A communication method and apparatus

Abstract

The present application discloses a communication method and apparatus. The method includes: in a scenario where a second cell under a second network device supports multiple PLMNs, a first network device may send a first request message to the second network device, and the location information of the terminal device and the information of a first PLMN are carried in the first request message, where the first PLMN is the target PLMN determined by the first network device for the terminal device to access. In this way, the second network device may determine whether the PLMN requested by the terminal device to access is reasonable according to the location information of the terminal device in the first request message. If the location where the terminal device is located is outside the first area corresponding to the first PLMN, the second network device may reject the handover request of the terminal device, thereby preventing the terminal device from accessing from a country / carrier other than the one to which its location belongs, and ensuring that the communication behavior of the terminal device under the NTN cell can comply with the communication policy of the country / carrier to which its location belongs.

Description

Technical Field

[0001] This application relates to the field of wireless communication technologies, and in particular, to a communication method and apparatus. Background Art

[0002] In a non-terrestrial network (NTN) communication system, by deploying the functions of access network devices or some access network devices on non-ground devices such as high-altitude platforms or satellites, seamless coverage is provided for terminal devices. Moreover, since high-altitude platforms or satellites are located at high altitudes and are less affected by natural disasters, the NTN communication system has relatively high reliability.

[0003] Another important feature of the NTN communication system is that the coverage area of an NTN cell is usually relatively large. For example, the cell coverage diameter can reach dozens to thousands of kilometers. Therefore, there may be a situation where an NTN cell covers the geographical areas of multiple countries or the service areas of multiple operators. Taking the NTN system as a satellite communication system as an example, the satellite can indicate that it can support the services of multiple countries or operators by broadcasting the information of multiple public land mobile networks (PLMNs).

[0004] In the prior art, as long as the terminal device is within the coverage area of the cell, the terminal device can receive the signal of the satellite and report the measurement results based on the received signal, so that the network can perform handover decisions according to the measurement results reported by the terminal device. However, in the scenario where the target cell supports multiple PLMNs, the corresponding communication strategies of different PLMNs are different. At this time, if the handover to the target cell is only performed based on the measurement results of the cell reported by the terminal device, there may be a situation where the terminal device requests to access a PLMN 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 it requests to access, thereby causing the handover process to fail and affecting the communication performance. Summary of the Invention

[0005] A communication method and apparatus in an embodiment of this application are used to enable a terminal device to switch / access to a target cell from a PLMN that matches its location when the target cell is an NTN cell that supports multiple PLMNs, so as to meet the corresponding communication strategy requirements.

[0006] In a first aspect, an embodiment of this application provides a communication method. This method can be executed by a first network device or by components (such as chips or circuits) configured in the first network device. In the following description of this application, the example of the first network device executing this method will be used for illustration.

[0007] The method may include: a first network device sending a first request message to a second network device, where the first request message is used to request to access a terminal device to a second cell under the second network device, the first request message includes the location information of the terminal device and the information of a first PLMN, and the first PLMN is the target PLMN determined by the first network device for the terminal device to access; the first network device receiving a first response message from the second network device, the first response message includes the information of a second PLMN, and the second PLMN is the PLMN that the second network device allows the terminal device to access; wherein, the location where the terminal device is located is outside the first area corresponding to the first PLMN and within the second area corresponding to the second PLMN, and both the first PLMN and the second PLMN are PLMNs supported by the second network device.

[0008] With the above technical solution, in a scenario where the second cell supports multiple PLMNs, the first network device can provide the location information of the terminal device to the second network device, so that the target network device can determine whether the PLMN requested by the terminal device to access is reasonable according to the location information of the terminal device, thereby avoiding the terminal device from accessing from a country / carrier that does not belong to its location, and ensuring that the communication behavior of the terminal device under the NTN cell can comply with the communication policy of the country / carrier where its location belongs.

[0009] In a possible design of the first aspect, the method further includes: the first network device receiving second indication information from the terminal device or the second network device, where the second indication information is used to indicate that the second cell is an NTN cell, or the second indication information is used to indicate that the second cell is an NTN cell and the number of PLMNs supported by the second cell is at least two.

[0010] In a possible design of the first aspect, the method further includes: the first network device receiving the cell information of the second cell from the terminal device or the second network device, and the cell information of the second cell includes the information of at least two PLMNs supported by the second cell, and the at least two PLMNs include the first PLMN and the second PLMN.

[0011] In a possible design of the first aspect, the first response message further includes second indication information, where the second indication information is used to indicate that the location where the terminal device is located does not match the first PLMN requested to access.

[0012] In a possible design of the first aspect, the method further includes: the first network device sending third indication information to the terminal device, where the third indication information is used to indicate that the terminal device carries the location information of the terminal device when reporting the measurement result of the second cell.

[0013] In a possible design of the first aspect, the first network device sending the first request message to the second network device may specifically include: the first network device sending the first request message to the second network device through the core network device. Correspondingly, the first network device receiving the first response message from the second network device may specifically include: the first network device receiving the first response message from the second network device from the core network device.

[0014] In a second aspect, an embodiment of the present application provides a communication method. This method can be executed by the second network device or by components (such as chips or circuits) configured in the second network device. In the following description of the present application, the example of the second network device executing this method will be used for illustration.

[0015] This method may include: the second network device receiving a first request message from the first network device. This first request message is used to request to connect the terminal device to a cell under the second network device. The first request message includes the location information of the terminal device and the information of a first PLMN. The first PLMN is the target PLMN determined by the first network device for the terminal device to access; if the location where the terminal device is located is outside the first area corresponding to the first PLMN and within the second area corresponding to the second PLMN, then the second network device determines the second PLMN as the target PLMN that allows the terminal device to access. Both the first PLMN and the second PLMN are PLMNs supported by the second network device.

[0016] In a possible design of the second aspect, this method further includes: the second network device sending a first indication information to the first network device. This first indication information is used to indicate that the second cell is an NTN cell, or this second indication information is used to indicate that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two.

[0017] In a possible design of the second aspect, this method further includes: the second network device sending the cell information of the second cell to the first network device. The cell information of the second cell includes the information of at least two PLMNs supported by the second cell. The at least two PLMNs include the first PLMN and the second PLMN.

[0018] In a possible design of the second aspect, the first response message further includes a second indication information. This second indication information is used to indicate that the location where the terminal device is located does not match the first PLMN for which access is requested.

[0019] In a possible design of the second aspect, the second network device receiving the first request message from the first network device may specifically include: the second network device receiving the first request message from the first network device from the core network device. Correspondingly, the second network device sending the first response message to the first network device may specifically include: the second network device sending the first response message to the first network device through the core network device.

[0020] In a third aspect, an embodiment of the present application provides a communication method. This method can be executed by a terminal device or by components (such as chips or circuits) configured in the terminal device. In the following description of the present application, the example of the terminal device executing this method will be used for illustration.

[0021] This method may include: the terminal device receiving third indication information from the first network device, where the third indication information is used to indicate that the terminal device carry its location information when reporting the measurement result of the second cell, and the second cell is a cell under the second network device; the terminal device sending a measurement report to the first network device, and the measurement report includes the location information of the terminal device.

[0022] In a possible design of the third aspect, this method further includes: the terminal device sending first indication information to the first network device, where the first indication information is used to indicate that the second cell is an NTN cell, or the first indication information is used to indicate that the second cell is an NTN cell and the PLMN supported by the second cell is at least two.

[0023] In a possible design of the third aspect, this method further includes: the terminal device sending cell information of the second cell to the first network device, and the cell information of the second cell includes information of at least two PLMNs supported by the second cell.

[0024] In a fourth aspect, an embodiment of the present application provides a communication device. This device may also have the function of the first network device in the above-mentioned first aspect or any possible design of the first aspect, or have the function of the second network device in the above-mentioned second aspect or any possible design of the second aspect. This device can be a network device or a chip included in the network device.

[0025] This device has the function of the terminal device in the above-mentioned third aspect or any possible design of the third aspect, or has the function of the first network device in the above-mentioned fourth aspect or any possible design of the fourth aspect. This device can be a terminal device or a chip included in the terminal device.

[0026] The functions of the above communication device can be implemented by hardware or by hardware executing corresponding software, and the hardware or software includes one or more modules or units or means corresponding to the above functions.

[0027] In a possible design, the structure of the device includes a processing module and a transceiver module. The processing module is configured to support the device to execute the corresponding functions of the first network device in the above first aspect or any design of the first aspect, or execute the corresponding functions of the second network device in the above second aspect or any design of the second aspect, or execute the corresponding functions of the terminal device in the above third aspect or any possible design of the third aspect. The transceiver module is used to support the communication between the device and other communication devices. For example, when the device is the first network device, it can send a first request message to the second network device and receive the first response information from the second network device. The communication device may further include a storage module, which is coupled to the processing module and stores the necessary program instructions and data of the device. As an example, the processing module may be a processor, the transceiver module may be a transceiver, and the storage module may be a memory. The memory may be integrated with the processor or may be separately provided from the processor. The present application does not limit this.

