Communication method, apparatus and system

Abstract

The present application relates to the technical field of communications, and discloses a communication method, apparatus and system. The method comprises: a terminal device acquiring service supporting information of M networks, the service supporting information of each network among the M networks being used for indicating the supporting status of each network for a first service at a first location, the first location being the location of the terminal device, and M being an integer greater than 1; on the basis of the service supporting information of the M networks, selecting a first network from among the M networks; and transmitting data of the first service by means of the first network. In this way, a terminal device selects a network on the basis of the service supporting statuses of a plurality of networks at a first location, thereby meeting service requirements and achieving service continuity.

Description

A communication method, apparatus and system

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411026441.9, filed on July 27, 2024, entitled "A Communication Method, Apparatus and System", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method, apparatus and system. Background Technology

[0004] Before accessing a network for data transmission, a terminal device needs to search for a network, i.e., perform a network selection operation. This network selection operation can be divided into two processes: public land mobile network (PLMN) selection and cell search. During PLMN selection, the terminal device maintains a list of PLMNs, which are sorted by priority, and then the search proceeds from highest to lowest priority. After selecting a PLMN, the terminal device selects a cell that meets the corresponding criteria to access the network through a cell selection process.

[0005] However, since different networks support services differently in different regions, and the current network selection process does not take into account the network's support for services, the selection process using the existing methods cannot meet the service requirements. Summary of the Invention

[0006] This application provides a communication method, apparatus, and system for enabling a terminal device to select a network based on the service support of multiple networks at a first location (i.e., the location where the terminal device is located), thereby facilitating the fulfillment of service requirements and achieving service continuity.

[0007] In a first aspect, embodiments of this application provide a communication method that can be applied to a first communication device, such as a terminal device or a component (e.g., a circuit or a chip) within the terminal device. For example, in the communication method provided in the first aspect, the terminal device acquires service support information from M networks, where the service support information of each of the M networks indicates the support status of each network for a first service at a first location, where the first location is the location of the terminal device; M is an integer greater than 1; based on the service support information of the M networks, a first network is selected from the M networks; and data for the first service is transmitted through the first network.

[0008] Using the above method, the terminal device selects a network based on the service support of multiple networks at the first location (i.e., the location where the terminal device is located), thereby facilitating the fulfillment of service requirements and achieving service continuity.

[0009] In one possible design, obtaining service support information for M networks includes: receiving service support information for the M networks from a core network element of a second network, wherein the M networks include the second network.

[0010] In this way, terminal devices can receive service support information from multiple networks from the core network elements of the second network, which helps reduce signaling interaction.

[0011] In one possible design, obtaining service support information for M networks includes: receiving service support information for M1 networks from the core network element of the second network, wherein the M networks include the M1 networks, the M1 networks include the second network, and M1 is an integer greater than or equal to 1 and less than M.

[0012] In one possible design, obtaining service support information for M networks further includes: receiving service support information for M2 networks from the core network element of the third network, wherein the M networks include the M2 networks, the M2 networks include the third network, and M2 is an integer greater than or equal to 1 and less than M.

[0013] In this way, terminal devices can receive service support information from different network core network elements, enabling greater flexibility.

[0014] In one possible design, the method further includes: sending a first request message to a core network element in the second network, the first request message being used to request service support status of the network at the first location.

[0015] Thus, when the terminal device actively triggers the first request information, the core network element of the second network sends one or more network service support information to the terminal device, thereby enabling the targeted sending of one or more network service support information to the terminal device based on the triggering of the terminal device.

[0016] In one possible design, the first request information is carried in a registration request message.

[0017] In one possible design, sending a first request message to a core network element in the second network includes: sending the first request message to a core network element in the second network under certain conditions; wherein, the conditions include at least one of the following: the terminal device has a service continuity map, the service continuity map is unavailable, or the service corresponding to the service continuity map does not include the service that the terminal device wishes to use; the service continuity map is obtained based on service support information of at least one network; the terminal device does not have the service continuity map; the service that the terminal device wishes to use is unavailable or the signal is below a threshold in the currently registered network.

[0018] In one possible design, the method further includes sending location information to a core network element in the second network, the location information being used to indicate the first location.

[0019] In one possible design, the method further includes: sending a service list to a core network element in the second network, the service list including service identifiers of N services, wherein the first service is one of the N services, and N is an integer greater than or equal to 1.

[0020] Thus, since different terminal devices may have different service requirements, the terminal device can send a service list, which allows the network to determine the service support information for the services in the service list, making it easier to meet the personalized needs of different terminal devices.

[0021] In one possible design, the service list is obtained by the terminal device based on the historical service usage habits of the users of the terminal device; or, the service list is obtained by the terminal device based on the service priority specified by the user; or, the service list is obtained by the terminal device based on the scarcity of resources required for the service and / or the importance of the service.

[0022] In one possible design, selecting a first network from the M networks based on the service support information of the M networks includes: determining the scores of the M networks based on the weight of the first service and the service support information of the M networks; and selecting the first network from the M networks based on the scores of the M networks, wherein the score of the first network is greater than or equal to a threshold.

[0023] In one possible design, the weight of the first service is obtained based on at least one of the following: the frequency of use of the first service; the duration of each use of the first service; the priority of the resources required by the first service; and whether the first service is currently being used by the user of the terminal device.

[0024] In one possible design, the different PLMNs of the M networks are different, and / or the different communication standards of the M networks are different.

[0025] Secondly, embodiments of this application provide a communication method that can be applied to a second communication device, such as a data management network element in the home network of a terminal device or a component (e.g., a circuit or a chip) within that data management network element. For example, in the communication method provided in the second aspect, the data management network element of the home network sends a second request message to a core network element in a third network. The second request message requests service support information from the network at a first location, where the first location is the location of the terminal device. The core network element in the third network receives service support information from M2 networks, where the service support information of each of the M2 networks indicates the support status of each network for a first service at the first location, and M2 is an integer greater than or equal to 1.

[0026] In one possible design, the M2 networks belong to the first PLMN.

[0027] In one possible design, the method further includes sending location information to a core network element in the third network, the location information being used to indicate the first location.

[0028] In one possible design, the method further includes: sending a service list to a core network element in the third network, the service list including service identifiers of N services, wherein the first service is one of the N services, and N is an integer greater than or equal to 1.

[0029] In one possible design, the method further includes: sending the service information subscribed by the terminal device in the M2 networks to the core network element in the third network, wherein the service information subscribed by the terminal device in each of the M2 networks includes the identifier of the service subscribed by the terminal device in each of the networks.

[0030] In one possible design, the method further includes: receiving third request information from a core network element of the second network, the third request information being used to request service support status of the network at the first location; or, receiving a query message from a core network element of the second network, the query message requesting a query of the subscription information of the terminal device.

[0031] In one possible design, the method further includes: sending service support information of the M2 networks to the terminal device through the core network element of the second network.

[0032] Thirdly, embodiments of this application provide a communication method that can be applied to a third communication device, such as a core network element of a second network or a component (e.g., a circuit or a chip) within the core network element of the second network. For example, in the communication method provided in the third aspect, the core network element of the second network acquires service support information from M1 networks, including the second network; and sends the service support information from the M1 networks to a terminal device. The service support information of each of the M1 networks is used to indicate the support status of each network for a first service at a first location, where the first location is the location of the terminal device, and M1 is an integer greater than or equal to 1.

[0033] In one possible design, the method further includes: receiving reporting information from at least one network device, the at least one network device including a second network device, the reporting information of the second network device including coverage information and wireless load information of the second network device, the reporting information of the at least one network device being used to determine service support information of the second network.

[0034] In one possible design, the method further includes sending a query request to the at least one network device, the query request being used to query coverage information and wireless load information of the at least one network device, the at least one network device being determined based on the first location.

[0035] In one possible design, the method further includes: receiving first request information from the terminal device, the first request information being used to request network service support status at the first location.

[0036] In one possible design, the method further includes: receiving location information from the terminal device, the location information being used to indicate the first location.

[0037] In one possible design, the method further includes: receiving a service list from the terminal device, the service list including service identifiers of N services, wherein the first service is one of the N services, and N is an integer greater than or equal to 1.

[0038] In one possible design, the M1 networks include a fourth network; obtaining service support information from the M1 networks includes: sending a fourth request message to a core network element in the fourth network, the fourth request message being used to request service support status of the network at the first location; the at least one network further includes the fourth network; and receiving service support information from the fourth network.

[0039] In one possible design, the method further includes: receiving service information subscribed by the terminal device in the fourth network; and sending the service information subscribed by the terminal device in the fourth network to a core network element in the fourth network.

[0040] Fourthly, this application provides a communication device that has the functions involved in any of the first to third aspects described above. For example, the communication device includes modules, units, or means corresponding to the operations involved in any of the first to third aspects described above. The functions, units, or means can be implemented by software, or by hardware, or by hardware executing corresponding software.

[0041] In one possible design, the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to transmit and receive signals to enable communication between the communication device and other devices; the processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the communication unit can correspond to the operations involved in any of the first to third aspects described above.

[0042] In one possible design, the communication device includes a processor that can be coupled to a memory. The memory can store necessary computer programs or instructions for implementing the functions involved in any of the first to third aspects described above. The processor can execute the computer programs or instructions stored in the memory, causing the communication device to implement the methods in any possible design or implementation of the first to third aspects described above when the computer programs or instructions are executed.

[0043] In one possible design, the communication device includes a processor and a memory, the memory of which may store necessary computer programs or instructions for implementing the functions involved in any of the first to third aspects described above. The processor may execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the first to third aspects described above.

[0044] In one possible design, the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices via the interface circuit and to execute the methods in any possible design or implementation of the first to third aspects described above.

