends a response message to the first user equipment.

[0356] Example 2: After the first user equipment completes the satellite handover, the PCF notifies the P-CSCF, and the P-CSCF initiates the process of triggering the first user equipment to initiate IMS re-negotiation

[0357] As shown in Figure 10, the process is as follows:

[0358] 0. The first user equipment establishes a PDU session. The PDU session of the first user equipment uses the first ground UPF as PSA1;

[0359] The first user equipment completes IMS registration.

[0360] 1. The P-CSCF subscribes to the PCF for information about the first user equipment, such as access network information, via Npcf_PolicyAuthorization_Subscribe.

[0361] 2. The first user equipment performs USU communication with the second user equipment, and the first user equipment completes the process of switching from other satellites to the target satellite.

[0362] 3. The PCF sends a notification message to the P-CSCF, such as Npcf_PolicyAuthorization_Notify, which carries the information of the first user equipment, including the satellite ID / CGI.

[0363] 4-5. If the P-CSCF determines that the satellite of the first user equipment has changed, it sends a second message to the first user equipment. The second message is used to trigger the first user equipment to perform SDP or SIP re-negotiation or send a re-INVITE message. The first user equipment returns a response message, such as a 200 OK message.

[0364] The second message may be a re-invitation message, a notification message, or an information message carrying the first indication information.

[0365] The first indication information is used to instruct the first user equipment to perform SDP or SIP re-negotiation or send a re-invite message.

[0366] The way in which the P-CSCF determines that the satellite of the first user equipment has changed is as follows:

[0367] The P-CSCF receives the satellite ID / CGI sent by the PCF, and compares the stored satellite ID / CGI with the satellite ID / CGI sent by the PCF. When the two values ​​are different, it is determined that the satellite of the first user equipment has changed.

[0368] Optionally, the P-CSCF may further determine whether USU communication is possible between the first user equipment and the second user equipment. The P-CSCF makes this determination based on the stored satellite ID / CGI of the second user equipment and the satellite ID / CGI of the first user equipment. USU communication is possible when the two satellites are the same satellite or different satellites connected by an ISL.

[0369] 6. The first user equipment sends a re-invite message according to the second message.

[0370] 7. Follow steps 3-16 in Example 1.

[0371] The above process is a process in which the P-CSCF directly triggers the first user equipment to initiate IMS re-negotiation.

[0372] Step 4 can be replaced with the process shown in Figure 11. In the process shown in Figure 11, the P-CSCF first sends a message to the S-CSCF or AS, and then the S-CSCF or AS sends a trigger message to the first user equipment. This process is more consistent with relevant standard processes.

[0373] For example, the P-CSCF sends third information to the S-CSCF or the AS, where the third information is used to instruct the S-CSCF or the AS to send the second message to the first user equipment.

[0374] The third information may be carried in an information message and may include at least one of the following:

[0375] an identifier of the first user equipment;

[0376] Information used to indicate sending a second message;

[0377] satellite ID / CGI;

[0378] Information indicating changes in satellites;

[0379] Information indicating that a satellite switch has occurred;

[0380] Information indicating an updated media path;

[0381] Information indicating that the AGW should be updated.

[0382] The S-CSCF or AS sends a second message to the first user equipment. Optionally, the S-CSCF or AS may first send the second message to the P-CSCF, which then forwards the second message to the first user equipment. The second message is used to trigger the first user equipment to perform SDP or SIP renegotiation or send a re-INVITE message.

[0383] The second message may be a re-invitation message, a notification message, or an information message carrying the second indication information.

[0384] The second indication information is used to instruct the first user equipment to perform SDP or SIP re-negotiation or send a re-invite message.

[0385] Example 3: After the first user equipment completes the handover, the PCF notifies the P-CSCF, which initiates the IMS renegotiation process.

[0386] Idea 1: The P-CSCF first initiates re-negotiation with the second user equipment, and then initiates re-negotiation with the first user equipment.

[0387] As shown in Figure 12, the process is as follows:

[0388] 0-3. Same as steps 0-3 in Example 2.

[0389] 4. Repeat steps 3-15 in Example 1.

[0390] The difference is that the SDP offer sent by the P-CSCF to the user equipment is generated by the P-CSCF itself.

[0391] 5-6. The P-CSCF generates a re-invite message, includes Tr_IP-2 in the SDP offer, and sends it to the first user equipment. The first user equipment returns a response message, includes IP-1 in the SDP answer.

[0392] In the above process, the P-CSCF directly sends the re-invite message.

[0393] Step 5 can be replaced with the process shown in Figure 13. In the process shown in Figure 13, the P-CSCF first sends a message to the S-CSCF or AS, which then sends a re-invite message. This process is more consistent with relevant standard processes.

[0394] Correspondingly, in step 4 of the process shown in FIG. 12 , the P-CSCF may trigger the S-CSCF or the AS to initiate a re-invite message to the second user equipment.

[0395] For example, the P-CSCF sends fourth information to the S-CSCF or the AS, where the fourth information is used to instruct the S-CSCF or the AS to send a re-invite message to the first user equipment.

[0396] The fourth information may be carried in the information message, and the fourth information includes at least one of the following:

[0397] an identifier of the first user equipment;

[0398] Tr_IP-2;

[0399] Information for instructing to send a third message;

[0400] satellite ID / CGI;

[0401] Information indicating changes in satellites;

[0402] Information indicating that a satellite switch has occurred;

[0403] Information indicating an updated media path;

[0404] Information indicating that the AGW should be updated.

[0405] The S-CSCF or AS sends a third message, such as a re-invite message, to the first user equipment, including Tr_IP-2 in the SDP offer. Optionally, the S-CSCF or AS may first send the third message to the P-CSCF, which then forwards it to the first user equipment.