[0028] In another possible design, the structure of the device includes a processor and may further include a memory. The processor is coupled to the memory and can be used to execute the computer program instructions stored in the memory, so that the device executes the method in the above first aspect or any possible design of the first aspect, or executes the method in the above second aspect or any possible design of the second aspect, or executes the method in the above third aspect or any possible design of the third aspect. Optionally, the device further 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 may be a transceiver or an input / output interface; when the device is a chip included in a network device or a terminal device, the communication interface may be the input / output interface of the chip. Optionally, the transceiver may be a transceiver circuit, and the input / output interface may be an input / output circuit.

[0029] In a fifth aspect, an embodiment of the present application provides a chip system, including: a processor, where the processor is coupled to a memory, and the memory is used to store programs or instructions. When the programs or instructions are executed by the processor, the chip system implements the method in the above first aspect or any possible design of the first aspect, or implements the method in the above second aspect or any possible design of the second aspect, or implements the method in the above third aspect or any possible design of the third aspect.

[0030] Optionally, the chip system further includes an interface circuit for interacting code instructions to the processor.

[0031] Optionally, there may be one or more processors in the chip system, and the processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor that implements by reading software code stored in a memory.

[0032] Optionally, there may also be one or more memories in the chip system. The memory may be integrated with the processor or may be separately provided from the processor, which is not limited in this application. Exemplarily, the memory may be a non-transitory processor, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or may be separately provided on different chips. This application does not specifically limit the type of the memory and the setting manner of the memory and the processor.

[0033] In a sixth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer program or instruction is stored. When the computer program or instruction is executed, the computer is caused to execute the method in the first aspect or any possible design in the first aspect, or execute the method in the second aspect or any possible design in the second aspect, or execute the method in the third aspect or any possible design in the third aspect.

[0034] In a seventh aspect, an embodiment of the present application provides a computer program product. When a computer reads and executes the computer program product, the computer is caused to execute the method in the first aspect or any possible design in the first aspect, or execute the method in the second aspect or any possible design in the second aspect, or execute the method in the third aspect or any possible design in the third aspect.

[0035] In an eighth aspect, an embodiment of the present application provides a communication system, which includes the first network device, the second network device, and at least one terminal device described in the above aspects, where the first network device may be a source network device and the second network device may be a target network device. Optionally, a core network device may also be included in the communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1a and Figure 1b is a schematic diagram of a network architecture of a satellite communication system applicable to an embodiment of the present application;

[0037] Figure 2 is a schematic diagram showing different regions covered by a satellite cell corresponding to different PLMNs in an embodiment of the present application;

[0038] Figure 3 It is a schematic flowchart of a communication method provided by an embodiment of the present application;

[0039] Figure 4 It is a schematic diagram for the first network device in an embodiment of the present application to determine that the second cell is an NTN cell, or to determine that the second cell is an NTN cell and there are at least two PLMNs in the second cell;

[0040] Figure 5 It is an example of a communication method provided by an embodiment of the present application;

[0041] Figure 6 It is another example of a communication method provided by an embodiment of the present application;

[0042] Figure 7 It is a schematic diagram of each neighboring cell of the first cell in an embodiment of the present application;

[0043] Figure 8 It is a schematic diagram for the first network device in an embodiment of the present application to instruct the terminal device to report location information;

[0044] Figure 9 It is a schematic structural diagram of a communication device provided by an embodiment of the present application;

[0045] Figure 10 It is another schematic structural diagram of a communication device provided by an embodiment of the present application;

[0046] Figure 11 It is a schematic structural diagram of another communication device provided by an embodiment of the present application;

[0047] Figure 12 It is another schematic structural diagram of another communication device provided by an embodiment of the present application. Detailed implementation manners

[0048] In order to make the objectives, 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.

[0049] The technical solution of the embodiment 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 Telecommunications System (UMTS), 5th generation (5G) system or NR system, or applied to future communication systems or other similar communication systems, etc.

[0050] The technical solution provided by the embodiment of the present application can be applied to a Non-Terrestrial Network (NTN) communication system, and can also be applied to a scenario of hybrid deployment of NTN and Terrestrial Networks (TN). The NTN communication system may include a satellite communication system, a High Altitude Platform Station (HAPS) communication system, or other non-ground communication systems.

[0051] Taking the NTN communication system as a satellite communication system as an example, the network architecture to which the present application is applied will be described in detail below.

[0052] Please refer to Figure 1a , which is a schematic diagram of a network architecture of a satellite communication system applicable to the embodiment of the present application. The network architecture includes a core network device 110, a radio access network device 120, a satellite 130, and at least one terminal device (such as Figure 1a the terminal device 140 shown in Figure 1a . As an example,

[0053] 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 different physical devices, or the functions of the core network device and the logical functions of the radio access network device can be integrated on 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 on a 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 the access network device in 5G, such as a gNB or an ng-eNB, and in a 4G system, it corresponds to the access network device in 4G, such as an eNB or an en-gNB.

[0054] The communication between the radio access network device and the terminal device is through satellite signal forwarding. That is, the satellite can receive the signal of the radio access network device and forward the signal to the ground to form a satellite cell, thereby providing service coverage for the terminal device on the ground. At this time, the satellite is equivalent to a relay node or a repeater. Therefore, this scenario can also be called the transparent forwarding form of the satellite.

[0055] In the transparent forwarding form, the satellite cell can be fixed on the ground (which can be denoted as a "fixed cell"), or it can move on the ground as the satellite moves (which can be denoted as a "mobile cell"). For the scenario of a "fixed cell", the satellite cell being fixed on the ground means that the coverage of the satellite cell on the ground is fixed, which can be fixed for a period of time or permanently fixed. For example, for a geostationary satellite, since the satellite remains stationary relative to the ground, the satellite cell formed by it is generally also fixed relative to the ground. For a low-earth orbit satellite, since the satellite moves relative to the ground, the satellite can adjust the emission angle of its antenna or other physical parameters so that the formed satellite cell is fixed relative to the ground.

[0056] For the scenario of a "mobile cell", the satellite cell moves as the satellite moves. That is, when the satellite moves, the satellite cell also moves on the ground following the satellite. Usually, the reason for the generation of a mobile cell is that as the satellite moves, the satellite does not dynamically adjust the direction of the beam, resulting in the projection of the beam generated by the satellite on the ground moving following the movement of the satellite.

[0057] It should be noted that the embodiments of the present application do not specifically limit the existence scenarios of mobile cells. When the satellite provides service coverage in a transparent relay form, a possible existence scenario of a mobile cell can be as follows: The satellite establishes a connection with the original radio access network device. As the satellite moves, the cell under the original radio access network device relayed by the satellite follows the satellite for a period of time, that is, the satellite maintains a connection with the original radio access network device for a period of time; at a certain moment, the connection between the satellite and the original radio access network device is disconnected due to reasons such as long distance and weak signal, and the satellite connects to a new radio access network device. Thereafter, the satellite starts to relay the signal of the new radio access network device to form a new satellite cell. It can be understood that although the satellite is constantly operating, since the positions of the radio access network devices on the ground remain unchanged, for the scenario where there is a mobile cell, if the satellite relays the signal of a certain radio access network device on the ground, then the satellite cell formed under the radio access network device will also move within a certain range as the satellite operates, but the movement range of the satellite cell is usually around the periphery of the radio access network device.

[0058] Please refer to Figure 1b , which is another schematic diagram of the network architecture of the satellite communication system applicable to the embodiments of the present application. This network architecture includes a core network device 110, a satellite 130, and at least one terminal device (such as Figure 1b the terminal device 140 shown in Figure 1b . As an example,

[0059] In Figure 1a the network architecture shown in Figure 1b , a radio access network device, such as a base station, can be deployed on the satellite. The satellite can generate cell signals by itself and relay them to the ground to form satellite cells, thereby providing service coverage for the terminal devices on the ground. Therefore, this scenario can also be referred to as the regenerative form of the satellite.

[0060] In the regenerative form, the satellite cell moves as the satellite moves, that is, when the satellite moves, the cell it generates also moves on the ground, so it can be called a "mobile cell". Since this "mobile cell" is generated by the satellite itself, this satellite "mobile cell" can move on the ground following the orbit of the satellite. Generally, when the satellite moves away, a new satellite will move in later to ensure as continuous coverage as possible. The coverage areas of the new satellite and the previous satellite can be the same or different. It can be understood that due to the different operating directions, beam emission directions, and beam emission capabilities of the satellites, the ground coverage areas of two satellites may not be exactly the same.

[0061] Although Figure 1aAnd Figure 1b Only one terminal device is shown in the figure, but it should be understood that a radio access network device, a satellite, or a core network device can serve one or more terminal devices. The embodiments of the present application do not limit the number of core network devices, radio access network devices, satellites, and terminal devices included in the satellite communication system. In addition, the terminal device can be fixed in position or movable, and the present application does not limit this either.