[0045] Understandably, in the fourth aspect mentioned above, the processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc.; when implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. Furthermore, there can be one or more processors, and one or more memories. The memory can be integrated with the processor, or the memory and processor can be separate. In specific implementations, the memory can be integrated with the processor on the same chip, or it can be set on different chips. This application does not limit the type of memory or the arrangement of the memory and processor.

[0046] Fifthly, this application provides a communication system that may include a first communication device, a second communication device, and a third communication device; wherein the first communication device is used to perform the method described in the first aspect, the second communication device is used to perform the method described in the second aspect, and the third communication device is used to perform the method described in the third aspect.

[0047] In a sixth aspect, this application provides a computer-readable storage medium storing a computer program (or computer-readable instructions) in which, when a computer reads and executes some or all of the computer-readable instructions, the method in any of the possible designs in the first to third aspects described above is executed.

[0048] For example, a computer-readable storage medium can be any available medium that a computer can access. This includes, but is not limited to, non-transient computer-readable media, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), CD-ROM or other optical disc storage, magnetic disk storage media, or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer.

[0049] In a seventh aspect, this application provides a computer program product that, when read and executed by a computer, causes any of the possible designs in the first to third aspects described above to be performed.

[0050] Eighthly, this application provides a chip (or chip system) including a processor coupled to a memory storing a computer program; the processor is configured to invoke part or all of the computer program in the memory, such that any of the possible designs in the first to third aspects described above are executed. Attached Figure Description

[0051] Figure 1 is a schematic diagram of the network architecture of a communication system to which this application applies;

[0052] Figure 2 is a schematic diagram of a more specific network architecture applicable to the embodiments of this application;

[0053] Figure 3 is a schematic diagram of a network architecture applicable to a roaming scenario according to an embodiment of this application;

[0054] Figure 4A is a flowchart illustrating the communication method provided in the embodiments of this application;

[0055] Figure 4B is an example of a business continuity map provided in an embodiment of this application;

[0056] Figure 5 is a schematic diagram of a possible implementation process for a terminal device to obtain service support information from M networks.

[0057] Figure 6 is a schematic diagram of another possible implementation process for a terminal device to obtain service support information of M networks.

[0058] Figure 7 is a schematic diagram of another possible implementation process for a terminal device to obtain service support information of M networks.

[0059] Figure 8 is an exemplary block diagram of the apparatus involved in the embodiments of this application;

[0060] Figure 9 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0061] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings. This application will focus on various aspects, embodiments, or features of a system that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these solutions may also be used.

[0062] In the embodiments of this application, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as an "example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "example" is intended to present concepts in a concrete manner. In the embodiments of this application, "of," "corresponding, relevant," and "corresponding" may sometimes be used interchangeably, and it should be noted that their intended meanings are consistent unless their distinction is emphasized.

[0063] The technical solutions in this application embodiment can be applied to various communication systems, such as Universal Mobile Telecommunications System (UMTS), Wireless Local Area Network (WLAN), Wireless Fidelity (Wi-Fi) system, 4th generation (4G) mobile communication system (such as Long Term Evolution (LTE) system), 5th generation (5G) mobile communication system (such as New Radio (NR) system), Future Communication System, or other similar communication systems, without limitation.

[0064] Figure 1 is a schematic diagram of a network architecture for a communication system applicable to this application. This network architecture comprises four components: terminal equipment, access network (AN), core network (CN), and data network (DN). The access network can be a radio access network (RAN).

[0065] Terminal equipment, access network, and core network are the main components of the aforementioned network architecture. Logically, they can be divided into two parts: the user plane and the control plane. The control plane is responsible for the management of the mobile network, while the user plane is responsible for the transmission of service data. For example, as shown in Figure 1, in a 5G communication system, the next generation (NG)2 reference point is located between the access network control plane and the core network control plane, the NG3 reference point is located between the access network user plane and the core network user plane, and the NG6 reference point is located between the core network user plane and the data network.

[0066] (1) Terminal equipment

[0067] A terminal device is a device that provides voice and / or data connectivity to a user. Terminal devices may also be referred to as user equipment (UE), terminal, access terminal, terminal unit, terminal station, mobile station (MS), remote station, remote terminal, mobile terminal (MT), wireless communication equipment, terminal agent, or terminal equipment, etc.

[0068] For example, the terminal device can be a handheld device with wireless connectivity, or a vehicle with communication capabilities, such as in-vehicle equipment (e.g., in-vehicle communication device, in-vehicle communication chip). Examples of current terminal devices include: mobile phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistant (PDA) devices, handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, tablet computers, computers with wireless transceiver capabilities, laptops, handheld computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving vehicles, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes.

[0069] Terminal devices can be deployed on land, including indoors or outdoors, handheld, wearable, or vehicle-mounted; they can also be deployed on water (such as ships); and they can also be deployed in the air (such as airplanes, balloons, and satellites). This application does not limit the specific technologies, device forms, application scenarios, or names used in the terminal devices.

[0070] (2) Access Network

[0071] The access network is deployed close to the terminal equipment, providing network access functionality for authorized users in a specific area. It can determine different quality transmission tunnels to transmit user data based on user level, service requirements, and other factors. The access network manages and utilizes its own resources efficiently, providing access services to terminal equipment on demand, and is responsible for forwarding control signals and service data between the terminal equipment and the core network.

[0072] The access network can be an access network in the 3rd generation partnership project (3GPP), such as 4G, 5G, or future networks. The RAN can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a communication network combining two or more of the above.

[0073] The access network deploys network equipment to connect terminal devices to the wireless network. Network equipment is typically connected to the core network via wired links (such as fiber optic cables). Network equipment can also be called network devices or RAN devices / nodes. Network equipment can be base stations, evolved NodeBs (eNodeBs), transmission reception points (TRPs), next-generation NodeBs (gNBs) in 5G mobile communication systems, and base stations in future mobile communication systems, etc.

[0074] Network equipment can also be modules or units that perform some of the functions of a base station. For example, it can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). Here, the CU performs the functions of the radio resource control (RRC) and PDCP protocols of the base station, and can also perform the functions of the service data adaptation protocol (SDAP). The CU can be further divided into a CU control plane (CP) (i.e., CU-CP) and a CU user plane (UP) (i.e., CU-UP). The DU performs the functions of the RLC and MA layers of the base station, and can also perform some or all of the physical layer functions. For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications. The CU and DU can be set up separately, or they can be included in the same network element, such as in the baseband unit (BBU). The RU can be included in radio frequency equipment or radio frequency units, such as in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). In different systems, CU, DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, and RU can also be called O-RU. Any of the CU (or CU-CP, CU-UP), DU, and RU units in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. The RA device can be a macro base station (as shown in Figure 1, 110a), a micro base station or an indoor station (as shown in Figure 1, 110b), or a relay node or donor node, etc. The embodiments of this application do not limit the specific technology or specific device form used in the network equipment.

[0075] (3) Core Network

[0076] The core network is responsible for maintaining the subscription data of the mobile network, managing the network elements of the mobile network, and providing terminal devices with functions such as session management, mobility management, policy management, and security authentication.

[0077] Specifically, this may include: providing network access authentication for the terminal device when it attaches; allocating network resources for the terminal device when it has a service request; updating network resources for the terminal device when it moves; providing a fast recovery mechanism for the terminal device when it is idle; releasing network resources for the terminal device when it detaches; and providing data routing functions for the terminal device when it has service data, such as forwarding uplink data to the data network, or receiving downlink data from the data network and forwarding it to the access network, and then sending it to the terminal device.

[0078] (4) Data Network

[0079] A data network, also known as a packet data network (PDN), is a network located outside of the carrier's network. A carrier's network can connect to multiple data networks. These data networks can deploy application servers for various services (such as application servers for XR services), providing a variety of possible services to terminal devices. Data networks can be private networks, such as local area networks (LANs), external networks not controlled by the carrier, such as the Internet, or dedicated networks jointly deployed by carriers; the specific type is not limited.

[0080] Figure 2 is a schematic diagram of a more specific network architecture applicable to the embodiments of this application. This network architecture is the network architecture of a 5G communication system. As shown in Figure 2, this network architecture includes terminal devices, network devices, various types of core network elements / functional entities, and data networks.

[0081] The core network user plane includes user plane function (UPF) network elements. The core network control plane includes, but is not limited to: access and mobility management function (AMF) network elements, session management function (SMF) network elements, authentication server function (AUSF) network elements, network exposure function (NEF) network elements, network function repository function (NRF) network elements, policy control function (PCF) network elements, unified data management (UDM) network elements, network slice selection function (NSSF) network elements, network data analytics function (NWDAF) network elements, application function (AF) network elements, and network slice specific authentication and authorization function (NSSAAF).

[0082] UPF network elements are primarily responsible for connecting to external networks and for forwarding user data packets according to the routing rules of SMF network elements. For example, uplink data is sent to the data network or other UPF network elements, and downlink data is sent to other UPF network elements or network devices.

[0083] AMF network elements are mainly responsible for the access management and mobility management of terminal devices, such as the status maintenance of terminal devices, the reachability management of terminal devices, the forwarding of non-access-stratum (MM NAS) messages, and the forwarding of session management (SM) N2 messages.

[0084] SMF (Service Provider Function) network elements are primarily responsible for session management in mobile networks, including establishing sessions for terminal devices, allocating and releasing resources for sessions, such as session quality of service (QoS), session paths, and forwarding rules. For example, they may allocate Internet Protocol (IP) addresses to terminal devices and select UPF (User Provider Function) network elements that provide packet forwarding functions.

[0085] The AUSF network element is primarily responsible for performing security authentication of terminal devices.

[0086] NEF network elements are used to connect other internal network elements of the core network with external application servers of the core network, so as to provide network capability information to external application servers, or to provide information from external application servers to core network elements.

