Communication method and communication apparatus

Abstract

The present application relates to the field of communications. Provided are a communication method and a communication apparatus, which can be applied to the field of satellite communications, for example, NTNs. The method comprises: a terminal device receiving first configuration information, wherein the first configuration information is used for indicating that a first access network device has a first communication link for accessing a first core network, the first core network comprises a registration parameter of the terminal device, the first access network device is associated with a second core network, and the first core network is different from the second core network; and the terminal device accessing the first core network by means of the first access network device. In the embodiments of the present application, a terminal device is notified, by means of first configuration information, that another network has a return access link, such as a first communication link, for return access to an originally registered core network, such that when the terminal device camps within a coverage range of the other network , a condition for return access to the originally registered core network is provided, thereby facilitating a reduction in the frequency of the terminal device executing a registration process, and thus facilitating a reduction in communication delay.

Description

Communication method and communication apparatus

[0001] The present application claims priority to the Chinese patent application No. 202411295353.9, filed on September 13, 2024, and entitled "Communication method and communication apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication, in particular to a communication method and a communication apparatus. BACKGROUND

[0003] In a communication process, a terminal device usually needs to register to a network to obtain some services provided by the network. When the topology of the accessed network changes, the terminal device needs to re-register to the network. For a scenario where the network topology changes frequently, such as a non-terrestrial network (NTN) communication scenario, the terminal device needs to frequently perform a registration process, which will cause a certain communication delay. SUMMARY

[0004] The present application provides a communication method and a communication apparatus, which can reduce the communication delay caused by frequent registration processes.

[0005] In a first aspect, a communication method is provided, which includes: a terminal apparatus receiving first configuration information, the first configuration information being used to indicate that a first access network device has a first communication link to a first core network, the first core network including a registration parameter of the terminal apparatus, the first access network device being associated with a second core network, the first core network and the second core network being different; and the terminal apparatus accessing the first core network through the first access network device.

[0006] Exemplarily, the communication method can be implemented by a terminal apparatus. For example, the terminal apparatus can be a terminal device, or a module or component with terminal device function, or a communication chip that can be applied to a terminal device, such as a processor, a circuit, a chip or a chip system, etc.

[0007] Exemplarily, the communication method can be applied to various communication scenarios, such as a ground network scenario and an NTN scenario.

[0008] Exemplarily, the first core network can be a core network that manages and / or maintains the registration parameter of the terminal apparatus, or the terminal apparatus has registered in the first core network. For example, the first core network can be a core network in a home network of the terminal apparatus. For another example, the first core network can be a core network in a roaming network, but the terminal apparatus has registered in the roaming network.

[0009] Exemplarily, the second core network is a core network that the first access network device accesses by default, or in other words, the second core network is a core network that the first access network device prefers to access.

[0010] Exemplarily, the first core network is a core network that the second access network device accesses by default, or in other words, the first core network is a core network that the second access network device prefers to access.

[0011] Exemplarily, the registration parameters of the terminal device managed and / or maintained by the second core network and the first core network are not completely same.

[0012] Exemplarily, the second core network and the first core network belong to different public land mobile networks (PLMNs), or in other words, the second core network and the first core network are core networks in different PLMNs.

[0013] Exemplarily, the second core network and the first core network are core networks of different operators.

[0014] Exemplarily, the second core network and the first core network are core networks of the same operator, but the second core network and the first core network can provide network services for different geographic areas.

[0015] In the embodiments of the present application, the first configuration information informs the terminal device that the other network has a back-visit link, such as the first communication link, to the originally registered core network, which provides a condition for the terminal device to back-visit the originally registered core network when the terminal device resides in the coverage range of the other network, helps to reduce the frequency of the terminal device performing the registration process, and thus helps to reduce the communication delay.

[0016] In some embodiments, the first communication link includes a gateway or a second access network device, and the second access network device is associated with the first core network.

[0017] Exemplarily, the gateway can serve as an intermediate node of the first communication link, that is, the communication nodes in the first communication link include the first access network device, the gateway, and the first core network. This scheme is convenient to implement.

[0018] Exemplarily, the second access network device can serve as an intermediate node of the first communication link, that is, the communication nodes in the first communication link include the first access network device, the second access network device, and the first core network. Since there is a communication link between the second access network device and the first core network, the first communication link can reuse the above communication link, thereby saving configuration overhead.

[0019] In some embodiments, the terminal device accesses the first core network through the first access network device, comprising: the terminal device sends first information to the first access network device, the first information being used to indicate the first core network and / or the first communication link; and the terminal device receives information from the first core network.

[0020] Since the first access network device can access the first core network and the second core network, the first information helps the first access network device determine the core network that the terminal device wants to access.

[0021] In some embodiments, the first configuration information is carried in a registration success feedback message from the first core network, or the first configuration information is carried in a system message of the first access network device.

[0022] The various carrying manners of the first configuration information help improve the flexibility of configuration. For example, the carrying manner of the first configuration information can be selected according to the use requirement and the resource state, etc.

[0023] In a second aspect, a communication method is provided, comprising: receiving first configuration information, the first configuration information being used to indicate that a first access network device has a first communication link to access a first core network, the first core network including a registration parameter of a terminal device, the first access network device being associated with a second core network, the first core network and the second core network being different; and sending the first configuration information to the terminal device.

[0024] Exemplarily, the communication method can be implemented by the first access network device, or by a component inside the first access network device, such as a processor, a circuit, a chip or a chip system. Optionally, the first access network device can be a fourth generation (4G) base station, a fifth generation (5G) base station or a base station in a future communication system, etc.

[0025] In the embodiments of the present application, the first configuration information informs the terminal device that other networks have a back-visit link, such as the first communication link, to visit the original registration core network, which provides a condition for the terminal device to visit the original registration core network when the terminal device stays in the coverage range of the other networks, helps reduce the frequency of the terminal device performing the registration process, and thus helps reduce the communication delay.

[0026] In some embodiments, first information is received from the terminal device, the first information being used to indicate the first core network and / or the first communication link; and configuration information of the first communication link is activated.

[0027] That is, after the configuration information of the first communication link is generated, the configuration information can not be activated immediately. For example, the configuration information of the first communication link can be activated when the first communication link is used, which helps to reduce the overhead of the system.

[0028] In a third aspect, a communication method is provided, which includes: sending first configuration information, the first configuration information being used to indicate that a first access network device has a first communication link to access a first core network, the first core network including a registration parameter of a terminal device, the first access network device being associated with a second core network, the first core network and the second core network being different.

[0029] Exemplarily, the communication method can be implemented by the first core network, or by a component in the first core network, such as a processor, a circuit, a chip or a chip system.

[0030] Optionally, the communication method can be implemented by a network element in the first core network. As an example, the communication method can be implemented by an access and mobility management function (AMF) network element in the first core network, or by a circuit, a chip or a chip system that implements the function of the AMF network element.

[0031] In the embodiments of the present application, the first configuration information informs the terminal device that other networks have a back-visit link, such as the first communication link, to the original registration core network, which provides a condition for the terminal device to back-visit the original registration core network when the terminal device stays in the coverage of the other networks, helps to reduce the frequency of the terminal device to perform the registration process, and thus helps to reduce the communication delay.

[0032] In some embodiments, the first communication link includes a gateway or a second access network device, and the second access network device is associated with the first core network.

[0033] Exemplarily, the gateway can be used as an intermediate node of the first communication link, that is, the communication nodes in the first communication link include the first access network device, the gateway and the first core network. This scheme is convenient to implement.

[0034] Exemplarily, the second access network device can be used as an intermediate node of the first communication link, that is, the communication nodes in the first communication link include the first access network device, the second access network device and the first core network. Since the second access network device and the first core network have a communication link, the first communication link can reuse the communication link, thereby saving the configuration overhead.

[0035] In some embodiments, before the sending the first configuration information, the method further includes: sending, to the gateway or the second access network device, second information, where the second information is used to indicate establishment of the first communication link.

[0036] The second information can be used to determine the timing of creating the first communication link. Since the first core network can communicate with the nodes in the first communication link, the first core network initiates the creation of the first communication link, which is simple.

[0037] In some embodiments, the first configuration information includes one or more of the following: indication information of the first access network device; indication information of the first communication link; or priority information of the first communication link.

[0038] For example, the first configuration information can include the indication information of the first access network device, where the indication information of the first access network device can include: identification information of the first access network device; identification information of a network to which the first access network device belongs, such as identification information of a PLMN to which the first access network device belongs; or identification information of a cell in which the first access network device provides services, etc. In this way, the terminal device can determine, according to the first configuration information, the access network device that has the capability of visiting the first core network. In the case where the terminal device resides in an area covered by multiple access network devices, the terminal device can preferentially access the access network device that has the capability of visiting the first core network, which helps to reduce the registration frequency and thus helps to reduce the communication delay caused by registration.

[0039] For example, the indication information of the first communication link can be used to indicate the target core network of the first communication link, i.e., the first core network, which helps to reduce the indication overhead.

[0040] For example, the indication information of the first communication link can be used to indicate the path information of the first communication link. In the case where there are multiple communication links that visit the first core network, the path information of the first communication link can be used to assist the terminal device in selecting the communication link that visits the first core network, thereby helping to improve the system performance.

[0041] For example, the configuration information of the first communication link and the identification of the first communication link can be pre-configured, and the identification of the first communication link is dynamically indicated by the first configuration information, so as to save the indication overhead.

[0042] For example, the first configuration information can include the priority information of the first communication link. The priority information of the first communication link can assist the terminal device in selecting the communication link that visits the first core network, so as to improve the reliability and / or timeliness of transmission of the visiting traffic.

[0043] In a fourth aspect, a communication method is provided. The method includes receiving second information, the second information being used to indicate establishment of a first communication link, the first communication link being used for a first access network device to access a first core network, the first core network including a registration parameter of a terminal device, the first access network device being associated with a second core network, the first core network being different from the second core network; and establishing a mapping relationship between a first interface and a second interface, the first interface being used for communication with the first core network, and the second interface being used for communication with the first access network device.

[0044] Exemplarily, in a case where the second access network device is an intermediate node of the first communication link, the communication method can be implemented by the second access network device, or implemented by a component inside the second access network device, such as a processor, a circuit, a chip or a chip system. The second access network device can be, for example, a 4G base station, a 5G base station or a base station in a future communication system.

[0045] Exemplarily, in a case where the gateway is an intermediate node of the first communication link, the communication method can be implemented by the gateway device, or implemented by a component inside the gateway device, such as a processor, a circuit, a chip or a chip system.

[0046] In the embodiments of the present application, the first configuration information is used to inform the terminal device that the other network has a back-visit link, such as the first communication link, to the original registration core network, so as to provide a condition for the terminal device to back-visit the original registration core network when the terminal device stays in a coverage range of the other network, which helps to reduce the frequency of the terminal device performing a registration process, thereby helping to reduce communication latency.

[0047] The first aspect to the fourth aspect introduce a method of creating a first communication link and back-visit an original registration core network through the first communication link. The fifth aspect to the eighth aspect introduce a pre-registration method.

[0048] In a fifth aspect, a communication method is provided. The method includes: a terminal device sending a first registration request message to a second access network device, the second access network device being associated with a first core network, wherein the first registration request message includes first indication information, the first indication information being used to indicate the first core network and a second core network, or the first registration request message includes second indication information and auxiliary information, the second indication information being used to indicate the first core network, and the auxiliary information being used to determine the second core network; and the terminal device receiving first registration parameters and second registration parameters, the first registration parameters being registration parameters of the terminal device in the first core network, and the second registration parameters being registration parameters of the terminal device in the second core network.

[0049] Exemplarily, the communication method can be implemented by a terminal device. For example, the terminal device can be a terminal equipment, or a module or component with terminal equipment function, or a communication chip capable of being applied to a terminal equipment, such as a processor, a circuit, a chip or a chip system.

[0050] Exemplarily, the first indication information can be determined by the terminal device, that is, a plurality of networks performing registration for the terminal device are determined by the terminal device.

[0051] Exemplarily, the first core network can determine the second core network according to the assistance information. That is, the network performing pre-registration for the terminal device is determined by the core network side, or the candidate network is determined by the core network side.

[0052] Embodiments of the present application complete the registration process of the terminal device in other networks in advance, or generate the registration parameters of the terminal device in other networks in advance, so that the terminal device can directly obtain the generated registration parameters when accessing other networks, without waiting for the generation process of the registration parameters, thereby helping to reduce the communication delay caused by registration.

[0053] In some embodiments, the assistance information includes one or more of the following: location information of the terminal device; a first time, expecting not to perform the registration process of the terminal device within the first time; or a first location area, expecting not to perform the registration process of the terminal device within the first location area.

[0054] In some embodiments, the first indication information is carried in a non-access stratum (NAS) message, or the first indication information is carried in a radio resource control (RRC) setup completion message.

[0055] In some embodiments, the first registration parameter is carried in a registration success feedback message from the first core network, the second registration parameter is carried in a registration success feedback message from the first core network, or the second registration parameter is carried in a registration success feedback message from the second core network.

[0056] The various carrying modes of the second registration parameter help to improve the flexibility of configuring the registration parameter.

[0057] In some embodiments, the method further comprises: activating the second registration parameter if a first condition is met, wherein the first condition comprises one or more of the following: the terminal device establishes a connection with the first access network device, the first access network device is associated with the second core network; the terminal device is located within a coverage of the first access network device; it is predicted that the terminal device is located within the coverage of the first access network device; an indication information of activating the second registration parameter is received; or a public land mobile network (PLMN) in which the terminal device is located is a PLMN to which the second core network belongs.

[0058] It should be noted that activating a registration parameter can be understood as that the registration parameter is valid, or the registration parameter is used, and deactivating a registration parameter can be understood as that the registration parameter is invalid, or the registration parameter is not used. The meanings of activating and deactivating are introduced below by taking the first registration parameter as an example.

[0059] Activating the first registration parameter can be understood as that the first registration parameter is a valid registration parameter or the first registration parameter is used as the registration parameter of the terminal device. Deactivating the first registration parameter can be understood as that the first registration parameter is an invalid registration parameter or the first registration parameter is not used as the registration parameter of the terminal device.

[0060] In some embodiments, the second registration parameter comprises a plurality of groups of registration parameters, the plurality of groups of registration parameters are registration parameters of the terminal device in a plurality of the second core networks, and the activating the second registration parameter if the first condition is met comprises: determining a target registration parameter in the second registration parameter based on priorities of the plurality of groups of registration parameters if the first condition is met; and activating the target registration parameter.

[0061] The priority information of the registration parameter can assist the terminal device in selecting a suitable registration parameter.

[0062] In some embodiments, a priority of a registration parameter in a home network is higher than a priority of a registration parameter in a roaming network, and / or a size of a tracking area in which the second core network provides a service is proportional to a priority of a registration parameter of the terminal device in the second core network.

[0063] Preferentially activating a registration parameter in a home network helps to reduce a data transmission overhead between a roaming network and the home network. The larger a tracking area associated with a registration parameter is, the higher a priority of the registration parameter is. That is, preferentially activating a registration parameter corresponding to a largest tracking area helps to reduce a frequency of mobility registration update, thereby helping to further reduce a communication latency.

[0064] In some embodiments, the first condition is carried in a registration success feedback message of the first core network or a registration success feedback message of the second core network.