[0062] Between the radio access network device and the terminal device, as well as between terminal devices, communication can be carried out through licensed spectrum, or through unlicensed spectrum, or through both licensed spectrum and unlicensed spectrum simultaneously. Between the radio access network device and the terminal device, as well as between terminal devices, communication can be carried out through spectrum below 6 gigahertz (GHz), or through spectrum above 6 GHz, or through both spectrum below 6 GHz and spectrum above 6 GHz simultaneously. The embodiments of the present application do not limit the spectrum resources used between the radio access network device and the terminal device.

[0063] The network architecture and service scenarios described in the embodiments of the present application are for more clearly explaining the technical solutions of the embodiments of the present application, and do not constitute a limitation to the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art know that with the evolution of the communication network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0064] The cell involved in the embodiments of the present application can be an NTN cell. Here, taking the NTN cell as a satellite cell as an example, the cell in the present application will be described in detail.

[0065] In addition to the above-mentioned characteristics related to mobility, another important characteristic of a satellite cell is its large coverage. The coverage diameter of a satellite cell can reach dozens to thousands of kilometers. Therefore, there are cases where a satellite cell covers the geographical areas of multiple countries or the service areas of multiple operators. Generally speaking, a satellite can indicate that it can support services of multiple countries / operators / network service providers / service types by broadcasting information of multiple PLMNs (such as PLMN identification information, etc.), or information of the access and mobility management function (AMF) (such as AMF identification information, etc.), or network service providers (which can also be called network identification information, such as standalone non-public network (SNPN) identification information, or closed access group (CAG) identification information, etc.), or service type information (such as slice identification). The terminal device can determine a suitable country / operator / network service provider / service type to access based on its own location, the mapping relationship between the area information covered by the cell and the country / operator / network service provider / service type.

[0066] For example, physical cell C covers the geographical areas of country A and country B. Among them, country A corresponds to PLMN1 / AMF1, and country B corresponds to PLMN2 / AMF2. Then, physical cell C can broadcast the information of PLMN1 and the information of PLMN2. It can be understood that country A corresponding to PLMN1 / AMF1 means that the PLMN deploying to manage cell C in country A is PLMN1, or the AMF connected to the access network device to which cell C belongs is AMF1; country B corresponding to PLMN2 / AMF2 means that the PLMN deploying to manage cell C in country B is PLMN2, or the AMF connected to the access network device to which cell C belongs is AMF2.

[0067] In this way, for UE1 located within the coverage area of cell C in country A, UE1 can access cell C through PLMN1 / AMF1; or rather, when UE1 wants to access cell C, it can access cell C through PLMN1 / AMF1; or rather, when UE1 wants to access cell C, UE1 can access the cell corresponding to PLMN1 / AMF1; or rather, when UE1 wants to access cell C, the core network device connected to the access network device that UE1 can access is AMF1, and the access network device that UE1 can access belongs to PLMN1.

[0068] Similarly, for UE2 located in country B and within the coverage area of cell C, UE2 can access cell C through PLMN2 / AMF2; or rather, when UE2 wants to access cell C, it can access cell C through PLMN2 / AMF2; or rather, when UE2 wants to access cell C, UE2 can access the cell corresponding to PLMN2 / AMF2; or rather, when UE2 wants to access cell C, the core network device connected to the access network device that UE2 can access is AMF2, and the access network device that UE2 can access belongs to PLMN2.

[0069] Considering that the communication strategies of different countries, operators, network service providers, or service types may vary, satellite cells can be further divided into finer granularities. For example, the entire service coverage area of a satellite cell can be divided into multiple regions with regular or irregular shapes, which can be referred to as virtual cells or virtual regions, so as to better fit the geographical regions of different countries, the service areas of different operators, the service areas of different network service providers, or the service areas of different service types. As Figure 2 shown, different regions under the same satellite cell can correspond to different PLMNs, thus forming multiple logical cells under the same satellite cell, and then the mobility of terminal devices can be effectively managed according to different regions. Combining the above examples, from the perspective of communication management, the access network device and / or the core network device will reject UE1 from accessing through PLMN2 and reject UE2 from accessing through PLMN1. It can be understood that the division of virtual cells or virtual regions can have partially overlapping regions or be completely isolated, that is, there are no overlapping regions at all.

[0070] The embodiments of the present application can also be applied to the scenario of cell handover. The terminal device may switch from the source network device to the target network device due to factors such as location movement, service change, network coverage change, or other reasons. Among them, the source network device refers to the network device that the terminal device accessed before the handover, or the network device that provided services to the terminal device before the handover; the target network device refers to the network device that the terminal device needs to switch to, or the network device that the terminal device accesses after successfully performing the handover, or the network device that provides services to the terminal device after the handover is successful. Correspondingly, the source cell refers to the cell that the terminal device accessed before the handover, and this source cell is the cell covered by the source network device, or 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 the handover, and this target cell is the cell covered by the target network device, or the cell under the jurisdiction of the target network device, or the target cell belongs to the target network device.

[0071] It can be understood that the source cell and / or target cell in the embodiments of the present application can be the NTN cells introduced above, such as satellite cells, or other cells covering different countries / operators / network service providers / service types. That is, the service coverage area of the source cell and / or target cell can be divided into multiple regions, and different regions can correspond to different PLMNs and / or AMFs to form different logical cells.

[0072] The following explains some terms in the embodiments of the present application to facilitate the understanding of those skilled in the art.

[0073] 1) The terminal device involved in the embodiments of the present application is a device with wireless transceiver functions, which can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface (such as a ship, etc.); it can also be deployed in the air (such as an airplane, a balloon, a satellite, etc.). The terminal device can communicate with the core network via a 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 functions, 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 the present application do not limit the application scenarios. The terminal device can sometimes also be referred to as a user equipment (UE), a mobile station, a remote station, etc. The embodiments of the present application do not limit the specific technologies, device forms, and names adopted by the terminal device.

[0074] By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. A wearable device may also be referred to as a wearable intelligent device or a smart wearable device, etc. It is a general term for devices developed by applying wearable technology to the intelligent design of daily wear, such as glasses, gloves, watches, clothing, shoes, etc. A wearable device is a portable device that is directly worn on the body or integrated into the user's clothes or accessories. A wearable device is not just a hardware device, but also realizes powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable intelligent devices include those with full functions and large sizes that can achieve complete or partial functions without relying on a smart phone, such as smart watches or smart glasses, etc., and those that only focus on a certain type of application function and need to cooperate with other devices such as smart phones, such as various smart bracelets for vital sign monitoring, smart helmets, smart jewelry, etc.

[0075] In the embodiments of the present application, the terminal device may also be an in-vehicle module, an in-vehicle module group, an in-vehicle component, an in-vehicle chip, or an in-vehicle unit that is built into a vehicle as one or more components or units. The vehicle can implement the method of the present application through the built-in in-vehicle module, in-vehicle module group, in-vehicle component, in-vehicle chip, or in-vehicle unit.

[0076] 2) The radio access network device involved in the embodiments of the present application is a device used to connect a terminal device to a wireless network in the network. The radio access network device may be a node in the radio access network, also referred to as a base station, and may also be referred to as a RAN node. In the present 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 abbreviated as an access network device or a network device.

[0077] The access network device may include an evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in an LTE system or an evolved LTE system (LTE-Advanced, LTE-A), such as a traditional macro eNB and a micro 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 baseband unit (BBU), a BBU pool, or a wireless fidelity (WiFi) access point (AP), an integrated access and backhaul (IAB) node, etc. Or it may also include a centralized unit (CU) and / or a distributed unit (DU) in a cloud radio access network (CloudRAN) system. The embodiments of the present application are not limited thereto.

[0078] For example, in a network architecture, the network device can be a CU node, or a DU node, or an access network device including a CU node and a DU node. Further, the CU node can be divided into a control plane (CU-CP) and a user plane (CU-UP). Among them, the CU-CP is responsible for control plane functions, mainly including radio resource control (RRC) and packet data convergence protocol (PDCP)-C. PDCP-C is mainly responsible for encryption, decryption, integrity protection, data transmission, etc. of control plane data. The CU-UP is responsible for user plane functions, mainly including service data adaptation protocol (SDAP) and PDCP-U. SDAP is mainly responsible for processing the data of the core network and mapping the flow to the bearer. PDCP-U is mainly responsible for encryption, decryption, integrity protection, header compression, sequence number maintenance, data transmission, etc. The CU-CP and the CU-UP can be connected through the E1 interface. The CU-CP represents the CU to connect to the core network through the Ng interface and connect to the DU through the F1-C (control plane). The CU-UP is connected to the DU through the F1-U (user plane). Of course, there is also a possible implementation where PDCP-C is also in the CU-UP.