[0406] Idea 2: The P-CSCF initiates renegotiation with the first UE first, and then initiates renegotiation with the second UE

[0407] As shown in Figure 14, the process is as follows:

[0408] 0-3. Same as steps 0-3 in Example 2.

[0409] 4. Follow steps 8-9 in Example 1.

[0410] 5-6. The P-CSCF generates a re-invite message, includes Tr_IP-2 in the SDP offer, and sends it to the first user equipment. The first user equipment returns a response message, and includes IP-1 in the SDP response.

[0411] 7. Follow steps 3-7 in Example 1.

[0412] The difference is that the SDP proposal sent by the P-CSCF to the first user equipment is generated by the P-CSCF itself.

[0413] 8. Follow steps 10-15 in Example 1.

[0414] In the above process, the P-CSCF directly sends the re-invite message.

[0415] Step 5 can be replaced with the process shown in Figure 13. In the process shown in Figure 13, the P-CSCF can first send a message to the S-CSCF or AS, and the S-CSCF or AS will send a re-invite message. This process is more in line with relevant standard processes.

[0416] Correspondingly, in step 7 of the process shown in FIG. 14 , the P-CSCF may trigger the S-CSCF or the AS to initiate a re-invite message to the second user equipment.

[0417] Corresponding to the above method embodiment, an embodiment of the present application further provides a communication method, as shown in FIG15 , which includes the following steps:

[0418] S1510: When determining that the satellite of the first user equipment has changed, the first user equipment sends an eighth message to the first network-side apparatus, where the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation.

[0419] Alternatively, the first user equipment sends a fourth message to the first network side device when receiving the second message from the first network side device, where the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0420] Alternatively, the first user equipment receives a third message from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

[0421] By applying the method provided in the embodiment of the present application, when the first user device determines that the satellite of the first user device has changed, the first user device sends an eighth message to the first network side device to initiate SIP renegotiation or SDP renegotiation, or, when the second message is received from the first network side device, the first network side device sends a fourth message to the first network side device to perform SIP renegotiation or SDP renegotiation, or, the third message is received from the first network side device to perform SIP renegotiation or SDP renegotiation with the first network side device. Through the above process, the second network side device on the target satellite can be added to the communication path, so that when USU communication is performed between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0422] In some embodiments of the present application, the method further comprises:

[0423] The first user equipment determines that the satellite of the first user equipment has changed according to the change of the received satellite identifier or global cell identification code.

[0424] In some embodiments of the present application, the eighth message carries first information, and the first information includes at least one of the following:

[0425] a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user equipment;

[0426] The first global cell identifier of the target satellite;

[0427] Information indicating changes in satellites;

[0428] Information indicating that a satellite switch has occurred;

[0429] Information indicating an updated media path;

[0430] Used to indicate the update of access gateway information.

[0431] In some embodiments of the present application, the method further comprises:

[0432] The first user equipment receives a first address from the first network side device. The first address is an address allocated to the first user equipment by the second network side device on the target satellite of the first user equipment. The target satellite is the changed satellite of the first user equipment.

[0433] In some embodiments of the present application, the method further comprises:

[0434] The first user equipment uses the first address as the destination address of the first data packet and sends the first data packet to the second network side device.

[0435] The communication method provided in the embodiment of the present application can be found in the description of the method embodiment shown in Figure 7. To avoid repetition, it will not be repeated here.

[0436] Corresponding to the above method embodiment, the embodiment of the present application further provides a communication method, as shown in FIG16 , which includes the following steps:

[0437] S1610: The fourth network-side device receives third information or fourth information from the first network-side device;

[0438] S1620: The fourth network-side apparatus sends a second message to the first network-side apparatus based on the third information, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation.

[0439] Alternatively, the fourth network-side apparatus sends a third message to the first network-side apparatus according to the fourth information, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0440] By applying the method provided in the embodiment of the present application, the fourth network side device can receive the third information or the fourth information from the first network side device, and send a second message to the first network side device based on the third information, so that the first network side device forwards the second message to the first user equipment, for instructing the first user equipment to initiate SIP renegotiation or SDP renegotiation, or send a third message to the first network side device based on the fourth information, so that the first network side device forwards the third message to the first user equipment, for performing SIP renegotiation or SDP renegotiation with the first user equipment. In this way, the second network side device on the target satellite of the first user equipment can be added to the communication path of the first user equipment, so that when USU communication is performed between user equipment, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0441] In some embodiments of the present application, the third information includes at least one of the following:

[0442] an identifier of the first user equipment;

[0443] Information used to indicate sending a second message;

[0444] a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user equipment;

[0445] The first global cell identifier of the target satellite;

[0446] Information indicating changes in satellites;

[0447] Information indicating that a satellite switch has occurred;

[0448] Information indicating an updated media path;

[0449] Used to indicate the update of access gateway information.

[0450] In some embodiments of the present application, the fourth information includes at least one of the following:

[0451] an identifier of the first user equipment;

[0452] A first address, where the first address is an address allocated to the first user equipment by the second network-side device on the target satellite of the first user equipment, and the target satellite is the changed satellite of the first user equipment;

[0453] Information for instructing to send a third message;

[0454] The first satellite identifier of the target satellite;

[0455] The first global cell identifier of the target satellite;

[0456] Information indicating changes in satellites;

[0457] Information indicating that a satellite switch has occurred;

[0458] Information indicating an updated media path;

[0459] Used to indicate the update of access gateway information.

[0460] In some embodiments of the present application, the method further comprises:

[0461] The fourth network-side apparatus sends a seventh message to the first network-side apparatus, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

[0462] The communication method provided in the embodiment of the present application can be found in the description of the method embodiment shown in Figure 7. To avoid repetition, it will not be repeated here.

