Communication method and device

Abstract

The present application discloses a communication method and apparatus, comprising: a target network device receiving a handover request message from a source network device, the handover request message including the terminal device's location information and information about a first PLMN to which the source network device belongs or information about a first AMF to which the source network device is connected; the target network device determining, based on the terminal device's location information, that the terminal device is located within a first area covered by a target cell, and that the first PLMN corresponding to the first area does not include the first PLMN, or the AMF corresponding to the first area does not include the first AMF, and then sending a handover failure message to the source network device. This technical solution ensures that the terminal device's access / handover process complies with the communication policy requirements of the country / operator to which the terminal device belongs, preventing the terminal device from accessing from a country / operator other than the country / operator to which the terminal device belongs.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a communication method and device. Background Art

[0002] Non-terrestrial networks (NTN) communication systems provide seamless coverage for terminal devices by deploying access network equipment or some of its functions on non-ground devices such as high-altitude platforms or satellites. Since high-altitude platforms or satellites are located at high altitudes, they are less affected by natural disasters. Therefore, NTN communication systems have high reliability.

[0003] Another key feature of NTN communication systems is that NTN cells typically have a relatively large coverage area. For example, a cell coverage diameter can reach tens to thousands of kilometers. Therefore, a single NTN cell may cover geographical areas in multiple countries or the service areas of multiple operators. For example, if the NTN system is a satellite communication system, a satellite can indicate that it supports services in multiple countries or operators by broadcasting information about multiple public land mobile networks (PLMNs). Alternatively, a satellite can indicate that it supports services in multiple countries or operators by broadcasting information about multiple access and mobility management functions (AMFs).

[0004] During the cell switching process, if the target cell is an NTN cell that supports multiple PLMNs or multiple AMFs, since the communication strategies corresponding to different PLMNs or different AMFs are different, if the solution in the existing technology is used to determine the switching to the target cell based only on the cell quality, there may be a situation where the terminal device requests access to a PLMN or AMF that does not match its location. At this time, the communication behavior of the terminal device cannot meet the communication strategy requirements of the PLMN or AMF it requests access to, which will cause the switching process to fail and affect the communication performance. Summary of the Invention

[0005] The present application provides a communication method and apparatus for providing a cell switching method when the target cell is an NTN cell that supports multiple PLMNs or multiple AMFs, so that the switching process of the terminal device can comply with the communication policy requirements of the country or operator to which it is located, thereby effectively improving the switching success rate.

[0006] In the first aspect, an embodiment of the present application provides a communication method, which can be executed by a target network device or by a component (such as a chip or circuit) configured on the target network device. In the following description of this application, the target network device will be used as an example to illustrate the execution of this method.

[0007] The method includes: a target network device receives a handover request message from a source network device, the handover request message being used to request that a terminal device be handed over to the target network device, the handover request message including location information of the terminal device, and information of a first PLMN to which the source network device belongs or information of a first AMF to which the source network device is connected when the terminal device communicates with the source network device; the target network device determines, based on the location information of the terminal device, that the location of the terminal device is within a first area covered by a target cell, and that the PLMN corresponding to the first area does not include the first PLMN, or the AMF corresponding to the first area does not include the first AMF, wherein the target network device manages the target cell; and the target network device sends a handover failure message to the source network device.

[0008] By adopting this technical solution, the target network device can make reasonable decisions when access control or switching decisions or other scenarios are required based on the mapping relationship between at least one area covered by its own target cell and the PLMN and / or AMF, as well as the location information of the terminal device, to determine the PLMN to which the target network device belongs or the AMF to which the target network device is connected that the terminal device can access / switched, so that the access / switching process of the terminal device complies with the communication policy requirements of the country / operator to which it is located, and avoids the terminal device from accessing from a country / operator to which it is not located.

[0009] In a possible design of the first aspect, the switching failure message includes one or more of the following information: failure cause information, information about the PLMN that the target network device allows the terminal device to access, and information about the AMF that the target network device allows the terminal device to access; wherein the failure cause information is used to indicate that the reason for the switching failure is an invalid PLMN, or an invalid AMF, or invalid location information, or an illegal request.

[0010] In a possible design of the first aspect, the switching failure message includes location information of at least one area covered by the target cell, and information of the PLMN corresponding to the at least one area and / or information of the AMF.

[0011] On the second aspect, an embodiment of the present application provides a communication method, which can be executed by a source network device or by a component (such as a chip or circuit) configured in the source network device. In the following description of this application, the source network device will be used as an example to illustrate the execution of this method.

[0012] The method includes: a source network device sends a handover request message to a target network device, where the handover request message is used to request that the terminal device be handed over to the target network device, and the handover request message includes location information of the terminal device, and information about a first PLMN to which the source network device belongs or information about a first AMF to which the source network device is connected when the terminal device communicates with the source network device; and the source network device receives a handover failure message from the target network device.

[0013] In a possible design of the second aspect, the switching failure message includes one or more of the following information: failure cause information, information about the PLMN that the target network device allows the terminal device to access, and information about the AMF that the target network device allows the terminal device to access; wherein the failure cause information is used to indicate that the reason for the switching failure is an invalid PLMN, or an invalid AMF, or invalid location information, or an illegal request.

[0014] In a possible design of the second aspect, the switching failure message includes location information of at least one area covered by the target cell, and information of the PLMN corresponding to the at least one area and / or information of the AMF.

[0015] In a possible design of the second aspect, the method also includes: the source network device sends location measurement configuration information to the terminal device, the location measurement configuration information instructing the terminal device to perform location measurement; and the source network device obtains the location information of the terminal device.

[0016] On the third aspect, an embodiment of the present application provides a communication method, which can be executed by a source network device or by a component (such as a chip or circuit) configured in the source network device. In the following description of this application, the source network device will be used as an example to illustrate the execution of this method.

[0017] The method includes: a source network device obtains location information of a terminal device; the source network device determines, based on the location information of the terminal device, that the terminal device is located in a first area covered by a target cell, and the first area covered by the target cell corresponds to a second PLMN or a second AMF; the source network device sends a handover request message to the target network device, where the handover request message is used to request that the terminal device be handed over to the target network device, and the handover request message includes first information, where the first information indicates that the PLMN requested to be accessed is the second PLMN or the AMF requested to be connected is the second AMF; and the source network device receives a handover request confirmation message from the target network device.

[0018] By adopting the above technical solution, according to the mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF, the source network device can send information about the PLMN requested to access or information about the AMF requested to connect to the target network device, so that the target network device can access / switch the terminal device to the PLMN or AMF corresponding to the location of the terminal device, so that the access / switching process of the terminal device complies with the communication policy requirements of the country / operator to which its location belongs, avoids the terminal device from accessing from a country / operator to which its location does not belong, and effectively improves the switching success rate.

[0019] In a possible design of the third aspect, the method also includes: the source network device sends a first message to the terminal device, the first message including first indication information, the first indication information indicating the terminal device to report the location information of at least one area covered by the target cell, and the PLMN information and / or AMF information corresponding to the at least one area; the source network device receives a second message from the terminal device, the second message including the location information of at least one area covered by the target cell, and the PLMN information and / or AMF information corresponding to the at least one area.

[0020] In a possible design of the third aspect, the method also includes: the source network device receives a third message from the target network device, the third message including location information of at least one area covered by the target cell, and information of the PLMN and / or AMF corresponding to the at least one area.

[0021] Fourthly, an embodiment of the present application provides a communication method, which can be executed by a terminal device or by a component (such as a chip or circuit) configured in the terminal device. In the following description of this application, the method executed by a terminal device will be used as an example for illustration.

[0022] The method includes: a terminal device receives a first message from a network device, the first message includes first indication information, the first indication information instructs the terminal device to report the location information of at least one area covered by a neighboring cell, and the PLMN information and / or AMF information corresponding to the at least one area; the terminal device obtains the location information of at least one area covered by the neighboring cell, and the PLMN information and / or AMF information corresponding to the at least one area according to the first indication information; the terminal device sends a second message to the network device, the second message includes the location information of at least one area covered by the neighboring cell, and the PLMN information and / or AMF information corresponding to the at least one area.

[0023] By adopting the above technical solution, the terminal device can obtain / report the mapping relationship information between at least one area covered by the neighboring area and the PLMN / AMF. In this way, the service network device of the terminal device can make reasonable switching decisions / switching requests / acceptance controls for the terminal device based on the mapping relationship and the location information of the terminal device after obtaining the above mapping relationship of the adjacent network device, so that the switching / access of the terminal device can comply with the communication policy requirements of the country / operator to which it is located, and avoid the terminal device from accessing from a country / operator to which it is not located.

[0024] In a possible design of the fourth aspect, the method also includes: the terminal device receives location measurement configuration information from the network device, and the location measurement configuration information instructs the terminal device to perform location measurement; and the terminal device sends the location information of the terminal device to the network device.

[0025] In a possible design of the fourth aspect, the first message also includes second indication information, and the second indication information instructs the terminal device to report the cell global identifier CGI of the neighboring area.

[0026] In the fifth aspect, an embodiment of the present application provides a communication method, which can be executed by a network device or by a component (such as a chip or circuit) configured in the network device. In the following description of this application, the method executed by a network device will be used as an example for illustration.

[0027] The method includes: a network device sends a first message to a terminal device, the first message including first indication information, the first indication information instructing the terminal device to report the location information of at least one area covered by a neighboring cell, and the PLMN information and / or AMF information corresponding to the at least one area; the network device receives a second message from the terminal device, the second message including the location information of at least one area covered by the neighboring cell, and the PLMN information and / or AMF information corresponding to the at least one area.

[0028] In a possible design of the fifth aspect, the method also includes: the network device sends location measurement configuration information to the terminal device, the location measurement configuration information instructing the terminal device to perform location measurement; and the network device receives the location information sent by the terminal device.

[0029] In a possible design of the fifth aspect, the first message also includes second indication information, and the second indication information instructs the terminal device to report the cell global identifier CGI of the neighboring area.

[0030] In a sixth aspect, an embodiment of the present application provides a communication method, which can be executed by a first network device or by a component (such as a chip or circuit) configured in the first network device. In the following description of this application, the method executed by the first network device will be used as an example for illustration.

[0031] The method includes: a first network device generates a third message, which includes location information of at least one area covered by a first cell managed by the first network device, and PLMN information and / or AMF information corresponding to at least one area covered by the first cell; the first network device sends the third message to a second network device.

[0032] In a possible design of the sixth aspect, the method also includes: the first network device receives a fourth message from the second network device, the fourth message including location information of at least one area covered by the second cell managed by the second network device, and PLMN information and / or AMF information corresponding to at least one area covered by the second cell.

[0033] By adopting the above technical solution, it is possible to realize the mapping relationship between at least one area covered by each cell and PLMN / AMF between network devices, so that the first network device or the second network device can obtain the mapping relationship of the other party. Based on the mapping relationship, when subsequent access control or switching decisions are required or in other scenarios, reasonable decisions can be made, so that the access / switching of the terminal device can comply with the communication policy requirements of the country / operator to which it is located, and avoid the terminal device from accessing from a country / operator to which it is not located.

[0034] In a seventh aspect, an embodiment of the present application provides a communication device, which has the function of implementing the first aspect or any possible target network device in the design of the first aspect, or has the function of implementing the second aspect or any possible source network device in the design of the second aspect, or has the function of implementing the third aspect or any possible source network device in the design of the third aspect, or has the function of implementing the fifth aspect or any possible network device in the design of the fifth aspect, or has the function of implementing the sixth aspect or any possible first network device in the design of the sixth aspect. The device can be a network device, or a chip or circuit included in the network device.

[0035] The communication device may also have the function of implementing the fourth aspect or any possible design of the fourth aspect. The device may be a terminal device, or a chip or circuit included in the terminal device.

[0036] The functions of the above-mentioned communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules, units or means corresponding to the above-mentioned functions.