[0087] The NRF network element is primarily responsible for providing other network elements with the functions of storing and selecting network function entity information.

[0088] The PCF network element is mainly responsible for user policy management, including policy authorization, quality of service and generation of billing rules, and distributing the corresponding rules to the UPF network element through the SMF network element to complete the installation of the corresponding policies and rules.

[0089] UDM network elements are primarily responsible for data management and control. For example, UDM network elements can manage user subscription information, including obtaining subscription information and providing it to other network elements (such as AMF network elements); generating 3GPP authentication credentials for terminal devices; and registering and maintaining the network elements currently serving the terminal devices (for example, the AMF represented by AMF ID1 is the current serving AMF of the terminal device, i.e., the serving AMF).

[0090] NSSF network elements are used to select network slices for terminal devices.

[0091] The NWDAF network element is mainly used to collect data (including one or more of the following: terminal device data, network device data, core network data, and third-party application device data). This data can be the data of the terminal device, network device, core network element, or third-party application device itself, or it can be the data of the terminal device on the network device, core network element, or third-party application device. Then, the collected data is analyzed, and the data analysis results are output for use by the network, network management equipment, and application execution strategy decisions.

[0092] The AF (Area Function) network element is mainly responsible for providing various application service data to the control plane network elements of the operator's communication network, or obtaining network data and control information from the control plane network elements of the communication network.

[0093] The NSSAAF network element is used for slice authentication of terminal devices.

[0094] Although not shown, the above network architecture may include other possible network elements, without any specific limitations.

[0095] The various functions in the core network shown in Figure 2 (such as NWDAF, AMF, SMF, etc.) are collectively referred to as network functions (NFs). Communication between NFs within the core network can be achieved by using service-oriented interfaces to invoke corresponding service-oriented operations. In Figure 2, Npcf, Namf, Nudm, Nsmf, Naf, Nnwdaf, and Nnssf are the service-oriented interfaces provided by PCF, AMF, UDM, SMF, AF, NWDAF, and NSSF, respectively. Figure 2 also includes interfaces N1, N2, N3, N4, and N6; the meanings of these interfaces can be found in existing protocols.

[0096] Figure 3 is a schematic diagram of a network architecture applicable to a roaming scenario according to an embodiment of this application. Here, we first introduce the PLMN: The PLMN is used to distinguish different mobile communication operators in different countries or regions. A PLMN consists of a mobile country code (MCC) and a mobile netcode (MNC). The MCC uniquely represents the country of origin of the mobile user, and the MNC uniquely represents the network within that country. For example, China Mobile's PLMNs may include 46000, 46002, 46004, 46007, and 46008; China Unicom's PLMNs may include 46001, 46006, 46009, and 46010; China Telecom's PLMNs may include 46003, 46011, and 46012; and China Broadcasting Network's PLMN may include 46015. In the future, the PLMNs corresponding to each operator may include others, which are not limited in this embodiment of the application.

[0097] As shown in Figure 3, this network architecture includes two parts: the home PLMN (H-PLMN) and the visited PLMN (V-PLMN). The H-PLMN is the PLMN to which the UE is registered, representing the UE's home operator. The V-PLMN is the PLMN the UE accesses after leaving the coverage area of ​​the H-PLMN. It can be understood that when a UE leaves the coverage area of ​​the H-PLMN due to movement or other reasons, if a PLMN meets the following conditions: 1) it can cover the UE's current location, and 2) the operator of this PLMN has signed a roaming agreement with the operator of the UE's H-PLMN, then the UE can access this PLMN, which is called the V-PLMN. The UE's access to the V-PLMN is called roaming.

[0098] Specifically, a V-PLMN includes network elements such as NSSF, NEF, NRF, PCF, AF, AMF, SMF, NWDAF, and the visit security edge protection proxy (vSEPP). These network elements can communicate with each other based on service-oriented interfaces. An H-PLMN includes network elements such as UDM, NRF, PCF, AUSF, NEF, NSSAAF, NWDAF, and the home security edge protection proxy (hSEPP). These network elements can also communicate with each other based on service-oriented interfaces. vSEPP and hSEPP can communicate via the N32 interface. During roaming, when a terminal device connects to the V-PLMN, the core network elements (such as AMF, SMF, and UDM) within the V-PLMN and H-PLMN are connected to hSEPP via vSEPP, enabling network elements within the V-PLMN to communicate with those within the H-PLMN.

[0099] It is understood that Figures 2 and 3 illustrate the core network control plane using a service-oriented architecture as an example. In this architecture, each control plane network element is connected to a service bus, and the interaction between control plane network elements is achieved through service calls. That is, a control plane network element exposes its services to other control plane network elements for them to call. In other possible implementations, the core network control plane can also adopt a point-to-point communication method. In point-to-point communication, the communication interfaces between control plane network elements will have a specific set of messages. Of course, in future communication systems, the names of these interfaces may remain unchanged or may be replaced with other names; this application does not limit this. In future communication systems, the aforementioned network elements or devices can still use their names from the 5G communication system, or have other names; the functions of the aforementioned network elements or devices can be performed by a single network element or by several network elements working together; this application's embodiments do not limit this.

[0100] The network elements / functional entities in the various possible network architectures described above can be network components in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). Optionally, the aforementioned network elements or functional entities can be implemented by a single device, multiple devices working together, or different functional modules within a single device; this application embodiment does not specifically limit this. In actual deployment, the aforementioned network elements can be co-located. For example, the access and mobility management function network element can be co-located with the session management function network element; the session management function network element can be co-located with the user plane function network element. When two network elements are co-located, the interaction between these two network elements provided in this application embodiment becomes an internal operation of the co-located network element or can be omitted.

[0101] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of communication system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0102] Before accessing a network for data transmission, a terminal device needs to search for a network, i.e., perform a network selection operation. This network selection operation can be divided into two processes: PLMN selection and cell search. During PLMN selection, the terminal device maintains a list of PLMNs, which are sorted by priority, and then the search proceeds from highest to lowest priority. After selecting a PLMN, the terminal device selects a cell that meets the corresponding criteria to access the network through the cell selection process.

[0103] However, as business development continues to increase, different businesses require different network resources. Since different networks support these businesses differently in different regions, terminal devices need to be able to proactively select a network based on its support for the business in order to provide optimal service. However, current network selection operations do not consider network support for the business, resulting in the inability to meet business needs through existing methods. The network involved in this application's embodiments can refer to a specific PLMN, or it can refer to a network of a specific communication standard within a PLMN. The communication standard can be 3G, 4G, or 5G, etc., and is not specifically limited. The following description will use "a network of a specific communication standard within a specific PLMN" as an example.

[0104] There may be several reasons why different networks support services differently in different areas. For example: (1) The current protocol defines a large number of areas, such as service area restriction, forbidden timing advance index (TAI), local area data network (LADN), and slice-related areas (such as partially allowed network slicing selection assistance information (NSSAI) areas and partially rejected NSSAI areas). As a result, when terminal devices enter these areas, they will have different granular restrictions on different services according to the configuration of these areas. (2) The actual base station configuration of the network leads to different support for different services in different areas. For example, the base station near Shanghai Hongqiao Metro is configured to fall back to the evolved package system (EPS) for voice services (i.e., EPS fallback). Therefore, terminal devices cannot use 5G for voice services. (3) Terminal equipment contracts are signed independently for each standard, with 2G / 3G / 4G / 5G contracts signed separately. Different operators have different support and coverage for each standard in different regions. For example, China Broadcasting Network has relatively few networks and mostly leases base stations from China Mobile. China Telecom leases base stations from China Unicom for some standards, which leads to different support for services by different operators' networks for different standards in different regions.

[0105] Based on this, embodiments of this application provide a communication method for enabling a terminal device to select a network based on the service support of multiple networks at a first location (i.e., the location where the terminal device is located), thereby facilitating the fulfillment of service requirements and achieving service continuity.

[0106] The following is an explanation of the relevant terms used in the embodiments of this application. Unless otherwise specified, these explanations are provided to support the meaning of the relevant terms and to make the embodiments of this application easier to understand, and should not be regarded as a strict limitation of the relevant terms within the scope of protection claimed by this application.

[0107] (1) Business

[0108] The services in this application embodiment can follow the existing protocol to distinguish service flows. For example, the services in this application embodiment can be divided into: IP multi-media service (IMS), multimedia messaging service (MMS), Internet service, location service (LCS), Internet of Things (IoT) delay-tolerant, downlink streaming, uplink streaming, etc. For details, please refer to the description in the "3GPP 24526 connection capabilities type" section.

[0109] For example, referring to the service definitions in "3GPP 23501 Table 5.7.4-1: Standardized 5QI to QoS characteristics mapping" or "3GPP 23501 Table 5.15.2.2-1: Standardized SST values", services are divided into: conversational voice, video, real-time gaming, mission-critical user plane push to talk voice, non-mission-critical user plane push to talk voice, mission-critical video user plane, vehicle to everything (V2X), and mission-critical delay-sensitive signalling, etc.

[0110] (2) Communication device

[0111] The communication method provided in this application involves multiple communication devices, such as a first communication device, a second communication device, and a third communication device. The first communication device is a terminal device or a component of a terminal device, such as a chip or chip system disposed in the terminal device. The second communication device is a core network element of a second network (such as a network of a certain communication standard of V-PLMN) or a component of a core network element of the second network, such as a chip or chip system disposed in a core network element of the second network. The core network element of the second network can be an AMF network element or other possible network elements of the second network, without specific limitations. The third communication device is a data management network element of a home network (such as a network of a certain communication standard of H-PLMN) or a component of a data management network element of the home network, such as a chip or chip system disposed in a data management network element of the home network. The data management network element of the home network can be a UDM network element or other possible network elements, without specific limitations. This application uses the example of "the first communication device being a terminal device, the second communication device being a core network element of the second network, and the third communication device being a data management network element of the home network" for description.