[0463] Corresponding to the above method embodiment, an embodiment of the present application further provides a communication method, as shown in FIG17 , which includes the following steps:

[0464] S1710: The fifth network-side device receives fifth information;

[0465] S1720: The fifth network-side device performs a second operation according to the fifth information;

[0466] The second operation includes at least one of the following:

[0467] Release the connection between the source upstream split and the target upstream split;

[0468] Release the tunnel between the source upstream split and the target upstream split;

[0469] Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

[0470] By applying the method provided in the embodiment of the present application, after the fifth network side device receives the fifth information, it releases the connection or tunnel between the source uplink diversion and the target uplink diversion according to the fifth information, or updates the uplink diversion function of the sixth network side device on the target satellite of the first user device, so as to send the received data packet of the first user device to the PSA of the sixth network side device through the uplink diversion function. In this way, when USU communication is carried out between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0471] In some embodiments of the present application, the fifth information includes at least one of the following:

[0472] Information indicating that the access gateway update is complete;

[0473] Information used to indicate the release of the connection between upstream splits;

[0474] Information used to instruct the release of the tunnel between upstream splits;

[0475] Information indicating the update of voice bearer.

[0476] In some embodiments of the present application, the fifth network-side device updates the uplink offload function of the sixth network-side device on the target satellite of the first user equipment, including:

[0477] The fifth network side device sends an uplink diversion rule to the uplink diversion function of the sixth network side device on the target satellite of the first user equipment, and the uplink diversion rule is used to instruct the sixth network side device to send the received data packet of the first user equipment to the PDU session anchor point of the sixth network side device.

[0478] The communication method provided in the embodiment of the present application can be found in the description of the method embodiment shown in Figure 7. To avoid repetition, it will not be repeated here.

[0479] The communication method provided in the embodiment of the present application can be executed by a communication device. In the embodiment of the present application, the communication device provided in the embodiment of the present application is described by taking the communication method executed by the communication device as an example.

[0480] As shown in FIG18 , the communication apparatus 1800 includes the following modules:

[0481] A first execution module 1810 is configured to execute a first operation when it is determined that a satellite of the first user equipment changes;

[0482] The first operation includes at least one of the following:

[0483] Sending a first message to a second network-side device on a target satellite of the first user equipment, where the first message is used to request the second network-side device to allocate a first address to the first user equipment, and the target satellite is the changed satellite of the first user equipment;

[0484] Sending a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0485] A third message is sent to the first user equipment, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0486] By using the device provided in the embodiment of the present application, when it is determined that the satellite of the first user device has changed, a first message is sent to the second network-side device on the target satellite of the first user device to request the second network-side device to assign a first address to the first user device, or a second message is sent to the first user device to instruct the first user device to initiate SIP renegotiation or SDP renegotiation, or a third message is sent to the first user device to perform SIP renegotiation or SDP renegotiation with the first user device. Through the above process, the second network-side device on the target satellite can be added to the communication path, so that when USU communication is performed between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0487] In some embodiments of the present application, the communication apparatus 1800 further includes a first transmission module configured to:

[0488] receiving first information from a first user device;

[0489] It is determined, according to the first information, that a satellite of the first user equipment changes.

[0490] In some embodiments of the present application, the first information includes at least one of the following:

[0491] a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user equipment;

[0492] The first global cell identifier of the target satellite;

[0493] Information indicating changes in satellites;

[0494] Information indicating that a satellite switch has occurred;

[0495] Information indicating an updated media path;

[0496] Used to indicate the update of access gateway information.

[0497] In some embodiments of the present application, when the first information includes the first satellite identifier or the first global cell identifier, the first transmission module is specifically configured to:

[0498] When the first satellite identifier is different from the satellite identifier associated with the first user equipment stored in the first network side device, determining that the satellite of the first user equipment has changed;

[0499] Alternatively, when the first global cell identification code is different from the global cell identification code associated with the first user equipment stored in the first network side device, it is determined that the satellite of the first user equipment has changed.

[0500] In some embodiments of the present application, the communication apparatus 1800 further includes a first receiving module and a first determining module;

[0501] A first receiving module is configured to receive information of a first user equipment from a third network-side device, where the information of the first user equipment includes a second satellite identifier or a second global cell identifier;

[0502] A first determining module is configured to determine that the satellite of the first user equipment has changed when the second satellite identifier is different from the satellite identifier associated with the first user equipment stored in the first network side device;

[0503] Alternatively, when the second global cell identification code is different from the global cell identification code associated with the first user equipment stored in the first network side device, it is determined that the satellite of the first user equipment has changed.

[0504] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0505] receiving a fourth message from the first user equipment, where the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0506] A fifth message is sent to the third network side device, where the fifth message is used to obtain information of the first user equipment.

[0507] In some embodiments of the present application, the first execution module 1810 is specifically configured to:

[0508] When it is determined that the satellite of the first user equipment has changed and the first user equipment and the second user equipment can perform user equipment-satellite-user equipment (USU) communication, a first operation is performed.

[0509] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0510] It is determined whether the first user equipment and the second user equipment can perform USU communication or not according to the satellite identifier or global cell identifier associated with the first user equipment and the satellite identifier or global cell identifier associated with the second user equipment.

[0511] In some embodiments of the present application, the satellite identifier or global cell identification code associated with the second user equipment is stored by the first network side device, or is obtained by the first network side device from a third network side device, or is obtained by the first network side device from a request message or response message sent by the second user equipment, or is obtained by the first network side device from a request message or response message sent by the network side device corresponding to the second user equipment.

[0512] In some embodiments of the present application, the first execution module 1810 is specifically configured to:

[0513] Determining a second network-side device according to a satellite identifier or a global cell identifier of the target satellite;

[0514] A first message is sent to the second network-side device.