[0065] In some embodiments, the tracking area in which the first core network provides services is a first tracking area, and the tracking area in which the second core network provides services is a second tracking area. The method further comprises: receiving indication information of a third tracking area from a third access network device, the third access network device providing coverage for a region in which the terminal device currently resides; and triggering a mobility registration procedure if the first tracking area does not include the third tracking area and the second tracking area does not include the third tracking area.

[0066] The method helps to reduce the frequency of triggering a mobility registration update by the terminal device, thereby helping to reduce system overhead.

[0067] In a sixth aspect, a communication method is provided, which comprises: receiving a first registration request message from a terminal device, the first registration request message comprising first indication information, the first indication information being used to indicate a first core network and a second core network; sending the first registration request message to the first core network; or sending the first registration request message to the first core network and sending the first registration request message to the second core network.

[0068] Exemplarily, the communication method can be implemented by a second access network device, or by a component inside the second access network device, such as a processor, a circuit, a chip or a chip system. The second access network device can be, for example, a 4G base station, a 5G base station or a base station in a future communication system.

[0069] Embodiments of the present application complete the registration procedure of the terminal device in other networks in advance, or in other words, generate registration parameters of the terminal device in other networks in advance, so that the terminal device can directly obtain the registration parameters generated in advance when accessing other networks, without waiting for the generation process of the registration parameters, thereby helping to reduce the communication delay caused by registration.

[0070] In a seventh aspect, a communication method is provided. The method includes receiving a first registration request message, the first registration request message including first indication information indicating the first core network and a second core network, or the first registration request message including second indication information indicating the first core network and assistance information used to determine the second core network; and sending a registration success feedback message, the registration success feedback message including first registration parameters for the terminal device in the first core network, or the registration success feedback message including the first registration parameters and second registration parameters for the terminal device in the second core network.

[0071] Exemplarily, the communication method can be implemented by the first core network, or by a component in the first core network, such as a processor, a circuit, a chip or a chip system. Alternatively, the communication method can be implemented by a network element in the first core network, such as an AMF.

[0072] Embodiments of the present application pre-complete the registration process of the terminal device in other networks, or pre-generate the registration parameters of the terminal device in other networks, so that the terminal device can directly obtain the pre-generated registration parameters when accessing other networks, without waiting for the generation process of the registration parameters, thereby helping to reduce the communication delay caused by registration.

[0073] In some embodiments, the method further includes determining the second core network based on the assistance information, and sending a second registration request message to the second core network, the second registration request message being used to request the second registration parameters.

[0074] That is, the network for performing pre-registration for the terminal device is determined by the core network side, or the candidate network is determined by the core network side.

[0075] Exemplarily, the first core network can determine the timing of sending the second registration request message to the second core network. If there are multiple second core networks, the timing of sending the second registration request message to the multiple second core networks by the first core network is not completely the same, thereby helping to avoid congestion of registration signaling on the first core network side.

[0076] In some embodiments, the assistance information includes one or more of the following: location information of the terminal device; a first time, in which it is expected that the registration process of the terminal device is not performed; or a first location area, in which it is expected that the registration process of the terminal device is not performed.

[0077] In some embodiments, the method further comprises: generating first registration parameters; and sending part or all of the first registration parameters to the second core network.

[0078] That is, the second core network can reuse part or all of the first registration parameters in the process of generating the second registration parameters, thereby omitting part of the steps in the registration procedure, which helps to reduce the processing overhead of the second core network.

[0079] In some embodiments, the method further comprises: in response to receiving indication information for deactivating the first registration parameters or a first timer expiring, deactivating the first registration parameters, wherein the first timer starts at the first registration parameter activation time.

[0080] In an eighth aspect, a communication method is provided, which comprises: receiving a second registration request message from a second access network device or a first core network, the second registration request message being used to request a second registration parameter of a terminal device in a second core network, the second access network device being associated with the first core network; and sending the second registration parameter.

[0081] Exemplarily, the communication method can be implemented by the second core network, or by a component inside the second core network, such as a processor, a circuit, a chip or a chip system. Alternatively, the communication method can be implemented by a network element in the second core network.

[0082] In some embodiments, before the sending the second registration parameter, the method further comprises: receiving part or all of the first registration parameters, the first registration parameters being registration parameters of the terminal device in the first core network; and generating the second registration parameters based on the part or all of the first registration parameters.

[0083] That is, the second core network can reuse part or all of the first registration parameters in the process of generating the second registration parameters, thereby omitting part of the steps in the registration procedure, which helps to reduce the processing overhead of the second core network.

[0084] In some embodiments, the method further comprises: if a first condition is met, activating the second registration parameters, wherein the first condition comprises one or more of the following: the terminal device establishes a connection with the first access network device, the first access network device being associated with the second core network; the terminal device is located within a coverage range of the first access network device; it is predicted that the terminal device is located within the coverage range of the first access network device; receiving indication information for activating the second registration parameters; or a public land mobile network (PLMN) in which the terminal device resides is a PLMN to which the second core network belongs.

[0085] The embodiment of the present application pre-completes the registration process of the terminal device in other networks, or pre-generates the registration parameters of the terminal device in other networks, so that the terminal device can directly obtain the pre-generated registration parameters when accessing other networks, without waiting for the generation process of the registration parameters, thereby helping to reduce the communication delay caused by registration.

[0086] In a ninth aspect, a communication apparatus is provided, which comprises: means for performing each step in any possible implementation manner of the first aspect and the fifth aspect. Exemplarily, the communication apparatus can be a terminal device.

[0087] In a tenth aspect, a communication apparatus is provided, which comprises: means for performing each step in any possible implementation manner of the second aspect. Exemplarily, the communication apparatus can be a first access network device.

[0088] In an eleventh aspect, a communication apparatus is provided, which comprises: means for performing each step in any possible implementation manner of the third aspect and the seventh aspect. Exemplarily, the communication apparatus can be a first core network or a functional node in the first core network.

[0089] In a twelfth aspect, a communication apparatus is provided, which comprises: means for performing each step in any possible implementation manner of the fourth aspect. Exemplarily, the communication apparatus can be a gateway.

[0090] In a thirteenth aspect, a communication apparatus is provided, which comprises: means for performing each step in any possible implementation manner of the fourth aspect and the sixth aspect. Exemplarily, the communication apparatus can be a second access network device.

[0091] In a fourteenth aspect, a communication apparatus is provided, which comprises: means for performing each step in any possible implementation manner of the eighth aspect. Exemplarily, the communication apparatus can be a second core network or a functional node in the second core network.

[0092] In a fifteenth aspect, a communication apparatus is provided, which comprises at least one processor coupled with a memory, the memory being used to store programs or instructions, and the programs or instructions being executed by the processor to perform the method in any possible implementation manner of the first aspect and the fifth aspect.

[0093] In a sixteenth aspect, a communication apparatus is provided, which comprises at least one processor coupled with a memory, the memory being configured to store program or instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the second aspect.

[0094] In a seventeenth aspect, a communication apparatus is provided, which comprises at least one processor coupled with a memory, the memory being configured to store program or instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the third aspect or the seventh aspect.

[0095] In an eighteenth aspect, a communication apparatus is provided, which comprises at least one processor coupled with a memory, the memory being configured to store program or instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the fourth aspect.

[0096] In a nineteenth aspect, a communication apparatus is provided, which comprises at least one processor coupled with a memory, the memory being configured to store program or instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the fourth aspect or the sixth aspect.

[0097] In a twentieth aspect, a communication apparatus is provided, which comprises at least one processor coupled with a memory, the memory being configured to store program or instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the eighth aspect.

[0098] In a twenty-first aspect, a communication apparatus is provided, which comprises at least one processor and a memory, the processor and the memory being coupled, and the memory storing program instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the first aspect or the fifth aspect.

[0099] In a twenty-second aspect, a communication apparatus is provided, which comprises at least one processor and a memory, the processor and the memory being coupled, and the memory storing program instructions, which, when executed by the processor, perform the method in any possible implementation of the method according to the second aspect.

[0100] In a twenty-third aspect, a communication apparatus is provided, which comprises at least one processor and a memory coupled to the processor, the memory storing program instructions that, when executed by the processor, perform the method of any possible implementation of the third aspect, the seventh aspect.

[0101] In a twenty-fourth aspect, a communication apparatus is provided, which comprises at least one processor and a memory coupled to the processor, the memory storing program instructions that, when executed by the processor, perform the method of any possible implementation of the fourth aspect.

[0102] In a twenty-fifth aspect, a communication apparatus is provided, which comprises at least one processor and a memory coupled to the processor, the memory storing program instructions that, when executed by the processor, perform the method of any possible implementation of the fourth aspect, the sixth aspect.

[0103] In a twenty-sixth aspect, a communication apparatus is provided, which comprises at least one processor and a memory coupled to the processor, the memory storing program instructions that, when executed by the processor, perform the method of any possible implementation of the eighth aspect.

[0104] In a twenty-seventh aspect, a communication apparatus is provided, which comprises at least one processor and an interface circuit for sending and / or receiving signals, such that the processor performs the method of any possible implementation of the first aspect, the fifth aspect.

[0105] In a twenty-eighth aspect, a communication apparatus is provided, which comprises at least one processor and an interface circuit for sending and / or receiving signals, such that the processor performs the method of any possible implementation of the second aspect.

[0106] In a twenty-ninth aspect, a communication apparatus is provided, which comprises at least one processor and an interface circuit for sending and / or receiving signals, such that the processor performs the method of any possible implementation of the third aspect, the seventh aspect.

[0107] In a thirtieth aspect, a communication apparatus is provided, which comprises at least one processor and an interface circuit for sending and / or receiving signals, such that the processor performs the method of any possible implementation of the fourth aspect.

[0108] In a thirty-first aspect, a communication apparatus is provided, which comprises at least one processor and interface circuitry for transmitting and / or receiving signals, such that the processor performs the method in any possible implementation of the fourth aspect, the sixth aspect.

[0109] In a thirty-second aspect, a communication apparatus is provided, which comprises at least one processor and interface circuitry for transmitting and / or receiving signals, such that the processor performs the method in any possible implementation of the eighth aspect.

[0110] In a thirty-third aspect, a computer program product is provided, which comprises a computer program for performing the method in any possible implementation of the first aspect to the eighth aspect when the computer program is executed by a processor.

[0111] In a thirty-fourth aspect, a computer-readable storage medium is provided, which stores a computer program for performing the method in any possible implementation of the first aspect to the eighth aspect when the computer program is executed.

[0112] In a thirty-fifth aspect, a chip is provided, which comprises a processor for invoking and running a computer program from a memory, such that a communication device installed with the chip performs the method in any possible implementation of the first aspect to the eighth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0113] FIG. 1 is a schematic diagram of an architecture of a communication system to which embodiments of the present application are applied;

[0114] FIG. 2 is a schematic diagram of an application architecture of a satellite communication network provided by embodiments of the present application;

[0115] FIG. 3 is a schematic diagram of a structure of a roaming architecture provided by embodiments of the present application;

[0116] FIG. 4 is a schematic diagram of a flow of a communication method provided by embodiments of the present application;

[0117] FIG. 5 is a schematic diagram of a first communication link provided by embodiments of the present application;

[0118] FIG. 6 is an example diagram of the first communication link in FIG. 5;

[0119] FIG. 7 is another example diagram of the first communication link provided by embodiments of the present application;

[0120] FIG. 8 is a schematic diagram of a flow of another communication method provided by embodiments of the present application;

[0121] FIG. 9 is a flow diagram illustrating another method of communication, according to embodiments of the present disclosure;

[0122] FIG. 10 is a flow diagram illustrating another method of communication, according to embodiments of the present disclosure;

[0123] FIG. 11 is a flow diagram illustrating another method of communication, according to embodiments of the present disclosure;

[0124] FIG. 12 is a schematic block diagram of a communication device, according to embodiments of the present disclosure;

[0125] FIG. 13 is a schematic block diagram of another communication device, according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0126] The technical solutions in the embodiments of the present disclosure will be described below with reference to the drawings.

[0127] In the description of the embodiments of the present disclosure, unless otherwise specified, " / " represents that the objects before and after the " / " are in an "or" relationship, for example, A / B can represent A or B; "and / or" in the embodiments of the present disclosure is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. In addition, in the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or the like means any combination of the items, including any combination of single item or multiple items. For example, at least one of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple. In addition, in order to clearly describe the technical solutions of the embodiments of the present disclosure, the same items or similar items with basically the same functions and effects are distinguished by "first", "second", etc. in the embodiments of the present disclosure. Those skilled in the art can understand that "first", "second", etc. do not limit the quantity and execution order, and "first", "second", etc. also do not necessarily mean different.

[0128] In the method embodiments of the embodiments of the present disclosure, the size of the serial number does not mean the execution order, and the execution order should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure.

[0129] It can be understood that, in the embodiments of the present application, "in the case of", "if", "when", "if" and the like can be used instead. And these descriptions all mean that the corresponding processing will be made under certain objective conditions, not limited in time, and also does not require the judgment action when implementing, nor means that there are other limitations.

[0130] It can be understood that, in the embodiments of the present application, some optional features can be implemented independently in some scenarios, without relying on other features, such as the scheme currently based on, to solve the corresponding technical problems and achieve the corresponding effects. Also, in some scenarios, they can be combined with other features according to needs. Correspondingly, the devices given in the embodiments of the present application can also implement these features or functions, which will not be described here.

[0131] In the embodiments of the present application, the same or similar parts between different embodiments can be mutually referred to, unless otherwise specified. In the embodiments of the present application, and in each implementation / implementation method / realization method in each embodiment, if there is no special specification and logical conflict, the terms and / or descriptions between different embodiments, and between each implementation / implementation method / realization method in each embodiment, are consistent and can be mutually referred to. The technical features in different embodiments, and in each implementation / implementation method / realization method in each embodiment, can be combined to form new embodiments, implementations, implementation methods, or realization methods according to their inherent logical relationship. The implementation methods of the present application described below do not constitute a limitation on the scope of protection of the present application.

[0132] The embodiments of the present application can be applied to various communication systems. For ease of understanding, the communication system 10 shown in FIG. 1 is taken as an example to describe the communication system to which the embodiments of the present application are applicable.

[0133] FIG. 1 is a schematic diagram of an architecture of a communication system 10 to which embodiments of the present application are applied. As shown in FIG. 1, the communication system includes a radio access network (RAN) 100, which includes at least one RAN node (e.g., 110a and 110b, collectively 110, in FIG. 1) and at least one terminal (e.g., 120a-120j, collectively 120, in FIG. 1). The RAN 100 can also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 1). The terminals 120 are wirelessly connected to the RAN nodes 110. Terminals and terminals, and RAN nodes and RAN nodes, can be connected to each other by wire or wirelessly. The communication system 10 can also include a core network 200. The RAN nodes 110 are connected to the core network 200 by wire or wirelessly. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 can be independent and different physical devices, or can be the same physical device integrated with the logical functions of the core network devices and the logical functions of the RAN nodes. The communication system 10 can also include the Internet 300.

[0134] The RAN 100 can be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, and a future wireless access system defined in the 3rd generation partnership project (3GPP). The RAN 100 can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. The RAN 100 can also be a communication system in which two or more of the above systems are fused.