[0112] The communication method provided in this application is described below with reference to specific embodiments.

[0113] Figure 4A is a flowchart illustrating the communication method provided in an embodiment of this application. As shown in Figure 4A, the process may include:

[0114] S401, the terminal device obtains service support information from M networks.

[0115] The service support information of each of the M networks is used to indicate the support status of each network for the first service at the first location, where M is an integer greater than 1. Optionally, the service support information of each of the M networks can also be used to indicate the support status of each network for other services besides the first service at the first location. In other words, the service support information of each network is used to indicate the support status of each network for one or more services at the first location. The first location is the location of the terminal device. For example, the first location can refer to a specific address location, such as latitude and longitude, altitude, etc., or it can be a location that the operator's network can identify, such as a cell, tracking area, etc., without any specific limitation.

[0116] For example, different networks in the M networks belong to different PLMNs, and / or different networks in the M networks belong to different communication standards. In this embodiment, the example described is "a network referring to a network of a certain PLMN and a certain communication standard". For instance, the M networks include network a1, network a2, network b1, and network b2. Network a1 and network a2 both belong to PLMN-a, with communication standard 1 for network a1 and communication standard 2 for network a2. Similarly, network b1 and network b2 both belong to PLMN-b, with communication standard 1 for network b1 and communication standard 2 for network b2. The PLMNs of the M networks can all be V-PLMNs of terminal devices, or the PLMNs of the M networks can include H-PLMNs and V-PLMNs of terminal devices; the specifics are not limited.

[0117] Taking one of the M networks (such as the first network) as an example, the service support information of the first network will be described below in conjunction with implementation method 1 and implementation method 2.

[0118] (1) Implementation method 1

[0119] For example, the service support information of the first network includes at least one of the following ① to ⑦:

[0120] ① Does the first network support the first service at the first location?

[0121] ② The continuous coverage range of the first network for the first service. This continuous coverage range can be the continuous coverage range with the first location as the origin. For example, if the first network supports the first service within a 50-kilometer (km) range with the first location as the origin, then the continuous coverage range of the first network for the first service is 50km.

[0122] ③ A list and number of cells, TAIs, frequency bands, etc., that support the first service within the continuous coverage area of ​​the first network.

[0123] ④ Information such as the TAI, cell list, and frequency bands that cannot be used by the first service in the first network.

[0124] ⑤ Frequency band information that supports the first service in the first network.

[0125] ⑥ Information such as the resource congestion ratio and availability of network devices covering the first location in the first network (e.g., used resources / total resources; number of connected terminal devices / number of accessible terminal devices).

[0126] ⑦ Whether the first network supports the slice or data network name (DNN) requested by the terminal device, and the slice identifier, DNN, or access point name (APN) supported by the first network. The slice can be identified using single network slice selection assistance information (S-NSSAI).

[0127] It is understood that the above-listed items are just some examples. In specific implementation, other information that may be used to assess the support of the business can also be included, without any specific limitations.

[0128] For example, the M networks include network a1, network a2, network b1, and network b2, as described above. The service support information for each of the M networks indicates the network's support for two services (such as voice service and real-time gaming service) at the first location. See Table 1 for an example of the service support information for the M networks.

[0129] Table 1: Examples of Service Support Information for M Networks

[0130] (2) Implementation Method 2

[0131] For example, the service support information of the first network can be a score of the first network at the service granularity. For instance, the service support information of the first network includes a score of the first network for a first service. This score can be out of 10 or 100 points, and there is no specific limitation. This helps to reduce the exposure of the operator's network distribution.

[0132] For example, the M networks include network a1, network a2, network b1, and network b2, as described above. The service support information for each of the M networks indicates the network's support for two services (such as voice service and real-time gaming service) at the first location. See Table 2 for an example of the service support information for the M networks.

[0133] Table 2: Examples of Service Support Information for M Networks

[0134] S402, the terminal device selects the first network from the M networks based on the service support information of the M networks.

[0135] For example, the terminal device determines the scores of the M networks based on the weight of the first service and the service support information of the M networks, and then selects the first network from the M networks based on the scores of the M networks.

[0136] For example, if the weight of the first service is 1, meaning only the first service is considered, and assuming the first service is a voice service, and the M networks include network a1, network a2, network b1, and network b2, then if the service support information of the M networks is as shown in Table 1, the terminal device can determine the scores of the M networks for the first service based on this information. If the service support information of the M networks is as shown in Table 2, the terminal device can directly obtain the scores of the M networks for the first service. For example, the scores of the M networks for the first service are 9, 6, 8, and 5 respectively (see Table 2). Since only the first service is considered, the scores of the M networks for the first service are the scores of the M networks themselves.

[0137] In this case, if the score of the first network is greater than or equal to the threshold, and there are multiple networks among the M networks with scores greater than or equal to the threshold, the terminal device can select one of these networks. Alternatively, the score of the first network is greater than or equal to the scores of all other networks among the M networks except the first network, meaning the first network is the network with the highest score among the M networks.

[0138] For example, if the weight of the first service is less than 1, meaning that other services are considered in addition to the first service, then the terminal device can determine the scores of each service across the M networks based on the weights of the multiple services and the service support information of the M networks. Furthermore, based on the scores of each service across the M networks, the final score of the M networks is determined. The multiple services include the first service. Assuming the multiple services include voice service and real-time gaming service, with a weight of 0.8 for voice service and 0.2 for real-time gaming service, and the scores of the M networks for voice service are 9, 6, 8, and 5 respectively, and the scores for real-time gaming service are 8, 5, 7, and 3 respectively, then the final score of each of the M networks is equal to the product of the score for voice service and the weight of the voice service, plus the product of the score for real-time gaming service and the weight of the real-time gaming service. For example, the score of network a1 is 0.8*9 + 0.2*8 = 8.8, and the score of network a2 is 0.8*6 + 0.2*5 = 5.8. The scores of other networks can be calculated by reference, and will not be listed one by one.

[0139] For example, taking a first service as an example, the weight of the first service can be obtained based on at least one of the following: the frequency of use of the first service; the duration of each use of the first service; the priority of resources required by the first service; and whether the first service is currently being used by the user of the terminal device. Alternatively, the user can set the weight or priority of the service themselves. This application embodiment does not limit the specific implementation for determining the weight of the first service.

[0140] Understandably, when determining the rating of various networks, terminal devices can also consider other possible factors, such as the home network's billing policy. Some roaming operators charge relatively high fees, while others charge relatively low fees. Therefore, by considering the home network's billing policy, it is easier to determine the network rating based on more dimensions to meet user needs.

[0141] Optionally, the terminal device can generate and store a service continuity map based on the service support information of M networks. Taking the first service as an example, the service continuity map is used to indicate the areas (e.g., cells) in the first network that allow (i.e. support) the first service and the areas (e.g., cells) that prohibit (i.e. do not support) the first service, as shown in Figure 4B, which is an example of a service continuity map.

[0142] S403, the terminal device transmits the data of the first service through the first network.

[0143] For example, if the terminal device was previously registered with another PLMN but not with the PLMN to which the first network belongs, then after selecting the first network, the terminal device can register from the other PLMN and register with the PLMN to which the first network belongs, thereby accessing the first network and transmitting data for the first service through the first network. Optionally, the terminal device can also transmit data for other services through the first network, and there is no specific limitation.

[0144] If the terminal device has already registered with the PLMN to which the first network belongs before selecting the first network, then for idle terminal devices, after selecting the first network, the terminal device can access the first network and transmit the data of the first service through the first network. Optionally, when accessing the first network, the terminal device can determine information such as cells supporting the first service based on the service continuity map, and then select the cell to access, thereby avoiding service unavailability areas in the current region.

[0145] For connected terminal devices, after selecting a first network, the terminal device can switch to the first network and transmit data for the first service through the first network. For example, the terminal device reports the measurement results of multiple candidate cells to the network device. The network device then determines the target cell for handover based on the measurement results of the multiple candidate cells and instructs the terminal device to handover to the target cell. When reporting, the terminal device can, based on the service continuity map, report the measurement results of candidate cells that support the first service, and not report the measurement results of candidate cells that do not support the first service. This ensures that the target cell determined by the network device is a cell that supports the first service, thereby avoiding service unavailability areas in the current region.

[0146] Using the above method, the terminal device obtains the service support information of M networks at the first location, and selects a network based on the service support information of the M networks at the first location, thereby facilitating the fulfillment of service requirements and achieving service continuity.

[0147] In S401 above, there are multiple ways for the terminal device to obtain service support information from M networks. The following describes two possible implementations in conjunction with implementation method 1 and implementation method 2.

[0148] (1) Implementation method 1

[0149] The terminal device receives service support information from M networks from the core network element of the second network, where the second network is one of the M networks. The service support information for the M networks is obtained by the core network element of the second network from the data management network element of its home network. Two possible implementation processes are described below with reference to Figures 5 and 6.

[0150] Figure 5 illustrates a possible implementation process for a terminal device to obtain service support information from M networks. As shown in Figure 5, this process may include:

[0151] S501, the terminal device sends a registration request message to the core network element of the second network (referred to as network a1); correspondingly, the core network element of network a1 receives the registration request message.

[0152] For example, network a1 can belong to PLMN-a, such as PLMN-a being the V-PLMN or H-PLMN of the terminal device.

[0153] S502, the core network element of network a1 sends a query message to the data management network element of the home network based on the registration request message of the terminal device. The query message is used to query the subscription information of the terminal device; correspondingly, the data management network element of the home network receives the query message.