[0515] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0516] In a case where the first operation includes sending a first message to a second network-side device on a target satellite of the first user equipment, receiving a first address from the second network-side device;

[0517] The first address is sent to the first user equipment.

[0518] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0519] Sending a sixth message to the second network side apparatus, where the sixth message is used to request the second network side apparatus to allocate a second address to the first user equipment;

[0520] A second address is received from the second network-side device, and the second address is sent to the second user equipment.

[0521] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0522] sending second information to the third network-side device;

[0523] The second information includes at least one of the following:

[0524] Information indicating that the access gateway update is complete;

[0525] Information used to indicate the release of the connection between upstream splits;

[0526] Information used to instruct the release of the tunnel between upstream splits;

[0527] Information indicating the update of voice bearer.

[0528] In some embodiments of the present application, the first execution module 1810 is specifically configured to:

[0529] receiving a second message from a fourth network-side device;

[0530] A second message is sent to the first user equipment.

[0531] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0532] Sending third information to the fourth network-side device, where the third information includes at least one of the following:

[0533] an identifier of the first user equipment;

[0534] Information used to indicate sending a second message;

[0535] a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user equipment;

[0536] The first global cell identifier of the target satellite;

[0537] Information indicating changes in satellites;

[0538] Information indicating that a satellite switch has occurred;

[0539] Information indicating an updated media path;

[0540] Used to indicate the update of access gateway information.

[0541] In some embodiments of the present application, the first execution module 1810 is specifically configured to:

[0542] receiving a third message from a fourth network-side device;

[0543] A third message is sent to the first user equipment.

[0544] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0545] Sending fourth information to the fourth network-side device, where the fourth information includes at least one of the following:

[0546] An identifier of a first user device; a first address; information for indicating sending a third message; a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user device; a first global cell identification code of the target satellite; information for indicating a change in the satellite; information for indicating a switching of the satellite; information for indicating an update of a media path; and information for indicating an update of an access gateway.

[0547] In some embodiments of the present application, the first execution module 1810 is further configured to:

[0548] In a case where the first operation includes sending a third message to the first user equipment, a seventh message is sent to the second user equipment, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

[0549] In some embodiments of the present application, the first execution module 1810 is specifically configured to:

[0550] receiving a seventh message from a fourth network-side device;

[0551] A seventh message is sent to the second user equipment.

[0552] In some embodiments of the present application, the first message includes a re-Invite message;

[0553] Alternatively, the second message includes a Notify message, a re-Invite message, or an information Message message;

[0554] Alternatively, the third message includes a re-Invite message.

[0555] In some embodiments of the present application, the first network-side device includes a proxy call session control function P-CSCF;

[0556] Alternatively, the second network-side device includes an access gateway AGW;

[0557] Alternatively, the third network side device includes a policy control function PCF;

[0558] Alternatively, the fourth network-side device includes a serving call session control function S-CSCF or an application server AS.

[0559] The communication device 1800 provided in the embodiment of the present application can implement the various processes implemented in the method embodiment shown in Figure 7 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0560] As shown in FIG19 , the communication apparatus 1900 includes a first sending module 1910 or a second sending module 1920 or a second receiving module 1930 :

[0561] The first sending module 1910 is configured to send an eighth message to the first network-side apparatus when it is determined that the satellite of the first user equipment has changed, where the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0562] A second sending module 1920 is configured to send a fourth message to the first network side apparatus when the second message is received from the first network side apparatus, where the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0563] The first receiving module 1930 is configured to receive a third message from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

[0564] By using the device provided in the embodiment of the present application, when it is determined that the satellite of the first user device has changed, an eighth message is sent to the first network side device to initiate SIP renegotiation or SDP renegotiation, or, when a second message is received from the first network side device, a fourth message is sent to the first network side device to perform SIP renegotiation or SDP renegotiation, or a third message is received from the first network side device to perform SIP renegotiation or SDP renegotiation with the first network side device. Through the above process, the second network side device on the target satellite can be added to the communication path, so that when USU communication is performed between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0565] In some embodiments of the present application, the communication apparatus 1900 further includes a second determining module configured to:

[0566] It is determined that the satellite of the first user equipment has changed according to the change of the received satellite identifier or global cell identification code.

[0567] In some embodiments of the present application, the eighth message carries first information, and the first information includes at least one of the following:

[0568] The first satellite identifier of the target satellite, where the target satellite is the changed satellite of the first user equipment; the first global cell identifier of the target satellite; information indicating a change in the satellite; information indicating a satellite switch; information indicating an update of a media path; and information indicating an update of an access gateway.

[0569] In some embodiments of the present application, the communication apparatus 1900 further includes a third receiving module configured to:

[0570] A first address is received from the first network side device, where the first address is an address allocated to the first user equipment by the second network side device on a target satellite of the first user equipment, and the target satellite is a changed satellite of the first user equipment.

[0571] In some embodiments of the present application, the first sending module 1910 is further configured to:

[0572] The first address is used as the destination address of the first data packet, and the first data packet is sent to the second network side device.

[0573] The communication device 1900 provided in the embodiment of the present application can implement each process implemented by the method embodiment shown in Figure 15 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0574] As shown in FIG20 , the communication apparatus 2000 includes the following modules:

[0575] The fourth receiving module 2010 is configured to receive the third information or the fourth information from the first network-side device;

[0576] A third sending module 220 is configured to send a second message to the first network-side apparatus according to the third information, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0577] Alternatively, according to the fourth information, a third message is sent to the first network-side apparatus, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

[0578] By using the device provided in the embodiment of the present application, the third information or the fourth information can be received from the first network side device, and based on the third information, a second message can be sent to the first network side device, so that the first network side device forwards the second message to the first user device, for instructing the first user device to initiate SIP renegotiation or SDP renegotiation, or a third message can be sent to the first network side device based on the fourth information, so that the first network side device forwards the third message to the first user device, for performing SIP renegotiation or SDP renegotiation with the first user device. In this way, the second network side device on the target satellite of the first user device can be added to the communication path of the first user device, so that when USU communication is performed between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0579] In some embodiments of the present application, the third information includes at least one of the following:

[0580] An identifier of a first user device; information for indicating sending a second message; a first satellite identifier of a target satellite, where the target satellite is a changed satellite of the first user device; a first global cell identification code of the target satellite; information for indicating a change in the satellite; information for indicating a switching of the satellite; information for indicating an update of a media path; and information for indicating an update of an access gateway.