[0135] The RAN node 110 (may also be referred to as an access network device, a RAN entity, or an access node, etc.) is configured to help terminals to access to the communication system through wireless manner. In a possible scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a WiFi system, etc. The RAN node can be a macro base station (e.g., 110a in FIG. 1), a micro base station or an indoor station (e.g., 110b in FIG. 1), a relay node or a donor node, or a wireless controller in a CRAN scenario. In the scenario of satellite communication, such as NTN, the RAN node can be a base station deployed on a satellite, e.g., a 4G base station, a 5G base station, or a base station in a future communication system. In the case that the access network device is deployed on a satellite, the RAN node can also refer to a satellite with access network function. Alternatively, the RAN node can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in vehicle to everything (V2X) technology can be a road side unit (RSU).

[0136] In another possible scenario, a terminal is assisted by multiple RAN nodes to implement wireless access, and different RAN nodes respectively implement part of functions of a base station. For example, a RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU), etc. Here, the CU can complete functions of a radio resource control protocol and PDCP of the base station, and can also complete a function of a service data adaptation protocol (SDAP); the DU can complete functions of a radio link control layer and a medium access control (MAC) layer of the base station, and can also complete a function of part of a physical layer or all of the physical layer. For specific descriptions of the above protocol layers, refer to related technical specifications of the 3GPP. The RU can be used to implement functions of transceiving a radio frequency signal. The CU and the DU can be two independent RAN nodes, or can be integrated in a same RAN node, for example, integrated in a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, for example, included in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). The CU can be further divided into a CU-control plane (CP) and a CU-user plane (UP) two types of RAN nodes.

[0137] In different systems, a RAN node can have different names. For example, in an O-RAN system, a CU can be referred to as an open CU (O-CU), a DU can be referred to as an open DU (O-DU), and a RU can be referred to as an open RU (O-RU). Correspondingly, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. For ease of description, in embodiments of the present application, the CU, the CU-CP, the CU-UP, the DU, and the RU are taken as examples for description.

[0138] All or part of the functions of the RAN node in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform, such as a cloud platform. The RAN node can also be provided with a communication module, circuit or chip for performing corresponding communication functions, and program instructions for performing corresponding communication functions. The RAN node in the present application can also be a logical node, logical module or software capable of realizing all or part of the functions of the RAN node. The embodiments of the present application do not limit the specific technology and specific device form of the RAN node.

[0139] The terminal 120 is a device with wireless transceiving function, which can send signals to the base station or receive signals from the base station. The terminal can also be referred to as user equipment (UE), terminal device, access terminal, subscriber unit, subscriber station, mobile station (MS), remote station, remote terminal, mobile terminal (MT), user terminal, wireless communication device, user agent, and user equipment, etc. The terminal 120 can be a mobile phone, tablet computer, computer with wireless transceiving function, wearable device, vehicle, unmanned aerial vehicle, helicopter, airplane, ship, robot, mechanical arm, smart home device, etc. The embodiments of the present application do not limit the device form of the terminal.

[0140] Exemplarily, the terminal 120 can be an internet of things (IoT) device (e.g., a sensor, an electricity meter, a water meter, etc.), a V2X device, a station (ST) in a wireless local area network (WLAN), a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a handheld device having wireless communication function, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device (which can also be referred to as a smart wearable device), a tablet computer or a computer with wireless transceiver function, a virtual reality (VR) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical treatment, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a vehicle terminal, a vehicle with vehicle-to-vehicle (V2V) communication capability, a smart connected vehicle, a drone with UAV to UAV (U2U) communication capability, etc.

[0141] The roles of the base stations and the terminals can be relative, for example, the network element 120i in FIG. 1 can be a helicopter or a drone, which can be configured as a mobile base station, for those terminals 120j accessing to the wireless access network 100 through 120i, the terminal 120i is a base station; but for the base station 110a, 120i is a terminal, that is, 110a and 120i communicate through a wireless air interface protocol. Of course, 110a and 120i can also communicate through a base station-to-base station interface protocol, at this time, 120i is also a base station relative to 110a. Therefore, the base stations and the terminals can be collectively referred to as communication apparatuses, 110a and 110b in FIG. 1 can be referred to as communication apparatuses with base station function, and 120a-120j in FIG. 1 can be referred to as communication apparatuses with terminal function.

[0142] The base station and the terminal can be fixed in position or mobile. The base station and the terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on water; can also be deployed on an airplane, a balloon and a man-made satellite. Embodiments of the present application do not limit the application scenarios of the base station and the terminal.

[0143] With the development of information technology, more urgent requirements are put forward for efficient, mobile and diverse communication. At present, a development focus in the field of communication systems is global mobile communication, and an important part of global mobile communication is NTN communication. A typical NTN communication is satellite communication. In some important fields such as space communication, aviation communication and maritime communication, satellites play an irreplaceable role.

[0144] The 5G mobile communication network technology standard published by the 3GPP standard organization studies the space-ground integrated communication technology. This technology mainly integrates the existing 5G standard and satellite communication technology to meet the global full coverage.

[0145] Satellite communication has the characteristics of long communication distance, large coverage area and flexible networking, and can provide services for fixed terminals and various mobile terminals. Satellites are divided into low earth orbit (LEO) satellites, medium earth orbit (MEO) satellites, geostationary earth orbit (GEO) satellites, high elliptical orbit (HEO) satellites and the like according to the different orbital heights. In addition to satellites, NTN can also include some aircrafts, such as high altitude platforms (HAPs), unmanned aircraft systems (UAS) and the like.

[0146] The NTN involved in the embodiments of the present application can be implemented by any one of a satellite, a high altitude platform or an unmanned aircraft system. In addition, the NTN in the embodiments of the present application can be a 4G-based NTN, an NR-based NTN, an internet of things (IoT) based NTN, a narrow band internet of things (NB-IoT) based NTN, an NTN based on current other technologies or other technologies that can appear in the future.

[0147] Compared with a traditional ground network, the NTN adopts a typical satellite to participate in network deployment, for example, an access network device or part of the access network device function is deployed on the satellite to provide coverage for terminal devices, or a satellite is used as a relay to forward signals of a ground access network device to provide coverage for terminal devices.

[0148] Exemplarily, FIG. 2 is a schematic diagram of an application architecture of a satellite communication network provided by an embodiment of the present application. The architecture shown in FIG. 2 combines satellite communication technology and 5G communication technology. The architecture shown in FIG. 2 can include a terminal device 201, an access network device 202, a ground station 203, a core network (including 204a and 204b), and a data network 205. Among them, the terminal device can access the network through a 5G new air interface; the access network device is deployed on a satellite and connected to the ground core network through a wireless link. At the same time, there is a wireless link between the satellites, which is used for signaling interaction and user data transmission between the access network devices. The following describes each unit in FIG. 2 and its interface.

[0149] Terminal device 201: a mobile device supporting a 5G new air interface. For example, the terminal device 201 can be a mobile device such as a smart phone, a smart watch, and a tablet computer, or any of the terminal devices mentioned above. The terminal device 201 can access the satellite network through the air interface and initiate a call, online service, etc.

[0150] Access network device 202: mainly provides wireless access services, such as scheduling wireless resources for access terminals, providing reliable wireless transmission protocols and data encryption protocols, etc. The access network device 202 shown in FIG. 2 can be a 5G base station.

[0151] Core network: provides user access control, mobility management, session management, user security authentication, charging, etc. The core network can include multiple functional units. In some embodiments, the core network can be divided into a control plane functional entity 204a and a data plane functional entity (also referred to as a user plane functional entity) 204b. It should be noted that the functional entity can be understood as a network element, a network function, etc., which is not limited in the present application.

[0152] A user plane function (UPF) network element is configured to manage the transmission of user plane data, traffic statistics, and the like. Control plane function entities can include, for example, at least an access and mobility management function (AMF) network element and a session management function (SMF) network element. The AMF network element can be configured to manage user access, security authentication, and mobility, such as terminal location updating, network registration, access control, terminal mobility management, terminal attachment and detachment, and the like. The SMF network element can be configured to select a user plane network element for a terminal device, redirect a user plane network element for a terminal device, assign an internet protocol (IP) address for a terminal device, establish a bearer (also referred to as a session) between a terminal device and a UPF network element, modify and release a session, and perform QoS control.

[0153] Ground station 203: can also be referred to as a gateway, responsible for forwarding signaling and service data between a satellite and a 5G core network.

[0154] 5G New Radio: a wireless link between a terminal device and an access network device.

[0155] Xn interface: an interface between 5G access network devices, mainly used for signaling interaction such as handover.

[0156] NG interface: an interface between a 5G access network device and a 5G core network, mainly used for interaction of non-access stratum (NAS) signaling and user service data of the core network.

[0157] During communication, a terminal device usually needs to register with the network to obtain some services provided by the network. During the registration process, the core network can assign an identifier to the terminal device, obtain the location information, routing information, and subscription information of the terminal device, and the like. In some embodiments, the registration type can be divided into initial registration, mobility registration, and periodic registration. The terminal device can perform initial registration when it is powered on for the first time or enters a network coverage area. After completing the initial registration, the terminal device can periodically update its registration parameters in the network to ensure that the network is aware of the current location and state of the terminal device, i.e., periodic registration (or periodic registration update). When the network topology accessed by the terminal device changes, such as when the terminal device switches from one cell to another, a mobility registration (or mobility registration update) can be triggered to ensure the continuity of communication. In addition, the registration process can also be triggered when the terminal device updates its capabilities, renegotiates protocol parameters, or in an emergency.

[0158] Taking a roaming scenario as an example, a home public land mobile network (HPLMN) is a network where a terminal device is originally registered. When the terminal device resides in a visited public land mobile network (VPLMN), the terminal device needs to be re-registered and accessed in the VPLMN. During the re-registration in the VPLMN, the HPLMN can provide a session anchor, policy and subscription data and the like.

[0159] FIG. 3 is a structural schematic diagram of a roaming architecture provided by an embodiment of the present application. The architecture shown in FIG. 3 can support the registration and access of the terminal device in the VPLMN as described above. Referring to FIG. 3, the core network of the HPLMN and the core network of the VPLMN can each include a user plane function (UPF) network element, an access and mobility management function (AMF) network element, a session management function (SMF) network element, a policy control function (PCF) network element, an application function (AF) network element, a data network (DN), a network slice selection function (NSSF), an authentication server function (AUSF), a unified data management (UDM) and the like. It should be noted that some network elements are not shown in FIG. 3. The network elements involved in the registration process and their functions are briefly introduced as follows.

[0160] The AMF network element can be used to manage access authorization and authentication. When the terminal device is registered to a service network, the AMF network element of the service network sends an authentication initial request to the AUSF network element of the home network and receives an authentication vector from the AUSF network element of the home network, thereby completing the authentication of the terminal device in the service network. After the terminal device is authenticated in the service network, the AMF network element initiates a registration process, and the AMF network element obtains user subscription data in the UDM network element.

[0161] The AUSF network element is used to receive a request for identity verification of the terminal device by the AMF, request a key from the UDM, and then forward the issued key to the AMF for authentication processing.

[0162] The UDM network element is used for generation and storage of user subscription data, management of authentication data, and the like, and supports interaction with external third-party servers. In a registration process, after receiving a registration message sent by the AMF, the UDM network element can return subscription data.

[0163] Exemplarily, the HPLMN and the VPLMN can interact through a security edge protection proxy (SEPP). The visited SEPP (vSEPP) and the home SEPP (hSEPP) can interact control plane data, and the security edge protection proxy for user plane (SEPP-U) can interact user plane data.

[0164] For a scenario in which a network topology frequently changes, such as an NTN scenario, a terminal device needs to frequently perform a registration process, which will cause a certain communication delay. The following takes a typical NTN communication, i.e., a satellite communication scenario, as an example to introduce the above problem.

[0165] Due to the motion characteristics of a satellite, a satellite network topology is dynamically changed. The motion of the satellite will cause a core network parameter of the terminal device to change, or in other words, a core network accessed by the terminal device to change. This is because: in the case where the core network is deployed on the ground, as the satellite moves, the satellite connected by the terminal device changes, and the terminal device accesses different core networks through different satellites; in the case where the core network is deployed on the satellite, as the satellite moves (i.e., the core network itself moves), the satellite connected by the terminal device changes, thereby causing the core network accessed by the terminal device to change.

[0166] In this way, the terminal device needs to frequently perform operations such as registration update and inter-network roaming. After the above operations are completed, the terminal device can perform data communication with the newly accessed core network, and therefore, frequently performing the registration process will cause a certain communication delay.

[0167] To solve the above problem, an embodiment of the present application provides a communication method, which creates a communication link between an original registration core network and other networks, so that the terminal device can revisit the original registration core network when the terminal device stays in a coverage range of the other networks. In this case, the terminal device does not need to perform a registration process in the above other networks, which helps to reduce the frequency of performing the registration process by the terminal device, thereby helping to reduce the communication delay.

[0168] FIG. 4 is a flow diagram of a communication method according to an embodiment of the present application. The method shown in FIG. 4 can involve interactions between a terminal device, a first access network device, a second access network device, and a first core network.

[0169] It should be understood that the terminal device can be a terminal device, or a module or component with terminal device functions, or a communication chip that can be applied to a terminal device, such as a processor, a circuit, a chip, or a chip system.

[0170] It should be understood that the first access network device and the second access network device can be any type of access network device mentioned above, or a chip, a chip system, or a processor that supports the access network device to implement the method. For example, the first access network device and the second access network device can be a 4G base station, a 5G base station, or a base station in a future communication system. For another example, the first access network device and the second access network device can be partially or entirely deployed on a satellite.

[0171] It should be understood that the first core network can be any functional entity (such as any network element) or logical unit in the core network, or a chip, a chip system, or a processor that supports the core network to implement the method.

[0172] The method provided by the embodiments of the present application is described below from the perspective of interactions between the terminal device, the first access network device, and the first core network.

[0173] The method shown in FIG. 4 can include step S410 and step S420. The method provided by the embodiments of the present application is described below with the terminal device as an example.

[0174] S410, the terminal device receives first configuration information. The first configuration information can be used to indicate that the first access network device has a first communication link to access the first core network.

[0175] In some embodiments, the first core network can include a registration parameter of the terminal device. For example, the first core network can be a core network that manages and / or maintains the registration parameter of the terminal device, or the terminal device has registered in the first core network. For example, the first core network can be a core network in a home network of the terminal device. For another example, the first core network can be a core network in a roaming network, but the terminal device has registered in the roaming network.

[0176] In some embodiments, the first access network device is associated with a second core network. For example, the first access network device can be used to access the second core network and cannot access other core networks. For example, the first access network device can be used to access multiple core networks, and the second core network is a default core network accessed by the first access network device, or in other words, the second core network is a preferred core network accessed by the first access network device.

[0177] In some embodiments, the second access network device is associated with the first core network. Illustratively, the second access network device can be used to access the first core network and cannot access other core networks. Illustratively, the second access network device can be used to access multiple core networks, and the first core network is the core network that the second access network device accesses by default, or in other words, the first core network is the preferred core network that the second access network device accesses.

[0178] The second core network is different from the first core network.