[0037] In one possible design, the structure of the device includes a processing module and a transceiver module, wherein the processing module is configured to support the device in executing the corresponding functions of the target network device in the first aspect or any of the designs of the first aspect, or executing the corresponding functions of the source network device in the second aspect or any of the designs of the second aspect, or executing the corresponding functions of the source network device in the third aspect or any of the possible designs of the third aspect, or executing the corresponding functions of the terminal device in the fourth aspect or any of the possible designs of the fourth aspect, or executing the corresponding functions of the network device in the fifth aspect or any of the possible designs of the fifth aspect, or executing the corresponding functions of the first network device in the sixth aspect or any of the possible designs of the sixth aspect. The transceiver module is used to support communication between the device and other communication devices. For example, when the device is the target network device, it can receive a handover request message from the source network device. The communication device may also include a storage module, which is coupled to the processing module and stores program instructions and data necessary for the device. As an example, the processing module may be a processor, the communication module may be a transceiver, and the storage module may be a memory. The memory may be integrated with the processor or provided separately from the processor, which is not limited in this application.

[0038] In another possible design, the structure of the device includes a processor and may also include a memory. The processor is coupled to the memory and can be used to execute computer program instructions stored in the memory to cause the device to perform the method in the first aspect or any possible design of the first aspect, or the method in the second aspect or any possible design of the second aspect, or the method in the third aspect or any possible design of the third aspect, or the method in the fourth aspect or any possible design of the fourth aspect, or the method in the fifth aspect or any possible design of the fifth aspect, or the method in the sixth aspect or any possible design of the sixth aspect. Optionally, the device also includes a communication interface, and the processor is coupled to the communication interface. When the device is a network device or a terminal device, the communication interface can be a transceiver or an input / output interface; when the device is a chip included in the network device or a chip included in the terminal device, the communication interface can be the input / output interface of the chip. Optionally, the transceiver can be a transceiver circuit, and the input / output interface can be an input / output circuit.

[0039] In an eighth aspect, an embodiment of the present application provides a chip system, comprising: a processor, the processor being coupled to a memory, the memory being used to store programs or instructions, and when the program or instructions are executed by the processor, the chip system implements the method of the first aspect or any possible design of the first aspect, or implements the method of the second aspect or any possible design of the second aspect, or implements the method of the third aspect or any possible design of the third aspect, or implements the method of the fourth aspect or any possible design of the fourth aspect, or implements the method of the fifth aspect or any possible design of the fifth aspect, or implements the method of the sixth aspect or any possible design of the sixth aspect.

[0040] Optionally, the chip system further includes an interface circuit for interacting code instructions with the processor.

[0041] Optionally, there may be one or more processors in the chip system, and the processor may be implemented in hardware or software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0042] Optionally, the memory in the chip system may be one or more memories. The memory may be integrated with the processor or may be provided separately from the processor, which is not limited in this application. For example, the memory may be a non-transient processor, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or provided on different chips. This application does not specifically limit the type of memory or the configuration of the memory and the processor.

[0043] In the ninth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program or instruction stored thereon. When the computer program or instruction is executed, the computer executes the method of the first aspect or any possible design of the first aspect, or executes the method of the second aspect or any possible design of the second aspect, or executes the method of the third aspect or any possible design of the third aspect, or executes the method of the fourth aspect or any possible design of the fourth aspect, or executes the method of the fifth aspect or any possible design of the fifth aspect, or executes the method of the sixth aspect or any possible design of the sixth aspect.

[0044] In a tenth aspect, an embodiment of the present application provides a computer program product. When a computer reads and executes the computer program product, the computer executes the method of the first aspect or any possible design of the first aspect, or executes the method of the second aspect or any possible design of the second aspect, or executes the method of the third aspect or any possible design of the third aspect, or executes the method of the fourth aspect or any possible design of the fourth aspect, or executes the method of the fifth aspect or any possible design of the fifth aspect, or executes the method of the sixth aspect or any possible design of the sixth aspect.

[0045] In an eleventh aspect, an embodiment of the present application provides a communications system, comprising a network device and at least one terminal device. Optionally, the network device in the communications system may include a source network device and a destination network device. Optionally, the network device may include a first network device and / or a second network device. Optionally, the communications system may further include a core network device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1a and Figure 1b A schematic diagram of a network architecture of a satellite communication system applicable to embodiments of the present application;

[0047] Figure 2 This is a schematic diagram of different logical cells corresponding to different areas covered by satellite cells in an embodiment of the present application;

[0048] Figure 3 A flow chart of a communication method provided in an embodiment of the present application;

[0049] Figure 4 This is a schematic diagram of a network device configuring location measurement for a terminal device in an embodiment of the present application;

[0050] Figure 5 A schematic diagram of a specific example of a communication method provided in an embodiment of the present application;

[0051] Figure 6 A schematic diagram of another specific example of a communication method provided in an embodiment of the present application;

[0052] Figure 7 A flowchart of another communication method provided in an embodiment of the present application;

[0053] Figure 8 A flowchart of another communication method provided in an embodiment of the present application;

[0054] Figure 9 A flowchart of another communication method provided in an embodiment of the present application;

[0055] Figure 10 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0056] Figure 11 Another structural diagram of a communication device provided in an embodiment of the present application;

[0057] Figure 12 A schematic structural diagram of another communication device provided in an embodiment of the present application;

[0058] Figure 13 Another structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0060] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), LTE system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), fifth generation (5G) system or NR system, or applied to future communication systems or other similar communication systems.

[0061] The technical solutions provided in the embodiments of the present application can be applied to non-terrestrial network (NTN) communication systems, as well as to scenarios where NTN and terrestrial networks (TN) are deployed in a hybrid manner. The NTN communication system may include a satellite communication system, a high altitude platform station (HAPS) communication system, or other non-terrestrial communication systems.

[0062] The following uses the NTN communication system as a satellite communication system as an example to explain in detail the network architecture of the present application.

[0063] Please refer to Figure 1a, is a schematic diagram of a network architecture of a satellite communication system applicable to an embodiment of the present application, wherein the network architecture includes a core network device 110, a wireless access network device 120, a satellite 130 and at least one terminal device (such as Figure 1a As an example, Figure 1a The core network equipment, wireless access network equipment and terminal equipment are located on the ground, while the satellites are located in the sky.

[0064] Among them, the radio access network device communicates with the core network device in a wireless or wired manner. The core network device and the radio access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the radio access network device can be integrated into the same physical device, or the functions of part of the core network device and part of the radio access network device can be integrated into one physical device. It should be understood that the radio access network device mentioned in the embodiments of the present application may correspond to different devices in different communication systems, for example, in a 5G system, it corresponds to an access network device in 5G, such as gNB or ng-eNB, and in a 4G system, it corresponds to an access network device in 4G, such as eNB or en-gNB.

[0065] Communication between wireless access network equipment and terminal devices is achieved through satellite signal forwarding. This means that the satellite receives signals from wireless access network devices and forwards them to the ground, forming a satellite cell. This in turn provides coverage for terminal devices on the ground. In this scenario, the satellite acts as a relay node or transponder, and this scenario is also referred to as transparent satellite forwarding.

[0066] In the transparent forwarding mode, the satellite cell can be fixed on the ground (which can be denoted as a "fixed cell") or can move on the ground as the satellite moves (which can be denoted as a "mobile cell"). In the "fixed cell" scenario, the satellite cell is fixed on the ground, which means that the coverage of the satellite cell on the ground is fixed. It can be fixed for a period of time or permanently fixed. For example, for high-orbit satellites, since the satellite remains stationary relative to the ground, the satellite cell it forms is generally fixed relative to the ground. For low-orbit satellites, since the satellite moves relative to the ground, the satellite can adjust the launch angle of its antenna or other physical parameters to make the satellite cell formed relative to the ground fixed.

[0067] In a "mobile cell" scenario, the satellite cell moves with the satellite. That is, when the satellite moves, the satellite cell also moves on the ground with the satellite. Mobile cells typically occur because the satellite doesn't dynamically adjust its beam direction as it moves, causing the projection of the satellite's beam on the ground to move with it.

[0068] It should be noted that the embodiments of the present application do not specifically limit the existence scenario of mobile cells. When the satellite provides service coverage in the form of transparent forwarding, a possible existence scenario of mobile cells can be: the satellite establishes a connection with the original wireless access network device. As the satellite moves, the cell under the original wireless access network device forwarded by the satellite moves with the satellite for a period of time, that is, the satellite and the original wireless access network device maintain a connection for a period of time; at a certain moment, the connection between the satellite and the original wireless access network device is disconnected due to reasons such as long distance and weak signal, and the satellite connects to a new wireless access network device. Thereafter, the satellite begins to forward the signal of the new wireless access network device, forming a new satellite cell. It can be understood that although the satellite is constantly operating, the position of the wireless access network device on the ground does not change. Therefore, for the scenario where mobile cells exist, if the satellite forwards the signal of a wireless access network device on the ground, the satellite cell under the wireless access network device formed will also move within a certain range as the satellite moves, but the movement range of the satellite cell is usually around the wireless access network device.

[0069] Please refer to Figure 1b , is another network architecture diagram of a satellite communication system applicable to an embodiment of the present application, wherein the network architecture includes a core network device 110, a satellite 130 and at least one terminal device (such as Figure 1b As an example, Figure 1b The core network equipment and terminal equipment are located on the ground, while the satellites are located in the sky.

[0070] and Figure 1a The difference between the network architecture shown in is that Figure 1b In the network architecture shown, satellites can be equipped with wireless access network equipment, such as base stations. The satellites can generate their own cell signals and forward them to the ground to form satellite cells, providing coverage for devices on the ground. Therefore, this scenario can also be called a regenerative satellite operation.

[0071] In regenerative mode, a satellite cell moves with the satellite. That is, when the satellite moves, the cell it generates also moves on the ground, hence the term "mobile cell." Because this "mobile cell" is generated by the satellite itself, it can follow the satellite's orbit and move on the ground. Generally, when a satellite moves, a new satellite moves in to ensure the greatest possible continuity of coverage. The coverage area of ​​the new satellite can be the same as or different from the previous one. It is understood that due to differences in the satellite's orbital direction, beam transmission direction, and beam transmission capabilities, the ground coverage areas of two satellites may not be exactly the same.

[0072] although Figure 1aand Figure 1b Although only one terminal device is shown, it should be understood that a single radio access network device, satellite, or core network device can provide services for one or more terminal devices. The present embodiment of the present application does not limit the number of core network devices, radio access network devices, satellites, and terminal devices included in the satellite communication system. Furthermore, the terminal device may be fixed or mobile, which is also not limited in the present application.

[0073] The wireless access network device and the terminal device, as well as the terminal devices and the terminal devices, can communicate through the licensed spectrum (licensed spectrum), can also communicate through the unlicensed spectrum (unlicensed spectrum), or can also communicate through the licensed spectrum and the unlicensed spectrum at the same time. The wireless access network device and the terminal device, as well as the terminal devices and the terminal devices, can communicate through the spectrum below 6 gigahertz (GHz), can also communicate through the spectrum above 6 GHz, and can also communicate using the spectrum below 6 GHz and the spectrum above 6 GHz at the same time. The embodiments of the present application do not limit the spectrum resources used between the wireless access network device and the terminal device.

[0074] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field can know that with the evolution of communication network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0075] The cell involved in the embodiment of the present application may be an NTN cell. The cell in the present application is described in detail below by taking the NTN cell as a satellite cell as an example.

[0076] In addition to the aforementioned mobility features, another important feature of satellite cells is their wide coverage. The coverage diameter of a satellite cell can reach tens to thousands of kilometers. Therefore, there are situations where a satellite cell covers the geographical areas of multiple countries or covers the service areas of multiple operators. Generally speaking, a satellite can indicate that it can support services in multiple countries / operators by broadcasting information about multiple PLMNs (such as PLMN identification information, etc.) or AMF information (such as AMF identification information, etc.). Terminal devices can determine the appropriate PLMN / AMF to access based on the mapping relationship between their own location, the area covered by the cell, and the PLMN / AMF.

[0077] For example, physical cell C covers the geographic areas of countries A and B. Country A corresponds to PLMN1 / AMF1, and country B corresponds to PLMN2 / AMF2. Physical cell C can broadcast information about PLMN1 / AMF1 and PLMN2 / AMF2. It can be understood that "country A corresponds to PLMN1 / AMF1" means that the PLMN deployed in country A that manages cell C is PLMN1, or that the AMF connected to the access network equipment belonging to cell C is AMF1; and "country B corresponds to PLMN2 / AMF2" means that the PLMN deployed in country B that manages cell C is PLMN2, or that the AMF connected to the access network equipment belonging to cell C is AMF2.