[0581] In some embodiments of the present application, the fourth information includes at least one of the following:

[0582] An identifier of a first user device; a first address, where the first address is an address assigned to the first user device by a second network-side device on a target satellite of the first user device, and the target satellite is a changed satellite of the first user device; information for indicating sending a third message; a first satellite identifier of the target satellite; a first global cell identification code of the target satellite; information for indicating a change in the satellite; information for indicating a switching of the satellite; information for indicating an update of a media path; and information for indicating an update of an access gateway.

[0583] In some embodiments of the present application, the third sending module 2020 is further configured to:

[0584] A seventh message is sent to the first network-side apparatus, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

[0585] The communication device 2000 provided in the embodiment of the present application can implement the various processes implemented in the method embodiment shown in Figure 16 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0586] As shown in FIG21 , the communication apparatus 2100 includes the following modules:

[0587] A fifth receiving module 2110 is configured to receive fifth information;

[0588] A second execution module 2120, configured to execute a second operation according to the fifth information;

[0589] The second operation includes at least one of the following:

[0590] Release the connection between the source upstream split and the target upstream split;

[0591] Release the tunnel between the source upstream split and the target upstream split;

[0592] Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

[0593] The device provided in the embodiment of the present application is applied. After receiving the fifth information, the connection or tunnel between the source uplink diversion and the target uplink diversion is released according to the fifth information, or the uplink diversion function of the sixth network side device on the target satellite of the first user device is updated, so as to send the received data packet of the first user device to the PSA of the sixth network side device through the uplink diversion function. In this way, when USU communication is carried out between user devices, it is no longer forwarded through the UPF on the satellite before the change, which helps to save satellite resources and improve the stability of USU communication.

[0594] In some embodiments of the present application, the fifth information includes at least one of the following:

[0595] Information used to indicate that the access gateway update is completed; information used to indicate the release of the connection between the uplink branches; information used to indicate the release of the tunnel between the uplink branches; information used to indicate the update of the voice bearer.

[0596] In some embodiments of the present application, the second execution module 2120 is specifically configured to:

[0597] An uplink offload rule is sent to the uplink offload function of the sixth network side device on the target satellite of the first user equipment, where the uplink offload rule is used to instruct the sixth network side device to send the received data packet of the first user equipment to the PDU session anchor point of the sixth network side device.

[0598] The communication device 2100 provided in the embodiment of the present application can implement the various processes implemented in the method embodiment shown in Figure 17 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0599] As shown in Figure 22, an embodiment of the present application further provides a communication device 2200, including a processor 2201 and a memory 2202. The memory 2202 stores programs or instructions that can be run on the processor 2201. For example, when the communication device 2200 is a user device, the program or instruction, when executed by the processor 2201, implements the various steps of the method embodiment shown in Figure 15 above, and can achieve the same technical effect. When the communication device 2200 is a network-side device, the program or instruction, when executed by the processor 2201, implements the various steps of the method embodiment shown in Figure 7, Figure 16, or Figure 17 above, and can achieve the same technical effect. To avoid repetition, they are not repeated here.

[0600] The present application also provides a user device, including a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is configured to execute a program or instruction to implement the steps of the method embodiment shown in FIG15 . This user device embodiment corresponds to the above-mentioned user device-side method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment can be applied to this user device embodiment and can achieve the same technical effect. Specifically, FIG23 is a schematic diagram of the structure of a user device implementing an embodiment of the present application.

[0601] The user equipment 2300 includes but is not limited to: a radio frequency unit 2301, a network module 2302, an audio output unit 2303, an input unit 2304, a sensor 2305, a display unit 2306, a user input unit 2307, an interface unit 2308, a memory 2309 and at least some of the components of the processor 2310.

[0602] Those skilled in the art will appreciate that the user equipment 2300 may also include a power supply (such as a battery) to power various components. The power supply may be logically connected to the processor 2310 through a power management system, thereby implementing functions such as charging, discharging, and power consumption management through the power management system. The user equipment structure shown in Figure 23 does not constitute a limitation of the user equipment. The user equipment may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be described in detail here.

[0603] It should be understood that in an embodiment of the present application, the input unit 2304 may include a graphics processing unit (GPU) 23041 and a microphone 23042, and the graphics processor 23041 processes the image data of a static picture or video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 2306 may include a display panel 23061, and the display panel 23061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 2307 includes a touch panel 23071 and at least one of other input devices 23072. The touch panel 23071 is also called a touch screen. The touch panel 23071 may include two parts: a touch detection device and a touch controller. Other input devices 23072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be repeated here.

[0604] In the embodiment of the present application, after receiving downlink data from the network-side device, the RF unit 2301 can transmit the data to the processor 2310 for processing. In addition, the RF unit 2301 can send uplink data to the network-side device. Generally, the RF unit 2301 includes but is not limited to an antenna, an amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, etc.

[0605] Memory 2309 can be used to store software programs or instructions and various data. Memory 2309 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store an operating system, applications or instructions required for at least one function (such as a sound playback function, an image playback function, etc.). Furthermore, memory 2309 may include volatile memory or non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DRRAM). The memory 2309 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0606] Processor 2310 may include one or more processing units. Optionally, processor 2310 integrates an application processor and a modem processor. The application processor primarily handles operations related to the operating system, user interface, and application programs, while the modem processor primarily processes wireless communication signals, such as a baseband processor. It is understood that the modem processor may not be integrated into processor 2310.