[0079] 3) The core network devices involved in the embodiments of the present application refer to the devices in the core network (CN) that provide service support for terminal devices. Currently, 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 terminal devices; the SMF entity is responsible for session management, such as the session establishment of users, etc.; the UPF entity is a functional entity of the user plane, mainly responsible for connecting to external networks. It should be noted that the entities in the present application can also be referred to as network elements or functional entities, that is, the AMF entity can also be referred to as the AMF network element or AMF functional entity, and the SMF entity can also be referred to as the SMF network element or SMF functional entity. In the following description of the present application, the core network device can refer to the AMF.

[0080] 4) In the embodiments of the present application, the satellite involved refers to the network device located on the satellite. For the convenience of description, the "network device on the satellite" can be simply referred to as "satellite". The satellite may be a low earth orbiting (LEO) satellite, a medium earth orbit satellite, or other network devices moving at high altitudes. Generally speaking, according to the orbital altitude of the satellite, the satellites in the satellite communication system can be divided into three categories: geostationary earth orbiting (GEO) satellites, low earth orbiting (LEO) satellites, and medium earth orbit satellites. Among them, the GEO satellite can also be called a geostationary satellite. The running speed of the GEO satellite is the same as the earth's rotation speed. Therefore, the GEO satellite remains stationary relative to the ground. Correspondingly, the satellite cell formed by the GEO satellite is also stationary. The LEO satellite can also be called a near-earth orbit satellite. The LEO satellite moves relatively fast relative to the ground. Therefore, the satellite cell formed by the LEO satellite can move with the movement of the satellite. The medium earth orbit satellite refers to a satellite located at an orbital altitude between the GEO satellite and the LEO satellite.

[0081] 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, understood as one, two, or more. For example, including at least one means including one, two, or more, and does not limit which ones are included. For example, including at least one of A, B, and C, then what is included can 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 kind" is similar. "And / or" describes the association relationship of associated objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / ", unless otherwise specified, generally represents an "or" relationship between the front and back associated objects.

[0082] Unless otherwise stated, 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, time sequence, priority, or importance degree of multiple objects, and the descriptions of "first" and "second" do not necessarily limit that the objects are different.

[0083] It can be understood that in the embodiments of the present application, the terminal device and / or the network device can execute some or all of the steps in the embodiments of the present application. These steps or operations are only examples. The embodiments of the present application can also execute other operations or various deformations of the operations. In addition, each step can be executed in a different order presented in the embodiments of the present application, and it is possible not to execute all the operations in the embodiments of the present application.

[0084] In the embodiments of the present application, the methods involved are described by taking the PLMN and AMF entities as examples, but the present invention is not limited to the PLMN and AMF entities. The PLMN can also be other communication networks or devices that implement some functions of the communication network. The AMF entity can also be other entities or devices that can implement the mobile management function, or entities or devices that implement similar functions in the communication network.

[0085] Please refer to Figure 3 , which is a schematic flowchart of a communication method provided by the embodiments of the present application. The method includes:

[0086] Step S301: A first network device sends a first request message to a second network device. The first request message is used to request to access a terminal device to a second cell under the second network device. The first request message includes the location information of the terminal device and the information of a first PLMN. The first PLMN is the target PLMN determined by the first network device for the terminal device to access.

[0087] Optionally, the first request message may further include the mobility restriction information of the terminal device. The mobility restriction information may include the information of the country / carrier / network service provider / service type allowed for the terminal device to access. For example, the mobility restriction information may indicate the PLMN information allowed for the terminal device to access.

[0088] Correspondingly, the second network device may receive the first request message from the first network device.

[0089] In the embodiments of the present application, the first network device may be a source network device, and the second network device may be a target network device. The first cell may be a source cell, which is managed by the first network device, or the first cell is a cell under the first network device or the first cell belongs to the first network device. The second cell may be a target cell, which is managed by the second network device, or the second cell is a cell under the second network device or the second cell belongs to the second network device. The first cell and the second cell may be adjacent cells, and the first cell and the second cell may be NTN cells.

[0090] 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 in this application. In a possible implementation manner, the location information may 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 manner, the location information may also be used to describe a general area range, that is, an area range where the terminal device is currently located. For example, this area range may be represented by the longitude, latitude, and altitude of the center point, plus parameters such as the diameter or radius of this area range. In yet another possible implementation manner, the location information or area information may be represented by an identifier. For example, the identifier may be an index or an ID. The mapping relationship between the identifier and the location information or area information may be agreed upon by the protocol, or sent by the network device / core network device to the terminal device. That is to say, the terminal device, network device, or core network device can determine the corresponding location or area according to the identifier. Of course, the description of this area range may also have other forms, and this application will not list them one by one.

[0091] Further, the location information of the terminal device may be received by the first network device from the terminal device. For example, the first 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 measured by itself. Or, the location information of the terminal device may be received by the first network device from other network devices. For example, the first network device may receive the location information of the terminal device from the core network device. Or, the location information of the terminal device may also be determined by the first network device itself. For example, the first network device may perform location positioning on the terminal device to obtain the location information of the terminal device. The location information of the terminal device may also be obtained by the first network device through other means, which is not limited in this application.

[0092] The information of the first PLMN may include the identification information of the first PLMN, such as the ID of the first PLMN (i.e., PLMN-identifier). Similarly, the information of the second PLMN described below may include the identification information of the second PLMN, such as the ID of the second PLMN (i.e., PLMN-identifier). It can be understood that the embodiments of this application use PLMN as an example, and it can also be extended to countries / carriers / network service providers / service types, which is not limited in this application.

[0093] Optionally, before the first network device sends a first request message to the second network device, such as Figure 4As shown in the figure, the first network device may determine that the second cell is an NTN cell, or determine that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two, or determine that the PLMNs supported by the second cell are at least two, and there is a correspondence between regions and PLMNs.

[0094] As a possible implementation, as shown in steps S401a and S401b, the first network device may receive first indication information from the terminal device or the second network device. The first indication information is used to indicate that the second cell is an NTN cell, or the first indication information is used to indicate that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two, or the first indication information is used to indicate that the PLMNs supported by the second cell are at least two, and there is a correspondence between regions and PLMNs. It can be understood that the fact that the PLMNs supported by the second cell are at least two means that the number of PLMNs supported by the second cell is greater than or equal to two, or in other words, the second cell supports multiple PLMNs. In this way, through the above method, the first network device can learn that the second cell under the second network device is an NTN cell, and the PLMNs supported by the second cell are at least two. It can be understood that the existence of the correspondence between regions and PLMNs in the second cell may mean that terminal devices in different regions of the second cell need to access or handover to the second cell from the corresponding PLMN. It can be understood that the embodiments of the present application are exemplified by NTN cells, and can also be extended to cells supporting multiple countries / operators / network service providers / service types. The present application is not limited.

[0095] Exemplarily, the terminal device may learn that the second cell is an NTN cell, or learn that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two, or learn that the PLMNs supported by the second cell are at least two, and there is a correspondence between regions and PLMNs by reading the system message of the second cell. Furthermore, the terminal device may send the first indication information to the first network device.

[0096] As another possible implementation, as shown in steps S402a and step 402b, the first network device may receive the cell information of the second cell from the terminal device or the second network device. The cell information of the second cell may include information of at least two PLMNs supported by the second cell. Optionally, the cell information of the second cell may further indicate that the second cell is an NTN cell, or may indicate the existence of a correspondence between regions and PLMNs in the second cell. In this way, the first network device determines the first PLMN accessed by the terminal device from at least two PLMNs supported by the second cell according to the cell information of the second cell, so as to ensure that the first PLMN carried in the first request message is a PLMN supported by the second network device.

[0097] Optionally, after the first network device determines that the second cell is an NTN cell, or determines that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two, or determines that the PLMNs supported by the second cell are at least two and there is a corresponding relationship between the area and the PLMN, as Figure 4 shown in step S404 in Figure 4 , the first network device may send third indication information to the terminal device, where the third indication information is used to indicate that the terminal device carries the location information of the terminal device when reporting the measurement result of the second cell. Subsequently, the terminal device may send a measurement report to the first network device, where the measurement report includes the measurement result of the second cell and the location information of the terminal device. Optionally, the third indication information may be included in the location measurement configuration information sent by the first network device to the terminal device, and the location measurement configuration information is used to indicate the terminal device to perform location measurement. In this way, the terminal device may perform location measurement according to the received location measurement configuration information, and according to the indication of the third indication information therein, when reporting the measurement result of the second cell, send the measured location information of itself to the first network device through the measurement report.

[0098] It should be noted that Figure 4 the illustration shown in Figure 4 is only a schematic, and the present application embodiment does not limit the order of the first network device receiving the first indication information and receiving the cell information of the second cell. Moreover, when the first network device receives the first indication information from the terminal device, the first network device may still receive the cell information of the second cell from the terminal device, or may receive the cell information of the second cell from the second network device, which is not limited. Similarly, when the first network device receives the first indication information from the second network device, the first network device may still receive the cell information of the second cell from the second network device, or may receive the cell information of the second cell from the terminal device, which is also not limited.