[0078] In this way, for UE1 in country A and within the coverage of cell C, UE1 can access cell C through PLMN1 / AMF1; or, when UE1 wants to access cell C, it can access cell C through PLMN1 / AMF1; or, when UE1 wants to access cell C, UE1 can access the cell corresponding to PLMN1 / AMF1; or, when UE1 wants to access cell C, the core network device to which the access network device that UE1 can access is connected is AMF1, and the access network device that UE1 can access belongs to PLMN1.

[0079] Similarly, for UE2 in country B and within the coverage of cell C, UE2 can access cell C through PLMN2 / AMF2; or, when UE2 wants to access cell C, it can access cell C through PLMN2 / AMF2; or, when UE2 wants to access cell C, UE2 can access the cell corresponding to PLMN2 / AMF2; or, when UE2 wants to access cell C, the core network device to which the access network device that UE2 can access is connected is AMF2, and the access network device that UE2 can access belongs to PLMN2.

[0080] Taking into account the different communication strategies of different countries or operators, satellite cells can be divided into finer granularity, for example, the entire service coverage area of ​​a satellite cell can be divided into multiple areas of regular or irregular shapes, which can be called virtual cells or virtual areas, so as to better fit the geographical areas of different countries or the service areas of different operators. Figure 2 As shown, different areas under the same satellite cell can correspond to different PLMN / AMFs, thereby forming multiple logical cells under the same satellite cell, and then effectively managing the mobility of terminal devices according to different areas.

[0081] The embodiments of the present application can also be applied to the scenario of cell switching, where the terminal device may switch from the source network device to the target network device due to movement of location, change of service, change of network coverage or other reasons. Wherein, the source network device refers to the network device that the terminal device accesses before performing the switching, or the network device that provides services to the terminal device before the switching; the target network device refers to the network device to which the terminal device needs to switch, or the network device that the terminal device accesses after successfully performing the switching, or the network device that provides services to the terminal device after the switching is successful. Correspondingly, the source cell refers to the cell that the terminal device accesses before performing the switching, and the source cell is the cell covered by the source network device, or the source cell is the cell under the jurisdiction of the source network device, or the source cell belongs to the source network device. The target cell refers to the cell that the terminal device accesses after performing the switching, and the target cell is the cell covered by the target network device, or the target cell is the cell under the jurisdiction of the target network device, or the target cell belongs to the target network device.

[0082] It is understood that the source cell and / or target cell in the embodiments of the present application may be the NTN cell described above, such as a satellite cell. That is, the service coverage area of ​​the source cell and / or target cell may be divided into multiple areas, and different areas may correspond to different PLMNs and / or AMFs, forming different logical cells.

[0083] Some of the terms used in the embodiments of the present application are explained below to facilitate understanding by those skilled in the art.

[0084] 1) The terminal device involved in the embodiments of the present application is a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (for example, on airplanes, balloons and satellites, etc.). The terminal device can communicate with the core network via the radio access network (RAN) and exchange voice and / or data with the RAN. The terminal device can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a mobile internet device (MID), a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The embodiments of this application do not limit the application scenarios. Terminal devices may also be referred to as user equipment (UE), mobile stations, and remote stations. The embodiments of this application do not limit the specific technology, device form, or name used by the terminal devices.

[0085] As an example and not a limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices or smart wearable devices, etc., which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, etc., as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets, smart helmets, and smart jewelry for vital sign monitoring.

[0086] The terminal device in the embodiment of the present application can also be a vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit that is built into the vehicle as one or more components or units. The vehicle can implement the method of the present application through the built-in vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit.

[0087] 2) The radio access network device involved in the embodiments of this application is a device in the network used to connect terminal devices to the wireless network. The radio access network device can be a node in the radio access network, also known as a base station or a RAN node. In this application, the radio access network device refers to a radio access network device deployed on the ground. In the following description, the radio access network device may be simply referred to as an access network device or a network device.

[0088] The access network device may include an evolved base station (NodeB or eNB or e-NodeB, evolutionary Node B) in an LTE system or an evolved LTE system (LTE-Advanced, LTE-A), such as a traditional macro base station eNB and a micro base station eNB in ​​a heterogeneous network scenario, or may also include a next generation node B (gNB) in a 5G system or an NR system, or may also include a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a transmission reception point (TRP), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a base band unit (BBU), a base band pool BBU pool, or a wireless fidelity (WiFi) access point (AP), an integrated access and backhaul (IAB) node, etc., or may also include a cloud radio access network (CNA). The embodiments of the present application are not limited to the centralized unit (CU) and / or distributed unit (DU) in the CloudRAN system.

[0089] For example, in one network architecture, a network device can be a CU node, a DU node, or an access network device that includes both a CU node and a DU node. Furthermore, a CU node can be divided into a control plane (CU-CP) and a user plane (CU-UP). The CU-CP is responsible for control plane functions, primarily including radio resource control (RRC) and packet data convergence protocol (PDCP)-C. PDCP-C is primarily responsible for encryption, decryption, integrity protection, and data transmission of control plane data. The CU-UP is responsible for user plane functions, primarily including service data adaptation protocol (SDAP) and PDCP-U. SDAP is primarily responsible for processing core network data and mapping flows to bearers. PDCP-U is primarily responsible for encryption, decryption, integrity protection, header compression, sequence number maintenance, and data transmission of the data plane. The CU-CP and CU-UP can be connected via the E1 interface. The CU-CP represents the CU, connecting to the core network via the Ng interface and connecting to the DU via F1-C (control plane). The CU-UP is connected to the DU via the F1-U (user plane). Of course, another possible implementation is to also include the PDCP-C in the CU-UP.

[0090] 3) The core network device involved in the embodiments of the present application refers to the device in the core network (CN) that provides service support for the terminal device. At present, some examples of core network devices include: AMF entity, session management function (SMF) entity, user plane function (UPF) entity, etc. Among them, the AMF entity is responsible for the access management and mobility management of the terminal device; the SMF entity is responsible for session management, such as user session establishment, etc.; the UPF entity is a functional entity of the user plane, mainly responsible for connecting to the external network. It should be noted that the entities in this application can also be referred to as network elements or functional entities, that is, the AMF entity can also be referred to as an AMF network element or an AMF functional entity, and the SMF entity can also be referred to as an SMF network element or an SMF functional entity. In the description below in this application, the core network device may refer to AMF.

[0091] 4) The satellite involved in the embodiments of the present application refers to a network device located on a satellite. For the sake of convenience, the "network device on the satellite" may be referred to as a "satellite". The satellite may be a low earth orbiting satellite (LEO) or a medium orbit satellite or other network device located in the sky and moving. Generally speaking, according to the orbital altitude of the satellite, the satellites in the satellite communication system can be divided into three categories: high orbit satellites (GEO), low orbit satellites (LEO) and medium orbit satellites. Among them, high orbit satellites can also be called geostationary satellites. The running speed of high orbit satellites is the same as the rotation speed of the earth. Therefore, high orbit satellites remain stationary relative to the ground. Correspondingly, the satellite cells formed by high orbit satellites are also stationary. Low orbit satellites can also be called near-Earth orbit satellites. Low orbit satellites move faster relative to the ground. Therefore, the satellite cells formed by low orbit satellites can move with the movement of the satellite. Medium orbit satellites refer to satellites whose orbital altitudes are between high orbit satellites and low orbit satellites.

[0092] 5) It should be noted that the terms "system" and "network" in the embodiments of the present application can be used interchangeably. "Multiple" means two or more. In view of this, in the embodiments of the present application, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then the included ones may be A, B, C, A and B, A and C, B and C, or A and B and C. Similarly, the understanding of descriptions such as "at least one" is similar. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0093] Unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects, and the descriptions of "first" and "second" do not limit the objects to be different.

[0094] It is understood that in the embodiments of the present application, the terminal device and / or the network device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all of the operations in the embodiments of the present application need to be performed.

[0095] The embodiments of this application use the PLMN and AMF entities as examples to illustrate the methods involved, but the present invention is not limited to PLMN and AMF entities. The PLMN may also be another communication network or a device that implements some functions of a communication network. The AMF entity may also be another entity or device that can implement mobility management functions, or an entity or device that implements similar functions in a communication network.

[0096] Please refer to Figure 3 , is a flow chart of a communication method provided in an embodiment of the present application, the method comprising:

[0097] Step S301: The source network device sends a handover request message to the target network device, wherein the handover request message is used to request handover of the terminal device to the target network device. Accordingly, the target network device can receive the handover request message from the source network device.

[0098] The handover request message includes the location information of the terminal device, as well as information about the first PLMN to which the source network device belongs or information about the first AMF to which the source network device is connected when the terminal device communicates with the source network device. The PLMN information may include PLMN identification information, such as PLMN-identifier. Similarly, the AMF information may include AMF identification information, such as AMF-identifier.

[0099] In some scenarios, if the target cell can support / correspond to multiple PLMNs and / or multiple AMFs, but the source network device does not know the mapping relationship between at least one area covered by the target cell and the PLMNs and / or AMFs supported / corresponded by the target cell, then if the terminal device accesses the source cell through PLMN1 or AMF1, the source terminal device will usually also request to access the target cell through PLMN1 or AMF1 when requesting to switch the terminal device to the target cell. In view of this, the information of the first PLMN included in the handover request message can also be understood as the terminal device requesting to access the target cell through the first PLMN, or the terminal device believes that the target cell requested to be accessed belongs to the first PLMN. Similarly, the information of the first AMF included in the handover request message can also be understood as the terminal device requesting to access the target cell through the first AMF, or the terminal device believes that the target cell requested to be accessed is a cell managed by the first AMF, or the terminal device believes that the AMF to which the target network device requested to be accessed is connected is the first AMF.

[0100] In an embodiment of the present application, the location information of the terminal device in the handover request message may include one or more of longitude information, latitude information, and altitude information, or may be other forms of location information, which is not limited by the present application. In one possible implementation, the location information can be used to describe a specific location point, such as the longitude, latitude, and altitude information of the location point where the terminal device is currently located. In another possible implementation, the location information can also be used to describe a rough area range, that is, an area range where the terminal device is currently located, such as the area range can be represented by the longitude, latitude, and altitude of the center point, plus parameters such as the diameter or radius of the area range. In another possible implementation, the location information or area information can be represented by an identifier, such as the identifier can be an index or ID, and the mapping relationship between the identifier and the location information or area information can be agreed upon by the protocol, or sent to the terminal device by the network device / core network device, that is, the terminal device, network device, or core network device can determine the corresponding location or area based on the identifier. Of course, the description of the area range can also have other forms of expression, and this application will no longer give examples one by one.

[0101] Furthermore, the location information of the terminal device may be received by the source network device from the terminal device. For example, the source network device may receive a measurement report reported by the terminal device, and the measurement report may include the location information of the terminal device itself measured by the terminal device. Alternatively, the location information of the terminal device may be received by the source network device from other network devices. For example, the source network device may receive the location information of the terminal device from the core network device. Alternatively, the location information of the terminal device may be determined by the source network device itself. For example, the source network device may locate the terminal device and obtain the location information of the terminal device. The location information of the terminal device may also be obtained by the source network device through other means, which is not limited in this application.

[0102] In a possible implementation, before the source network device sends a handover request message to the target network device, the source network device may configure the terminal device to perform location measurement. Figure 4 As shown in steps S304 to S305, the source network device may send location measurement configuration information to the terminal device, instructing the terminal device to perform location measurement. The terminal device may then perform location measurement based on the location measurement configuration information and send the measured location information to the source network device via a measurement report.

[0103] Step S302: The target network device determines, based on the location information of the terminal device, that the location of the terminal device is within the first area covered by the target cell, and the PLMN corresponding to the first area does not include the first PLMN, or the AMF corresponding to the first area does not include the first AMF.

[0104] Step S303: The target network device sends a handover failure message to the source network device, where the handover failure message is used to refuse handover of the terminal device to the target network device. Accordingly, the source network device can receive the handover failure message from the target network device.

[0105] That is to say, in an embodiment of the present application, the target network device can determine whether to allow the terminal device to access the target network device based on the location information of the terminal device, the location information of at least one area covered by the target cell, and the PLMN information and / or AMF information corresponding to the at least one area.