[0154] For example, the data management network element of the home network can determine that the terminal device has triggered a registration request based on the query message. Therefore, the data management network element of the home network can obtain service support information of M networks, that is, execute steps S503 and S509.

[0155] It is understood that the data management network element of the home network can also send the terminal device's subscription information to the core network element of network a1. Furthermore, the core network element of network a1 can also send a registration response message to the terminal device. This application embodiment does not limit these possible steps.

[0156] S503, the data management network element of the home network sends request information a1 to the core network element of network a1. Request information a1 is used to request the service support status of the network at the first location.

[0157] For example, for PLMN-a, the data management network element of the home network can select a network (such as network a1) in PLMN-a and send request information a1 to the core network element of network a1. This application embodiment does not limit the specific implementation of the home network's data management network element selecting network a1.

[0158] For example, the data management network element of the home network can also send location information to the core network element of network a1, and the location information is used to indicate the first location. There are several ways for the data management network element of the home network to obtain location information. For example, the terminal device sends location information to the core network element of network a1 during the registration process, and then the core network element of network a1 sends the location information to the data management network element of the home network.

[0159] For example, the data management network element of the home network can also send a second service list (or service list a1) to the core network element of network a1. Service list a1 includes service identifiers of N1 types of services, and the first service mentioned above is one of the N1 types of services. Service list a1 is used to instruct the core network element of network a1 to obtain the support status of the services in service list a1 at the first position of network a1. There are several ways for the data management network element of the home network to obtain service list a1. For example, during the registration process, the terminal device sends the first service list to the core network element of network a1, and then the core network element of network a1 sends the first service list to the data management network element of the home network. The first service list includes service identifiers of N types of services, and the N1 types of services are some or all of the N types of services.

[0160] For example, the data management network element of the home network determines service list a1 based on the service information subscribed by the terminal device in network a1 and the first service list. The service information subscribed by the terminal device in network a1 includes the identifier of the service subscribed by the terminal device in network a1. If the first service list includes service a, but the services subscribed by the terminal device in network a1 do not include service a, then service a can be deleted from the first service list, and the service list after deletion is service list a1.

[0161] For example, the data management element of the home network directly uses the first service list as service list a1, meaning service list a1 and the first service list are the same service list. In this case, the data management element of the home network can send the service information subscribed by the terminal device in network a1 to the core network of network a1, so that the core network of network a1 can update the first service list based on the service information subscribed by the terminal device in network a1 (i.e., filter out services that the terminal device has not subscribed to in network a1 from the first service list), thereby obtaining the support status of network a1 for services in the updated service list at the first position. In addition, the data management element of the home network can also send the service information subscribed by the terminal device in other networks (other networks refer to networks belonging to the same PLMN as network a1, such as network a2) to the core network of network a1. This application embodiment mainly describes the example of service list a1 and the first service list being the same service list.

[0162] The aforementioned first service list may be obtained by the terminal device based on the user's historical service usage habits; or, the first service list may be obtained by the terminal device based on the service priority specified by the user; or, the first service list may be obtained by the terminal device based on the scarcity of resources required by the service (e.g., VR, AR, games require a large amount of guaranteed resources) and / or the importance of the service (e.g., emergency services, voice calls). Furthermore, the first service list (or service list a1) may also include other possible information, such as resource identifiers that the service depends on, such as slice identifiers, APNs, or DNNs.

[0163] The data management network element of the home network can also send other possible information about the terminal device to the core network element of network a1, such as the frequency band information supported by the terminal device (so that the core network element of network a1 can compare the frequency band supported by network a1 for the first service with the frequency band supported by the terminal device), without any specific limitation.

[0164] It is understood that the aforementioned request information a1, location information, service list a1, and frequency band information supported by the terminal device are carried in the same message, which can be called a service continuity probe request message. In other possible examples, request information a1 may include at least one of location information, service list a1, and frequency band information supported by the terminal device.

[0165] S504, the core network elements of network a1 obtain service support information of network a1.

[0166] For example, the core network element of network a1 obtains the service support information of network a1 based on the network layout of network a1, according to the location information and service list a1. The service support information of network a1 is used to indicate the support status of network a1 for some or all of the N services in the first location.

[0167] Optionally, network a1 obtains the service information of the terminal device subscribed to by the terminal device in network a1 from the data management network element of the home network, and then updates the service list a1 according to the service information of the terminal device subscribed to by the terminal device in network a1. For example, the updated service list includes the identifiers of some services among N services. Then the service support information of network a1 is used to indicate the support status of network a1 for some services among N services in the first position.

[0168] There are several specific implementations for the core network elements of network a1 to obtain service support information of network a1. For example, the core network elements of network a1 receive reported information from at least one network device in network a1. This at least one network device includes a first network device. The reported information from the first network device includes its coverage information and radio load information. Therefore, the core network elements of network a1 can determine the service support information of network a1 based on the reported information from at least one network device. The coverage information of the first network device can include a list and quantity of continuous coverage areas for the resources required by each service, cells supporting the first service within the continuous coverage area, TAI (Target Area), frequency bands (which can be compared with the frequency bands supported by the terminal device), etc. The radio load information of the first network device can include the resource congestion ratio and availability of the network device covering the first location.

[0169] It is understandable that at least one network device can proactively send reporting information (e.g., setting a threshold value for the corresponding information, and reporting is performed once the threshold value is met), or it can send reporting information based on a request from the core network element of network a1. For example, the core network element of network a1 determines at least one network device based on the first location (e.g., at least one network device is a network device within a preset range from the first location) and sends a query request to at least one network device. The query request is used to query the coverage information and wireless load information of at least one network device. Then, after receiving the query request, at least one network device sends reporting information to the core network element of network a1.

[0170] S505, the core network element of network a1 sends a fourth request message (referred to as request message a2) to the core network element of the fourth network (referred to as network a2). Request message a2 is used to request the service support status of the network at the first location.

[0171] For example, network a2 and network a1 belong to the same PLMN, such as both belonging to PLMN-a. Network a2 and network a1 belong to different communication standards. For example, network a1 belongs to the 5G communication standard, while network a2 belongs to the 4G communication standard. That is, network a2 and network a1 are networks of the same PLMN but different communication standards.

[0172] For example, the core network element of network a1 can also send at least one of the following to the core network element of network a2: location information, service list a2 (e.g., service list a2 is the first service list), and frequency band information supported by the terminal device.

[0173] Optionally, the core network element of network a1 sends the service information signed by the terminal device in network a2 to the core network element of network a2, so that the core network element of network a2 can update the service list a2 according to the service information signed by the terminal device in network a2.

[0174] S506, the core network elements of network a2 obtain service support information of network a2.

[0175] For example, the specific implementation of the core network element of network a2 obtaining service support information of network a2 can refer to the description of "core network element of network a1 obtaining service support information of network a1".

[0176] S507, the core network element of network a2 sends service support information of network a2 to the core network element of network a1.

[0177] S508, the core network element of network a1 sends service support information of M1 networks to the data management network element of the home network.

[0178] For example, M1 networks include network a1 and network a2.

[0179] It is understood that this embodiment of the application takes PLMN-a including networks a1 and a2 as an example. If PLMN-a also includes other networks, such as network a3, then the core network element of network a1 can also send request information a3 to the core network element of network a3 to obtain service support information of network a3. That is, after receiving request information a1 from the data management network element of the home network, network a1 can obtain the service support information of each network of PLMN-a and summarize it and send it to the data management network element of the home network. In other possible examples, the data management network element of the home network can also send request information to the core network elements of each network of PLMN-a respectively, and then the core network elements of each network send the service support information of each network to the data management network element of the home network according to the request information.

[0180] S509, the data management network element of the home network sends a second request message (referred to as request message b1) to the core network element of the third network (referred to as network b1). Request message b1 is used to request the service support status of the network at the first location.

[0181] For example, network b1 can belong to PLMN-b, such as PLMN-b being the V-PLMN of the terminal device. Specifically, for PLMN-b, the data management network element of the home network can select a network (such as network b1) within PLMN-b and send request information b1 to the core network element of network b1. This application embodiment does not limit the specific implementation of the home network's data management network element selecting network b1.

[0182] For example, the data management network element of the home network can also send at least one of the following to the core network element of network b1: location information, service list b2 (e.g., service list b2 is the first service list), and frequency band information supported by the terminal device. Specific implementation details can be found in the description in S503.

[0183] S510, the core network elements of network b1 obtain service support information of network b1.

[0184] For example, the specific implementation of the core network element of network b1 obtaining service support information of network b1 can refer to the description of "core network element of network a1 obtaining service support information of network a1".

[0185] S511, the core network element of network b1 sends request information b2 to the core network element of network b2. Request information b2 is used to request the service support status of the network at the first location.

[0186] For example, network b2 and network b1 belong to the same PLMN, such as both belonging to PLMN-b. Network b2 and network b1 belong to different communication standards. For example, network b1 belongs to the 5G communication standard, while network b2 belongs to the 4G communication standard. That is, network b2 and network b1 are networks of the same PLMN but with different communication standards.

[0187] S512, the core network elements of network b2 obtain service support information of network b2.

[0188] S513, the core network element of network b2 sends service support information of network b2 to the core network element of network b1.

[0189] S514, the core network element of network b1 sends service support information of M2 networks to the data management network element of the home network.

[0190] For example, M2 networks include network b1 and network b2.

[0191] It is understood that this embodiment of the application takes PLMN-b including networks b1 and b2 as an example. If PLMN-b also includes other networks, such as network b3, then the core network element of network b1 can also send request information b3 to the core network element of network b3 in order to obtain service support information of network b3. That is, after receiving request information b1 from the data management network element of the home network, network b1 can obtain the service support information of each network of PLMN-b and send it to the data management network element of the home network. In other possible examples, the data management network element of the home network can also send request information to the core network elements of each network of PLMN-b respectively, and then the core network elements of each network send the service support information of each network to the data management network element of the home network according to the request information.