[0607] The radio frequency unit 2301 is configured to send an eighth message to the first network side device when it is determined that the satellite of the first user equipment has changed, where the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation;

[0608] Alternatively, when the second message is received from the first network-side device, a fourth message is sent to the first network-side device, where the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation;

[0609] Alternatively, a third message is received from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

[0610] It can be understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the method embodiment and achieve the same or corresponding technical effects. To avoid repetition, it will not be described here.

[0611] The present application also provides a network-side device, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the method embodiment shown in Figure 7, Figure 16, or Figure 17. This network-side device embodiment corresponds to the aforementioned network-side device method embodiment, and each implementation process and implementation method of the aforementioned method embodiment can be applied to this network-side device embodiment and can achieve the same technical effects.

[0612] Specifically, the embodiment of the present application further provides a network side device. As shown in FIG24 , the network side device 2400 includes: a processor 2401, a network interface 2402, and a memory 2403. The network interface 2402 is, for example, a common public radio interface (CPRI).

[0613] Specifically, the network side device 2400 of the embodiment of the present application also includes: instructions or programs stored in the memory 2403 and executable on the processor 2401. The processor 2401 calls the instructions or programs in the memory 2403 to execute the methods executed by the modules shown in FIG. 7 or FIG. 16 or FIG. 17 and achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0614] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0615] The processor is the processor in the user equipment or network-side device described in the above embodiments. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0616] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned method embodiment and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0617] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0618] An embodiment of the present application further provides a computer program / program product, which is stored in a storage medium. The computer program / program product is executed by at least one processor to implement the various processes of the above-mentioned method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0619] An embodiment of the present application also provides a wireless communication system, including: a first user equipment, a first network side device, a fourth network side device, and a fifth network side device. The first user equipment can be used to execute the steps of the method embodiment shown in Figure 15 above, the first network side device can be used to execute the steps of the method embodiment shown in Figure 7 above, the fourth network side device can be used to execute the steps of the method embodiment shown in Figure 16 above, and the fifth network side device can be used to execute the steps of the method embodiment shown in Figure 17 above.

[0620] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0621] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general-purpose hardware platform, or of course, by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes a number of instructions for causing a user device or a network-side device to execute the methods described in each embodiment of the present application.

[0622] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of this application and the scope of protection of the claims. These implementation methods are all within the protection of this application.

Claims

1. A method of communication, wherein: include: The first network-side device performs a first operation when determining that the satellite of the first user equipment has changed; The first operation includes at least one of the following: Sending a first message to a second network-side device on a target satellite of the first user equipment, where the first message is used to request the second network-side device to allocate a first address to the first user equipment, and the target satellite is a changed satellite of the first user equipment; Sending a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation; A third message is sent to the first user equipment, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

2. The method according to claim 1, wherein The method further comprises: The first network side device receives first information from the first user equipment; The first network-side device determines, based on the first information, that a satellite of the first user equipment has changed.

3. The method according to claim 2, wherein: The first information includes at least one of the following: a first satellite identifier of the target satellite; A first global cell identification code of the target satellite; Information indicating changes in satellites; Information indicating that a satellite switch has occurred; Information indicating an updated media path; Used to indicate the update of access gateway information.

4. The method according to claim 3, wherein: In a case where the first information includes the first satellite identifier or the first global cell identifier, the first network-side apparatus determining, based on the first information, that the satellite of the first user equipment has changed includes: When the first satellite identifier is different from the satellite identifier associated with the first user equipment and stored by the first network side device, the first network side device determines that the satellite of the first user equipment has changed; Alternatively, when the first global cell identifier is different from the global cell identifier associated with the first user equipment stored by the first network side device, the first network side device determines that the satellite of the first user equipment has changed.

5. The method according to claim 1, wherein The method further comprises: The first network side device receives information of the first user equipment from a third network side device, where the information of the first user equipment includes a second satellite identifier or a second global cell identifier; When the second satellite identifier is different from the satellite identifier associated with the first user equipment and stored by the first network side device, the first network side device determines that the satellite of the first user equipment has changed; Alternatively, when the second global cell identification code is different from the global cell identification code associated with the first user equipment stored by the first network side device, the first network side device determines that the satellite of the first user equipment has changed.

6. The method according to claim 1 or 5, wherein: The method further comprises: The first network side device receives a fourth message from the first user equipment, where the fourth message is used to perform SIP renegotiation or SDP renegotiation; The first network side apparatus sends a fifth message to the third network side apparatus, where the fifth message is used to obtain information of the first user equipment.

7. The method according to any one of claims 1 to 6, wherein: When determining that the satellite of the first user equipment has changed, the first network-side device performs a first operation, including: The first network-side device performs a first operation when it is determined that the satellite of the first user equipment has changed and the first user equipment and the second user equipment can perform user equipment-satellite-user equipment (USU) communication.

8. The method according to claim 7, wherein: The method further comprises: The first network side device determines whether the first user equipment and the second user equipment can perform USU communication or not based on the satellite identifier or global cell identification code associated with the first user equipment and the satellite identifier or global cell identification code associated with the second user equipment.

9. The method according to claim 8, wherein The satellite identifier or global cell identification code associated with the second user equipment is stored by the first network side device, or is obtained by the first network side device from a third network side device, or is obtained by the first network side device from a request message or response message sent by the second user equipment, or is obtained by the first network side device from a request message or response message sent by the network side device corresponding to the second user equipment.