[0106] It should be noted that the location information of at least one area covered by the target cell and the information of the PLMN and / or AMF corresponding to the at least one area can be understood as the mapping relationship between the at least one area covered by the target cell and the PLMN and / or AMF. The information of the PLMN and / or AMF corresponding to the at least one area can be the information of the PLMN and / or AMF corresponding to each area in the at least one area, or the information of the PLMN and / or AMF corresponding to some areas in the at least one area, which is not limited in this application. Moreover, the information of the PLMN and / or AMF corresponding to different areas can be the same or different, which is also not limited in this application.

[0107] Specifically, when the terminal device is located within the first area covered by the target cell, but the PLMN corresponding to the first area does not include the first PLMN to which the source network device belongs, or the AMF corresponding to the first area does not include the first AMF connected to the source network device, the target network device may refuse the terminal device from switching to the target network device. Furthermore, the target network device may send a handover failure message to the source network device. The handover failure message may also be referred to as a handover preparation failure message, or have other names, which are not limited in this application.

[0108] Optionally, the handover failure message may include one or more of the following information:

[0109] 1) Failure reason information or handover failure reason value, used to indicate that the handover failure reason is an invalid or incorrect PLMN, or an invalid or incorrect AMF, or invalid location information, or an illegal request, or an unsupported requested PLMN, or an unsupported requested AMF, etc. Among them, an invalid or incorrect PLMN means that the target network device does not belong to the PLMN requested in the handover request message; an invalid or incorrect AMF means that the AMF requested in the handover request message is not responsible for managing the target network device; an illegal request means that the target network device does not support the handover request of the terminal device, or the target network device does not support the PLMN or AMF requested in the handover request message.

[0110] 2) Information about the PLMN that the target network device allows the terminal device to access, or information about the PLMN to which the target cell that the target network device allows the terminal device to access belongs, or information about the PLMN to which the target network device belongs.

[0111] It should be noted that the information of the PLMN that the target network device allows the terminal device to access may include: information of the PLMN that the terminal device is allowed to access corresponding to the target cell, and / or information of the PLMN that the terminal device is allowed to access corresponding to other non-target cells belonging to the target network device.

[0112] 3) Information about the AMF that the target network device allows the terminal device to access, or information about the AMF that manages the target cell that the target network device allows the terminal device to access, or information about the AMF that manages the target network device.

[0113] It should be noted that the information of the AMF that the target network device allows the terminal device to access may include: the information of the AMF that the terminal device is allowed to access corresponding to the target cell, and / or the information of the AMF that the terminal device is allowed to access corresponding to other non-target cells belonging to the target network device.

[0114] Optionally, the handover failure message may further include: location information of at least one area covered by the target cell, and information of the PLMN and / or AMF corresponding to the at least one area. That is, the handover failure message indicates the mapping relationship between the latest or available at least one area covered by the target cell and the PLMN and / or AMF.

[0115] Optionally, the handover failure message may further include: location information of at least one area covered by other non-target cells belonging to the target network device, and PLMN information and / or AMF information corresponding to the at least one area covered by the other non-target cells. That is, the handover failure message also indicates a mapping relationship between the at least one area covered by the other non-target cells belonging to the target network device and the PLMN and / or AMF.

[0116] It is understood that there may be one or more other non-target cells belonging to the target network device. When there are multiple other non-target cells belonging to the target device, the handover failure message may indicate the mapping relationship between the cell coverage area corresponding to all or part of the other non-target cells and the PLMN and / or AMF, which is not limited in this application.

[0117] In this way, after the source network device receives the switching failure message, it can determine the correct PLMN or AMF information corresponding to the terminal device at the current location when accessing the target network device / target cell based on the information contained in the switching failure message, and then send a switching request message again, requesting that the terminal device be switched to a logical cell in the target cell that matches its location.

[0118] When it is determined that the terminal device is located within the first area covered by the target cell, and the PLMN corresponding to the first area includes the first PLMN, or the AMF corresponding to the first area includes the first AMF, the target network device may determine that the terminal device is allowed to switch to the target cell or the cell corresponding to the first PLMN / first AMF belonging to the target network device, and send a handover request confirmation message to the source network device. The handover request confirmation message indicates that the terminal device is allowed to switch to the target network device. Furthermore, the source network device may send a handover message to the terminal device, instructing the terminal device to switch to the target cell.

[0119] For example, UE1 supports both PLMN1 and PLMN2, and UE2 supports both PLMN1 and PLMN2. The locations of UE1 and UE2 are as follows: Figure 2 As shown, both UE1 and UE2 are located within the coverage of the target cell, but UE1 is located within the area corresponding to PLMN1 / AMF1 in the target cell, and UE2 is located within the area corresponding to PLMN2 / AMF2 in the target cell.

[0120] In this way, if the current base station accessed by UE1 and UE2 is a source base station belonging to PLMN1, and requests to switch to a target base station belonging to PLMN1. Then for UE1, since UE1 located at the edge of the source cell is located in the area corresponding to PLMN1 / AMF1 in the target cell, the target base station can determine to allow UE1 to switch to the target cell belonging to PLMN1 or the logical cell corresponding to PLMN1 under it, or in other words, the target base station can determine to allow UE1 to switch to the target cell managed by AMF1 or the logical cell corresponding to AMF1 under it. Subsequently, for UE1, the target base station can send a switching request confirmation message to the source base station. Furthermore, after receiving the switching request confirmation message, the source base station can send a switching message to UE1, instructing UE1 to perform switching to the target cell. The switching message can also be called a reconfiguration message, or can have other names, which are not limited in this application.

[0121] For UE2, since UE2 located at the edge of the source cell is located in the area corresponding to PLMN2 / AMF2 in the target cell, the target base station can determine that it cannot support UE2's handover to the target cell belonging to PLMN1 or the logical cell corresponding to PLMN1, or the target base station can determine that it cannot support UE2's handover to the target cell belonging to AMF1 or the logical cell corresponding to AMF1, that is, the target base station needs to reject UE2's handover request. Subsequently, for UE2, the target base station can send a handover failure message to the source base station. Furthermore, after receiving the handover failure message, the source base station can send a handover request message to the target base station again based on the indication information included in the handover failure message that the PLMN allowed to be accessed by UE2 is PLMN2 or the AMF allowed to be accessed by UE2 is AMF2, requesting that UE2 be handed over to the target cell belonging to PLMN2 or the target cell managed by AMF2.

[0122] It can be seen from this that by adopting this technical solution, the target network device can make reasonable decisions when access control or switching decisions or other scenarios are required based on the mapping relationship between at least one area covered by its own target cell and the PLMN and / or AMF, allowing the terminal device to access / switch to the PLMN / AMF corresponding to its location, so that the access / switching process of the terminal device complies with the communication policy requirements of the country / operator to which its location belongs, and avoids the terminal device from accessing from a country / operator to which its location does not belong.

[0123] Furthermore, during the handover process, the target network device may also exchange with the source network device a mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. This facilitates the source network device to make a reasonable decision based on this mapping relationship and the terminal device's location, requesting the terminal device to be handed over to the logical cell corresponding to its location, thereby effectively improving the handover success rate.

[0124] Figure 5 and Figure 6 These are two specific examples of a switching process in a communication method provided in an embodiment of the present application. Figure 5 The specific example shown corresponds to a scenario where a directly connected interface exists between the source network device and the target network device. The source network device and the target network device can perform a handover process based on the directly connected interface. The directly connected interface can be, for example, an Xn interface. In this case, the handover process can also be referred to as an Xn-based handover (Xn-based HO) or an Xn handover process. Figure 5 The solution shown is also applicable to the case where the directly connected interface is an X2 interface, which is not limited in the present invention. Figure 6 The specific example shown corresponds to a scenario where there is no directly connected interface between the source network device and the target network device. The source network device and the target network device can perform a handover process based on the interface between the access network device and the core network device. The core network device can be, for example, an AMF, and the interface between the access network device and the core network device can be, for example, an NG interface. In this case, the handover process can also be referred to as a handover based on an NG interface (NG based HO) or an NG handover process. Figure 6 The solution shown is also applicable to the case where the interface between the access network device and the core network device is an S1 interface, which is not limited in the present invention.

[0125] like Figure 5 As shown, in step S501, the UE may send a measurement report to the source base station, and optionally, the measurement report includes the location information of the UE. In step S502, the source base station may send a handover request message to the target base station, and the handover request message includes the location information of the UE and the information of the PLMN1 and / or AMF1 that the UE requests to access. It should be noted that here, the location information of the UE included in the handover request message may be obtained by the source base station from the measurement report reported by the UE, or may be obtained by the source base station through other means, such as positioning the UE, or obtained from other network devices, and is not limited. The PLMN1 that the UE requests to access may be the PLMN that the UE accesses in the source cell or the PLMN to which the source cell belongs. Similarly, the AMF1 that the UE requests to access may be the AMF that the source base station connects to in the source cell or the AMF that manages the source cell.

[0126] In step S503, the target base station may determine whether to allow the UE to handover to the target cell based on the UE's location information and the mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. Specifically, if the UE is located within an area covered by the target cell, but this area corresponds to PLMN2 and / or AMF2, the target base station may determine that the handover has failed and reject the UE's handover request. Specifically, the target base station may reject the UE's handover request, i.e., reject the UE's handover to the target cell belonging to PLMN1 or reject the UE's handover to the target cell managed by AMF1. The target base station may then send a handover failure message to the source base station in step S504, carrying a handover failure cause value and information indicating the latest or available mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. In this way, for this UE, the source base station may subsequently determine the PLMN to which the target cell belongs, or the AMF that manages the target cell, based on the mapping relationship of the target cell and the UE's location information. Furthermore, optionally, the source base station may again initiate a handover request to switch the UE to a target cell / PLMN to which the target cell belongs / AMF that manages the target cell that matches its location, so that the UE can successfully access the target cell. For other UEs that need to be switched subsequently, the source base station may determine the PLMN and / or AMF that matches the UE's location based on the mapping relationship and the UE's location information, and then directly initiate a handover request to switch the UE to the target cell / target AMF that matches its location, thereby effectively improving the handover success rate.

[0127] like Figure 6 As shown, in step S601, the UE may send a measurement report to the source base station, and optionally, the measurement report includes the location information of the UE. In step S602, the source base station may send a first handover request message to AMF1, and the first handover request message may include the location information of the UE and the information of the PLMN1 to which the UE requests to access and / or the information of AMF1. The first handover request message may be a HO required message or other message, without limitation. The location information of the UE included in the first handover request message may be obtained by the source base station from the measurement report reported by the UE, or may be obtained by the source base station through other means, without limitation. The PLMN1 to which the UE requests to access may be the PLMN to which the UE accesses in the source cell or the PLMN to which the source cell belongs. Similarly, the AMF1 to which the UE requests to access may be the AMF to which the source base station is connected or the AMF that manages the source cell.

[0128] Furthermore, in step S603, AMF1 may send a second handover request message to the target base station. The second handover request message may include the UE's location information and information about the PLMN1 to which the UE requests access and / or information about AMF1. The second handover request message may be an HO request message or other message, without limitation.

[0129] It should be noted that here, the UE location information included in the second switching request message is obtained by AMF1 from the first switching request message, or it can be obtained by AMF1 through other means, such as locating the UE's position, or obtained from other network devices, without limitation.

[0130] In step S604, the target base station may determine whether to allow the UE to handover to the target cell based on the UE's location information and the mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. Specifically, if the UE is located within an area covered by the target cell, but the area corresponds to PLMN2 and / or AMF2, the target base station may determine that the handover has failed and needs to reject the UE's handover request, i.e., reject the UE's handover to a cell belonging to PLMN1 (such as the target cell) or reject the UE's handover to a cell managed by AMF1 (such as the target cell). Therefore, in step S605, the target base station may send a first handover failure message to AMF1, and the first handover failure message may include a handover failure cause value and information indicating the latest or available mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. The handover failure cause value may, for example, be an invalid or incorrect PLMN or an invalid or incorrect AMF. The first handover failure message may be a handover failure message or other message, without limitation.

[0131] Subsequently, in step S606, AMF1 may send a second handover failure message to the source base station. The second handover failure message carries a handover failure cause value and information indicating a mapping relationship between at least one area covered by the latest or available target cell and the PLMN and / or AMF. The handover failure cause value may be, for example, an invalid or erroneous PLMN, or an invalid or erroneous AMF. The second handover failure message may be a handover preparation failure message or other message, without limitation. Accordingly, the source base station may receive the second handover failure message.