[0192] S515, the data management network element of the home network sends service support information for M networks to the core network element of network a1.

[0193] For example, the M networks include M1 network and M2 network.

[0194] It is understood that the embodiments of this application are described using M networks, including M1 networks and M2 networks, as an example. If the V-PLMN of the terminal device also includes other possible PLMNs, such as PLMN-c, and PLMN-c includes M3 networks, then the data management network element of the home network can also send request information c1 to the core network element of network c1 to obtain service support information of the M3 networks. Network c1 is one of the M3 networks.

[0195] S516, the core network element of network a1 sends service support information of M networks to the terminal device; correspondingly, the terminal device receives service support information of M networks.

[0196] For example, since the terminal device is registered in network a1, the data management network element of the home network can send the aggregated service support information of M networks to the terminal device through the core network element of network a1.

[0197] In this way, after the terminal device triggers the registration process, the data management network element of the home network can obtain the service support information of M networks and send it to the terminal device through the core network element of the network to which the terminal device is registered. This makes it easier for the terminal device to select a network based on the service support information of M networks to meet service needs and achieve service continuity.

[0198] Figure 6 is a schematic diagram of a possible implementation process for a terminal device to obtain service support information from M networks. As shown in Figure 6, this process may include:

[0199] S601, the terminal device sends a first request message to the core network element of network a1. The first request message is used to request the service support status of the network at the first location.

[0200] For example, the terminal device can also send location information to the core network element of network a1, the location information being used to indicate the first location.

[0201] For example, the terminal device can also send a first service list to the core network element of network a1, the first service list including service identifiers of N services.

[0202] Optionally, the terminal device may also send other possible information about the terminal device to the core network elements of network a1, such as the frequency band information supported by the terminal device, without any specific limitation.

[0203] It is understood that the aforementioned first request information, location information, first service list, and frequency band information supported by the terminal device are carried in the same message. This message can be a message sent by the terminal device during the registration process, such as a registration request message. In this case, the service continuity detection process depends on the registration process. Alternatively, the message can also be a service continuity detection request message. For example, the terminal device may not initiate the registration process but instead send the service continuity detection request message after completing the identity authentication and authorization process. In this case, the service continuity detection process is independent of the registration process. In other possible implementations, the first request information may include at least one of the following: location information, first service list, and frequency band information supported by the terminal device.

[0204] Furthermore, there are multiple ways for a terminal device to send a first request message to a core network element in network a1. For example, the terminal device may send a first request message to a core network element in network a1 under certain conditions. These conditions include at least one of the following: the terminal device has a service continuity map; the service continuity map is unavailable (e.g., the terminal device has moved out of the area covered by the service continuity map, and / or the service continuity map has expired); or the service corresponding to the service continuity map does not include the service that the terminal device wishes to use; the service continuity map is obtained based on service support information from at least one network; the terminal device does not have a service continuity map; the service that the terminal device wishes to use is unavailable or the signal is below a threshold in the currently registered network; the terminal device is powered on; the terminal device has moved out of its registration area; the terminal device initiates a registration process; or the terminal device wishes to use a certain service.

[0205] S602, the core network elements of network a1 obtain service support information of network a1.

[0206] For example, S602 can be described with reference to S504.

[0207] S603, the core network element of network a1 sends request information a2 to the core network element of network a2. Request information a2 is used to request the service support status of the network at the first location.

[0208] S604, the core network elements of network a2 obtain service support information of network a2.

[0209] For example, S604 can be described with reference to S504.

[0210] S605, the core network element of network a2 sends service support information of network a2 to the core network element of network a1.

[0211] S606, the core network element of network a1 sends M1 network service support information and third request information to the data management network element of the home network.

[0212] For example, the service support information and third request information of M1 networks can be carried in the same message or different messages. For instance, the core network element of network a1 can first send the third request information to the data management network element of its home network, and then send the service support information of M1 networks, or it can send the service support information and third request information of M1 networks at the same time. This application embodiment does not limit the order in which the two are sent.

[0213] S607, the data management network element of the home network sends request information b1 to the core network element of network b1.

[0214] S608, the core network elements of network b1 obtain service support information of network b1.

[0215] For example, S608 can be described with reference to S504.

[0216] S609, the core network element of network b1 sends request information b2 to the core network element of network b2.

[0217] S610, the core network elements of network b2 obtain service support information of network b2.

[0218] For example, S610 can be described with reference to S504.

[0219] S611, the core network element of network b2 sends service support information of network b2 to the core network element of network b1.

[0220] S612, the core network element of network b1 sends service support information of M2 networks to the data management network element of the home network.

[0221] S613, the data management network element of the home network sends M network service support information to the core network element of network a1.

[0222] For example, the M networks include M1 network and M2 network.

[0223] S614, the core network element of network a1 sends M network service support information to the terminal device; correspondingly, the terminal device receives M network service support information.

[0224] It is understandable that the process illustrated in Figure 6 above is described using the example of "the data management network of the home network obtaining service support information from M networks and sending the service support information from M networks to the terminal device through the core network element of network a1". In other possible implementations, in S606, the core network element of network a1 can send a third request message to the data management network element of the home network instead of sending the service support information from M1 networks; correspondingly, in S613, the data management network element of the home network sends the service support information from M2 networks to the core network element of network a1; furthermore, in S614, the core network element of network a1 summarizes the service support information from M1 networks and the service support information from M2 networks to obtain the service support information from M networks, and sends the service support information from M networks to the terminal device.

[0225] (2) Implementation Method 2

[0226] The terminal device receives service support information for M1 networks from the core network elements of the second network (network a1), and receives service support information for M2 networks from the core network elements of the third network (network b1). A possible implementation process is described below with reference to Figure 7.

[0227] Figure 7 illustrates a possible implementation process for a terminal device to obtain service support information from M networks. As shown in Figure 7, this process may include:

[0228] S701, the terminal device sends a first request message to the core network element of network a1. The first request message is used to request the service support status of the network at the first location.

[0229] For example, network a1 can belong to PLMN-a, such as PLMN-a being the V-PLMN or H-PLMN of the terminal device.

[0230] For example, the terminal device may also send at least one of the following to the core network element of network a1: location information, first service list, and frequency band information supported by the terminal device. For specific implementation, please refer to the description of S601.

[0231] S702, the core network elements of network a1 obtain service support information of network a1.

[0232] For example, S702 can be described with reference to S504.

[0233] S703, the core network element of network a1 sends request information a2 to the core network element of network a2. Request information a2 is used to request the service support status of the network at the first location.

[0234] For example, network a2 and network a1 belong to the same PLMN, such as both belonging to PLMN-a.

[0235] For example, the core network element of network a1 may also send at least one of the following to the core network element of network a2: location information, a first service list, and frequency band information supported by the terminal device.

[0236] S704, the core network elements of network a2 obtain service support information of network a2.

[0237] For example, S704 can be described with reference to S504.

[0238] S705, the core network element of network a2 sends service support information of network a2 to the core network element of network a1.

[0239] S706, the core network element of network a1 sends M1 network service support information to the terminal equipment.

[0240] It is understandable that the above S701 is an optional step. That is to say, the core network element of network a1 can actively obtain the service support information of M1 networks and send it to the terminal device. For example, after the core network element of network a1 determines that the terminal device has initiated the registration process to network a1, it can obtain the service support information of M1 networks and send it to the terminal device.

[0241] Furthermore, in this embodiment of the application, the core network element of network a1 obtains service support information of M1 networks and sends it to the terminal device as an example. In other possible implementations, the terminal device may send request information to the core network element of each network of PLMN-a, and then the core network element of each network sends the service support information of each network to the terminal device according to the request information.

[0242] S707, the terminal device sends the first request information to the core network element of network b1.

[0243] For example, network b1 can belong to PLMN-b, such as PLMN-b being the V-PLMN of the terminal device.

[0244] For example, the terminal device may also send at least one of the following to the core network element of network b1: location information, first service list, and frequency band information supported by the terminal device. For specific implementation, please refer to the description of S601.

[0245] S708, the core network elements of network b1 obtain service support information of network b1.

[0246] For example, S708 can be described with reference to S504.

[0247] S709, the core network element of network b1 sends request information b2 to the core network element of network b2. Request information b2 is used to request the service support status of the network at the first location.

[0248] For example, network b2 and network b1 belong to the same PLMN, such as both belonging to PLMN-b.

[0249] For example, the core network element of network b1 may also send at least one of the following to the core network element of network b2: location information, a first service list, and frequency band information supported by the terminal device.

[0250] S710, the core network elements of network b2 obtain service support information of network b2.

[0251] For example, S710 can be described with reference to S504.

[0252] S711, the core network element of network b2 sends service support information of network b2 to the core network element of network b1.

[0253] S712, the core network element of network b1 sends service support information of M2 networks to the terminal equipment.

[0254] In this way, the terminal device can obtain service support information for M1 networks from the core network elements of network a1, and service support information for M2 networks from the core network elements of network b1.

[0255] Regarding the process shown in Figure 7 above, three possible implementation scenarios are described below.

[0256] ①Scene 1

[0257] In Scenario 1, it is assumed that the terminal device supports dual links (or dual connectivity), meaning that the terminal device can communicate in two networks simultaneously. Therefore, in S701, the terminal device can send request information a1 to the core network element of network a1 via a registration request message, thereby registering the terminal device in PLMN-a and performing the service process normally. While the terminal device is performing the service process, it can search for other available PLMNs, such as PLMN-b, and in S707, send request information b1 to the core network element of network b1 via a registration request message or a service continuity probe request message to obtain service support information for M2 networks. The PLMN where the terminal device performs the service process (i.e., PLMN-a) can be called the primary PLMN, and the PLMN where the terminal device probes service continuity but does not perform the service process (i.e., PLMN-b) can be called the secondary PLMN.