[0179] Illustratively, the registration parameters of terminal devices managed and / or maintained by the second core network and the first core network are not completely the same, for example, the second core network and the first core network can be used to manage and / or maintain the registration parameters of different terminal devices.

[0180] For example, the first core network is used to manage and / or maintain the registration parameters of the first terminal device, and the second core network is used to manage and / or maintain the registration parameters of the second terminal device. The first core network and the second core network are introduced.

[0181] For example, the first terminal device and the second terminal device are provided with services by different operators. For another example, the first terminal device and the second terminal device are provided with services by the same operator, but the first terminal device and the second terminal device are in different home locations.

[0182] It should be understood that in the future, the same operator can deploy more than one core network in the same home location, in which case, if multiple core networks in the same home location are used to manage and / or maintain the registration parameters of different terminal devices, then the first core network and the second core network can also be core networks in the same home location.

[0183] Illustratively, the second core network and the first core network belong to different PLMNs, or in other words, the second core network and the first core network are core networks in different PLMNs.

[0184] Illustratively, the second core network and the first core network are core networks of different operators.

[0185] Illustratively, the second core network and the first core network are core networks of the same operator, but the second core network and the first core network can provide network services for different geographic areas.

[0186] As mentioned above, the core network accessed by the first access network device by default is the second core network, and the first configuration information can be used to indicate that the first access network device has a first communication link to access the first core network. It can be understood that the first configuration information can be used to indicate that the first access network device has a path, i.e., the first communication link, to access a non-default core network (the registration core network of the terminal device).

[0187] S420, the terminal device accesses the first core network through the first access network device.

[0188] In some embodiments, the terminal device can send first information to the first access network device, the first information being used to indicate the first core network and / or the first communication link; and the terminal device can receive information from the first core network. That is, the terminal device can request to access the first core network through the first information. Since the first access network device can access the first core network and the second core network, the first information helps the first access network device to determine the core network that the terminal device wants to access.

[0189] In the embodiments of the present application, the terminal device is informed by the first configuration information that the other network has a back access link, such as the first communication link, for back accessing the originally registered core network, which provides a condition for the terminal device to back access the originally registered core network when the terminal device stays in the coverage of the other network, and helps to reduce the frequency of the terminal device performing the registration process, thereby helping to reduce the communication delay caused by registration.

[0190] The first configuration information can include various information, and the information that the first configuration information can include is introduced below.

[0191] In some embodiments, the first configuration information can include third indication information, which is used to indicate that the first communication link exists, i.e., the communication link for back accessing the first core network from the other network exists. In this way, when the network topology changes, such as when the network in which the terminal device stays changes, the terminal device can first determine whether the network in which the terminal device stays has a communication link for back accessing the first core network. If the first communication link exists, the terminal device can back access the first core network through the first communication link, thereby avoiding re-registering in the network in which the terminal device stays, and helping to reduce the registration frequency, thereby helping to reduce the communication delay caused by registration.

[0192] In some embodiments, the first configuration information can include indication information of the first access network device. Exemplarily, the indication information of the first access network device can include: identification information of the first access network device; identification information of the network to which the first access network device belongs, such as identification information of the PLMN to which the first access network device belongs; or identification information of the cell in which the first access network device provides services. In this way, the terminal device can determine the access network device with the capability of back accessing the first core network according to the first configuration information. In the case that the terminal device stays in an area covered by multiple access network devices, the terminal device can preferentially access the access network device with the capability of back accessing the first core network, which helps to reduce the registration frequency, thereby helping to reduce the communication delay caused by registration.

[0193] In some embodiments, the first configuration information can include indication information of the first communication link.

[0194] Exemplarily, the indication information of the first communication link can be used to indicate the target core network of the first communication link, i.e., the first core network, which helps to reduce the indication overhead. Since the registration information of the terminal device is included in the first core network, the terminal device can avoid re-registration when visiting the first core network, and thus, the terminal device can determine the communication link of the first core network according to the target core network of the communication link.

[0195] Exemplarily, the indication information of the first communication link can be used to indicate the path information of the first communication link. For example, the indication information of the first communication link can be used to indicate one or more communication nodes included in the first communication link, such as the indication information of the first communication link can include the identification information of the one or more communication nodes.

[0196] In the case where there are multiple communication links for visiting the first core network, the path information of the first communication link can be used to assist the terminal device to select the communication link for visiting the first core network, thereby helping to improve the system performance. For example, the communication quality, communication delay, and the like of the first communication link can be determined according to the path information of the first communication link. As an example, the terminal device can select a communication link with low communication delay to visit the first core network, which helps to reduce the communication delay. As another example, the terminal device can select a communication link with good communication quality to visit the first core network, which helps to improve the communication reliability.

[0197] For example, the terminal device can select the corresponding communication link according to the requirements of the service data. If the service data between the terminal device and the first core network has high requirements on reliability, the terminal device can select a communication link with good communication quality to visit the first core network. If the service data between the terminal device and the first core network has high requirements on delay, the terminal device can select a communication link with small communication delay to visit the first core network.

[0198] Exemplarily, the configuration information of the first communication link and the identification of the first communication link can be pre-configured, and the identification of the first communication link is dynamically indicated by the first configuration information, so as to save the indication overhead. In this case, the terminal device can determine the configuration information of the first communication link according to the correspondence between the identification of the first communication link and the configuration information of the first communication link. For example, the configuration information of the first communication link can include the target core network information of the first communication link. For another example, the configuration information of the first communication link can include the path information of the first communication link, such as one or more communication nodes included in the first communication link, and / or the port number, IP address, and the like of the communication port involved in the first communication link.

[0199] In some embodiments, the first configuration information can comprise priority information of the first communication link. The priority information of the first communication link may, for example, be related to the communication quality (e.g., quality of service (QoS)) and / or the communication latency of the communication link, etc. As an example, the priority of the first communication link is proportional to the communication quality of the communication link. As another example, the priority of the first communication link is proportional to the communication latency of the communication link.

[0200] Exemplarily, the priority information of the first communication link can be indicated by the value of a number of bits. For example, the higher the value of the number of bits, the higher the priority, or the lower the value of the number of bits, the higher the priority.

[0201] Exemplarily, the priority information of the first communication link can comprise information of the communication quality and / or the communication latency of the first communication link, etc.

[0202] It should be noted that the first configuration information can comprise one or more of the above information, which is not limited in the present application.

[0203] In some embodiments, S410 can be replaced by: the terminal device receives the first configuration information from the first core network.

[0204] Exemplarily, the terminal device can receive the first configuration information sent by the second access network device. Before the terminal device receives the first configuration information sent by the second access network device, the second access network device can receive the first configuration information sent by the first core network. The first configuration information may, for example, be carried in the registration success feedback message from the first core network. Specifically, in response to the registration request of the terminal device, the first core network configures the first configuration information for the terminal device and sends the first configuration information to the terminal device in the registration success feedback message.

[0205] Exemplarily, the terminal device can receive the first configuration information sent by the first access network device, and correspondingly, the first access network device can send the first configuration information to the terminal device. The first configuration information may, for example, be carried in the system message of the first access network. Before the first access network device sends the first configuration information to the terminal device, the first access network device can receive the first configuration information sent by the first core network.

[0206] Exemplarily, the terminal device can receive part of the first configuration information from the first access network device and receive part of the first configuration information from the second access network device, and some examples are given below.

[0207] For example, the first configuration information received by the terminal device from the second access network device can comprise the third indication information mentioned above, and the first configuration information received by the terminal device from the first access network device can comprise indication information of the first communication link. In this case, the indication information of the first communication link can comprise, for example, indication information of a target core network of the first communication link and / or identification information of the first communication link. Alternatively, the first configuration information received by the terminal device from the first access network device can further comprise priority information of the first communication link and / or path information of the first communication link.

[0208] Specifically, when the terminal device is located in a service area provided by the first core network, the terminal device can learn whether the first core network has a backhaul link or whether there is a communication link between the first core network and an access network device in another network through the first configuration information received from the second access network device. If there is a communication link backhauling the first core network, when the terminal device leaves the service area provided by the first core network or is located in a service area provided by another core network, the terminal device can first determine whether an access network device providing coverage for the current location of the terminal device can backhaul the first core network.

[0209] For example, the terminal device can determine, according to the first configuration information obtained from the first access network device, that the first access network device has a communication link backhauling the first core network, i.e., the first communication link. Further, the terminal device can initiate a request for backhauling the first core network to the first access network device according to the indication information of the first communication link.

[0210] For example, the first configuration information received by the terminal device from the second access network device can comprise the third indication information mentioned above, and the first configuration information received by the terminal device from the first access network device can comprise indication information of the first communication link. In this case, the indication information of the first communication link can comprise, for example, indication information of a target core network of the first communication link and / or identification information of the first communication link. Alternatively, the first configuration information received by the terminal device from the first access network device can further comprise priority information of the first communication link and / or path information of the first communication link.

[0211] Specifically, the terminal device can determine the access network device with the first core network capability based on the first configuration information received from the second access network device. Then, when the terminal device camps in an area covered by the first access network device, the terminal device can initiate a request for visiting the first core network instead of initiating a registration procedure in the second core network. In the case that the area where the terminal device camps is covered by multiple access network devices, the terminal device can preferentially select the first access network device based on the first configuration information received from the second access network device, thereby helping to reduce the registration frequency. Further, the terminal device can determine the indication information of the first communication link based on the first configuration information from the first access network device, and initiate the request for visiting the first core network based on the indication information.

[0212] In the above case, the first configuration information sent by the first core network to the first access network device can be the same as the first configuration information sent by the first access network device to the terminal device, or can include other information in addition to the first configuration information sent by the first access network device to the terminal device. Similarly, the first configuration information sent by the first core network to the second access network device can be the same as the first configuration information sent by the second access network device to the terminal device, or can include other information in addition to the first configuration information sent by the second access network device to the terminal device.

[0213] According to the communication nodes mainly included in the first communication link, the first communication link can be divided into two types: the first communication link includes a gateway; and the first communication link includes the second access network device. The gateway and the second access network device can also be referred to as intermediate nodes or relay nodes of the first communication link.

[0214] In addition, the communication nodes included in the first communication link also include an access node (the first access network device) of the first communication link and a target node of the first communication link, i.e., the first core network. Exemplarily, the target node of the first communication link can be a network element in the first core network, such as an AMF.

[0215] In some embodiments, the communication link between the first core network and the intermediate node can be referred to as link A, and the communication link between the first access network device and the intermediate node can be referred to as link B. Based on this, creating the first communication link can include establishing a mapping relationship between link A and link B, or creating the first communication link can include creating link A and / or link B and establishing a mapping relationship between link A and link B. In the case that there is a communication link between the first core network and the intermediate node, link A can reuse the existing communication link. In the case that there is a communication link between the first access network device and the intermediate node, link B can reuse the existing communication link.

[0216] Exemplarily, the first communication link, link A, link B can be based on a point-to-point protocol constituted by a stream control transmission protocol (SCTP) / internet protocol (IP), referred to as SCTP / IP; a transmission control protocol (TCP) / IP, referred to as TCP / IP; a user datagram protocol (UDP) / IP, referred to as UDP / IP; and layer 2 / layer 2, referred to as L2 / L2.

[0217] In some embodiments, the intermediate node can include a first interface for communicating with the first core network, and a second interface for communicating with the first access network device. Correspondingly, the first core network can include a third interface for communicating with the intermediate node, and the first access network device can include a fourth interface for communicating with the intermediate node. Based on this, creating the first communication link can include establishing a mapping relationship between the first interface and the second interface. Optionally, before establishing the mapping relationship between the first interface and the second interface, one or more of the first interface to the fourth interface can be created. Part or all of the first interface to the fourth interface can reuse an existing communication interface, or can be a newly created interface for creating the first communication link.

[0218] Exemplarily, part or all of the first interface to the fourth interface described above can be a transport network layer (TNL) interface.

[0219] It should be noted that the communication link between the first core network and the intermediate node can include other communication nodes (communication devices), or can not include other communication nodes; the communication link between the first access network device and the intermediate node can include other communication nodes, or can not include other communication nodes.

[0220] The first communication link will be exemplarily introduced below in combination with FIGS. 5 to 7.

[0221] FIG. 5 is a schematic diagram of the first communication link provided by an embodiment of the present application. Referring to FIG. 5, the PLMN 1 includes the first core network, the PLMN 2 includes the second core network, the first communication link can include link A and link B, and the first communication link includes a gateway. That is, the terminal device can access the first access network device, transit through the gateway, and then access the first core network in the PLMN 1.

[0222] FIG. 6 is an example diagram of the first communication link in FIG. 5. FIG. 6 includes a terminal device, a first access network device, a gateway, and a first core network. Referring to FIG. 6, the first communication link can include a link A (which can be statically configured), a link B, and the gateway. The gateway is configured to establish a mapping relationship between the link A and the link B. In addition, the terminal device and the first core network can communicate through a non-access stratum (NAS) message, and the terminal device and the first access network device can communicate through a Uu interface.

[0223] Exemplarily, the communication interface between the first access network device and the gateway, and the communication interface between the gateway and the first core network can be a TNL interface.

[0224] In some embodiments, the first communication link can be implemented by a UPF network element, and data transmission through the first communication link can include data transmission through multi-hop UPF relay. In this process, the application layer transmission between the access network device and the first core network is data of a user plane. Specifically, a protocol data unit (PDU) session is established between the access network device and the first core network for backhaul of next generation application protocol (NGAP) messages.

[0225] FIG. 7 is another example diagram of the first communication link provided by the embodiments of the present application. FIG. 7 shows the first communication link in which the intermediate node is a second access network device. FIG. 7 includes a terminal device, a first access network device, a second access network device, and a first core network. Referring to FIG. 7, the first communication link can include a link A, a link B, and the second access network device. The second access network device is configured to establish a mapping relationship between the link A and the link B. Exemplarily, the backhaul traffic of the terminal device can be transmitted to the second access network device through an Xn interface between the first access network device and the second access network device, and then transmitted to the first core network by the second access network device.

[0226] Exemplarily, the communication interface between the first access network device and the second access network device, and the communication interface between the second access network device and the first core network can be a TNL interface.

[0227] If the first access network device and the second access network device are deployed on a satellite, the backhaul traffic of the terminal device can be transmitted to the second access network device through an inter-satellite link between the first access network device and the second access network device, and then transmitted to the first core network by the second access network device.

[0228] In some embodiments, creating the first communication link can include generating configuration information of the first communication link (e.g., context information of the first access network device), and activating the configuration information of the first communication link (e.g., activating the context of the first access network device). Exemplarily, the configuration information of the first communication link is not activated immediately. That is, after the configuration information of the first communication link is generated, the configuration information is not activated immediately. For example, the configuration information of the first communication link can be activated when the first communication link is used, which helps to reduce the overhead of the system. As an example, the configuration information of the first communication link can be activated when the first information mentioned above is received.

[0229] As mentioned above, the first communication link includes a plurality of communication nodes, and the configuration information of the first communication link can include configuration information associated with each of the plurality of communication nodes. Each of the plurality of communication nodes can include the configuration information associated therewith.