[0132] In this way, for the UE, the source base station can subsequently determine the PLMN to which the target cell to which the UE needs to switch belongs, or the AMF that manages the target cell to which the UE needs to switch, based on the mapping relationship of the target cell and the location information of the UE. Optionally, the source base station can again initiate a handover request to switch the UE to the target cell / PLMN to which the target cell belongs / AMF that manages the target cell that matches its location, so that the UE can successfully switch to the target cell. For other UEs that need to be switched subsequently, the source base station can determine the PLMN and / or AMF that matches the UE's location based on the mapping relationship of the target cell and the location information of the UE, and then initiate a handover request to switch the UE to the target cell / target AMF that matches its location, thereby effectively improving the handover success rate.

[0133] It should be noted that Figure 6 The specific example shown is explained by taking the source base station and the target base station as belonging to the same AMF, that is, AMF1 shown in the figure. It can be understood that the source base station and the target base station may also belong to different AMFs. In this case, the handover process may also include a handover process between AMFs, and the handover message exchanged between AMFs may also include one or more of the following: UE location information, handover failure cause, mapping relationship between at least one area covered by the target base station and the PLMN and / or AMF, etc., which will not be repeated here.

[0134] Please refer to Figure 7 , is a flow chart of another communication method provided in an embodiment of the present application, the method comprising:

[0135] Step S701: The source network device obtains the location information of the terminal device.

[0136] In an embodiment of the present application, the location information of the terminal device may include one or more of longitude information, latitude information, and altitude information, or may be other forms of location information, which is not limited by the present application. In one possible implementation, the location information can be used to describe a specific location point, such as the longitude, latitude, and altitude information of the location point where the terminal device is currently located. In another possible implementation, the location information can also be used to describe a rough area range, that is, an area range where the terminal device is currently located, such as the area range can be represented by the longitude, latitude, and altitude of the center point, plus parameters such as the diameter or radius of the area range. In another possible implementation, the location information or area information can be represented by an identifier, such as the identifier can be an index or ID, and the mapping relationship between the identifier and the location information or area information can be agreed upon by the protocol, or sent to the terminal device by the network device / core network device, that is, the terminal device, network device, or core network device can determine the corresponding location or area based on the identifier. Of course, the description of the area range can also have other forms of expression, and this application will no longer give examples one by one.

[0137] Furthermore, the source network device can obtain the location information of the terminal device from the terminal device. For example, the source network device can receive a measurement report reported by the terminal device, and the measurement report includes the terminal device's own location information measured by the terminal device. Alternatively, the source network device can also obtain the location information of the terminal device from other network devices, such as obtaining the location information of the terminal device from the core network device. Alternatively, the source network device can also determine the location information of the terminal device by itself. For example, the source network device can locate the terminal device and then obtain the location information of the terminal device. The source network device can also obtain the location information of the terminal device by other means, which is not limited in this application.

[0138] Optionally, if the source network device obtains the terminal device's location information through a measurement report reported by the terminal device, the source network device may further configure the terminal device to perform location measurement before receiving the measurement report reported by the terminal device. Specifically, the source network device may send location measurement configuration information to the terminal device, where the location measurement configuration information is used to instruct the terminal device to perform location measurement. The terminal device may then send the measured location information to the source network device via a measurement report.

[0139] Step S702: The source network device determines, based on the location information of the terminal device, that the terminal device is located within the first area covered by the target cell, and the first area covered by the target cell corresponds to the second PLMN or the second AMF.

[0140] Step S703: The source network device sends a handover request message to the target network device. The handover request message is used to request handover of the terminal device to the target network device. The handover request message may include first information, where the first information indicates that the PLMN requested for access is the second PLMN or the AMF requested for connection is the second AMF. That is, the first information may be information about the second PLMN and / or information about the second AMF.

[0141] If the first information indicates that the PLMN requested to be accessed is a second PLMN, the first information may include information about the second PLMN, indicating that access is requested to the cell corresponding to the second PLMN, or access is requested to the target cell belonging to the second PLMN, or the target cell requested to be accessed belongs to the second PLMN, wherein the PLMN information may include identification information of the PLMN, such as PLMN-identifier. Similarly, if the first information indicates that the AMF requested to be connected is a second AMF, the first information may include information about the second AMF, indicating that access is requested to the cell corresponding to the second AMF, or access is requested to the target cell managed by the second AMF, or the target cell requested to be accessed is managed by the second AMF, wherein the AMF information may include identification information of the AMF, such as AMF-identifier.

[0142] In an embodiment of the present application, the source network device may determine, based on the location information of the terminal device, the location information of at least one area covered by the target cell, and the information of the PLMN and / or AMF corresponding to the at least one area, that the current location of the terminal device is within the first area covered by the target cell, and that the first area corresponds to the second PLMN or the second AMF. Furthermore, a handover request message may be sent to the target network device to request that the terminal device be handed over to a cell belonging to the second PLMN or a cell managed by the second AMF.

[0143] As described above, the location information of at least one area covered by the target cell and the information of the PLMN and / or AMF corresponding to the at least one area can be understood as indicating the mapping relationship between the at least one area covered by the target cell and the PLMN and / or AMF.

[0144] In one possible implementation, the source network device may receive, from the terminal device, information indicating a mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. For the specific process of this implementation, reference may be made to the following description of steps S801 to S803.

[0145] In another possible implementation, the source network device may receive information from the target network device that indicates the mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF. It should be noted that the information received from the target network device that indicates the above-mentioned mapping relationship may refer to the source network device receiving the information indicating the mapping relationship through a handover failure message or a handover preparation failure message in a handover process previously performed between the source network device and the target network device, as described in step S303 above; or, it may also refer to the process of the source network device and the adjacent network device exchanging the mapping relationship information between at least one area covered by their respective cells and the PLMN and / or AMF in a non-handover scenario. For a detailed description of this process, please refer to the relevant description of steps S901 to S903 below.

[0146] Step S704: The target network device sends a handover request confirmation message to the source network device. Correspondingly, the source network device can receive the handover request confirmation message from the target network device.

[0147] It can be seen from this that by adopting this technical solution, the source network device can make a reasonable decision when a switching decision or other scenarios are required based on the mapping relationship between at least one area covered by the target cell and the PLMN and / or AMF, and request the terminal device to access / switch to a suitable target cell / PLMN / AMF corresponding to its location, so that the access / switching process of the terminal device complies with the communication policy requirements of the country / operator to which its location belongs, avoids the terminal device from accessing from a country / operator to which its location does not belong, and effectively improves the switching success rate.

[0148] It should be noted that Figure 5 、 Figure 6 The switching process shown in the above steps S701 to S704 is similar to the switching process described in the above steps S701 to S704. The switching process can be implemented based on the directly connected interface between the access network devices (such as Xn or X2 interface), or based on the interface between the access network device and the core network device (such as NG or S1 interface). This application will not give examples one by one here.

[0149] Please refer to Figure 8 , is a flow chart of another communication method provided in an embodiment of the present application, the method comprising:

[0150] Step S801: The network device sends a first message to the terminal device, where the first message includes first indication information, and the first indication information instructs the terminal device to obtain and / or report the location information of at least one area covered by the neighboring cell, as well as the PLMN information and / or AMF information corresponding to the at least one area.

[0151] Correspondingly, the terminal device can receive the above-mentioned first message from the network device.

[0152] In an embodiment of the present application, the location information of at least one area covered by the neighboring cell, and the information of the PLMN and / or AMF corresponding to the at least one area can be understood as information indicating the mapping relationship between the at least one area covered by the neighboring cell and the PLMN and / or AMF. Correspondingly, the first indication information can also be understood as information indicating that the terminal device obtains and / or reports the mapping relationship between each area covered by the neighboring cell and the PLMN and / or AMF. It should be noted that in an embodiment of the present application, the mapping relationship between the at least one area covered by the neighboring cell and the PLMN and / or AMF can be one-to-one, one-to-many, or many-to-one, and this application does not limit it.

[0153] The location information of each area in at least one area covered by the neighboring area is used to describe the geographical range contained in the area. In one possible embodiment, the location information of an area may include one or more of at least one longitude information, at least one latitude information, and at least one height information (such as altitude information or height information relative to the ground plane or other) of the area, which are respectively used to represent the geographical range covered by the area in the three dimensions of longitude, latitude and altitude. In another possible embodiment, the location information of an area can also be represented by an identifier (such as an ID or an index), wherein there is an association or mapping relationship between the identifier of the area and the specific location of the area (that is, the specific geographical range contained in the area), and the association or mapping relationship can be predefined by the system, or can be sent by the network device to the terminal device through a system message or an RRC message or a layer 2 message, which is not limited by this application. In other words, both the network device and the terminal device can determine their corresponding area information / location information based on the identifier (such as an ID or an index).

[0154] The neighboring cell may be an adjacent cell of the cell currently accessed by the terminal device, or an adjacent cell of the service cell of the terminal device. The cell currently accessed by the terminal device or the service cell of the terminal device are both cells under the jurisdiction of the network device, that is, the cell currently accessed by the terminal device belongs to the network device, or the service cell of the terminal device belongs to the network device. It should be noted that the cell currently accessed by the terminal device and the service cell of the terminal device may be the same concept. In the following description, the expression of the cell currently accessed by the terminal device will be uniformly used to describe the technical solution of the present application in detail.

[0155] In the embodiment of the present application, the PLMN information may be identification information of the PLMN, such as PLMN-identifier. The AMF information may be identification information of the AMF, i.e., AMF-identifier.

[0156] It should be noted that, in one implementation, the first indication information in the embodiment of the present application may be at the cell level (per cell), that is, the first indication information is for a certain neighboring cell of the cell currently accessed by the terminal device, and is used to instruct the terminal device to obtain and / or report the mapping relationship information between at least one area covered by the neighboring cell and the PLMN and / or AMF. It can be understood that the cell currently accessed by the terminal device or the service cell of the terminal device may have one or more neighboring cells, and different neighboring cells may correspond to different first indication information. In another implementation, the first indication information may be at the terminal device level (per UE), that is, the first indication information is for all neighboring cells that can be detected by the terminal device, and is used to instruct the terminal device to obtain and / or report the mapping relationship information between at least one area covered by each neighboring cell in all neighboring cells that can be detected by the terminal device and the PLMN and / or AMF. It can be understood that the neighboring cells that can be detected by the terminal device include one or more cells, each of which corresponds to the first indication information.

[0157] The present application will hereinafter specifically illustrate the technical solution of the present application by taking one of the one or more neighboring areas as an example.

[0158] Specifically, the first message may be an RRC message, a layer 2 message, or other message, which is not limited in this application.

[0159] The first indication information may be indication information represented by a binary value or a Boolean value, or may be a certain information element carried in the first message, or may have other forms of expression, which is not limited in this application.

[0160] For example, if the first indication information is represented by a binary value, then the first indication information can be a flag bit occupying 1 bit in the first message. When the value of the flag bit is "1", it indicates that the terminal device needs to obtain and / or report the mapping relationship information between at least one area included in the neighboring area and the PLMN and / or AMF. When the value of the flag bit is "0", it indicates that the terminal device does not need to obtain and / or report the mapping relationship information between at least one area included in the neighboring area and the PLMN and / or AMF.

[0161] If the first indication information is represented by a Boolean value, then the first indication information can be a Boolean type flag in the first message. When the value of the flag is "TRUE", it indicates that the terminal device needs to obtain and / or report the mapping relationship information between at least one area included in the neighboring area and the PLMN and / or AMF. When the value of the flag is "FALSE", it indicates that the terminal device does not need to obtain and / or report the mapping relationship information between at least one area included in the neighboring area and the PLMN and / or AMF.

[0162] If the first indication information is a certain information element carried in the first message, then the first indication information can be an "AcquireMapping" information element contained in the first message, that is, when the first message includes the "AcquireMapping" information element, it may indicate that the terminal device needs to obtain and / or report the mapping relationship information between at least one area included in the neighboring area and the PLMN and / or AMF; when the first message does not include the "AcquireMapping" information element, it indicates that the terminal device does not need to obtain and / or report the mapping relationship information between at least one area included in the neighboring area and the PLMN and / or AMF.