10. The method according to any one of claims 1 to 9, wherein: The first network-side device sending a first message to a second network-side device on a target satellite of the first user equipment includes: The first network side device determines the second network side device according to the satellite identifier or global cell identifier of the target satellite; The first network-side device sends the first message to the second network-side device.

11. The method according to any one of claims 1 to 10, wherein: In a case where the first operation includes sending a first message to a second network-side device on a target satellite of the first user equipment, the method further includes: The first network side device receives a first address from the second network side device; The first network-side device sends the first address to the first user equipment.

12. The method according to any one of claims 1 to 11, wherein The method further comprises: The first network side apparatus sends a sixth message to the second network side apparatus, where the sixth message is used to request the second network side apparatus to allocate a second address to the first user equipment; The first network-side device receives the second address from the second network-side device, and sends the second address to the second user equipment.

13. The method according to any one of claims 1 to 12, wherein: The method further comprises: The first network side device sends second information to the third network side device; The second information includes at least one of the following: Information indicating that the access gateway update is complete; Information used to indicate the release of the connection between upstream splits; Information used to instruct the release of the tunnel between upstream splits; Information indicating the update of voice bearer.

14. The method according to any one of claims 1 to 13, wherein: The first network side device sending a second message to the first user equipment includes: The first network side device receives a second message from a fourth network side device; The first network-side device sends the second message to the first user equipment.

15. The method according to claim 14, wherein The method further comprises: The first network-side device sends third information to the fourth network-side device, where the third information includes at least one of the following: an identifier of the first user equipment; Information used to indicate sending a second message; a first satellite identifier of the target satellite, where the target satellite is a changed satellite of the first user equipment; A first global cell identification code of the target satellite; Information indicating changes in satellites; Information indicating that a satellite switch has occurred; Information indicating an updated media path; Used to indicate the update of access gateway information.

16. The method according to any one of claims 1 to 15, wherein: The first network side device sending a third message to the first user equipment includes: The first network side device receives a third message from a fourth network side device; The first network-side device sends the third message to the first user equipment.

17. The method according to claim 16, wherein The method further comprises: The first network-side device sends fourth information to the fourth network-side device, where the fourth information includes at least one of the following: an identifier of the first user equipment; the first address; Information for instructing to send a third message; a first satellite identifier of the target satellite; A first global cell identification code of the target satellite; Information indicating changes in satellites; Information indicating that a satellite switch has occurred; Information indicating an updated media path; Used to indicate the update of access gateway information.

18. The method according to any one of claims 1 to 17, wherein, when the first operation comprises sending a third message to the first user equipment, the method further comprises: The first network-side device sends a seventh message to the second user equipment, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

19. The method according to claim 18, wherein The first network side device sending a seventh message to the second user equipment includes: The first network side device receives a seventh message from the fourth network side device; The first network-side device sends the seventh message to the second user equipment.

20. The method according to any one of claims 1 to 19, wherein The first message includes a re-Invite message; or, The second message includes a Notify message, a re-Invite message, or an information Message message; or, The third message includes a re-Invite message.

21. The method according to any one of claims 1 to 20, wherein: The first network side device includes a proxy call session control function P-CSCF; or, The second network side device includes an access gateway AGW; or, The third network side device includes a policy control function PCF; or, The fourth network-side device includes a serving call session control function S-CSCF or an application server AS.

22. A method of communication, wherein: include: When determining that the satellite of the first user equipment has changed, the first user equipment sends an eighth message to the first network side device, where the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation; Alternatively, the first user equipment sends a fourth message to the first network side apparatus when receiving the second message from the first network side apparatus, where the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation; Alternatively, the first user equipment receives a third message from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

23. The method according to claim 22, wherein The method further comprises: The first user equipment determines, based on a change in a received satellite identifier or a global cell identification code, that a satellite of the first user equipment has changed.

24. The method according to claim 22 or 23, wherein The eighth message carries first information, where the first information includes at least one of the following: a first satellite identifier of a target satellite, where the target satellite is the changed satellite of the first user equipment; a first global cell identification code of the target satellite; Information indicating changes in satellites; Information indicating that a satellite switch has occurred; Information indicating an updated media path; Used to indicate the update of access gateway information.

25. The method according to any one of claims 22 to 24, wherein: The method further comprises: The first user equipment receives a first address from the first network side device, where the first address is an address allocated to the first user equipment by the second network side device on a target satellite of the first user equipment, and the target satellite is a changed satellite of the first user equipment.

26. The method according to claim 25, wherein The method further comprises: The first user equipment uses the first address as the destination address of the first data packet and sends the first data packet to the second network side device.

27. A method of communication, wherein: include: The fourth network-side device receives the third information or the fourth information from the first network-side device; The fourth network-side device sends a second message to the first network-side device according to the third information, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation; Alternatively, the fourth network-side apparatus sends a third message to the first network-side apparatus according to the fourth information, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

28. The method according to claim 27, wherein The third information includes at least one of the following: an identifier of the first user equipment; Information used to indicate sending a second message; a first satellite identifier of a target satellite, where the target satellite is the changed satellite of the first user equipment; a first global cell identification code of the target satellite; Information indicating changes in satellites; Information indicating that a satellite switch has occurred; Information indicating an updated media path; Used to indicate the update of access gateway information.

29. The method according to claim 27 or 28, wherein The fourth information includes at least one of the following: an identifier of the first user equipment; a first address, where the first address is an address allocated to the first user equipment by a second network-side device on a target satellite of the first user equipment, and the target satellite is a changed satellite of the first user equipment; Information for instructing to send a third message; a first satellite identifier of the target satellite; a first global cell identification code of the target satellite; Information indicating changes in satellites; Information indicating that a satellite switch has occurred; Information indicating an updated media path; Used to indicate the update of access gateway information.