[0099] Among the at least two PLMNs supported by the second cell, there are a first PLMN and a second PLMN. Correspondingly, the second cell covers at least a first area corresponding to the first PLMN and a second area corresponding to the second PLMN. Since the PLMNs supported by the second cell are at least two, when the number of PLMNs supported by the second cell is two, the first PLMN and the second PLMN are all the PLMNs supported by the second cell; when the number of PLMNs supported by the second cell is greater than two, the first PLMN and the second PLMN are two of all the PLMNs supported by the second cell, that is, the second cell may support other PLMNs in addition to the first PLMN and the second PLMN, which is not limited in the present application.

[0100] Step S302, the second network device determines whether to allow the access / handover of the terminal device according to the location information of the terminal device.

[0101] Specifically, the second network device determines whether the terminal device is located within the first area corresponding to the first PLMN based on the location information of the terminal device. If it is determined that the terminal device is located within the first area corresponding to the first PLMN, the second network device may accept the access / handover request of the terminal device. Optionally, the second network device may also reject the access / handover request of the terminal device. For example, the second network device further determines to reject the access / handover request of the terminal device after further judgment based on other handover decision factors (such as a high load in the second cell).

[0102] If it is determined that the terminal device is outside the first area corresponding to the first PLMN and within the second area corresponding to the second PLMN, the second network device may reject the access / handover request of the terminal device. Further, the second network device may determine whether the terminal device supports the second PLMN according to the mobility restriction information of the terminal device. If the terminal device supports the second PLMN, the second network device determines the second PLMN as the target PLMN allowing the terminal device to access, and both the first PLMN and the second PLMN are supported by the second network device.

[0103] Step S303: The second network device sends a first response message to the first network device. Correspondingly, the first network device may receive the first response message from the second network device.

[0104] Optionally, the first response message includes information about the second PLMN, and the second PLMN is the target PLMN that the second network device allows the terminal device to access. That is, the second network device may carry the information about the target PLMN allowing the terminal device to access in the first response message. When the location where the terminal device is located is within the second area corresponding to the second PLMN and the terminal device supports the second PLMN, the second network device may determine the second PLMN as the target PLMN allowing the terminal device to access. The second PLMN matches the location where the terminal device is located and is the PLMN corresponding to the area where the terminal device is currently located. In this way, the first network device may re-initiate a handover request according to the second PLMN to access the second cell for the terminal device from the second PLMN corresponding to the area where its location is located, thereby effectively improving the handover success rate.

[0105] Optionally, the first response message may also include second indication information for indicating that the location of the terminal device does not match the first PLMN to which the terminal device requests access. The situation that the location of the terminal device does not match the first PLMN to which the terminal device requests access may mean that the location of the terminal device is not within the range of the first area corresponding to the first PLMN to which access is requested. In this way, after receiving the second indication information, the first network device can determine that it is because the location of the terminal device does not match the first PLMN determined to be accessed previously that the second network device rejects the terminal device's access to the second cell. The second indication information may be used to indicate the cause of handover failure, and the second indication information may also have other expressions, such as indicating that the requested PLMN is invalid or incorrect, etc.

[0106] It can be seen that in the embodiment of the present application, since the first network device can receive the cell information of the second cell from the terminal device or the second network device and determine the PLMN to which access is requested according to the cell information of the second cell, it can be ensured that the PLMN accessed by the terminal device must be the PLMN supported by the second network device, thereby avoiding other situations of handover failure caused by the second network device not supporting the accessed PLMN.

[0107] It should be noted that the first response message may include the information of the target PLMN and / or the second indication information. That is to say, neither the information of the target PLMN nor the second indication information is an essential information in the first response message. The first response message may include one or both of the information of the target PLMN and the second indication information, and both of these two pieces of information have the function of indicating handover failure.

[0108] Optionally, if the location of the terminal device is within the first area corresponding to the first PLMN to which access is requested, the second network device may allow the terminal device to access the second cell from the first PLMN. At this time, the first response message may also be referred to as a handover request confirmation message or a handover command message or a reconfiguration message, or have other names, which are not limited in the present application.

[0109] In an embodiment of the present application, the first network device may carry the location information of the terminal device in the first request message, and the second network device may perform a handover / access decision based on the location information of the terminal device in the first request message to determine whether to allow the terminal device to handover / access to the second cell. When the terminal device requests to access the first PLMN, but the location where the terminal device is located is outside the first area corresponding to the first PLMN, the second network device may determine that the PLMN requested by the terminal device is incorrect, or in other words, the location where the terminal device is located does not match the PLMN to which access is requested, and the handover request of the terminal device needs to be rejected, that is, the terminal device is not allowed to handover / access from the first PLMN to the second cell. At this time, the first response message may also be referred to as a handover failure message.

[0110] Figure 5 and Figure 6 are two specific examples related to the handover process in a communication method provided in an embodiment of the present application. Among them, Figure 5 The specific example shown corresponds to a scenario where there is a directly connected interface between the first network device and the second network device. The first network device and the second network device may perform the handover process based on this directly connected interface. This directly connected interface may be, for example, the Xn interface. At this time, the handover process may 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 the X2 interface, and the present application does not make a limitation. Figure 6 The specific example shown corresponds to a scenario where there is no directly connected interface between the first network device and the second network device. The first network device and the second network device may perform the handover process based on the interface between the access network device and the core network device. The core network device may be, for example, the AMF, and the interface between the access network device and the core network device may be, for example, the NG interface. At this time, the handover process may also be referred to as an NG-based handover (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 the S1 interface (correspondingly, at this time, the core network device may be a mobility management entity (MME), and the present application does not make a limitation.

[0111] As Figure 5 shown, in step S501, the UE may send a measurement report to the first base station. Optionally, the measurement report includes the location information of the UE.

[0112] In step S502, the first base station may send a handover request message to the second base station. The handover request message includes the location information of the UE and the information of the PLMN1 to which the UE is connected as determined by the first base station. It should be noted that here, the location information of the UE included in the handover request message may be obtained by the first base station from the measurement report reported by the UE, or may be obtained by the first base station through other means, such as by positioning the location of the UE, or by obtaining it from other network devices, which is not limited. PLMN1 is a PLMN supported by the second base station. The PLMN1 may be determined by the first base station according to the cell information of the second cell under the second base station, or may also be determined by the first base station according to the cell information of the second cell, in combination with the mobility restriction information and / or subscription information of the UE. Optionally, the handover request message may further include the mobility restriction information of the UE. Regarding the cell information and mobility restriction information, reference may be made to the relevant description in step S301 above, which will not be elaborated here.

[0113] Furthermore, in step S503, after receiving the handover request message, the second base station may determine whether to allow the UE to access / handover to the second cell according to the location information of the UE.

[0114] Specifically, in step S504a, if the location where the UE is located is outside the first area covered by the second cell, and the first area corresponds to the PLMN1 to which the UE is to be connected, then the second base station may determine that the handover fails and needs to reject the handover request of the UE, that is, reject the UE's access to the second cell from PLMN1. Correspondingly, the second base station may send a handover failure message to the first base station in step S504a, and carry second indication information in the handover failure message. The second indication information is used to indicate that the location of the UE does not match the first PLMN, that is, to indicate the reason for the handover failure.

[0115] Or, if the second base station determines that the terminal device is outside the first area corresponding to PLMN1 and inside the second area corresponding to PLMN2, the second network device may determine whether the terminal device supports PLMN2 according to the mobility restriction information of the terminal device. If the terminal device supports PLMN2, the second base station may send a handover failure message to the first base station in step S504a, and carry the information of PLMN2 and / or second indication information in the handover failure message. The PLMN2 is the target PLMN determined by the second base station to allow the UE to access, and the PLMN2 is the PLMN corresponding to the second area where the location of the UE is located.

[0116] In this way, for this UE, the first base station may subsequently initiate a handover request to access the second PLMN again so that the UE can successfully handover to the second cell. The handover failure message may also be referred to as a handover preparation failure message, or have other names, which is not limited.

[0117] In step S503, if the location where the UE is located is within the first area covered by the second cell, and this first area corresponds to the PLMN1 to which the UE wants to attach, then the second base station can accept the handover request of the UE and determine to allow the UE to attach to the second cell from PLMN1. Thus, the second base station can send a handover request confirmation message to the first base station in step S504b, and subsequently in step S505, the first base station can further send an RRC reconfiguration message to the UE.

[0118] As Figure 6 shown, in step S601, the UE can send a measurement report to the first base station. Optionally, the measurement report includes the location information of the UE.