[0163] Optionally, before the network device sends the first message to the terminal device, the network device may also send location measurement configuration information to the terminal device, instructing the terminal device to perform location measurement. In this way, the terminal device can measure its own location based on the location measurement configuration information and report the measured location information to the network device.

[0164] Among them, the location information measured by the terminal device is the location measurement result obtained by the terminal device performing location measurement on its own location, and the location information may include one or more of longitude information, latitude information and altitude information, or the location information may include an identifier (such as an ID or index). In one possible implementation, the location information can be used to describe a specific location point, such as the longitude, latitude and altitude information of the location point where the terminal device is currently located. Alternatively, in another possible implementation, the location information can also be used to describe a rough area range, that is, an area range where the terminal device is currently located, such as the area range can be represented by the longitude, latitude and altitude of the center point, plus parameters such as the diameter or radius of the area range; or, the area range can be represented by parameters such as multiple longitude values, multiple latitude values, and multiple altitude values. Of course, the description of the area range can also have other forms of expression, and this application will no longer give examples one by one.

[0165] Optionally, before the network device sends the first message to the terminal device, the network device may also send measurement configuration information to the terminal device, where the signal measurement configuration information instructs the terminal device to measure the signal quality of the neighboring cell. The measurement configuration information may include frequency information to indicate the object or frequency point that the terminal device needs to measure. For example, the frequency information may include the absolute frequency position of a synchronization signal block (SSB) and / or a reference resource module.

[0166] In this way, the terminal device can perform signal quality measurement according to the measurement configuration information, and after detecting a new cell (such as a neighboring cell of the service cell), the physical cell identifier (PCI) and signal quality of the cell can be reported to the network device. Subsequently, if the network device determines that the cell detected by the terminal device is a new neighboring cell, the network device can send a second indication information for indicating the reporting of the cell global identifier (CGI) of the cell through the above-mentioned first message. The second indication information may include a PCI value, and accordingly, the second indication information is used to indicate that the terminal device reports the CGI of the cell whose cell identifier is the PCI value, or the second indication information may include frequency information, and accordingly, the second indication information is used to indicate that the terminal device reports the CGI of the cell corresponding to the frequency information. The second indication information may also be called measurement task information, or CGI measurement indication, or have other names, which are not limited in this application.

[0167] It should be noted that the network device may send location measurement configuration information and / or measurement configuration information for performing signal quality measurement to the terminal device. When the network device sends location measurement configuration information and measurement configuration information for performing signal quality measurement to the terminal device, the location measurement configuration information and the measurement configuration information for performing signal quality measurement may be sent in the same message or in different messages, for example, in different RRC messages, which is not limited in this application.

[0168] Step S802: The terminal device obtains the location information of at least one area covered by the neighboring cell, as well as the PLMN information and / or AMF information corresponding to the at least one area according to the first indication information.

[0169] Specifically, the terminal device can read the system message of the neighboring cell according to the indication of the first indication information, and obtain the location information of at least one area included in the neighboring cell from the system message of the neighboring cell, as well as the PLMN information and / or AMF information corresponding to the at least one area.

[0170] Step S803: The terminal device sends a second message to the network device, where the second message includes location information of at least one area covered by the neighboring cell, and information of the PLMN and / or AMF corresponding to the at least one area.

[0171] That is to say, the second message may include information for indicating the mapping relationship between at least one area covered by the neighboring cell and the PLMN and / or AMF. It should be noted that the PLMN information and / or AMF information corresponding to the at least one area may be the PLMN information and / or AMF information corresponding to all areas covered by the neighboring cell, or the PLMN information and / or AMF information corresponding to part of the areas covered by the neighboring cell, which is not limited in this application.

[0172] For example, the cell currently accessed by the terminal device has a neighboring cell that covers countries A and B. Assume that the area in this neighboring cell belonging to country A is denoted as area 1, and the area belonging to country B is denoted as area 2. Furthermore, country A corresponds to PLMN1 / AMF1, and country B corresponds to PLMN2 / AMF2. The information broadcast in the system message for this neighboring cell may include one or more of the following: location information for area 1, identification information for PLMN1 and / or AMF1, location information for area 2, and identification information for PLMN2 and / or AMF2.

[0173] In this way, the information obtained by the terminal device from the system message of the neighboring cell to indicate the mapping relationship between at least one area covered by the neighboring cell and the PLMN and / or AMF can be expressed as {location information of area 1, identification information of PLMN1 and / or AMF1}, {location information of area 2, identification information of PLMN2 and / or AMF2}. Furthermore, the terminal device can report this information to the network device through a second message.

[0174] The second message may be an RRC message, a layer 2 message, or other message, which is not limited in this application.

[0175] Optionally, the second message may also include the CGI of the neighboring area measured by the terminal device.

[0176] It can be seen from this that by adopting this technical solution, the terminal device can obtain / report the mapping relationship information between at least one area covered by the neighboring cell and the PLMN / AMF. For example, in the automatic neighbor relation (ANR) process, the service base station of the terminal device can obtain the above-mentioned mapping relationship of the neighboring base station. It can make a reasonable switching decision / switching request for the switching process of the terminal device based on the mapping relationship and combined with the location information of the terminal device, so that the switching / access of the terminal device can comply with the communication policy requirements of the country / operator to which its location belongs, and avoid the terminal device from accessing from a country / operator to which its location does not belong.

[0177] Please refer to Figure 9 , is a flow chart of another communication method provided in an embodiment of the present application, the method comprising:

[0178] Step S901: The first network device generates a third message, which includes location information of at least one area covered by the first cell managed by the first network device, and information of the PLMN and / or AMF corresponding to the at least one area.

[0179] Step S902: The first network device sends a third message to the second network device. Correspondingly, the second network device can receive the third message from the first network device.

[0180] Step S903: The second network device generates a fourth message, which includes location information of at least one area covered by the second cell managed by the second network device, and information of the PLMN and / or AMF corresponding to the at least one area.

[0181] Step S904: The second network device sends a fourth message to the first network device. Correspondingly, the first network device can receive the fourth message from the second network device.

[0182] It should be noted that this application does not specifically limit the execution order between steps S902 and S904. That is, the first network device may first send the third message to the second network device, and after the second network device receives the third message, it may send the fourth message to the first network device in response to the third message. Alternatively, the second network device may first send the fourth message to the first network device, and after the first network device receives the fourth message, it may send the third message to the second network device in response to the fourth message.

[0183] In the embodiment of the present application, the PLMN information may include identification information of the PLMN, for example, PLMN-identifier. Similarly, the AMF information may include identification information of the AMF, for example, AMF-identifier.

[0184] In the NR system, the third message and the fourth message may be an XN SETUP REQUEST message or an XN SETUP RESPONSE message, or other messages. In the LTE system, the third message and the fourth message may be an X2 SETUP REQUEST message or an X2 SETUP RESPONSE message, or other messages.

[0185] In a possible implementation, the first network device and the second network device may be two adjacent access network devices, such as a base station, or may be CUs in two adjacent access network devices. When there is a directly connected interface (such as an X2 / Xn interface) between the two access network devices, they may exchange information on the mapping relationship between each area covered by the cell they manage and the PLMN / AMF through the interface. For example, information on the mapping relationship between each area covered by the cell and the PLMN / AMF may be included in the XN SETUP REQUEST message and the XN SETUPRESPONSE message. For information on the mapping relationship between each area covered by the cell and the PLMN / AMF, please refer to the description above and will not be repeated here.

[0186] For example, cell C belongs to gNB1 and covers countries A and B. Assume that the area in cell C belonging to country A is region 1, and the area in cell C belonging to country B is region 2. It is also assumed that country A corresponds to PLMN1 / AMF1, and country B corresponds to PLMN2 / AMF2. Cell D belongs to gNB2 and covers countries B and C. Assume that the area in cell D belonging to country B is region 3, and the area in cell D belonging to country C is region 4. It is also assumed that country B corresponds to PLMN2 / AMF2, and country C corresponds to PLMN3 / AMF3.

[0187] Taking the NR system as an example, the XN SETUP REQUEST message sent by gNB1 (or gNB1-CU) to gNB2 (or gNB2-CU) may include information on the mapping relationships between the various areas covered by cell C and the PLMN / AMF, such as {location information of area 1, identification information of PLMN1 and / or AMF1}, {location information of area 2, identification information of PLMN2 and / or AMF2}. Correspondingly, the XN SETUP RESPONSE message sent by gNB2 (or gNB2-CU) to gNB1 (or gNB1-CU) may include information on the mapping relationships between the various areas covered by cell D and the PLMN / AMF, such as {location information of area 3, identification information of PLMN2 and / or AMF2}, {location information of area 4, identification information of PLMN3 and / or AMF3}.

[0188] Alternatively, the XN SETUP REQUEST message sent by gNB2 (or gNB2-CU) to gNB1 (or gNB1-CU) may include information on the mapping relationships between the various areas covered by cell D and the PLMN / AMF, such as {location information of area 3, identification information of PLMN2 and / or AMF2}, and {location information of area 4, identification information of PLMN3 and / or AMF3}. Correspondingly, the XN SETUP RESPONSE message sent by gNB1 (or gNB1-CU) to gNB2 (or gNB2-CU) may include information on the mapping relationships between the various areas covered by cell C and the PLMN / AMF, such as {location information of area 1, identification information of PLMN1 and / or AMF1}, and {location information of area 2, identification information of PLMN2 and / or AMF2}.

[0189] Furthermore, considering the CU-DU architecture adopted by the access network device, in another possible implementation, the first network device and the second network device may also be a CU node and a DU node within the same access network device. That is, the CU node of a certain access network device may send information on the mapping relationship between at least one area covered by the cell of the access network device and the PLMN / AMF to the DU node of the access network device, and / or the DU node of the access network device may also send information on the mapping relationship between at least one area covered by the cell of the access network device and the PLMN / AMF to the CU node of the access network device.

[0190] For example, the F1 SETUP REQUEST message sent by the gNB-DU to the gNB-CU, the F1 SETUP RESPONSE message sent by the gNB-CU to the gNB-DU, the F1 SETUP FAILURE message sent by the gNB-CU to the gNB-DU, the UE CONTEXT SETUP REQUEST message sent by the gNB-CU to the gNB-DU, the UE CONTEXT SETUPRESPONSE message sent by the gNB-DU to the gNB-CU, the GNB-DU CONFIGURATION UPDATE message sent by the gNB-DU to the gNB-CU, the GNB-DU CONFIGURATION UPDATE ACKNOWLEDGE message sent by the gNB-CU to the gNB-DU, the GNB-DU CONFIGURATION UPDATE FAILURE message sent by the gNB-CU to the gNB-DU, the GNB-CU CONFIGURATION UPDATE message sent by the gNB-DU to the gNB-CU, and the GNB-CU CONFIGURATION UPDATE The ACKNOWLEDGE message, the GNB-CU CONFIGURATION UPDATE FAILURE message sent by the gNB-DU to the gNB-CU, etc. may include information about the mapping relationship between at least one area covered by the cell and the PLMN / AMF.

[0191] Furthermore, if the CU node in the access network device can be divided into CU-CP and CU-UP, then in another possible implementation, the first network device and the second network device can also be the CU-CP part and CU-UP part of the CU node. That is, the CU-CP of the CU node inside the access network device can send information on the mapping relationship between at least one area covered by the cell and the PLMN / AMF to the CU-UP of the CU node, and / or, the CU-UP of the CU node can send information on the mapping relationship between at least one area covered by the cell and the PLMN / AMF to the CU-CP of the CU node.