[0230] Exemplarily, the configuration information of the first communication link can include configuration information of the communication interface and configuration information of the mapping relationship of the communication interface. For example, the configuration information of the first communication link in the first access network device can include at least configuration information of the fourth interface, the configuration information of the first communication link in the first core network can include at least configuration information of the third interface, and the configuration information of the first communication link in the intermediate node can include at least configuration information of the first interface, configuration information of the second interface, and configuration information of the mapping relationship of the first interface and the second interface.

[0231] Based on this, as a possible implementation manner, the plurality of communication nodes in the first communication link can activate the configuration information of the first communication link associated therewith when the first information is received. For example, the first access network device can activate the configuration information of the first communication link associated with the first access network device (e.g., configuration information of the fourth interface) when the first information is received; the intermediate node can activate the configuration information of the first communication link associated with the intermediate node (e.g., configuration information of the first interface, configuration information of the second interface, and configuration information of the mapping relationship of the first interface and the second interface) when the first information is received; and the first core network can activate the configuration information of the first communication link associated with the first core network (e.g., configuration information of the third interface) when the first information is received.

[0232] As another possible implementation manner, when the first information is received, the first access network device can activate the configuration information of the first communication link associated with the first access network device, and send indication information of activating the configuration information of the first communication link to other nodes in the first communication link. In this way, the intermediate node does not need to decode the first information, which helps to reduce the processing complexity of the intermediate node.

[0233] In some embodiments, the first communication link can be a communication link between the first access network device and the first core network. Illustratively, the first communication link can include a fifth interface, such as a next generation (NG) interface, which can be used for communication between the first access network and the first core network. That is, the first access network device can include the fifth interface, the first core network can include the fifth interface, and the first core network and the first access network device can directly communicate through the fifth interface. For example, a network element of the first core network, such as an AMF network element, can initiate establishment of an NG interface to the first access network device, thereby enabling creation of the first communication link. Alternatively, before establishing the first communication link, it can be determined whether the first access network device and the first core network have the right to visit each other.

[0234] In some embodiments, the creation of the first communication link can be initiated by the terminal device or by the first core network.

[0235] Illustratively, the terminal device can determine whether to initiate creation of the first communication link according to a use scenario, such as whether the network topology of the terminal device will frequently change, etc. For example, in the case of service provided by the NTN, the terminal device can initiate creation of the first communication link, such as when the first core network performs registration.

[0236] Illustratively, the first core network can send second information to a communication node involved in the first communication link, such as the second access network device or the gateway, the second information being used to indicate creation of the first communication link. For example, when the terminal device initiates a registration procedure in the first core network, during execution of the registration procedure, or after the terminal device completes registration in the first core network, the first core network can send the second information to the communication node involved in the first communication link.

[0237] In some embodiments, the first core network can release the first communication link, such as deactivating configuration information of the first communication link, deleting configuration information of the first communication link, etc. Illustratively, the first core network can determine the timing of releasing the first communication link according to requirements, such as after the terminal device transmits data and / or signaling with the first core network through the first communication link, the first core network releases the first communication link.

[0238] For example, the first core network can release the first communication link when a second timer expires. The second timer is started or restarted when data and / or signaling is transmitted using the first communication link. That is, if the first communication link is not used within the timing duration of the second timer, the first core network releases the first communication link.

[0239] For another example, the first core network can determine the timing of releasing the first communication link according to fourth indication information from the first access network device or the terminal device. The fourth indication information is used to indicate whether there is data and / or signaling to be transmitted subsequently, or in other words, the fourth indication information is used to indicate whether to release the first communication link. As an example, the fourth indication information can be carried in data and / or signaling transmitted between the terminal device and the first core network, and the fourth indication information is used to indicate whether there is data and / or signaling to be transmitted subsequently. It should be understood that the data and / or signaling to be transmitted herein refers to data and / or signaling to be transmitted between the terminal device and the first core network.

[0240] As an example, the fourth indication information can be a 1-bit value, when the value of the bit is a first value, the first core network releases the first communication link, and when the value of the bit is a second value, the first core network does not release the first communication link.

[0241] In some embodiments, the communication link accessing the first core network includes the first communication link and the second communication link, and if the first core network receives the back visit traffic of the terminal device through the first communication link, the first core network can select to release the second communication link according to the needs to save resources.

[0242] The embodiments of the present application create a communication link between the original registration core network and other networks, such as the first communication link between the first core network and the first access network device, so that the terminal device can back visit the first core network through the first access network device. In this case, the terminal device does not need to perform a registration process in the second core network, which helps to reduce the frequency of the terminal device performing the registration process, thereby helping to reduce the communication delay. In addition, the terminal device does not need to perform a registration process in the second core network, which helps to reduce the mobility management overhead on the core network side.

[0243] As mentioned above, in the scenario of frequent changes in network topology, the terminal device needs to frequently perform a registration process, which will bring a certain communication delay. In order to solve this problem, the embodiments of the present application provide another communication method, by pre-completing the registration process of the terminal device in other networks, or in other words, by pre-generating the registration parameters of the terminal device in other networks, so that the terminal device can directly obtain the pre-generated registration parameters when accessing other networks, without waiting for the generation process of the registration parameters, thereby helping to reduce the communication delay caused by registration.

[0244] FIG. 8 is a flow diagram of another method of communication, provided by an embodiment of the present application. The method shown in FIG. 8 can involve the interaction between a terminal device, a second access network device, a first core network and a second core network. It should be understood that the terminal device can be any of the terminal devices mentioned above, or a chip, chip system, or processor, etc. that supports the terminal device to implement the method; the second access network device can be any of the access network devices mentioned above, or a chip, chip system, or processor, etc. that supports the access network device to implement the method; the first core network and the second core network can be any functional entity (such as any network element) or logical unit in the core network, or a chip, chip system, or processor, etc. that supports the core network to implement the method.

[0245] The method provided by an embodiment of the present application is described below from the perspective of the interaction between a terminal device, a second access network device, a first core network and a second core network.

[0246] It should be noted that in the embodiments of the present application, the first access network device is associated with the second core network, and the second access network device is associated with the first core network. The association relationship between the access network device and the core network can refer to the description above, and will not be described here.

[0247] The method shown in FIG. 8 can include step S810 and step S820.

[0248] S810, the terminal device sends a first registration request message to the second access network device. Correspondingly, the second access network device receives the first registration request message sent by the terminal device.

[0249] In some embodiments, the second access network device sends the first registration request message to the first core network, and correspondingly, the first core network receives the first registration request message sent by the second access network device.

[0250] In some embodiments, the first registration request message can include first indication information. The first indication information can be used to indicate multiple core networks, such as the first core network and the second core network. That is, the terminal device can initiate a registration process to multiple networks. The method can be applied in the initial registration, periodic registration and mobility registration processes. Exemplarily, the first indication information can indicate the core networks that need to perform the terminal device registration process through the identity of the network, such as the PLMN identity. The first indication information can be, for example, a network identity list.

[0251] Exemplarily, the first indication information can be determined by the terminal device, that is, the terminal device determines the multiple networks that perform the registration for the terminal device.

[0252] The first indication information can be carried in a NAS message. In this case, the second access network device does not decode the first indication information, but transmits the first indication information to the first core network, such as an AMF network element. Further, the first core network can forward the first registration request to the second core network, such as an AMF network element in the second core network. For example, the first core network can only forward information associated with the second core network in the first registration request to the second core network, or can forward all information in the first registration request to the second core network.

[0253] In some embodiments, the first indication information can be carried in a radio resource control (RRC) setup complete message. In this case, the second access network device can forward the first registration request to the first core network (such as an AMF network element) and the second core network (such as an AMF network element) according to the first indication information. Specifically, the second access network device can select AMF network elements of the first core network and the second core network according to the first indication information, and forward the first registration request to the selected AMF network elements.

[0254] In some embodiments, the second access network device can send a first registration request message to the first core network. In this case, the first core network can forward the first registration request message to the second core network. That is, the first core network forwards the first registration request message to a candidate network, such as the second core network.

[0255] In some embodiments, the second access network device can send a first registration request message to the first core network, and send a registration request message to the second core network. That is, the second access network device forwards the first registration request message to a candidate network, such as the second core network.

[0256] In some embodiments, the first registration request message can include second indication information and auxiliary information. For example, the second indication information can be used to indicate the first core network, and the auxiliary information can be used to determine the second core network. The first core network can be a core network currently performing a registration process for the terminal device (or a core network providing coverage for a current camping area of the terminal device, which can be referred to as a serving network), and the second core network can be a core network that needs to perform a registration process for the terminal device in advance (or a core network other than the first core network, which can be referred to as a candidate network).

[0257] In some embodiments, the first core network can determine the second core network according to the auxiliary information. That is, the core network side determines a network to perform pre-registration for the terminal device, or the core network side determines a candidate network.

[0258] In some embodiments, the first core network can send a second registration request message to the second core network. Illustratively, the second registration request message can be used to request the second core network to generate a second registration parameter, or in other words, the second registration request is used to initiate a pre-registration procedure to the second core network. The second registration parameter is a registration parameter of the terminal device in the second core network.

[0259] Illustratively, if the terminal device initiates a pre-registration procedure to multiple networks, or in other words, there are multiple second core networks, the first core network can determine the timing of sending the second registration request to multiple second core networks, such as the timing of sending the second registration request to multiple core networks is not completely the same, thereby helping to avoid signaling congestion.

[0260] For example, according to the timing at which the terminal device can access the second core network (i.e., t1 moment), the timing at which the first core network sends the second registration request to the second core network (i.e., t2 moment) can be determined. As an example, the t2 moment is before the t1 moment.

[0261] In some embodiments, the assistance information can include one or more of the following: location information of the terminal device; a first time, expecting not to perform a registration procedure of the terminal device within the first time; or a first location area, expecting not to perform a registration procedure of the terminal device within the first location area.

[0262] Illustratively, according to the location information of the terminal device, the change of the network topology can be predicted. Taking an NTN network as an example, according to the location information of the terminal device and the motion of the satellite, the second core network can be determined, and the timing at which the terminal device accesses the second core network can be predicted.

[0263] The location information of the terminal device mentioned here can include the location information of the terminal device carried in the registration request, and can also include the instant location information reported by the connected terminal device. For example, the location information of the terminal device can include the location information reported by the terminal device in the cell handover process. As another example, the location information of the terminal device can include the information of the tracking area in which the idle terminal device resides.

[0264] For example, the location information of the terminal device can include the cell in which the terminal device resides and / or the location coordinates of the terminal device, such as global positioning system (GPS) coordinates, etc.

[0265] Exemplarily, the second core network can be determined according to the first time. For example, according to the change of the network topology of the terminal device within the first time, the second core network can be determined. The smaller the value of the first time is, the less the network that the terminal device needs to pre-register is, and then the terminal device needs to re-register after exceeding the first time. The larger the value of the first time is, the more the network that the terminal device needs to pre-register is, and the management overhead of the core network side will be larger. Therefore, the terminal device can determine the value of the first time according to the demand.

[0266] Exemplarily, the second core network can be determined according to the first location area. For example, the core network that provides services for the first location area is the second core network.

[0267] In step S820, the terminal device receives the first registration parameter and the second registration parameter. The first registration parameter is the registration parameter of the terminal device in the first core network, and the second registration parameter is the registration parameter of the terminal device in the second core network.

[0268] In some embodiments, the first registration parameter and the second registration parameter are carried in the registration success feedback message from the first core network. Step S820 can be replaced by: the terminal device receives the first registration parameter and the second registration parameter sent by the second access network device. Before step S820, the second access network device can receive the first registration parameter and the second registration parameter sent by the first core network. The second registration parameter in the first core network can be received from the second core network.

[0269] In some embodiments, the first registration parameter can be carried in the registration success feedback message from the first core network, and the second registration parameter can be carried in the registration success feedback message from the second core network.

[0270] Step S820 can be replaced by: the terminal device receives the first registration parameter sent by the second access network device and receives the second registration parameter sent by the first access network device. Before step S820, the second access network device can receive the first registration parameter sent by the first core network, and the first access network device can receive the second registration parameter sent by the second core network.

[0271] Exemplarily, the terminal device sends a registration request message to the first access network device, and the terminal device receives the second registration parameter sent by the first access network device.

[0272] Embodiments of the present application pre-generate the registration parameter of the terminal device in the second core network, so that the terminal device can directly obtain the pre-generated registration parameter when accessing the second core network, without waiting for the generation process of the registration parameter, thereby helping to reduce the communication delay caused by registration.

[0273] In some embodiments, the first core network can send part or all of the parameters in the first registration parameters to the second core network. Before this step, the first core network can generate the first registration parameters. Illustratively, the second core network can generate the second registration parameters based on part or all of the received first registration parameters.

[0274] That is, the second core network can reuse part or all of the first registration parameters in the process of generating the second registration parameters, thereby omitting part of the steps in the registration process, which helps to reduce the processing overhead of the second core network. Illustratively, the second core network skips the authentication process of the terminal device. Optionally, the terminal device can determine whether the second core network allows to skip the authentication process according to the security policy.

[0275] According to the foregoing introduction, it is known that the registration parameters of the terminal device can include multiple sets of registration parameters, and therefore how to determine the activation and deactivation time of the registration parameters is a problem to be solved. The activation and deactivation time of the registration parameters is introduced as follows.

[0276] When the terminal device initiates the registration process, it resides in the area served by the first core network, and therefore the first registration parameters can take effect immediately. That is, the first registration parameters are activated immediately after being generated.

[0277] In some embodiments, if the first condition is met, the second registration parameters are activated.

[0278] Illustratively, the first condition is associated with one or more of the following: handover of the access network device, location information of the terminal device, satellite ephemeris information, and current time information. Or, the first condition includes one or more of the following: the terminal device establishes a connection with the first access network device, the first access network device is associated with the second core network; the terminal device is located within the coverage range of the first access network device; it is predicted that the terminal device is located within the coverage range of the first access network device.

[0279] In the case where the first condition is associated with the handover of the access network device, the first condition may, for example, include that the terminal device establishes a connection with the first access network device.

[0280] In the case where the first condition is associated with the location information of the terminal device, the first condition may, for example, include that the terminal device is located within the coverage range of the first access network device.

[0281] In the case where the first condition is associated with the location information of the terminal device, satellite ephemeris information, and current time, the first condition may, for example, include that it is predicted that the terminal device is located within the coverage range of the first access network device according to the location information of the terminal device, satellite ephemeris information, and current time.

[0282] Exemplarily, the first condition can comprise receiving indication information of activating the second registration parameter. The indication information of activating the second registration parameter can be sent by the first access network device or the first core network, for example. Before the first access network device sends the indication information of activating the second registration parameter to the second core network, the first access network device can receive the indication information of activating the second registration parameter sent by the terminal device.

[0283] Exemplarily, the first condition can comprise that a PLMN in which the terminal device camps is a PLMN to which the second core network belongs. For example, the terminal device can receive a PLMN issued by an access network device in a camping area. Specifically, the PLMN information can be carried in a tracing area identity (TAI). The PLMN in which the terminal device camps is the PLMN to which the second core network belongs, which can be understood as that the terminal device camps in an area served by the second core network.