[0119] In step S602, the first base station can send a first handover request message to AMF1. The first handover request message may include the location information of the UE and the information of the PLMN1 to which the UE is to attach as determined by the first base station. The first handover request message may be a HO required message or other messages, which is not limited. 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, which is not limited. PLMN1 is a PLMN supported by the second base station. The PLMN1 may be determined by the first base station according to the cell information of the second cell under the second base station, or may also be determined by the first base station according to the cell information of the second cell, in combination with the mobility restriction information and / or subscription information of the UE. Optionally, the handover request message may further include the mobility restriction information of the UE. For the relevant descriptions of the cell information and mobility restriction information, reference may be made to the relevant descriptions in step S301 above, which will not be elaborated here.

[0120] As another possible implementation manner, step S602 may be replaced by step S602'. The first base station can send a first handover request message to AMF1. The first handover request message may include indication information for indicating AMF1 to provide the location information of the UE, and the information of the PLMN1 to which the UE attaches as determined by the first base station. AMF1 can obtain the location information of the UE according to the indication information for indicating AMF1 to provide the location information of the UE, and carry the location information of the UE in the second handover request message in step S603. AMF1 obtains the location information of the UE, which may be the location information reported by the UE received by AMF1, or may be obtained by AMF1 through the location server of the UE, or may be obtained through other means, which is not limited. Optionally, the first handover request message may further include the mobility restriction information of the terminal device.

[0121] Furthermore, in step S603, AMF1 may send a second handover request message to the second base station. The second handover request message may include the location information of the UE and the information of PLMN1 to which the UE is to be attached as determined by the first base station. The second handover request message may be a HO request message or other messages, which is not limited. It should be noted that here, the location information of the UE included in the second handover request message is obtained by AMF1 from the first handover request message, or may be obtained by AMF1 through other means, such as positioning the location of the UE, or obtaining it from other network devices, which is not limited. Optionally, the second handover request message may further include the mobility restriction information of the terminal device.

[0122] Furthermore, in step S604, after receiving the second handover request message, the second base station may determine whether to allow the UE to access / hand over to the second cell according to the location information of the UE.

[0123] Specifically, in step S604a, if the location where the UE is located is outside the first area covered by the second cell, and the first area corresponds to PLMN1 to which the UE is to be attached, then the second base station may determine that the handover fails and needs to reject the handover request of the UE, that is, reject the UE from accessing the second cell from PLMN1. Correspondingly, the second base station may send a first handover failure message to AMF1 in step S605a, and carry second indication information in the first handover failure message, where the second indication information is used to indicate that the location of the UE does not match the first PLMN, that is, to indicate the reason for the handover failure.

[0124] Alternatively, if the second base station determines that the terminal device is outside the first area corresponding to PLMN1 and within the second area corresponding to PLMN2, the second network device may determine whether the terminal device supports PLMN2 according to the mobility restriction information of the UE. If the terminal device supports PLMN2, the second base station may send a first handover failure message to AMF1 in step S605a, and carry the information of PLMN2 and / or second indication information in the first handover failure message. The PLMN2 is the target PLMN determined by the second base station to allow the UE to access, and the PLMN2 is the PLMN corresponding to the area where the UE is located.

[0125] Subsequently, in step S606a, AMF1 may send a second handover failure message to the first base station, and carry the information of PLMN2 and / or second indication information in the second handover failure message. The second handover failure message may be a handoverpreparation failure message or other messages, which is not limited. Correspondingly, the first base station may receive the second handover failure message.

[0126] Thus, for this UE, the first base station may re-initiate a handover request to access the second PLMN, so that the UE can successfully hand over to the second cell. The second handover failure message may also be referred to as a handover preparation failure message, or have other names, which is not limited.

[0127] In step S604, if the location where the UE is located is within the first area covered by the second cell, and this first area corresponds to PLMN1 to which the UE wants to access, then the second base station may accept the handover request of the UE and determine to allow the UE to access the second cell from PLMN1. Thus, the second base station may send a handover request confirmation message to AMF1 in step S605b. Then, in step S606b, AMF1 may send a handover command message to the first base station. Subsequently, in step S607, the first base station may further send an RRC reconfiguration message to the UE.

[0128] It should be noted that Figure 6 The specific example shown is described by taking the first base station and the second base station belonging to the same AMF as an example, that is, AMF1 shown in the figure. It can be understood that the first base station and the second base station may also belong to different AMFs. At this time, the handover process may further include the handover process between AMFs, and the messages for handover interacted between AMFs also include one or more of information such as the location information of the UE, the information of the target PLMN allowing the UE to access, and the second indication information, which will not be elaborated here.

[0129] As mentioned above, the second cell is a neighbor cell of the first cell. In the embodiments of the present application, the first cell may also have other neighbor cells. Exemplarily, as Figure 7 shown, the first cell has two neighbor cells, namely the second cell and the third cell, and the first cell, the second cell, and the third cell are all NTN cells.

[0130] Among them, the first cell is a cell under the first network device, and the first cell only supports PLMN1, that is, the number of PLMNs supported by the first cell is one. It should be noted that the embodiments of the present application do not make specific limitations on the number of PLMNs supported by the first cell. This is only an example here. The second cell is a cell under the second network device, and the second cell supports PLMN1 and PLMN2. And PLMN1 corresponds to the first area, and PLMN2 corresponds to the second area, that is, the number of PLMNs supported by the second cell is two, and the second cell covers the first area corresponding to PLMN1 and the second area corresponding to PLMN2. The third cell is a cell under the third network device, and the third cell only supports PLMN1, that is, the number of PLMNs supported by the third cell is one.

[0131] Based on the above neighbor cell relationship of the first cell, as Figure 8As shown, the first network device can interact with the second network device and the third network device to respectively exchange cell information of their respective cells, and send indication information to the terminal device according to the situation of the PLMNs supported by each neighboring cell of the first cell, indicating whether the terminal device needs to report its location information.

[0132] Specifically, in step S801, the first network device can receive the cell information of the second cell from the second network device. The cell information of the second cell includes the information of the PLMNs supported by the second cell (such as the information of the first PLMN and the information of the second PLMN). Optionally, the cell information of the second cell may further include at least one of the identification information of the second cell, the frequency point information of the second cell, and the physical cell identify (PCI). Optionally, the second cell of the second cell may also indicate that the second cell is an NTN cell, or may indicate the corresponding relationship between the existence area and the PLMN of the second cell. In this way, the first network device can determine that there are multiple PLMNs supported by the second cell according to the cell information of the second cell.

[0133] Optionally, the first network device can also send the cell information of the first cell to the second network device, which will not be elaborated here.

[0134] In step S802, the first network device can receive the cell information of the third cell from the third network device. The cell information of the third cell includes the PLMN information supported by the third cell (such as the information of the first PLMN). Optionally, the cell information of the third cell may further include the identification information of the third cell, the frequency point information of the third cell, and the PCI. In this way, the first network device can determine that the PLMN supported by the third cell is one according to the cell information of the third cell.

[0135] Optionally, the first network device can also send the cell information of the first cell to the third network device, which will not be elaborated here.

[0136] It can be seen from this that since there are multiple PLMNs supported by the second cell and only one PLMN supported by the third cell, when the first network device determines to switch the terminal device to the second cell, the first network device needs to determine the information of the target PLMN at the time of switching according to the location information of the terminal device. Taking the first network device obtaining the location of the terminal device through the location information sent by the terminal device as an example, when the measurement report of the terminal device includes the measurement result of the second cell, the terminal device needs to report its own location information so that the target network device can judge whether its access is reasonable according to the location information of the terminal device, such as judging whether the location where the terminal device is located matches the PLMN it requests. And when the measurement report of the terminal device only includes the measurement result of the third cell, the terminal device does not need to report its own location information.

[0137] In view of this, in step S803, the first network device may send indication information to the terminal device, where the indication information is used to indicate whether the terminal device needs to report location information. Or rather, the indication information is used to indicate whether the terminal device needs to report location information when reporting a measurement report, or is used to indicate the conditions for the terminal device to report location information in its measurement report. The conditions for reporting location information may be, for example, when the measurement report includes measurement results of which cells, the terminal device needs to report its location information. The cells may be identified by the frequency point information of the cells, or the frequency point information and PCI. Optionally, the indication information may be included in the measurement configuration information or location measurement configuration information sent by the first network device to the terminal device, where the location measurement configuration information is used to indicate the terminal device to perform location measurement.

[0138] In step S804, after receiving the indication information, the terminal device may determine whether to report its location information and send a measurement report to the first network device.

[0139] It should be noted that the indication information may be configured per cell. For example, the third indication information may correspond to the second cell, and the fourth indication information may correspond to the third cell. The first network device may use the third indication information to indicate that location information needs to be reported when reporting the measurement results of the second cell. For example, the third indication information is sent to the terminal device in combination with the frequency point information and PCI of the second cell; the first network device may use the fourth indication information to indicate that location information does not need to be reported when reporting the measurement results of the third cell. In this way, the terminal device may determine that location information needs to be reported when the measurement report includes the measurement results of the second cell, and location information does not need to be reported when the measurement report only includes the measurement results of the third cell, based on the measurement results of the cells that need to be reported in the measurement report, as well as the third indication information and the fourth indication information.