[0258] For example, after the terminal device has completed detection or detected a network that better supports the service, it can proactively change its registration to switch to the network that better supports the service.

[0259] ②Scene 2

[0260] In Scenario 2, assuming the terminal device does not support dual connectivity, since there are already mature methods for dual reception, the terminal device can still monitor downlink paging messages from another PLMN. Therefore, in S701, the terminal device can send request information a1 to the core network element of network a1 via a registration request message, thereby registering the terminal device with PLMN-a and performing normal service processes. Furthermore, the terminal device can search for other available PLMNs, such as PLMN-b, in idle state, and in S707, send request information b1 to the core network element of network b1 via a registration request message or a service continuity probe request message to obtain service support information for M2 networks.

[0261] Specifically, when a terminal device is probing a new PLMN, if it detects that service data has been sent from the core network element currently providing the service, or if the terminal device has a service request, it can proactively interrupt the service continuity probing process and respond to the service request. Subsequently, after the service ends, the terminal device can re-probe the new PLMN.

[0262] ③Scene 3

[0263] In scenario 3, the terminal device can initiate a registration process or a service continuity detection process one by one according to the searched PLMNs, until all PLMNs around the terminal device have been detected. For example, the terminal device first executes S701 to S706 to obtain service support information for M1 networks; then it executes S707 to S712 to obtain service support information for M2 networks.

[0264] Regarding the above embodiments, it is understood that:

[0265] (1) In various embodiments of this application, "sending information to...(a network element or device)" can be understood as the destination of the information being a network element or device, and may include sending information directly or indirectly to a network element or device. "Receiving information from...(a network element or device)" can be understood as the source of the information being a network element or device, and may include receiving information directly or indirectly from a network element or device. Information may undergo necessary processing between the source and destination of information transmission, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way, and will not be repeated here.

[0266] (2) In the various embodiments of this application, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships. Furthermore, in the same embodiment, different implementations or different examples can also be referenced or referenced by each other.

[0267] (3) The various numerical designations used in this application are merely for descriptive convenience and are not intended to limit the scope of this application. The step numbers in the above flowcharts are only examples of the execution process and do not constitute a restriction on the order of execution of the steps. That is, the size of each step number does not imply the order of execution, and the execution order of each step should be determined by its function and internal logic. In addition, not all steps shown in the flowcharts are mandatory steps, and some steps can be added or deleted based on actual needs.

[0268] The above mainly describes the solution provided by the embodiments of this application from the perspective of the interaction between the first terminal device and the application server. It is understood that, in order to achieve the above functions, the first terminal device and the application server may include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0269] This application embodiment can divide the first terminal device and application server into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0270] In the case of using integrated units, FIG8 shows a possible exemplary block diagram of the device involved in the embodiments of this application. As shown in FIG8, the device 800 may include a processing unit 802 and a communication unit 803. The processing unit 802 is used to control and manage the operation of the device 800. The communication unit 803 is used to support communication between the device 800 and other devices. Optionally, the communication unit 803 is also called a transceiver unit, and may include a receiving unit and / or a sending unit, respectively used to perform receiving and sending operations. The device 800 may also include a storage unit 801 for storing the program code and / or data of the device 800.

[0271] (1) The device 800 can be the terminal device in the above embodiments. The processing unit 802 can support the device 800 in performing the actions of the terminal device in the above method embodiments. Alternatively, the processing unit 802 mainly performs the internal actions of the terminal device in the method embodiments, and the communication unit 803 can support communication between the device 800 and other devices.

[0272] For example, in one embodiment, the processing unit 802 is used to: obtain service support information of M networks, wherein the service support information of each of the M networks is used to indicate the support status of each network for the first service at a first location, wherein the first location is the location of the terminal device; M is an integer greater than 1; select a first network from the M networks according to the service support information of the M networks; and the communication unit 803 is used to: transmit the data of the first service through the first network.

[0273] In one possible design, the communication unit 803 is specifically used to: receive service support information of the M networks, including the second network, from the core network element of the second network.

[0274] In one possible design, the communication unit 803 is specifically used to: receive service support information of M1 networks from the core network element of the second network, wherein the M1 networks include the second network, and M1 is an integer greater than or equal to 1 and less than M.

[0275] In one possible design, the communication unit 803 is specifically used to: receive service support information of M2 networks from the core network element of the third network, wherein the M networks also include the M2 networks, the M2 networks include the third network, and M2 is an integer greater than or equal to 1 and less than M.

[0276] In one possible design, the communication unit 803 is further configured to: send a first request message to a core network element in the second network, the first request message being used to request service support status of the network at the first location.

[0277] In one possible design, the first request information is carried in a registration request message.

[0278] In one possible design, the communication unit 803 is specifically used to: send the first request information to a core network element in the second network when certain conditions are met; wherein, the conditions include at least one of the following: the terminal device has a service continuity map, the service continuity map is unavailable, or the service corresponding to the service continuity map does not include the service that the terminal device wishes to use; the service continuity map is obtained based on service support information of at least one network; the terminal device does not have the service continuity map; the service that the terminal device wishes to use is unavailable or the signal is below a threshold in the currently registered network.

[0279] In one possible design, the communication unit 803 is further configured to: send location information to a core network element in the second network, the location information being used to indicate the first location.

[0280] In one possible design, the communication unit 803 is further configured to: send a service list to the core network element in the second network, the service list including service identifiers of N services, the first service being one of the N services, where N is an integer greater than or equal to 1.

[0281] In one possible design, the processing unit 802 is specifically configured to: determine the scores of the M networks based on the weight of the first service and the service support information of the M networks; and select the first network from the M networks based on the scores of the M networks, wherein the score of the first network is greater than or equal to a threshold.

[0282] In one possible design, the weight of the first service is obtained based on at least one of the following: the frequency of use of the first service; the duration of each use of the first service; the priority of the resources required by the first service; and whether the first service is currently being used by the user of the terminal device.

[0283] In one possible design, the different PLMNs of the M networks are different, and / or the different communication standards of the M networks are different.

[0284] (2) The device 800 can be a data management network element of the home network in the above embodiments. The processing unit 802 can support the device 800 in performing the actions of the data management network element in the above method embodiments. Alternatively, the processing unit 802 mainly performs the internal actions of the data management network element in the method embodiments, and the communication unit 803 can support communication between the device 800 and other devices.

[0285] For example, in one embodiment, the communication unit 803 is used to: send a second request message to a core network element in a third network, the second request message being used to request service support status of the network at a first location, the first location being the location of the terminal device; and receive service support information from M2 networks from the core network element in the third network, the service support information of each of the M2 networks being used to indicate the support status of each network for a first service at the first location, where M2 is an integer greater than or equal to 1.

[0286] In one possible design, the M2 networks belong to the first PLMN.

[0287] In one possible design, the communication unit 803 is further configured to: send location information to a core network element in the third network, the location information being used to indicate the first location.

[0288] In one possible design, the communication unit 803 is further configured to: send a service list to the core network element in the third network, the service list including service identifiers of N services, the first service being one of the N services, where N is an integer greater than or equal to 1.

[0289] In one possible design, the communication unit 803 is further configured to: send the service information subscribed by the terminal device in the M2 networks to the core network element in the third network, wherein the service information subscribed by the terminal device in each of the M2 networks includes the identifier of the service subscribed by the terminal device in each of the networks.

[0290] In one possible design, the communication unit 803 is further configured to: receive a third request message from a core network element of the second network, the third request message being used to request service support status of the network at the first location; or, receive a query message from a core network element of the second network, the query message requesting a query of the subscription information of the terminal device.

[0291] In one possible design, the communication unit 803 is also used to: send service support information of the M2 networks to the terminal device through the core network element of the second network.

[0292] (3) The device 800 can be a core network element of the second network in the above embodiments. The processing unit 802 can support the device 800 in performing the actions of the core network element of the second network in the above method embodiments. Alternatively, the processing unit 802 mainly performs the internal actions of the core network element of the second network in the method embodiments, and the communication unit 803 can support communication between the device 800 and other devices.

[0293] For example, in one embodiment, the processing unit 802 is used to: obtain service support information of M1 networks, the M1 networks including the second network; the communication unit 803 is used to: send the service support information of the M1 networks to the terminal device, the service support information of each of the M1 networks is used to indicate the support status of each network for the first service at a first location, the first location being the location of the terminal device, and M1 being an integer greater than or equal to 1.

[0294] In one possible design, the communication unit 803 is further configured to: receive first request information from the terminal device, the first request information being used to request network service support status at the first location.

[0295] In one possible design, the communication unit 803 is further configured to: receive location information from the terminal device, the location information being used to indicate the first location.

[0296] In one possible design, the communication unit 803 is further configured to: receive a service list from the terminal device, the service list including service identifiers of N services, wherein the first service is one of the N services, and N is an integer greater than or equal to 1.

[0297] In one possible design, the M1 networks include a fourth network; the communication unit 803 is further configured to: send a fourth request message to a core network element in the fourth network, the fourth request message being used to request service support status of the network at the first location; the at least one network further includes the fourth network; and receive service support information from the fourth network.

[0298] It should be understood that the division of units in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, all units in the device can be implemented entirely through software calls from processing elements; all units can be implemented entirely in hardware; or some units can be implemented through software calls from processing elements, and some units can be implemented in hardware. For example, each unit can be a separate processing element, or it can be integrated into a chip within the device. Alternatively, it can be stored as a program in memory, called and executed by a processing element of the device. Moreover, these units can be fully or partially integrated together, or implemented independently. The processing element mentioned here can also be called a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, the operations of the above methods or the various units mentioned above can be implemented through integrated logic circuits in the processor element or through software calls from processing elements.