[0284] Exemplarily, the first condition can be associated with a priority of the second registration parameter. For example, in a case where the second registration parameter comprises a plurality of sets of registration parameters, which are registration parameters of the terminal device in a plurality of second core networks, if the first condition is met, a target registration parameter in the second registration parameter is determined based on a priority of the plurality of sets of registration parameters, and the target registration parameter is activated. Specifically, in a case where the first condition associated with the plurality of sets of registration parameters is met, the terminal device can select a target registration parameter based on a priority of the plurality of sets of registration parameters, and activate the target registration parameter. For example, the target registration parameter is a registration parameter with the highest priority in the plurality of sets of registration parameters.

[0285] As an example, a priority of a registration parameter in a home network is higher than a priority of a registration parameter in a roaming network, and / or a size of a tracing area in which the second core network provides services is proportional to a priority of a registration parameter of the terminal device in the second core network. That is, the larger the tracing area range is, the higher the priority of the registration parameter of the core network corresponding to the tracing area is.

[0286] As another example, a priority of a registration parameter in a home network is higher than a priority of a registration parameter corresponding to a largest tracing area, or in other words, the registration parameter of the home network is preferentially activated, and then a registration parameter corresponding to a network with the largest tracing area is selected to be activated.

[0287] In some embodiments, the first condition is carried in a registration success feedback message of the first core network or a registration success feedback message of the second core network.

[0288] In some embodiments, when the first condition is met, the first registration parameter can be deactivated.

[0289] In some embodiments, the first registration parameter is deactivated in response to receiving the indication information of deactivating the first registration parameter. The indication information of deactivating the first registration parameter is sent by the second access network device or the second core network. Before the second access network device sends the indication information of deactivating the first registration parameter to the first core network, the second access network device can receive the indication information of deactivating the first registration parameter sent by the terminal device.

[0290] In some embodiments, the first registration parameter is deactivated if the first timer expires. The start time of the first timer is the activation time of the first registration parameter. The timing duration of the first timer is the valid duration of the first registration parameter.

[0291] It should be noted that activating a registration parameter can be understood as the registration parameter being valid, or using the registration parameter, and deactivating a registration parameter can be understood as the registration parameter being invalid, or not using the registration parameter. The meanings of activation and deactivation are introduced below by taking the first registration parameter as an example.

[0292] Activating the first registration parameter can be understood as: the first registration parameter is a valid registration parameter or the first registration parameter is used as the registration parameter of the terminal device. Deactivating the first registration parameter can be understood as: the first registration parameter is an invalid registration parameter or the first registration parameter is not used as the registration parameter of the terminal device.

[0293] It should be understood that activating a registration parameter can include the terminal device activating the registration parameter, and the network side (such as the access network device and the core network) activating the registration parameter. When the terminal device activates the registration parameter, the terminal device can trigger the network side to activate the registration parameter. Similarly, when the network side activates the registration parameter, the terminal device can be triggered to activate the registration parameter. For example, the first condition is met, the terminal device activates the second registration parameter, and the terminal device triggers the network side to activate the second registration parameter. As an example, the terminal device can send its identity information, such as a subscription permanent identifier (SUPI) / globally unique temporary UE identity (GUTI), to the network side, triggering the network side to activate the second registration parameter.

[0294] In the related art, after the terminal device completes registration, the terminal device receives a TAI list from the network in the registration success feedback. If the terminal device moves in the tracking area described by the TAI list without triggering mobility registration update, if the terminal device moves outside the tracking area described by the TAI list, mobility registration update is triggered.

[0295] TAI = mobile country code (MCC) + mobile network code (MNC) + tracking area code (TAC). The MCC and MNC uniquely identify an operator, and the TAC is a unique code allocated by the operator for each tracking area.

[0296] In the embodiments of the present application, a mobility registration update strategy different from related technologies can be used to reduce the frequency of triggering the mobility registration update by the terminal device. The mobility registration update strategy in the embodiments of the present application is introduced below.

[0297] The tracking area in which the first core network provides services is the first tracking area (such as the first tracking area list), and the tracking area in which the second core network provides services is the second tracking area (such as the second tracking area list). In some embodiments, the terminal device receives indication information (such as the third tracking area list) of the third tracking area from the third access network device, and the third access network device provides coverage for the area in which the terminal device currently resides; if the first tracking area does not include the third tracking area, and the second tracking area also does not include the third tracking area, the mobility registration process is triggered. Or, none of the tracking areas in the third tracking area list is included in the first tracking area list and the second tracking area list, and the mobility registration process is triggered.

[0298] That is, the union of the tracking area list issued by the serving network and the tracking area list issued by the candidate network is used as the judgment condition for triggering the mobility registration process. When the tracking area issued by the resident network does not belong to the tracking area list of the serving network or the tracking area list of the candidate network, the mobility registration process is triggered. This method helps to reduce the frequency of triggering the mobility registration update by the terminal device, thereby helping to reduce the system overhead.

[0299] In some embodiments, the registration parameters can include the GUTI allocated by the AMF, the periodic registration timer, the tracking area list, the slice parameter, or the list of functions supported by the core network, and the like. It should be understood that the registration parameters can also include other parameters not shown, which are not limited in the present application.

[0300] It should be noted that in the embodiments of the present application, the registration parameters and the registration information can be replaced with each other.

[0301] It should be noted that the registration frequency can be understood as the registration frequency and / or the registration number.

[0302] It should be noted that the method provided by the embodiments of the present application can be applied to a ground network scenario, and can also be applied to an NTN scenario.

[0303] For the convenience of understanding, the method provided by the embodiments of the present application will be exemplarily introduced below in combination with FIG. 9 to FIG. 11. It should be noted that the RAN 1 described below can be the second access network device mentioned above, and the RAN 2 can be the first access network device mentioned above.

[0304] FIG. 9 is a flow diagram of another communication method provided by the embodiments of the present application. In the method shown in FIG. 9, the pre-created back-visit link (such as the first communication link mentioned above) provides a condition for the terminal device to access the original registered core network (such as the first core network mentioned above).

[0305] It should be noted that the RAN 1 shown in FIG. 9 is associated with the core network 1, the RAN 2 is associated with the core network 2 (not shown in the figure), and the back-visit link includes a regional gateway.

[0306] The method shown in FIG. 9 can at least include steps 1 to 6b.

[0307] Step 1, the terminal device initiates a registration request to the core network 1 through the RAN 1.

[0308] Specifically, the terminal device sends a registration request to the RAN 1, and the RAN 1 forwards the registration request of the terminal device to the 5GC.

[0309] Step 2, the core network 1 completes the registration of the terminal device, such as generating the registration parameters of the terminal device.

[0310] Step 3, the core network 1 initiates the establishment of the back-visit link.

[0311] Through the establishment of the back-visit link, an interface that can visit the core network 1 is created for the terminal device on the RAN node that can be accessed. Taking the back-visit link between the RAN 2 and the core network 1 as an example, the creation of the back-visit link can include the establishment of the context of the RAN 2 in the core network 1, the regional gateway and the RAN 2.

[0312] First, the regional gateway can establish a TNL interface between the RAN 2 and the core network 1, as shown in FIG. 6. Specifically: 1) the regional gateway and the core network 1 establish a transmission link A (this link can be statically configured); 2) the regional gateway and the RAN 2 establish a transmission link B; 3) the transmission link can be a point-to-point protocol based on SCTP / IP, TCP / IP, UDP / IP and L2 / L2.

[0313] Secondly, the regional gateway can establish a mapping between the transmission links A and B, constituting the back-visit link. Optionally, the back-visit traffic of a specific terminal device can be associated with the back-visit link.

[0314] As an example, the visiting link can be implemented by a UPF, e.g., the application layer transmission between the core network 1 and the RAN 2 is implemented by the data of the user plane, and the visiting of the core network 1 is implemented by the multi-hop UPF.

[0315] Optionally, the core network 1 can create multiple visiting links and describe the priority information of the visiting links, to assist the terminal device in selecting the visiting link.

[0316] Step 4: The terminal device receives the registration success feedback from the core network 1.

[0317] As an example, the registration success feedback can include the registration parameter of the terminal device, whether the terminal device has the communication link for visiting the core network 1, the access network device that can visit the core network 1, the identifier of the visiting link, the target core network of the visiting link, and the like. Optionally, the registration success feedback message can also include the priority information of the visiting link.

[0318] Step 5: The terminal device accesses the RAN 2.

[0319] As an example, the terminal device accesses the RAN 2 through the random access process.

[0320] If the terminal device expects to visit the original registration core network, the terminal device can indicate the identifier of the target core network, the identifier of the visiting link, the identifier of the terminal device, and the like in the random access process. When the RAN 2 determines that the terminal device expects to visit the core network 1 according to the above information, the RAN 2 can activate the transmission configuration of the visiting link generated in step 3, such as activating the context of the RAN 2 established in step 3 (i.e., step 6a), to provide the condition for the data transmission between the terminal device and the core network 1.

[0321] Optionally, the RAN 2 can broadcast in the system message whether the link for visiting other core networks is available and the path of the visiting link. The terminal device can determine whether the RAN 2 includes the communication link for visiting the core network 1 according to the system message of the RAN 2. If the RAN 2 includes the communication link for visiting the core network 1, the terminal device can visit the core network 1 through the RAN 2; if the RAN 2 does not include the communication link for visiting the core network 1, the terminal device can visit the core network 1 through other access network devices or perform the registration process in the core network 2.

[0322] Step 6b: Transmit data / signaling through the visiting link.

[0323] As an example, after the core network 1 receives the visiting traffic from the terminal device, the core network 1 can instruct to release other optional visiting links as needed. For example, the communication link for visiting the core network 1 includes the visiting link 1 and the visiting link 2, and if the core network 1 receives the visiting traffic of the terminal device through the visiting link 1, the core network 1 can instruct to release the visiting link 2 according to the needs.

[0324] The above describes the backhaul link with the regional gateway as the intermediate node. The following describes two other types of backhaul links.

[0325] Exemplarily, the communication nodes in the backhaul link can include the core network 1, the RAN 1, and the RAN 2, that is, the backhaul link can take the RAN 1 as the intermediate node, as shown in FIG. 7. In this case, the backhaul traffic of the terminal device can be sent back to the RAN 1 via the Xn interface between the RAN 1 and the RAN 2, and then sent back to the core network 1 by the RAN 1.

[0326] Exemplarily, the communication nodes in the backhaul link can include the core network 1 and the RAN 2, that is, the backhaul link can not include the intermediate node. For example, the core network 1 can initiate the establishment of the NG interface to the RAN 2 to implement the creation of the backhaul link. In this case, the network to which the core network 1 belongs and the network to which the RAN 2 belongs have the inter-visit permission.

[0327] The embodiment of the present application creates the backhaul link between the core network 1 and the RAN 2, so that the terminal device can access the registered core network, that is, the core network 1, through the backhaul link, without accessing the core network 2, thereby avoiding triggering the re-registration. This scheme helps to reduce the frequency of the terminal device performing the registration process, thereby helping to reduce the communication delay caused by the registration. In addition, the terminal device does not need to perform the registration process in the second core network, which helps to reduce the mobility management overhead on the core network side.

[0328] FIG. 10 is a flow diagram of another communication method provided by an embodiment of the present application. In the method shown in FIG. 10, the registration process of the terminal device in the candidate network is triggered in advance, so that the terminal device can directly obtain the registration parameter when accessing the candidate network, without waiting for the generation process of the registration parameter, thereby helping to reduce the communication delay caused by the registration.

[0329] It should be noted that the RAN 1 in FIG. 10 is associated with the core network 1, and the RAN 2 (not shown in the figure) is associated with the core network 2. Among them, the core network 1 belongs to the PLMN 1, and the core network 2 belongs to the PLMN 2. Or, the core network 1 and the core network 2 belong to different PLMNs.

[0330] The method shown in FIG. 10 can include steps 1 to 5.

[0331] Step 1: The terminal device initiates a registration request.

[0332] The registration request can be used to trigger multiple core networks to perform the registration process of the terminal device.

[0333] Exemplarily, the indication information (such as the first indication information mentioned above) can be included in the registration request, which can be used to indicate multiple networks performing the terminal device registration procedure. For example, the indication information can be a PLMN list.

[0334] Optionally, the indication information can be carried in a NAS message. The RAN 1 can forward the NAS message to the AMF in the core network 1, and the AMF can forward the registration request to the AMF corresponding to other PLMNs (such as PLMN2) in the PLMN list.

[0335] Optionally, the indication information can be carried in the RRC setup complete message to the RAN 1, and the RAN 1 can select the AMF based on the indication message. If the terminal device indicates that multiple PLMN registration needs to be performed (such as the indication information mentioned above is carried in the registration request), the RAN 1 will correspondingly forward the registration request to the AMF corresponding to each PLMN. This scheme is suitable for the case where the RAN 1 and the core networks of multiple PLMNs already have an interface.

[0336] Step 2: The terminal device completes the registration procedure with multiple PLMNs.

[0337] In this process, the terminal device can complete the bidirectional authentication with multiple PLMNs, the AMF registers the registration information (location information, network information, etc.) to the UDM, and at the same time, the AMF further obtains the subscription information and policy information of the user from the UDM.

[0338] Step 3a: The terminal device receives the registration success feedback message from the core network 1.

[0339] The registration success feedback message can include the registration parameters allocated by the core network 1 to the terminal device, that is, the first registration parameters mentioned above.

[0340] Step 4a: The terminal device receives the registration success feedback message from the core network 2.

[0341] Before performing step 4a, the terminal device can send a registration request to the core network 2. At this time, the terminal device resides in the area served by the core network 2. In response to the registration request, the core network 2 can send a registration success feedback message to the terminal device, which can include the registration parameters allocated by the core network 2 to the terminal device, that is, the second registration parameters mentioned above.

[0342] Alternatively, the registration success feedback message from the core network 1 can include the registration parameters allocated by multiple networks to the terminal device. That is, the above steps 3a and 4a can be replaced by the following steps 3b and 4b.

[0343] Step 3b, the core network 1 receives the registration parameters allocated by the core network 2 for the terminal device, such as subscription data.

[0344] Step 4b, the terminal device receives the registration success feedback message from the core network 1. The registration success feedback message can include the registration parameters allocated by the core network 1 for the terminal device and the registration parameters allocated by the core network 2 for the terminal device.

[0345] Step 5, the registration parameters allocated by the core network 2 for the terminal device are activated. Correspondingly, other registration parameters, such as the registration parameters allocated by the core network 1 for the terminal device, are deactivated.

[0346] For example, the terminal device can switch the registration parameters of the terminal device according to the change of the network topology. The activation and deactivation conditions of the registration parameters can be associated with the switching of the air interface and / or time / location information, or the activation and deactivation conditions of the registration parameters can include receiving the indication information sent by the core network.

[0347] As an example, when the access network device is switched from RAN 1 to RAN 2, the registration parameters allocated by the core network 2 for the terminal device can be activated, and the registration parameters allocated by the core network 1 for the terminal device can be deactivated correspondingly.

[0348] As another example, the network topology can be predicted according to the time / location information. If it is predicted that the terminal device will be served by the core network 2, or the terminal device will be served by the core network 2 soon, the registration parameters allocated by the core network 2 for the terminal device can be activated, and the registration parameters allocated by the core network 1 for the terminal device can be deactivated correspondingly.

[0349] For the terminal device side, activating the registration parameters allocated by the core network 2 for the terminal device and deactivating the registration parameters allocated by the core network 1 for the terminal device can be understood as switching the registration parameters on the terminal device side, i.e., switching the registration parameters allocated by the core network 1 for the terminal device to the registration parameters allocated by the core network 2 for the terminal device.