30. The method according to any one of claims 27 to 29, wherein The method further comprises: The fourth network-side apparatus sends a seventh message to the first network-side apparatus, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

31. A method of communication, wherein: include: The fifth network-side device receives the fifth information; The fifth network-side device performs a second operation according to the fifth information; The second operation includes at least one of the following: Release the connection between the source upstream split and the target upstream split; Release the tunnel between the source upstream split and the target upstream split; Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

32. The method according to claim 31, wherein The fifth information includes at least one of the following: Information indicating that the access gateway update is complete; Information used to indicate the release of the connection between upstream splits; Information used to instruct the release of the tunnel between upstream splits; Information indicating the update of voice bearer.

33. The method according to claim 31 or 32, wherein The fifth network side device updates the uplink offload function of the sixth network side device on the target satellite of the first user equipment, including: The fifth network side device sends an uplink diversion rule to the uplink diversion function of the sixth network side device on the target satellite of the first user equipment, and the uplink diversion rule is used to instruct the sixth network side device to send the received data packet of the first user equipment to the PDU session anchor point of the sixth network side device.

34. A communication device, wherein: include: A first execution module is configured to execute a first operation when it is determined that a satellite of the first user equipment changes; The first operation includes at least one of the following: Sending a first message to a second network-side device on a target satellite of the first user equipment, where the first message is used to request the second network-side device to allocate a first address to the first user equipment, and the target satellite is a changed satellite of the first user equipment; Sending a second message to the first user equipment, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation; A third message is sent to the first user equipment, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

35. The apparatus of claim 34, wherein: The communication device further includes a first transmission module, configured to: receiving first information from the first user equipment; It is determined, according to the first information, that a satellite of the first user equipment changes.

36. The apparatus of claim 34, wherein: The communication device further includes a first receiving module and a first determining module; The first receiving module is configured to receive information about the first user equipment from a third network-side device, where the information about the first user equipment includes a second satellite identifier or a second global cell identifier; The first determining module is configured to determine that the satellite of the first user equipment has changed when the second satellite identifier is different from the satellite identifier associated with the first user equipment stored in the first network side device; Alternatively, when the second global cell identification code is different from the global cell identification code associated with the first user equipment stored in the first network-side device, it is determined that the satellite of the first user equipment has changed.

37. The device according to any one of claims 34 to 36, wherein The first execution module is further configured to: sending second information to the third network-side device; The second information includes at least one of the following: Information indicating that the access gateway update is complete; Information used to indicate the release of the connection between upstream splits; Information used to instruct the release of the tunnel between upstream splits; Information indicating the update of voice bearer.

38. The device according to any one of claims 34 to 37, wherein The first execution module is specifically configured to: receiving a second message from a fourth network-side device; sending the second message to the first user equipment; or, receiving a third message from a fourth network-side device; Send the third message to the first user equipment.

39. A communication device, wherein: Comprising a first sending module or a second sending module or a second receiving module: The first sending module is configured to send an eighth message to the first network-side device when it is determined that the satellite of the first user equipment has changed, wherein the eighth message is used to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation; The second sending module is configured to send a fourth message to the first network side device when receiving the second message from the first network side device, wherein the second message is used to instruct the first user equipment to initiate SIP renegotiation or SDP renegotiation, and the fourth message is used to perform SIP renegotiation or SDP renegotiation; The first receiving module is configured to receive a third message from the first network-side device, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first network-side device.

40. The apparatus of claim 39, wherein The communication apparatus further includes a second determining module, configured to: It is determined that the satellite of the first user equipment has changed according to the change of the received satellite identifier or global cell identification code.

41. A communication device, wherein: include: a fourth receiving module, configured to receive third information or fourth information from the first network-side device; A third sending module is configured to send a second message to the first network-side device according to the third information, where the second message is used to instruct the first user equipment to initiate a Session Initiation Protocol (SIP) renegotiation or a Session Description Protocol (SDP) renegotiation; Alternatively, a third message is sent to the first network-side apparatus according to the fourth information, where the third message is used to perform SIP re-negotiation or SDP re-negotiation with the first user equipment.

42. The apparatus according to claim 41, wherein The third sending module is further configured to: A seventh message is sent to the first network-side apparatus, where the seventh message is used to perform SIP re-negotiation or SDP re-negotiation with the second user equipment.

43. A communication device, wherein: include: a fifth receiving module, configured to receive fifth information; a second execution module, configured to execute a second operation according to the fifth information; The second operation includes at least one of the following: Release the connection between the source upstream split and the target upstream split; Release the tunnel between the source upstream split and the target upstream split; Update the uplink offload function of the sixth network side device on the target satellite of the first user equipment to send the received data packet of the first user equipment to the protocol data unit PDU session anchor point of the sixth network side device through the uplink offload function, and the target satellite is the changed satellite of the first user equipment.

44. The apparatus of claim 43, wherein: The second execution module is specifically configured to: An uplink offload rule is sent to the uplink offload function of the sixth network side device on the target satellite of the first user equipment, wherein the uplink offload rule is used to instruct the sixth network side device to send the received data packet of the first user equipment to the PDU session anchor point of the sixth network side device.

45. A user equipment, wherein The method comprises a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the communication method according to any one of claims 22 to 26 are implemented.

46. A network side device, wherein: The method comprises a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the method implements the steps of the communication method as described in any one of claims 1 to 21, or implements the steps of the communication method as described in any one of claims 27 to 30, or implements the steps of the communication method as described in any one of claims 31 to 33.

47. A readable storage medium, wherein: The readable storage medium stores a program or instruction, which, when executed by a processor, implements the steps of the communication method as described in any one of claims 1 to 21, or implements the steps of the communication method as described in any one of claims 22 to 26, or implements the steps of the communication method as described in any one of claims 27 to 30, or implements the steps of the communication method as described in any one of claims 31 to 33.

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