[0140] The embodiment of the present application further provides a communication device. Please refer to Figure 9 FIG. 9 is a schematic structural diagram of a communication device provided by an embodiment of the present application. The communication device 900 includes a transceiver module 910 and a processing module 920. The communication device may be used to implement the functions of the network device (such as the first network device or the second network device) involved in any of the above method embodiments. For example, the communication device may be a network device or a chip or circuit included in the network device.

[0141] Exemplarily, when the communication device executes Figure 3When performing the operations or steps corresponding to the first network device in the method embodiments shown, the processing module 920 is configured to generate a first request message for requesting to connect the terminal device to a second cell under a second network device. The first request message includes the location information of the terminal device and the information of a first PLMN, where the first PLMN is the target PLMN determined by the first network device for the terminal device to access; the transceiver module 910 is configured to send the first request message to the second network device and receive a first response message from the second network device. The first response message includes the information of a second PLMN, where the second PLMN is the target PLMN allowed by the second network device for the terminal device to access; wherein, the location where the terminal device is located is outside the first area corresponding to the first PLMN and within the second area corresponding to the second PLMN, and both the first PLMN and the second PLMN are PLMNs supported by the second network device.

[0142] In a possible design, the transceiver module 910 is further configured to receive first indication information from the terminal device or the second network device, where the first indication information is used to indicate that the second cell is an NTN cell, or is used to indicate that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two.

[0143] In a possible design, the transceiver module 910 is further configured to receive the cell information of the second cell from the terminal device or the second network device. The cell information of the second cell includes the information of at least two PLMNs supported by the second cell, and the at least two PLMNs include the first PLMN and the second PLMN.

[0144] In a possible design, the first response message further includes second indication information for indicating that the location of the terminal device does not match the first PLMN to which access is requested.

[0145] In a possible design, the transceiver module 910 is further configured to send third indication information to the terminal device, where the third indication information is used to indicate that the terminal device carries the location information of the terminal device when reporting the measurement result of the second cell.

[0146] In a possible design, the transceiver module 910 is specifically configured to send the first request message to the second network device through a core network device; and receive the first response message from the second network device from the core network device.

[0147] When this communication device executes Figure 3When implementing the operations or steps corresponding to the second network device in the method embodiments shown, the transceiver module 910 is configured to receive a first request message from the first network device, where the first request message is used to request to connect a terminal device to a second cell under the second network device. The first request message includes the location information of the terminal device and the information of a first PLMN, and the first PLMN is the target PLMN determined by the first network device for the terminal device to access; the processing module 920 is configured to, if the location where the terminal device is located is outside the first area corresponding to the first PLMN and within the second area corresponding to the second PLMN, determine the second PLMN as the target PLMN that allows the terminal device to access, where both the first PLMN and the second PLMN are PLMNs supported by the second network device; the transceiver module 910 is further configured to send a first response message to the first network device, and the first response message includes the information of the second PLMN.

[0148] In a possible design, the transceiver module 910 is further configured to send first indication information to the first network device, where the first indication information is used to indicate that the second cell is an NTN cell, or is used to indicate that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two.

[0149] In a possible design, the transceiver module 910 is further configured to send the cell information of the second cell to the first network device, and the cell information of the second cell includes the information of at least two PLMNs supported by the second cell, and the at least two PLMNs include the first PLMN and the second PLMN.

[0150] In a possible design, the first response message further includes second indication information, where the second indication information is used to indicate that the location where the terminal device is located does not match the first PLMN to which access is requested.

[0151] In a possible design, the transceiver module 910 is specifically configured to receive a first request message from the first network device from the core network device; and send a first response message to the first network device through the core network device.

[0152] It should be understood that the processing module 920 involved in this communication device may be implemented by at least one processor or processor-related circuit components, and the transceiver module 910 may be implemented by at least one transceiver or transceiver-related circuit components or communication interfaces. The operations and / or functions of each module in this communication device are respectively to achieve Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、or Figure 8The corresponding process of the method shown is not described herein again for the sake of brevity. Optionally, the communication device may further include a storage module, which may be used to store data and / or instructions. The transceiver module 910 and / or the processing module 920 may read the data and / or instructions in the access module, so that the communication device implements the corresponding method. The storage module may be implemented, for example, by at least one memory.

[0153] The above storage module, processing module, and transceiver module may exist separately, or all or some 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, etc.

[0154] Please refer to Figure 10 , which is another structural schematic diagram of a communication device provided in an embodiment of the present application. The communication device may specifically be a network device, such as a base station, for implementing the functions of the network device (such as the first network device or the second network device) involved in any of the above method embodiments.

[0155] The network device includes: one or more radio frequency units, such as a remote radio unit (RRU) 1001 and one or more baseband units (BBUs) (which may also be referred to as digital units, DUs) 1002. The RRU 1001 may be referred to as a transceiver unit, a transceiver, a transceiver circuit, or a transceiver, etc., and it may include at least one antenna 10011 and a radio frequency unit 10012. The RRU 1001 part is mainly used for the transceiver of radio frequency signals and the conversion between radio frequency signals and baseband signals. The BBU 1002 part is mainly used for baseband processing and controlling the base station, etc. The RRU 1001 and the BBU 1002 may be physically set together or physically separated, that is, a distributed base station.

[0156] The BBU 1002 is the control center of the base station and may also be referred to as a processing unit, mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, spreading, etc. For example, the BBU (processing unit) 1002 may be used to control the base station to execute the operation process of the network device in the above method embodiment.

[0157] In one example, the BBU 1002 may be composed of one or more single boards. The multiple single boards may jointly support a radio access network with a single access indication (such as an LTE network), or may separately support radio access networks with different access systems (such as an LTE network, a 5G network, or other networks). The BBU 1002 may further include a memory 10021 and a processor 10022. The memory 10021 is used to store necessary instructions and data. The processor 10022 is used to control the base station to perform necessary operations, such as controlling the base station to execute the sending operation in the above method embodiment. The memory 10021 and the processor 10022 may serve one or more single boards. That is to say, a memory and a processor may be separately provided on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board.

[0158] The embodiment of the present application further provides another communication device. Please refer to Figure 11 , which is a schematic structural diagram of another communication device provided by the embodiment of the present application. The communication device 1100 includes a transceiver module 1110 and a processing module 1120. This communication device can be used to implement the functions of the terminal device involved in any of the above method embodiments. For example, this communication device may be a terminal device, such as a handheld terminal device or a vehicle-mounted terminal device; this communication device may also be a chip or a circuit included in the terminal device, or a device including the terminal device, such as various types of vehicles, etc.

[0159] Exemplarily, when this communication device executes Figure 4 the operations or steps corresponding to the terminal device in the method embodiment shown, the transceiver module 1110 is used to receive third indication information from a first network device. The third indication information is used to indicate that the terminal device carries the location information of the terminal device when reporting the measurement result of a second cell. The second cell is a cell under a second network device; the processing module 1120 is used to generate a measurement report, and the measurement report includes the location information of the terminal device; the transceiver module 1110 is further used to send the measurement report to the first network device.

[0160] In a possible design, the transceiver module 1110 is further used to send first indication information to the first network device. The first indication information is used to indicate that the second cell is an NTN cell, or the first indication information is used to indicate that the second cell is an NTN cell and the PLMN supported by the second cell is at least two.

[0161] In a possible design, the transceiver module 1110 is further used to send the cell information of the second cell to the first network device. The cell information of the second cell includes information on at least two PLMNs supported by the second cell.

[0162] The processing module 1120 involved in the communication device may be implemented by at least one processor or processor-related circuit components, and the transceiver module 1110 may be implemented by at least one transceiver or transceiver-related circuit components or a communication interface. The operations and / or functions of each module in the communication device are respectively for implementing Figure 4 , Figure 5 , Figure 6 or Figure 8 The corresponding processes of the methods shown in, and for the sake of brevity, will not be elaborated here. Optionally, the communication device may further include a storage module, which may be used to store data and / or instructions. The transceiver module 1110 and / or the processing module 1120 may read the data and / or instructions in the access module, so that the communication device implements the corresponding method. The storage module may be implemented by at least one memory, for example.

[0163] The above 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, etc.

[0164] Please refer to Figure 12 , which is another structural schematic diagram of another communication device provided in the embodiment of the present application. The communication device may specifically be a terminal device, and the communication device may be used to implement the functions of the terminal device involved in any of the above method embodiments. For the convenience of understanding and illustration, in Figure 12 , the terminal device takes a mobile phone as an example. As Figure 12 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 an input / output device, etc. The processor is mainly used to process communication protocols and communication data, control the terminal device, execute software programs, process data of software programs, etc. The memory is mainly used to store software programs and data. The radio frequency circuit is mainly used for the conversion between baseband signals and radio frequency signals and the processing of radio frequency signals. The antenna is mainly used to transmit and receive radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touch screen, a display screen, a keyboard, etc., is 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 an input / output device.