[0350] For example, the registration success feedback message of the serving network can carry the activation condition, deactivation condition or switching condition of the registration parameters.

[0351] When the registration parameters are activated, a timer associated with the registration parameters can be started. For example, when the timer expires, the registration parameters can be deactivated, and / or re-registration can be triggered.

[0352] Exemplarily, when the PLMN information carried in the TAI issued by the base station in which the terminal device camps changes, the terminal device is triggered to activate the corresponding registration parameter and deactivate the old registration parameter. For example, when the PLMN carried in the TAI issued by the base station in which the terminal device camps changes from PLMN 1 to PLMN 2, the terminal device is triggered to activate the registration parameter allocated by the core network 2 for the terminal device and deactivate the registration parameter allocated by the core network 1 for the terminal device. Meanwhile, the terminal device can send identity information (such as SUPI / GUTI) to the core network 2, triggering the network side to activate the registration parameter.

[0353] Exemplarily, in the case of activating the registration parameter allocated by the core network 2 for the terminal device and deactivating the registration parameter allocated by the core network 1 for the terminal device, the terminal device or the core network 2 can send indication information for deactivating the registration parameter to the core network 1.

[0354] Exemplarily, the terminal device can activate the registration parameter according to a preset priority, for example, preferentially activating the registration parameter of the home network, and secondarily selecting the registration parameter corresponding to the network with the largest tracking area range.

[0355] Exemplarily, the union of the TAI List allocated by the PLMN 1 and the PLMN 2 can be used as a judgment condition for mobility registration update, that is, only when the terminal device camps on a base station and the TAI issued by the base station does not belong to any TAI in the union, the terminal device triggers mobility registration.

[0356] In the embodiments of the present application, the terminal device can trigger multi-network registration, for example, the core network 2 can pre-allocate a registration parameter for the terminal device, so that when the terminal device accesses the core network 2, the terminal device can directly obtain the pre-generated registration parameter without waiting for the generation process of the registration parameter, thereby helping to reduce the communication delay caused by registration.

[0357] FIG. 11 is a flow diagram of another communication method provided by the embodiments of the present application. In the method shown in FIG. 11, the registration process of the terminal device in the candidate network is triggered in advance, so that when the terminal device accesses the candidate network, the terminal device can directly obtain the registration parameter without waiting for the generation process of the registration parameter, thereby helping to reduce the communication delay caused by registration.

[0358] The main difference between the method shown in FIG. 11 and the method shown in FIG. 10 is that: 1) in the method shown in FIG. 10, the candidate network is determined by the terminal device, and in the method shown in FIG. 11, the candidate network is determined by the network side, such as the core network 1; 2) in the method shown in FIG. 10, the candidate network and the service network allocate the registration parameter for the terminal device independently; in the method shown in FIG. 11, the process of the candidate network allocating the registration parameter for the terminal device can reuse the registration parameter allocated by the service network for the terminal device.

[0359] It should be noted that the RAN 1 shown in FIG. 11 is associated with the core network 1, and the RAN 2 (not shown in the figure) is associated with the core network 2. Among them, the core network 1 belongs to the PLMN 1, and the core network 2 belongs to the PLMN 2. In other words, the core network 1 and the core network 2 belong to different PLMNs.

[0360] The method shown in FIG. 11 can include steps 1 to 6.

[0361] Step 1: The terminal device initiates a registration request.

[0362] Among them, the registration request can carry the PLMN identifier corresponding to the core network 1 (i.e. the second indication information mentioned above) and the auxiliary information.

[0363] Among them, the auxiliary information can include the expected registration-free duration, the geographical range description of the registration-free area, etc.

[0364] Exemplarily, the prediction result of the network topology can be obtained according to time, location information of the terminal device, ephemeris information, etc.

[0365] Step 2: The terminal device completes the registration process with the core network 1.

[0366] Step 3: The core network 1 determines the PLMN that needs to be pre-registered.

[0367] When the core network 1, such as the AMF in the core network 1, receives the registration request in step 1, it can determine the PLMN (list) that needs to be pre-registered based on the auxiliary information and the prediction result of the network topology, such as the PLMN corresponding to the core network 2.

[0368] Exemplarily, after determining the PLMN that needs to be pre-registered, the serving network can send a registration request to the PLMN that needs to be pre-registered to trigger pre-registration. For example, after the core network 1 determines that the terminal device needs to be pre-registered in the core network 2, it can initiate a registration request to the core network 2. As an example, the core network 1 can determine the timing of initiating a registration request to the core network 2 to avoid registration signaling congestion.

[0369] Optionally, the timing of initiating a registration request from the core network 1 to the core network 2 can be determined according to the instant location information reported by the connected terminal device. For example, according to the location information of the terminal device, it is predicted that the terminal device will soon reside in the area served by the core network 2, and then the core network 1 initiates a registration request to the core network 2.

[0370] It should be noted that the execution order of the above steps 2 and 3 can be reversed, and the embodiments of the present application do not limit this.

[0371] Step 4, the core network 1 interacts with the core network 2 to register parameters.

[0372] The core network 1 interacting with the core network 2 to register parameters can include the core network 1 sending the core network 2 the registration parameters allocated by the core network 1 for the terminal device, and the core network 1 receiving the registration parameters allocated by the core network 2 for the terminal device.

[0373] Exemplarily, based on the received registration parameters configured by the core network 1 for the terminal device, the core network 2 can skip the authentication process of the PLMN 2 when allocating the registration parameters for the terminal device.

[0374] Step 5, the terminal device receives a registration success feedback message from the core network 1.

[0375] The registration success feedback message can include the registration parameters allocated by the core network 1 for the terminal device (i.e. the first registration parameters mentioned above), and can also include the registration parameters allocated by the core network 2 for the terminal device (i.e. the second registration parameters mentioned above). For example, the registration parameters can include GUTI allocated by the AMF, periodic registration timer, tracking area list, slice parameter, and list of functions supported by the core network, etc.

[0376] Step 6, the registration parameters allocated by the core network 2 for the terminal device are activated. Correspondingly, other registration parameters are deactivated, such as the registration parameters allocated by the core network 1 for the terminal device.

[0377] The activation and deactivation of the registration parameters and the conditions for mobility registration update are described in the method shown in FIG. 10, which will not be described here.

[0378] The above describes the method embodiments provided by the present application, and the device embodiments provided by the present application will be described below. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments, and therefore, the content not described in detail can be referred to the method embodiments described above, which will not be described here for brevity.

[0379] FIG. 12 is a schematic block diagram of a communication device according to an embodiment of the present application. As shown in FIG. 12, the communication device 1200 can include a transceiver unit 1210 and / or a processing unit 1220. The transceiver unit 1210 can implement corresponding communication functions, and the processing unit 1220 is configured to perform data processing. The transceiver unit 1210 can also be referred to as a communication interface or a communication unit. Optionally, the device 1200 can also include a storage unit, which can be used to store instructions and / or data, and the processing unit 1220 can read the instructions and / or data in the storage unit to enable the device to implement the foregoing method embodiments.

[0380] In one possible design, the apparatus 1200 can be a terminal device in the method embodiments above. For example, the terminal device can be a terminal device, or a module or component with terminal device functions, or a communication chip (such as a processor, circuit, chip, or chip system) that can be applied to a terminal device.

[0381] Specifically, the transceiver 1210 can be configured to receive first configuration information, where the first configuration information is used to indicate that a first access network device has a first communication link to access a first core network, the first core network includes a registration parameter of the terminal device, the first access network device is associated with a second core network, and the first core network and the second core network are different. The transceiver 1210 can be configured to access the first core network through the first access network device.

[0382] In some embodiments, the first communication link includes a gateway or a second access network device, and the second access network device is associated with the first core network.

[0383] In some embodiments, the terminal device accesses the first core network through the first access network device, including: the terminal device sends first information to the first access network device, where the first information is used to indicate the first core network and / or the first communication link; and the terminal device receives information from the first core network.

[0384] In some embodiments, the first configuration information is carried in a registration success feedback message from the first core network, or the first configuration information is carried in a system message of the first access network device.

[0385] In one possible design, the apparatus 1200 can be a first access network device in the method embodiments above, or a chip, processor, or chip system that implements the functions of the first access network device. For example, the first access network device can be a 4G base station, a 5G base station, or a base station in a future communication system.

[0386] Specifically, the transceiver 1210 can be configured to receive first configuration information, where the first configuration information is used to indicate that a first access network device has a first communication link to access a first core network, the first core network includes a registration parameter of the terminal device, the first access network device is associated with a second core network, and the first core network and the second core network are different. The transceiver 1210 can be configured to send the first configuration information to the terminal device.

[0387] In some embodiments, the transceiver 1210 receives first information from the terminal device, where the first information is used to indicate the first core network and / or the first communication link. The processor 1202 activates the configuration information of the first communication link.

[0388] In a possible design, the apparatus 1200 can be a first core network in the method embodiments above, or can be a chip, processor or chip system for implementing a function of the first core network. Alternatively, the apparatus can be a network element in the first core network.

[0389] Specifically, the transceiver 1210 can be configured to send first configuration information, where the first configuration information is used to indicate that a first access network device has a first communication link for accessing a first core network, the first core network includes a registration parameter of a terminal device, the first access network device is associated with a second core network, and the first core network and the second core network are different.

[0390] In some embodiments, the first communication link includes a gateway or a second access network device, and the second access network device is associated with the first core network.

[0391] In some embodiments, before the sending of the first configuration information, the transceiver 1210 can be configured to send second information to the gateway or the second access network device, where the second information is used to indicate establishment of the first communication link.

[0392] In some embodiments, the first configuration information includes one or more of the following: indication information of the first access network device; indication information of the first communication link; or priority information of the first communication link.

[0393] In a possible design, the apparatus 1200 can be a second access network device in the method embodiments above, or can be a chip, processor or chip system for implementing a function of the second access network device. The second access network device can be, for example, a 4G base station, a 5G base station or a base station in a future communication system.

[0394] Specifically, the transceiver 1210 can be configured to receive second information, where the second information is used to indicate establishment of a first communication link, the first communication link is used for a first access network device to access a first core network, the first core network includes a registration parameter of a terminal device, the first access network device is associated with a second core network, and the first core network and the second core network are different. The processing unit 1220 can be configured to establish a mapping relationship between a first interface and a second interface, where the first interface is used for communication with the first core network, and the second interface is used for communication with the first access network device.

[0395] In a possible design, the apparatus 1200 can be a gateway in the method embodiments above, or can be a chip, processor or chip system for implementing a function of the gateway.

[0396] Specifically, the transceiver 1210 can be configured to receive second information, where the second information is used to indicate to establish a first communication link for a first access network device to access a first core network, the first core network includes a registration parameter of a terminal device, the first access network device is associated with a second core network, and the first core network and the second core network are different. The processing unit 1220 can be configured to establish a mapping relationship between a first interface and a second interface, where the first interface is used to communicate with the first core network, and the second interface is used to communicate with the first access network device.

[0397] In one possible design, the apparatus 1200 can be a terminal device in the above method embodiments. For example, the terminal device can be a terminal device, or a module or component with terminal device functions, or a communication chip (such as a processor, circuit, chip, or chip system) that can be applied to a terminal device.

[0398] Specifically, the transceiver 1210 can be configured to send, to a second access network device associated with a first core network, a first registration request message, where the first registration request message includes first indication information used to indicate the first core network and a second core network, or the first registration request message includes second indication information used to indicate the first core network and assistance information used to determine the second core network. The transceiver 1210 can also be configured to receive a first registration parameter and a second registration parameter, where the first registration parameter is a registration parameter of the terminal device in the first core network, and the second registration parameter is a registration parameter of the terminal device in the second core network.

[0399] In some embodiments, the assistance information includes one or more of the following: location information of the terminal device, a first time during which a registration procedure of the terminal device is expected not to be performed, or a first location area in which a registration procedure of the terminal device is expected not to be performed.

[0400] In some embodiments, the first indication information is carried in a non-access stratum (NAS) message, or the first indication information is carried in a radio resource control (RRC) setup complete message.

[0401] In some embodiments, the first registration parameter is carried in a registration success feedback message from the first core network, the second registration parameter is carried in a registration success feedback message from the first core network, or the second registration parameter is carried in a registration success feedback message from the second core network.

[0402] In some embodiments, the processing unit 1220 can be configured to activate the second registration parameter if a first condition is met, wherein the first condition comprises one or more of the following: the terminal device establishes a connection with the first access network device, the first access network device is associated with the second core network; the terminal device is located within a coverage of the first access network device; it is predicted that the terminal device is located within the coverage of the first access network device; an indication information of activating the second registration parameter is received; or a public land mobile network (PLMN) in which the terminal device camps is a PLMN to which the second core network belongs.

[0403] In some embodiments, the second registration parameter comprises a plurality of sets of registration parameters, the plurality of sets of registration parameters being registration parameters of the terminal device in a plurality of the second core networks, and the activating the second registration parameter if the first condition is met comprises: determining a target registration parameter in the second registration parameter based on priorities of the plurality of sets of registration parameters if the first condition is met; and activating the target registration parameter.

[0404] In some embodiments, a priority of a registration parameter in a home network is higher than a priority of a registration parameter in a roaming network, and / or a size of a tracking area in which the second core network provides services is proportional to a priority of a registration parameter of the terminal device in the second core network.

[0405] In some embodiments, the first condition is carried in a registration success feedback message of the first core network or a registration success feedback message of the second core network.

[0406] In some embodiments, the first core network provides services in a first tracking area, and the second core network provides services in a second tracking area, and the transceiver 1210 can be configured to receive indication information of a third tracking area from a third access network device, the third access network device providing coverage for an area in which the terminal device currently camps. The processing unit 1220 can be configured to trigger a mobility registration procedure if the first tracking area does not include the third tracking area and the second tracking area does not include the third tracking area.

[0407] In a possible design, the apparatus 1200 can be a second access network device in the above method embodiments, or can be a chip, processor or chip system that implements a function of the second access network device. The second access network device can be, for example, a 4G base station, a 5G base station, or a base station in a future communication system.

[0408] Specifically, the transceiver 1210 can be configured to receive a first registration request message from a terminal device, the first registration request message comprising first indication information, the first indication information being used to indicate a first core network and a second core network; send the first registration request message to the first core network; or send the first registration request message to the first core network and send the first registration request message to the second core network.

[0409] In one possible design, the apparatus 1200 can be the first core network in the method embodiments above, or can be a chip, processor or chip system for implementing the first core network function. Optionally, the apparatus can be a network element in the first core network.

[0410] Specifically, the transceiver 1210 can be configured to receive a first registration request message, the first registration request message comprising first indication information, the first indication information being used to indicate the first core network and a second core network, or the first registration request message comprising second indication information and auxiliary information, the second indication information being used to indicate the first core network, and the auxiliary information being used to determine the second core network; send a registration success feedback message, the registration success feedback message comprising first registration parameters, or the registration success feedback message comprising the first registration parameters and second registration parameters, the first registration parameters being registration parameters of a terminal device in the first core network, and the second registration parameters being registration parameters of the terminal device in the second core network.