[0192] For example, the GNB-CU-UP E1 SETUP REQUEST message sent by the gNB-CU-UP to the gNB-CU-CP, the GNB-CU-UP E1 SETUP RESPONSE message sent by the gNB-CU-CP to the gNB-CU-UP, the GNB-CU-UP E1 SETUP FAILURE message sent by the gNB-CU-CP to the gNB-CU-UP, the GNB-CU-CP E1 SETUP REQUEST message sent by the gNB-CU-CP to the gNB-CU-UP, the GNB-CU-CP E1 SETUP RESPONSE message sent by the gNB-CU-UP to the gNB-CU-CP, the GNB-CU-CP E1 SETUP FAILURE message sent by the gNB-CU-UP to the gNB-CU-CP, and the GNB-CU-UP CONFIGURATION message sent by the gNB-CU-UP to the gNB-CU-CP. The GNB-CU-UP CONFIGURATION UPDATE message, the GNB-CU-UP CONFIGURATION UPDATE ACKNOWLEDGE message sent by the gNB-CU-CP to the gNB-CU-UP, the GNB-CU-UP CONFIGURATION UPDATE FAILURE message sent by the gNB-CU-CP to the gNB-CU-UP, the GNB-CU-CP CONFIGURATION UPDATE message sent by the gNB-CU-CP to the gNB-CU-UP, the GNB-CU-CP CONFIGURATION UPDATE ACKNOWLEDGE message sent by the gNB-CU-UP to the gNB-CU-CP, and the GNB-CU-CP CONFIGURATION UPDATE FAILURE message sent by the gNB-CU-UP to the gNB-CU-CP may include information on the mapping relationship between at least one area covered by the cell and the PLMN / AMF.

[0193] It can be seen from this that in an embodiment of the present application, by introducing a mechanism for information on the mapping relationship between at least one area covered by an interactive cell between nodes and the PLMN / AMF, after the node obtains the above mapping relationship, it can make reasonable decisions based on the mapping relationship when subsequent access control or switching decisions are required or in other scenarios, so that the access / switching of the terminal device can comply with the communication policy requirements of the country / operator to which it is located, and avoid the terminal device from accessing from a country / operator to which it is not located.

[0194] The present application also provides a communication device, please refer to Figure 10, is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. The communication device 1000 includes a transceiver module 1010 and a processing module 1020. The communication device can be used to implement the functions of a network device (such as a first network device or a target network device) in any of the above method embodiments. For example, the communication device can be a network device or a chip or circuit included in the network device.

[0195] For example, when the communication device executes Figure 3 In the method embodiment shown in , when the operation or step of the target network device corresponds, the transceiver module 1010 is used to receive a handover request message from the source network device, the handover request message being used to request that the terminal device be handed over to the target network device, the handover request message including the location information of the terminal device, and information about the first public land mobile network PLMN to which the source network device belongs or the first access and mobility management function AMF to which the source network device is connected when the terminal device communicates with the source network device; the processing module 1020 is used to determine, based on the location information of the terminal device, that the location of the terminal device is within the first area covered by the target cell, and the PLMN corresponding to the first area does not include the first PLMN, or the AMF corresponding to the first area does not include the first AMF, wherein the target network device manages the target cell; the transceiver module 1010 is also used to send a handover failure message to the source network device.

[0196] In one possible design, the switching failure message includes one or more of the following information: failure cause information, information about the PLMN that the target network device allows the terminal device to access, and information about the AMF that the target network device allows the terminal device to access; wherein the failure cause information is used to indicate that the reason for the switching failure is an invalid PLMN, or an invalid AMF, or invalid location information, or an illegal request.

[0197] In one possible design, the handover failure message includes location information of at least one area covered by the target cell, and information of the PLMN corresponding to the at least one area and / or information of the AMF.

[0198] When the communication device executes Figure 3 In the method embodiment shown in , when the operation or step corresponds to the source network device, the transceiver module 1010 is used to send a switching request message to the target network device, where the switching request message is used to request that the terminal device be switched to the target network device. The switching request message includes the location information of the terminal device, and information about the first public land mobile network PLMN to which the source network device belongs when the terminal device communicates with the source network device, or information about the first access and mobility management function AMF to which the source network device is connected. The transceiver module 1010 is also used to receive a switching failure message from the target network device.

[0199] In one possible design, the switching failure message includes one or more of the following information: failure cause information, information about the PLMN that the target network device allows the terminal device to access, and information about the AMF that the target network device allows the terminal device to access; wherein the failure cause information is used to indicate that the reason for the switching failure is an invalid PLMN, or an invalid AMF, or invalid location information, or an illegal request.

[0200] In one possible design, the handover failure message includes location information of at least one area covered by the target cell, and information of the PLMN corresponding to the at least one area and / or information of the AMF.

[0201] In one possible design, the transceiver module 1010 is also used to send location measurement configuration information to the terminal device, where the location measurement configuration information instructs the terminal device to perform location measurement; and the processing module 1020 is used to obtain location information of the terminal device.

[0202] When the communication device executes Figure 7 In the method embodiment shown in , when the operation or step corresponds to the source network device, the transceiver module 1010 is used to obtain the location information of the terminal device; the processing module 1020 is used to determine, based on the location information of the terminal device, that the terminal device is located in the first area covered by the target cell, and the first area covered by the target cell corresponds to the second public land mobile network PLMN or the second access and mobility management function AMF; the transceiver module 1010 is also used to send a switching request message to the target network device, the switching request message being used to request that the terminal device be switched to the target network device, the switching request message including first information, the first information indicating that the PLMN requested to be accessed is the second PLMN or the AMF requested to be accessed is the second AMF; the transceiver module 1010 is also used to receive a switching request confirmation message from the target network device.

[0203] In one possible design, the transceiver module 1010 is also used to send a first message to the terminal device, where the first message includes first indication information, and the first indication information indicates that the terminal device reports the location information of at least one area covered by the target cell, and the PLMN information and / or AMF information corresponding to the at least one area; the transceiver module 1010 is also used to receive a second message from the terminal device, where the second message includes the location information of at least one area covered by the target cell, and the PLMN information and / or AMF information corresponding to the at least one area.

[0204] In one possible design, the transceiver module 1010 is also used to receive a third message from the target network device, which includes location information of at least one area covered by the target cell, and information of the PLMN and / or AMF corresponding to the at least one area.

[0205] When the communication device executes Figure 8 When the operation or steps of the corresponding network device in the method embodiment shown in the figure are performed, the transceiver module 1010 is used to send a first message to the terminal device, where the first message includes first indication information, and the first indication information indicates that the terminal device reports the location information of at least one area covered by the neighboring area, and the information of the public land mobile network PLMN corresponding to the at least one area and / or the information of the access and mobility management function AMF; the transceiver module 1010 is also used to receive a second message from the terminal device, where the second message includes the location information of at least one area covered by the neighboring area, and the information of the PLMN corresponding to the at least one area and / or the information of the AMF.

[0206] In one possible design, the transceiver module 1010 is also used to send location measurement configuration information to the terminal device, where the location measurement configuration information instructs the terminal device to perform location measurement; and the network device receives the location information sent by the terminal device.

[0207] In one possible design, the first message also includes second indication information, and the second indication information instructs the terminal device to report the cell global identifier CGI of the neighboring area.

[0208] When the communication device executes Figure 9 In the method embodiment shown in , when the operation or step corresponds to the first network device, the processing module 1020 is used to generate a third message, where the third message includes location information of at least one area covered by the first cell managed by the first network device, and information of the public land mobile network PLMN and / or access and mobility management function AMF corresponding to the at least one area covered by the first cell; the transceiver module 1010 is used to send the third message to the second network device.

[0209] In one possible design, the transceiver module 1010 is also used to receive a fourth message from the second network device, which includes location information of at least one area covered by a second cell managed by the second network device, and PLMN information and / or AMF information corresponding to at least one area covered by the second cell.

[0210] It should be understood that the processing module 1020 involved in the communication device can be implemented by at least one processor or processor-related circuit components, and the transceiver module 1010 can be implemented by at least one transceiver or transceiver-related circuit components or communication interfaces. The operations and / or functions of each module in the communication device are respectively to achieve Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 or Figure 9 For the sake of brevity, the corresponding process of the method shown in FIG. is not repeated here. Optionally, the communication device may further include a storage module, which can be used to store data and / or instructions. The transceiver module 1010 and / or the processing module 1020 can read the data and / or instructions in the access module, thereby enabling the communication device to implement the corresponding method. The storage module can be implemented, for example, by at least one memory.

[0211] The above-mentioned storage module, processing module and transceiver module may exist separately, or all or part of the modules may be integrated, for example, the storage module and the processing module are integrated, or the processing module and the transceiver module are integrated.

[0212] Please refer to Figure 11 , is another structural diagram of a communication device provided in an embodiment of the present application. The communication device may be specifically a network device, such as a base station, for implementing the functions of the network device (such as the first network device or the target network device) involved in any of the above method embodiments.

[0213] The network device includes: one or more radio frequency units, such as a remote radio unit (RRU) 1101 and one or more baseband units (BBU) (also called digital units, digital units, DU) 1102. The RRU 1101 can be called a transceiver unit, a transceiver, a transceiver circuit, or a transceiver, etc., and may include at least one antenna 11011 and a radio frequency unit 11012. The RRU 1101 is mainly used for transmitting and receiving radio frequency signals and converting radio frequency signals into baseband signals. The BBU 1102 is mainly used for baseband processing, controlling the base station, etc. The RRU 1101 and BBU 1102 can be physically set together or physically separated, that is, a distributed base station.

[0214] The BBU 1102 is the control center of the base station, which can also be called a processing unit. It is mainly used to perform baseband processing functions such as channel coding, multiplexing, modulation, spread spectrum, etc. For example, the BBU (processing unit) 1102 can be used to control the base station to execute the operation process of the network device in the above method embodiment.

[0215] In one example, the BBU 1102 may be composed of one or more single boards, and multiple single boards may jointly support a wireless access network with a single access indication (such as an LTE network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The BBU 1102 may also include a memory 11021 and a processor 11022, and the memory 11021 is used to store necessary instructions and data. The processor 11022 is used to control the base station to perform necessary actions, for example, to control the base station to perform the sending operation in the above method embodiment. The memory 11021 and the processor 11022 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. Alternatively, multiple single boards may share the same memory and processor. In addition, necessary circuits may be provided on each single board.

[0216] This application embodiment also provides another communication device, please refer to Figure 12 , is a schematic diagram of the structure of another communication device provided in an embodiment of the present application. The communication device 1200 includes a transceiver module 1210 and a processing module 1220. The communication device can be used to implement the functions of the terminal device in any of the above method embodiments. For example, the communication device can be a terminal device, such as a handheld terminal device or an in-vehicle terminal device; the communication device can also be a chip or circuit included in the terminal device, or a device that includes the terminal device, such as various types of vehicles.

[0217] For example, when the communication device executes Figure 8 When the operation or steps of the terminal device correspond to the method embodiment shown in , the transceiver module 1210 is used to receive a first message from the network device, the first message including first indication information, and the first indication information indicating that the terminal device reports the location information of at least one area covered by the neighboring area, and the information of the public land mobile network PLMN corresponding to the at least one area and / or the access and mobility management function AMF; the processing module 1220 is used to obtain the location information of at least one area covered by the neighboring area, and the information of the PLMN corresponding to the at least one area and / or the AMF information according to the first indication information; the transceiver module 1210 is also used to send a second message to the network device, the second message including the location information of at least one area covered by the neighboring area, and the information of the PLMN corresponding to the at least one area and / or the AMF information.

[0218] In one possible design, the transceiver module 1210 is also used to receive location measurement configuration information from the network device, which location measurement configuration information instructs the terminal device to perform location measurement; the processing module 1220 is also used to perform location measurement according to the instruction of the location measurement configuration; the transceiver module 1210 is also used to send the measured location information of the terminal device to the network device.

[0219] In one possible design, the first message also includes second indication information, which instructs the terminal device to report the cell global identifier CGI of the neighboring area.

[0220] The processing module 1220 involved in the communication device can be implemented by at least one processor or processor-related circuit components, and the transceiver module 1210 can be implemented by at least one transceiver or transceiver-related circuit components or communication interfaces. The operations and / or functions of each module in the communication device are respectively to achieve Figure 4 、 Figure 5 、 Figure 6 or Figure 8 For the sake of brevity, the corresponding process of the method shown in FIG. is not repeated here. Optionally, the communication device may further include a storage module, which can be used to store data and / or instructions. The transceiver module 1210 and / or the processing module 1220 can read the data and / or instructions in the storage module, thereby enabling the communication device to implement the corresponding method. The storage module can be implemented, for example, by at least one memory.

[0221] The above-mentioned storage module, processing module and transceiver module may exist separately, or all or part of the modules may be integrated, for example, the storage module and the processing module are integrated, or the processing module and the transceiver module are integrated.