[0299] In one example, a unit in any of the above devices can be one or more integrated circuits configured to implement the methods described above, such as: one or more application-specific integrated circuits (ASICs), or one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these forms of integrated circuits. As another example, when a unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (CPU), or other processor capable of calling programs. Furthermore, these units can be integrated together and implemented as a System-on-a-Chip (SoC).

[0300] The receiving unit described above is an interface circuit of the device, used to receive signals from other devices. For example, when the device is implemented as a chip, the receiving unit is an interface circuit for the chip to receive signals from other chips or devices. The transmitting unit described above is an interface circuit of the device, used to transmit signals to other devices. For example, when the device is implemented as a chip, the transmitting unit is an interface circuit for the chip to transmit signals to other chips or devices.

[0301] Based on the above embodiments, this application also provides a communication device. Referring to FIG9, the communication device 900 may include a processor 901. Optionally, the communication device 900 may further include a memory 902. The memory 902 may be disposed inside the communication device 900 or outside the communication device 900.

[0302] Specifically, the processor 901 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor 901 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0303] The processor 901 and the memory 902 are interconnected. Optionally, the processor 901 and the memory 902 are interconnected via a bus 903; the bus 903 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is used in Figure 9, but this does not mean that there is only one bus or one type of bus.

[0304] In one optional implementation, the memory 902 is used to store programs, etc. Specifically, the program may include program code, which includes computer operation instructions. The memory 902 may include RAM, and may also include non-volatile memory, such as one or more disk storage devices. The processor 901 executes the application program stored in the memory 902 to achieve the above-mentioned functions, thereby realizing the functions of the communication device 900.

[0305] For example, the communication device 900 may be a terminal device in the above embodiments; or it may be a network device in the above embodiments.

[0306] In one embodiment, when the communication device 900 implements the functions of the first terminal device in the above method embodiment, the transceiver can perform the transmit and receive operations executed by the first terminal device in the above method embodiment; the processor 901 can perform other operations besides the transmit and receive operations executed by the first terminal device in the above method embodiment. Specific details can be found in the relevant descriptions in the above embodiments, and will not be elaborated upon here.

[0307] In another embodiment, when the communication device 900 implements the functions of the application server in the above method embodiments, the transceiver can perform the send and receive operations executed by the application server in the above method embodiments; the processor 901 can perform other operations besides the send and receive operations executed by the application server in the above method embodiments. Specific details can be found in the relevant descriptions in the above embodiments, and will not be elaborated upon here.

[0308] This application also provides a communication system, which includes the first terminal device and application server mentioned in the above embodiments, and optionally, also includes the second terminal device mentioned in the above embodiments.

[0309] The terms "system" and "network" in this application embodiment are used interchangeably. "At least one" refers to one or more, and "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B, and C" includes A, B, C, AB, AC, BC, or ABC. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in this application embodiment are used to distinguish multiple objects and are not used to limit the order, sequence, priority, or importance of multiple objects.

[0310] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0311] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0312] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0313] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

Claims

1. A communication method, characterized in that, The method is applied to a terminal device or a chip in the terminal device, and the method includes: Obtain service support information for M networks, wherein the service support information of each of the M networks is used to indicate the support status of each network for the first service at a first location, where the first location is the location of the terminal device; M is an integer greater than 1. Based on the service support information of the M networks, select a first network from the M networks; The data for the first service is transmitted through the first network.

2. The method according to claim 1, characterized in that, The acquisition of service support information for M networks includes: The service support information of the M networks, including the second network, is received from the core network element of the second network.

3. The method according to claim 1, characterized in that, The acquisition of service support information for M networks includes: Receive service support information from M1 networks from the core network element of the second network. The M1 networks include the second network. M1 is an integer greater than or equal to 1 and less than M.

4. The method according to claim 3, characterized in that, The acquisition of service support information for M networks also includes: The network receives service support information from M2 networks from the core network element of the third network. The M networks include the M2 networks, and the M2 networks include the third network. M2 is an integer greater than or equal to 1 and less than M.

5. The method according to any one of claims 2 to 4, characterized in that, The method further includes: Send a first request message to the core network element in the second network. The first request message is used to request the network's service support status at the first location.

6. The method according to claim 5, characterized in that, The first request information is carried in the registration request message.

7. The method according to claim 5 or 6, characterized in that, Send a first request message to the core network element in the second network, including: If the conditions are met, the first request information is sent to the core network element in the second network; The conditions for meeting the requirements include at least one of the following: The terminal device has a service continuity map, but the service continuity map is unavailable, or the service corresponding to the service continuity map does not include the service that the terminal device wants to use; the service continuity map is obtained based on service support information of at least one network; The terminal device does not have the aforementioned service continuity map; The service that the terminal device wishes to use is unavailable on the currently registered network or the signal is below a threshold.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: Location information is sent to the core network element in the second network, and the location information is used to indicate the first location.

9. The method according to any one of claims 1 to 8, characterized in that, The method further includes: Send a service list to the core network element in the second network. The service list includes service identifiers for N types of services, where the first service is one of the N types of services and N is an integer greater than or equal to 1.

10. The method according to claim 9, characterized in that, The service list is compiled by the terminal device based on the historical service usage habits of the users of the terminal device; or, The service list is obtained by the terminal device based on the service priority specified by the user; or... The service list is obtained by the terminal device based on the scarcity of resources required for the services and / or the importance of the services.

11. The method according to any one of claims 1 to 10, characterized in that, Based on the service support information of the M networks, a first network is selected from the M networks, including: The scores of the M networks are determined based on the weight of the first service and the service support information of the M networks. Based on the scores of the M networks, the first network is selected from the M networks, wherein the score of the first network is greater than or equal to a threshold.

12. The method according to claim 11, characterized in that, The weight of the first type of business is obtained based on at least one of the following: The frequency of use of the first type of service; The duration of each use of the first type of service; The priority of the resources required for the first type of service; Is the first type of service currently being used by the user of the terminal device? 13. The method according to any one of claims 1 to 12, characterized in that, The M networks belong to different PLMNs, and / or the M networks belong to different communication standards.

14. A communication method, characterized in that, The method is applied to a data management network element in the home network of a terminal device or a chip in the data management network element, and the method includes: Send a second request message to the core network element of the third network. The second request message is used to request the network's service support status at a first location, where the first location is the location of the terminal device. The core network element of the third network receives service support information from M2 networks. The service support information of each of the M2 networks is used to indicate the support status of each network for the first service at the first position. M2 is an integer greater than or equal to 1.

15. The method according to claim 14, characterized in that, The method further includes: Location information is sent to the core network element of the third network, and the location information is used to indicate the first location.

16. The method according to claim 14 or 15, characterized in that, The method further includes: Send a service list to the core network element of the third network. The service list includes service identifiers of N services, where the first service is one of the N services and N is an integer greater than or equal to 1.

17. The method according to any one of claims 14 to 16, characterized in that, The method further includes: The terminal device sends the service information it has subscribed to in the M2 networks to the core network element of the third network. The service information it has subscribed to in each of the M2 networks includes the identifier of the service it has subscribed to in each network.

18. The method according to any one of claims 14 to 17, characterized in that, The method further includes: Receive a third request message from a core network element of the second network, the third request message being used to request service support status of the network at the first location; or... The system receives a query message from the core network element of the second network, the query message requesting a query of the subscription information of the terminal device.

19. The method according to claim 18, characterized in that, The method further includes: The core network element of the second network sends the service support information of the M2 networks to the terminal device.

20. A communication method, characterized in that, The method is applied to a core network element of a second network or a chip in a core network element of the second network, and the method includes: Obtain service support information for M1 networks, wherein the M1 networks include the second network; The service support information of the M1 networks is sent to the terminal device. The service support information of each of the M1 networks is used to indicate the support status of each network for the first service at a first location, where the first location is the location of the terminal device and M1 is an integer greater than or equal to 1.

21. The method according to claim 20, characterized in that, The method further includes: The system receives a first request from the terminal device, the first request being used to request network service support status at the first location.

22. The method according to claim 20 or 21, characterized in that, The method further includes: The location information received from the terminal device is used to indicate the first location.

23. The method according to any one of claims 20 to 22, characterized in that, The method further includes: The terminal device receives a service list, which includes service identifiers for N services, where the first service is one of the N services and N is an integer greater than or equal to 1.

24. The method according to any one of claims 20 to 23, characterized in that, The M1 networks include a fourth network; Obtain service support information for M1 networks, including: A fourth request message is sent to a core network element in the fourth network, the fourth request message being used to request service support status of the network at the first location; the at least one network further includes the fourth network. Receive service support information from the fourth network.

25. A communication device, characterized in that, Includes units for performing the method as described in any one of claims 1 to 24.

26. A communication device, characterized in that, The device includes a processor coupled to a memory in which a computer program is stored; the processor is configured to invoke part or all of the computer program in the memory such that the method as described in any one of claims 1 to 24 is executed.

27. A communication system, characterized in that, The communication system includes a first communication device, a second communication device, and a third communication device, wherein the first communication device is used to perform the method as described in any one of claims 1 to 13, the second communication device is used to perform the method as described in any one of claims 14 to 19, and the third communication device is used to perform the method as described in any one of claims 20 to 24.

28. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when some or all of the computer program is executed by a computer, causes the method described in any one of claims 1 to 24 to be performed.

29. A computer program product, characterized in that, When the computer reads and executes the computer program product, the method described in any one of claims 1 to 24 is performed.

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