[0411] In some embodiments, the processing unit 1220 can be configured to determine the second core network based on the auxiliary information. The transceiver 1210 can be configured to send a second registration request message to the second core network, the second registration request message being used to request the second registration parameters.

[0412] In some embodiments, the auxiliary information comprises one or more of the following: location information of the terminal device; a first time, during which it is expected that a registration procedure of the terminal device is not performed; or a first location area, within which it is expected that a registration procedure of the terminal device is not performed.

[0413] In some embodiments, the processing unit 1220 can be configured to generate the first registration parameters. The transceiver 1210 can be configured to send part or all of the first registration parameters to the second core network.

[0414] In some embodiments, the processing unit 1220 can be configured to deactivate the first registration parameter in response to receiving the indication information of deactivating the first registration parameter, or expiration of a first timer, wherein a starting time of the first timer is the first registration parameter activation time.

[0415] In a possible design, the apparatus 1200 can be a second core network in the method embodiments above, or can be a chip, processor or chip system for implementing a second core network function. Alternatively, the apparatus can be a network element in the second core network.

[0416] Specifically, the transceiver unit 1210 can be configured to receive a second registration request message from a second access network device or a first core network, the second registration request message being used to request a second registration parameter of a terminal apparatus in a second core network, the second access network device being associated with the first core network; and send the second registration parameter.

[0417] In some embodiments, before the sending of the second registration parameter, the transceiver unit 1210 can be configured to receive part or all of the parameters in the first registration parameter, the first registration parameter being a registration parameter of the terminal apparatus in the first core network. The processing unit 1220 can be configured to generate the second registration parameter based on the part or all of the parameters.

[0418] In some embodiments, the processing unit 1220 can be configured to activate the second registration parameter if a first condition is met, wherein the first condition comprises one or more of the following: the terminal apparatus establishes a connection with the first access network device, the first access network device being associated with the second core network; the terminal apparatus is located within a coverage range of the first access network device; the terminal apparatus is predicted to be located within the coverage range of the first access network device; receiving indication information of activating the second registration parameter; or a public land mobile network (PLMN) in which the terminal apparatus camps is a PLMN to which the second core network belongs.

[0419] It should be understood that the “units” in the apparatus 1200 can be implemented by hardware, or by software, or by execution of corresponding software by hardware. For example, the “units” can refer to application specific integrated circuits (ASIC), electronic circuits, processors (for example, shared processors, dedicated processors or group processors, etc.) and memories for executing one or more software or firmware programs, integrated logic circuits and / or other suitable components for supporting the described functions. For another example, the transceiver unit 1210 can be replaced by a transceiver circuit (which can include a receiving circuit and a sending circuit), and the processing unit 1220 can be replaced by a processor or a processing circuit.

[0420] FIG. 13 shows a schematic block diagram of another communication apparatus provided by the embodiments of the present application. The communication apparatus 1300 can be a terminal apparatus, an access network device, a core network device, a gateway, etc., and can also be a chip, a chip system, or a processor, etc. implemented in the terminal apparatus, the access network device, the core network device, the gateway, etc. and used to implement the methods described in the above method embodiments. The apparatus can be used to implement the methods described in the above method embodiments, and details can be referred to the descriptions in the above method embodiments.

[0421] The communication apparatus 1300 can include one or more processors 1310, which can also be referred to as processing units, and can implement certain control functions. The processor 1310 can be a general purpose processor or a special purpose processor, etc. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication apparatus, execute software programs, and process data of the software programs.

[0422] In an alternative design, the processor 1310 can also store instructions and / or data, which can be executed by the processor 1310, so that the communication apparatus 1300 implements the methods described in the above method embodiments.

[0423] In another alternative design, the communication apparatus 1300 can include a communication interface 1320 used to implement receiving and sending functions. For example, the communication interface 1320 can be a transceiver circuit, an interface, an interface circuit, or a transceiver, etc. The transceiver circuit, the interface, the interface circuit, or the transceiver used to implement the receiving and sending functions can be separate or integrated together. The transceiver circuit, the interface, the interface circuit, or the transceiver described above can be used for reading and writing of codes / data, or can be used for transmission or transfer of signals.

[0424] Optionally, the communication apparatus 1300 can include one or more memories 1330, which can store instructions executable by the processor 1310, so that the communication apparatus 1300 implements the methods described in the above method embodiments. Optionally, the memory 1330 can also store data. Optionally, the processor 1310 can also store instructions and / or data. The processor 1310 and the memory 1330 can be separately arranged or integrated together.

[0425] It should be understood that, in a possible design, each step in the method embodiments provided by the embodiments of the present application can be completed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, or the like. The storage medium is located in the memory, and the processor reads information in the memory and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0426] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above method embodiments can be completed by integrated logic circuits of hardware in the processor or instructions in the form of software. The processor mentioned above can be a general processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Each method, step and logic block disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, or the like. The storage medium is located in the memory, and the processor reads information in the memory and combines the hardware to complete the steps of the above method.

[0427] It is to be understood that the memory in the embodiments of the present application can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the nonvolatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, and not limitation, many forms of RAM can be used, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not be limited to, these and any other suitable types of memory.

[0428] The embodiments of the present application also provide a computer program product, which comprises computer program code, when the computer program code is run on a computer, so that the computer executes each step or process performed by the terminal device / access network device / core network device / gateway in any of the above method embodiments.

[0429] The embodiments of the present application also provide a computer readable storage medium, which stores program code, when the program code is run on a computer, so that the computer executes each step or process performed by the terminal device / access network device / core network device / gateway in any of the above method embodiments.

[0430] The embodiments of the present application also provide a communication device, which comprises a processor and an interface for transmitting and / or receiving signals, so that the processor executes each step or process performed by the terminal device / access network device / core network device / gateway in any of the above method embodiments.

[0431] The various device embodiments and method embodiments described above can fully correspond, with corresponding steps performed by corresponding modules or units, for example, the communication unit or communication interface performs the steps of receiving or sending in the method embodiments, and other steps except sending and receiving can be performed by the processing unit or processor.

[0432] In the embodiments of the present application, each term and English abbreviation is an exemplary example given for the convenience of description, and should not constitute any limitation on the present application. The embodiments of the present application do not exclude the possibility of defining other terms capable of achieving the same or similar functions in existing or future protocols.

[0433] The terms "component", "module", "system", and the like used in the present specification are used to represent computer-related entities, hardware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and / or thread of execution, and a component can be localized on one computer and / or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate via local and / or remote processes that are in accordance with a signal having one or more data packets (e.g., data from programs running on one or more computers in a network over a wired and / or a wireless medium). The data packets can carry any or all of the information that implements the various aspects of the disclosure.

[0434] Those of ordinary skill in the art can realize that the various illustrative logical blocks and steps described in connection with the embodiments disclosed herein can be implemented or performed with electronic hardware, or a combination of computer software and electronic hardware. The choice of whether to implement the described functions in hardware or software depends on the particular application and design constraints of the technical solution. A skilled person can use different methods to implement the described functions for each particular application, but such implementation should not be considered beyond the scope of the present application.

[0435] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can be based on the corresponding processes in the foregoing method embodiments, which will not be described here.

[0436] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiments are merely schematic. The division of the units is merely logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0437] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0438] In addition, each functional unit in the various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit.

[0439] In the above embodiments, the functions of each functional unit can be implemented wholly or partially by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are wholly or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another, for example, the computer instructions can be transferred from one website, computer, server or data center to another through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), optical media (such as DVD), or semiconductor media (such as solid state disk (SSD)) and the like.

[0440] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application or the parts that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0441] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method characterized by comprising: The method comprises: The terminal device receives first configuration information, wherein the first configuration information is used to indicate that a first access network device has a first communication link for accessing a first core network, the first core network comprises a registration parameter of the terminal device, the first access network device is associated with a second core network, and the first core network and the second core network are different. The terminal device accesses the first core network through the first access network device.

2. The method of claim 1, wherein, The first communication link comprises a gateway or a second access network device, and the second access network device is associated with the first core network.

3. The method according to claim 1 or 2, characterized in that, The terminal device accesses the first core network through the first access network device, comprising: The terminal device sends first information to the first access network device, wherein the first information is used to indicate the first core network and / or the first communication link. The terminal device receives information from the first core network.

4. The method according to any one of claims 1-3, characterized in that, The first configuration information is carried in a registration success feedback message from the first core network, or the first configuration information is carried in a system message of the first access network device.

5. A communication method characterized by comprising: The method comprises: The method comprises:

6. The method of claim 5, wherein, Before the first configuration information is sent, the method further comprises:

7. The method of claim 6, wherein, The gateway or the second access network device sends second information to the first access network device, wherein the second information is used to indicate that the first communication link is established. The first configuration information comprises one or more of the following:

8. The method according to any one of claims 5-7, characterized in that, Indication information of the first access network device; Indication information of the first communication link; or Priority information of the first communication link. The method comprises:

9. A communication method characterized by comprising: The method comprises: The terminal device sends a first registration request message to a second access network device, wherein the second access network device is associated with a first core network, the first registration request message comprises first indication information used to indicate the first core network and a second core network, or the first registration request message comprises second indication information used to indicate the first core network and auxiliary information used to determine the second core network. The method comprises:

10. A communication method characterized by comprising: ​ ​ The terminal device receives a first registration parameter and a second registration parameter, the first registration parameter being a registration parameter of the terminal device in the first core network, and the second registration parameter being a registration parameter of the terminal device in the second core network.

11. The method of claim 10, wherein, The assistance information comprises one or more of: location information of the terminal device; a first time, in which it is expected that a registration procedure of the terminal device is not performed; or a first location area, in which it is expected that a registration procedure of the terminal device is not performed.

12. The method of claim 10, wherein, The first indication information is carried in a non-access stratum (NAS) message or a radio resource control (RRC) setup complete message.

13. The method according to any one of claims 10-12, characterized in that, The first registration parameter is carried in a registration success feedback message from the first core network, the second registration parameter is carried in a registration success feedback message from the first core network, or the second registration parameter is carried in a registration success feedback message from the second core network.

14. The method according to any one of claims 10-13, characterized in that, The method further comprises: activating the second registration parameter if a first condition is met, wherein the first condition comprises one or more of: the terminal device establishes a connection with the first access network device, the first access network device is associated with the second core network; the terminal device is located within a coverage range of the first access network device; it is predicted that the terminal device is located within a coverage range of the first access network device; an indication information of activating the second registration parameter is received; or a public land mobile network (PLMN) in which the terminal device camps is a PLMN to which the second core network belongs.

15. The method of claim 14, wherein, The second registration parameter comprises a plurality of sets of registration parameters, the plurality of sets of registration parameters being registration parameters of the terminal device in a plurality of the second core networks, The activating the second registration parameter if the first condition is met comprises: if the first condition is met, determining a target registration parameter in the second registration parameter based on priorities of the plurality of sets of registration parameters; and activating the target registration parameter.

16. The method of claim 15, wherein, A priority of a registration parameter in a home network is higher than a priority of a registration parameter in a roaming network, and / or a size of a tracking area in which the second core network provides services is proportional to a priority of a registration parameter of the terminal device in the second core network.

17. The method according to any one of claims 14-16, characterized by, The first condition is carried in a registration success feedback message of the first core network or a registration success feedback message of the second core network.

18. The method of any one of claims 10-17, wherein, The first core network provides services in a first tracking area, and the second core network provides services in a second tracking area, and the method further comprises: receiving indication information of a third tracking area from a third access network device, the third access network device providing coverage for an area in which the terminal device currently camps; and if the first tracking area does not include the third tracking area and the second tracking area does not include the third tracking area, triggering a mobility registration procedure.

19. A method of communication, comprising: The method comprises: receiving a first registration request message, the first registration request message comprising first indication information indicating the first core network and the second core network, or the first registration request message comprising second indication information indicating the first core network and auxiliary information used to determine the second core network; sending a registration success feedback message, the registration success feedback message comprising first registration parameters of the terminal device in the first core network, or the registration success feedback message comprising the first registration parameters and second registration parameters of the terminal device in the second core network.

20. The method of claim 19, wherein, The method further comprises: determining the second core network based on the auxiliary information; sending a second registration request message to the second core network, the second registration request message being used to request the second registration parameters.

21. The method of claim 19 or 20, wherein, The auxiliary information comprises one or more of: location information of the terminal device; a first time during which it is expected that the registration procedure of the terminal device is not performed; or a first location area during which it is expected that the registration procedure of the terminal device is not performed.

22. The method of any one of claims 19-21, wherein, The method further comprises: generating the first registration parameters; sending part or all of the first registration parameters to the second core network.

23. The method of any one of claims 19-22, wherein, The method further comprises: deactivating the first registration parameters in response to receiving indication information to deactivate the first registration parameters or expiration of a first timer, wherein the first timer is started at the time when the first registration parameters are activated.

24. A method of communication, comprising: comprises: receiving a second registration request message from a second access network device or the first core network, the second registration request message being used to request second registration parameters of a terminal device in a second core network, the second access network device being associated with the first core network; sending the second registration parameters.

25. The method of claim 24, wherein, Before the sending of the second registration parameters, the method further comprises: receiving part or all of the first registration parameters of the terminal device in the first core network; generating the second registration parameters based on the part or all of the first registration parameters.

26. The method of claim 24 or 25, wherein, The method further comprises: activating the second registration parameters if a first condition is met, wherein the first condition comprises one or more of: the terminal device establishes a connection with the first access network device, the first access network device being associated with the second core network; the terminal device is located in a coverage area of the first access network device; it is predicted that the terminal device is located in the coverage area of the first access network device; receiving indication information to activate the second registration parameters; or a public land mobile network (PLMN) in which the terminal device is camped is a PLMN to which the second core network belongs.

27. A communications device, characterized by The apparatus comprises units configured to perform the steps of the method of any of claims 1-4, or the apparatus comprises units configured to perform the steps of the method of any of claims 10-18.

28. A communications device, characterized by comprising units for performing the individual steps of the method according to any one of claims 5-8, or comprising units for performing the individual steps of the method according to any one of claims 19-23.

29. A communications device, characterized by comprising units for performing the individual steps of the method according to claim 9.

30. A communications device, characterized by comprising units for performing the individual steps of the method according to any one of claims 24-26.

31. A communications device, characterized by comprising a processor coupled with a memory for storing programs or instructions, which when executed by the processor, cause the apparatus to perform the method according to any one of claims 1-4, or according to any one of claims 10-18.

32. A communications device, characterized by comprising a processor coupled with a memory for storing programs or instructions, which when executed by the processor, cause the apparatus to perform the method according to any one of claims 5-8, or according to any one of claims 19-23.

33. A communications device, characterized by comprising a processor coupled with a memory for storing programs or instructions, which when executed by the processor, cause the apparatus to perform the method according to claim 9.

34. A communications device, characterized by comprising a processor coupled with a memory for storing programs or instructions, which when executed by the processor, cause the apparatus to perform the method according to any one of claims 24-26.

35. A readable storage medium, on which a computer program or instructions are stored, characterized in that, The computer programs or instructions, when executed, cause the computer to perform the method according to any one of claims 1-26.

36. A computer program product, characterised in that, The computer programs or instructions, when executed, cause the computer to perform the method according to any one of claims 1-26. The computer programs or instructions, when executed, cause the computer to perform the method according to any one of claims 1-26.

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