[0165] When data needs to be sent, after the processor performs baseband processing on the data to be sent, it outputs a baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then sends the radio frequency signal outwards in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency 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 convenience of explanation, Figure 12Only one memory and one processor are shown. In an actual terminal device product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be set independently of the processor or integrated with the processor. The embodiments of the present application do not limit this.

[0166] In the embodiments of the present application, an antenna and a radio frequency circuit with transceiver functions may be regarded as the transceiver unit of the terminal device, and a processor with processing functions may be regarded as the processing unit of the terminal device. As Figure 12 shown, the terminal device includes a transceiver unit 1210 and a processing unit 1220. The transceiver unit may also be referred to as a transceiver, a transceiver machine, a transceiver device, etc. The processing unit may also be referred to as a processor, a processing board, a processing module, a processing device, etc. Optionally, the devices in the transceiver unit 1210 for implementing the receiving function may be regarded as the receiving unit, and the devices in the transceiver unit 1210 for implementing the sending function may be regarded as the sending unit, that is, the transceiver unit 1210 includes a receiving unit and a sending unit. The transceiver unit may sometimes also be referred to as a transceiver machine, a transceiver, or a transceiver circuit, etc. The receiving unit may sometimes also be referred to as a receiver, a receiver machine, or a receiving circuit, etc. The sending unit may sometimes also be referred to as a transmitter, a transmitter machine, or a transmitting circuit, etc. It should be understood that the transceiver unit 1210 is used to perform the sending operation and the receiving operation on the terminal device side in the above method embodiments, and the processing unit 1220 is used to perform other operations on the terminal device except for the transceiver operations in the above method embodiments.

[0167] The embodiments of the present application further provide a chip system, including: a processor, the processor is coupled to a memory, and the memory is used to store programs or instructions. When the programs or instructions are executed by the processor, the chip system implements the method corresponding to the terminal device or the method corresponding to the network device in any of the above method embodiments.

[0168] Optionally, the processor in the chip system may be one or more. The processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor, which realizes by reading the software code stored in the memory.

[0169] Optionally, the memory in the chip system may also be one or more. The memory may be integrated with the processor or set separately from the processor. The present application does not limit this. Exemplarily, the memory may be a non-transitory processor, such as a read-only memory ROM, which may be integrated with the processor on the same chip or may be set separately on different chips. The present application does not specifically limit the type of the memory and the setting manner of the memory and the processor.

[0170] Exemplarily, the chip system may be a field programmable gate array (FPGA), may be an application specific integrated circuit (ASIC), may also be a system on chip (SoC), may also be a central processing unit (CPU), may also be a network processor (NP), may also be a digital signal processing circuit (DSP), may also be a microcontroller unit (MCU), may also be a programmable logic device (PLD) or other integrated chips.

[0171] It should be understood that each step in the above method embodiments can be completed by the integrated logic circuit in the hardware of the processor or the instructions in the form of software. The method steps disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by the hardware processor, or executed and completed by the combination of the hardware and software modules in the processor.

[0172] The embodiments of the present application further provide a computer-readable storage medium, in which computer-readable instructions are stored. When the computer reads and executes the computer-readable instructions, the computer is caused to execute the method in any one of the above method embodiments.

[0173] The embodiments of the present application further provide a computer program product. When the computer reads and executes the computer program product, the computer is caused to execute the method in any one of the above method embodiments.

[0174] The embodiments of the present application further provide a communication system. The communication system includes a first network device, a second network device and at least one terminal device. Among them, the first network device may be a source network device, and the second network device may be a target network device. Optionally, the communication system may further include a core network device.

[0175] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0176] 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 ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (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 but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0177] 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 in the processor.

[0178] 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.

[0179] 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 and differentiation. The magnitude of the serial numbers of the above-mentioned processes or steps does not mean the sequence of execution. The execution sequence of each process or step should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0180] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0181] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0182] In several embodiments provided by the present 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 illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0183] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0184] In addition, the functional units in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0185] If the above-mentioned 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 such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0186] In various embodiments of this application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be cross-referenced. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0187] As described above, the above are only the specific implementation manners of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A communication method, characterized in that, The method includes: A first network device sends a first request message to a second network device. The first request message is used to request to connect a terminal device to a second cell under the second network device. The first request message includes the location information of the terminal device and the information of a first Public Land Mobile Network (PLMN). The first PLMN is the target PLMN determined by the first network device for the terminal device to access; The first network device receives a first response message from the second network device. The first response message includes the information of a second PLMN. The second PLMN is the target PLMN allowed by the second network device for the terminal device to access; Wherein, the first network device is a first access network device, and the second network device is a second access network device; The location where the terminal device is located is outside the first area corresponding to the first PLMN and within the second area corresponding to the second PLMN. Both the first PLMN and the second PLMN are PLMNs supported by the second network device.

2. The method according to claim 1, characterized in that The method further includes: The first network device receives first indication information from the terminal device or the second network device. The first indication information is used to indicate that the second cell is an NTN cell, or is used to indicate that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two.

3. The method according to claim 1, characterized in that The method further includes: The first network device receives the cell information of the second cell from the terminal device or the second network device. The cell information of the second cell includes the information of at least two PLMNs supported by the second cell. The at least two PLMNs include the first PLMN and the second PLMN.

4. The method according to any one of claims 1 to 3, characterized in that, The first response message further includes second indication information. The second indication information is used to indicate that the location where the terminal device is located does not match the first PLMN to which access is requested.

5. The method according to any one of claims 1 to 3, characterized in that The method further includes: The first network device sends third indication information to the terminal device. The third indication information is used to indicate that the terminal device carry its location information when reporting the measurement result of the second cell.

6. The method according to any one of claims 1 to 3, characterized in that, The first network device sending the first request message to the second network device includes: The first network device sends the first request message to the second network device through a core network device; The first network device receiving the first response message from the second network device includes: The first network device receives the first response message from the second network device from the core network device.

7. A communication method, characterized in that, The method includes: A second network device receives a first request message from a first network device. The first request message is used to request to connect a terminal device to a second cell under the second network device. The first request message includes the location information of the terminal device and the information of a first PLMN. The first PLMN is the target PLMN determined by the first network device for the terminal device to access; If the location where the terminal device is located is outside the first area corresponding to the first PLMN and inside the second area corresponding to the second PLMN, the second network device determines the second PLMN as the target PLMN that allows the terminal device to access, and both the first PLMN and the second PLMN are PLMNs supported by the second network device; The second network device sends a first response message to the first network device, and the first response message includes information of the second PLMN; wherein, the first network device is a first access network device, and the second network device is a second access network device.

8. The method according to claim 7, wherein The method further includes: The second network device sends first indication information to the first network device, and the first indication information is used to indicate that the second cell is an NTN cell, or is used to indicate that the second cell is an NTN cell and the PLMNs supported by the second cell are at least two.

9. The method according to claim 7, wherein The method further includes: The second network device sends cell information of the second cell to the first network device, and the cell information of the second cell includes information of at least two PLMNs supported by the second cell, and the at least two PLMNs include the first PLMN and the second PLMN.

10. The method according to any one of claims 7 to 9, characterized in that The first response message further includes second indication information, and the second indication information is used to indicate that the location where the terminal device is located does not match the first PLMN for which access is requested.

11. The method according to any one of claims 7 to 9, characterized in that, The second network device receives a first request message from the first network device, including: The second network device receives the first request message from the first network device from the core network device; The second network device sends a first response message to the first network device, including: The second network device sends the first response message to the first network device through the core network device.

12. A communication device, characterized in that, The apparatus includes units for performing the steps of the method according to any one of claims 1 to 6, or includes units for performing the steps of the method according to any one of claims 7 to 11.

13. A communication device, characterized in that, The apparatus includes at least one processor, and the at least one processor is coupled to at least one memory: The at least one processor is configured to execute computer programs or instructions stored in the at least one memory, so that the apparatus executes the method according to any one of claims 1 to 6, or so that the apparatus executes the method according to any one of claims 7 to 11.

14. A computer-readable storage medium, characterized in that, For storing instructions, when the instructions are executed, the method according to any one of claims 1 to 6 is implemented, or the method according to any one of claims 7 to 11 is implemented.

15. A communication device, characterized in that, Includes a processor and an interface circuit; The interface circuit is configured to interact code instructions to the processor; The processor is configured to run the code instructions to execute the method according to any one of claims 1 to 6, or the processor is configured to run the code instructions to execute the method according to any one of claims 7 to 11.

16. A computer program product, characterized in that, When the computer reads and executes the computer program product, the computer is caused to execute the method according to any one of claims 1 to 6, or execute the method according to any one of claims 7 to 11.

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