[0222] Please refer to Figure 13 , is another structural diagram of another communication device provided in an embodiment of the present application. The communication device may be a terminal device, which can be used to implement the functions of the terminal device involved in any of the above method embodiments. For ease of understanding and illustration, Figure 13 In this article, the terminal device is a mobile phone. Figure 13As shown, the terminal device includes a processor and may also include a memory. Of course, it may also include a radio frequency circuit, an antenna, and input and output devices. The processor is mainly used to process communication protocols and communication data, as well as to control the terminal device, execute software programs, and process software program data. The memory is mainly used to store software programs and data. The radio frequency circuit is mainly used for converting baseband signals into radio frequency signals and processing radio frequency signals. The antenna is mainly used to transmit and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are mainly used to receive data input by the user and output data to the user. It should be noted that some types of terminal devices may not have input and output devices.

[0223] When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs the baseband signal to the RF circuit. The RF circuit performs RF processing on the baseband signal and then transmits the RF signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data. For the sake of explanation, Figure 13 Only one memory and processor are shown. In actual terminal device products, one or more processors and one or more memories may exist. Memory may also be referred to as a storage medium or storage device. The memory may be provided independently of the processor or integrated with the processor, and this is not limited in the embodiments of the present application.

[0224] In the embodiment of the present application, the antenna and radio frequency circuit with transceiver functions can be regarded as the transceiver unit of the terminal device, and the processor with processing function can be regarded as the processing unit of the terminal device. Figure 13 As shown, the terminal device includes a transceiver unit 1310 and a processing unit 1320. The transceiver unit may also be referred to as a transceiver, transceiver, or transceiver device. The processing unit may also be referred to as a processor, processing board, processing module, or processing device. Optionally, the device in the transceiver unit 1310 that implements the receiving function may be considered a receiving unit, and the device in the transceiver unit 1310 that implements the transmitting function may be considered a transmitting unit, i.e., the transceiver unit 1310 includes a receiving unit and a transmitting unit. The transceiver unit may also be referred to as a transceiver, transceiver, or transceiver circuit. The receiving unit may also be referred to as a receiver, receiver, or receiving circuit. The transmitting unit may also be referred to as a transmitter, transmitter, or transmitting circuit. It should be understood that the transceiver unit 1310 is used to perform the transmitting and receiving operations on the terminal device side in the above-described method embodiments, and the processing unit 1320 is used to perform other operations on the terminal device in addition to the transmitting and receiving operations in the above-described method embodiments.

[0225] An embodiment of the present application also provides a chip system, including: a processor, the processor is coupled to a memory, the memory is used to store programs or instructions, when the program or instructions are executed by the processor, the chip system implements the method of the corresponding terminal device or the method of the corresponding network device in any of the above method embodiments.

[0226] Optionally, there may be one or more processors in the chip system. The processor may be implemented in hardware or software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0227] Optionally, the memory in the chip system may be one or more memories. The memory may be integrated with the processor or may be provided separately from the processor, which is not limited in this application. For example, the memory may be a non-transient processor, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or provided on different chips. This application does not specifically limit the type of memory or the configuration of the memory and the processor.

[0228] Exemplarily, the chip system can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0229] It should be understood that each step in the above method embodiment can be completed by hardware integrated logic circuits in a processor or by software instructions. The method steps disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware processor, or by a combination of hardware and software modules in a processor.

[0230] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-readable instructions. When a computer reads and executes the computer-readable instructions, the computer executes the method in any of the above method embodiments.

[0231] An embodiment of the present application further provides a computer program product. When a computer reads and executes the computer program product, the computer executes the method in any of the above method embodiments.

[0232] The present application also provides a communication system including at least one network device and at least one terminal device. The at least one network device may include a source network device and a target network device, or may include a first network device and a second network device. Optionally, the communication system may also include a core network device.

[0233] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0234] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0235] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) is integrated into the processor.

[0236] It should be noted that the memory described herein is intended to include, but not be limited to, these and any other suitable types of memory.

[0237] It should be understood that the various numerical numbers involved in the various embodiments of the present application are only for the convenience of description. The size of the serial numbers of the above-mentioned processes or steps does not mean the order of execution. The execution order of each process or step should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0238] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0239] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0240] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0241] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0242] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0243] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0244] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0245] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method comprises: The target network device receives a handover request message from the source network device, where the handover request message is used to request handover of the terminal device to the target network device, and the handover request message includes the location information of the terminal device, and information about a first public land mobile network PLMN to which the source network device belongs when the terminal device communicates with the source network device, or information about a first access and mobility management function AMF to which the source network device is connected; The target network device determines, based on the location information of the terminal device, that the location of the terminal device is within a first area covered by a target cell, and that the first PLMN corresponding to the first area does not include the first PLMN, or the AMF corresponding to the first area does not include the first AMF; wherein the target network device manages the target cell; The target network device sends a switching failure message to the source network device.

2. The method according to claim 1, characterized in that The handover failure message includes one or more of the following information: failure cause information, information about the PLMN that the target network device allows the terminal device to access, and information about the AMF that the target network device allows the terminal device to access; The failure cause information is used to indicate that the reason for the handover failure is an invalid PLMN, an invalid AMF, invalid location information, or an illegal request.

3. The method according to claim 1 or 2, characterized in that The handover failure message includes location information of at least one area covered by the target cell, and information of the PLMN corresponding to the at least one area and / or information of the AMF.

4. A communication method, characterized in that: The method comprises: The source network device sends a handover request message to the target network device, where the handover request message is used to request that the terminal device be handed over to the target network device. The handover request message includes the location information of the terminal device, and information about the first public land mobile network PLMN to which the source network device belongs when the terminal device communicates with the source network device, or information about the first access and mobility management function AMF to which the source network device is connected. The source network device receives a switching failure message from the target network device.

5. The method according to claim 4, characterized in that The handover failure message includes one or more of the following information: failure cause information, information about the PLMN that the target network device allows the terminal device to access, and information about the AMF that the target network device allows the terminal device to access; The failure cause information is used to indicate that the reason for the handover failure is an invalid PLMN, an invalid AMF, invalid location information, or an illegal request.

6. The method according to claim 4, characterized in that The handover failure message includes location information of at least one area covered by the target cell, and information of the PLMN corresponding to the at least one area and / or information of the AMF.

7. The method according to any one of claims 4 to 6, characterized in that The method further comprises: The source network device sends location measurement configuration information to the terminal device, where the location measurement configuration information instructs the terminal device to perform location measurement; The source network device obtains the location information of the terminal device.

8. A communication method, characterized in that: The method comprises: The source network device obtains the location information of the terminal device; The source network device determines, according to the location information of the terminal device, that the terminal device is located in a first area covered by a target cell, and the first area covered by the target cell corresponds to a second public land mobile network PLMN or a second access and mobility management function AMF; The source network device sends a handover request message to the target network device, where the handover request message is used to request that the terminal device be handed over to the target network device, and the handover request message includes first information, where the first information indicates that the PLMN requested to be accessed is the second PLMN or the AMF requested to be connected is the second AMF, wherein the target network device is a network device that manages the target cell; The source network device receives a handover request confirmation message from the target network device.

9. The method according to claim 8, characterized in that The method further comprises: The source network device sends a first message to the terminal device, where the first message includes first indication information, where the first indication information instructs the terminal device to report location information of at least one area covered by the target cell, and information of the PLMN and / or AMF corresponding to the at least one area; The source network device receives a second message from the terminal device, where the second message includes location information of at least one area covered by the target cell, and information of the PLMN and / or AMF corresponding to the at least one area.

10. The method according to claim 8, characterized in that The method further comprises: The source network device receives a third message from the target network device, where the third message includes location information of at least one area covered by the target cell, and information of the PLMN and / or AMF corresponding to the at least one area.

11. A communication method, characterized in that: The method comprises: The terminal device receives a first message from the network device, where the first message includes first indication information, where the first indication information indicates that the terminal device reports location information of at least one area covered by a neighboring cell, and information of a public land mobile network PLMN and / or information of an access and mobility management function AMF corresponding to the at least one area; The terminal device obtains, according to the first indication information, location information of at least one area covered by the neighboring cell, and information of the PLMN and / or AMF corresponding to the at least one area; The terminal device sends a second message to the network device, where the second message includes location information of at least one area covered by the neighboring cell, and information of the PLMN and / or AMF corresponding to the at least one area; The second message is used for cell switching of the terminal device.

12. The method according to claim 11, characterized in that The method further comprises: The terminal device receives location measurement configuration information from the network device, where the location measurement configuration information instructs the terminal device to perform location measurement; The terminal device sends the location information of the terminal device to the network device.

13. The method according to claim 11 or 12, characterized in that The first message also includes second indication information, and the second indication information instructs the terminal device to report the cell global identifier CGI of the neighboring area.

14. A communication method, characterized in that: The method comprises: The network device sends a first message to the terminal device, where the first message includes first indication information, where the first indication information instructs the terminal device to report location information of at least one area covered by a neighboring cell, and information of a public land mobile network PLMN corresponding to the at least one area and / or information of an access and mobility management function AMF; The network device receives a second message from the terminal device, the second message including location information of at least one area covered by the neighboring cell, and PLMN information and / or AMF information corresponding to the at least one area; wherein the second message is used for cell switching of the terminal device.

15. The method according to claim 14, characterized in that The method further comprises: The network device sends location measurement configuration information to the terminal device, where the location measurement configuration information instructs the terminal device to perform location measurement; The network device receives the location information sent by the terminal device.

16. The method according to claim 14 or 15, characterized in that The first message also includes second indication information, and the second indication information instructs the terminal device to report the cell global identifier CGI of the neighboring area.

17. A communication method, characterized in that: The method comprises: The first network device generates a third message, where the third message includes location information of at least one area covered by a first cell managed by the first network device, and information of a public land mobile network PLMN and / or information of an access and mobility management function AMF corresponding to the at least one area covered by the first cell; The first network device sends the third message to the second network device; The third message is used for cell switching of the terminal device.

18. The method according to claim 17, characterized in that The method further comprises: The first network device receives a fourth message from the second network device, wherein the fourth message includes location information of at least one area covered by the second cell managed by the second network device, and PLMN information and / or AMF information corresponding to at least one area covered by the second cell.

19. A communication device, characterized in that: The apparatus comprises a unit for performing the steps of the method according to any one of claims 1 to 3, or a unit for performing the steps of the method according to any one of claims 4 to 7, or a unit for performing the steps of the method according to any one of claims 8 to 10, or a unit for performing the steps of the method according to any one of claims 11 to 13, or a unit for performing the steps of the method according to any one of claims 14 to 16, or a unit for performing the steps of the method according to claim 17 or 18.

20. A communication device, characterized in that: The apparatus comprises at least one processor coupled to at least one memory: The at least one processor is configured to execute a computer program or instruction stored in the at least one memory, so that the apparatus performs the method according to any one of claims 1 to 3, or the apparatus performs the method according to any one of claims 4 to 7, or the apparatus performs the method according to any one of claims 8 to 10, or the apparatus performs the method according to any one of claims 11 to 13, or the apparatus performs the method according to any one of claims 14 to 16, or the apparatus performs the method according to claim 17 or 18.

21. A computer-readable storage medium, characterized in that Used to store instructions, which, when executed, enable the method according to any one of claims 1 to 3 to be implemented, or the method according to any one of claims 4 to 7 to be implemented, or the method according to any one of claims 8 to 10 to be implemented, or the method according to any one of claims 11 to 13 to be implemented, or the method according to any one of claims 14 to 16 to be implemented, or the method according to claim 17 or 18 to be implemented.

22. A communication device, characterized in that: including a processor and an interface circuit; The interface circuit is used to exchange code instructions with the processor; The processor is used to run the code instructions to execute the method according to any one of claims 1 to 3, or the processor is used to run the code instructions to execute the method according to any one of claims 4 to 7, or the processor is used to run the code instructions to execute the method according to any one of claims 8 to 10, or the processor is used to run the code instructions to execute the method according to any one of claims 11 to 13, or the processor is used to run the code instructions to execute the method according to any one of claims 14 to 16, or the processor is used to run the code instructions to execute the method according to claim 17 or 18.

23. A computer program product, characterized in that When a computer reads and executes the computer program product, the computer executes the method according to any one of claims 1 to 3, or the method according to any one of claims 4 to 7, or the method according to any one of claims 8 to 10, or the method according to any one of claims 11 to 13, or the method according to any one of claims 14 to 16, or the method according to claim 17 or 18.

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