CN113574936B - Wireless communication method, terminal equipment and network equipment - Google Patents

Abstract

A method of wireless communication, a terminal device and a network device, the method comprising: the terminal equipment determines a preferred core network type according to first information or second information, wherein the first information is information configured by the network equipment and used for core network selection, and the second information is history information selected by the core network of the terminal equipment; the terminal device preferably initiates a registration procedure to the core network of the preferred core network type.

Description

Wireless communication method, terminal device and network device

Technical Field

The embodiments of the present application relate to the field of communications, and specifically to a wireless communication method, terminal equipment, and network equipment.

Background technique

In the New Radio (NR) system, both Standalone (SA) networking and Non-standalone (NSA) networking are supported. For the SA network, the core network is the 5G Core (5G Core, 5GC), and for the NSA network, the core network is the Evolved Packet Core (EPC).

When the area where the terminal device is located includes both SA and NSA networks, that is, the network device is covered by 5GC and EPC, it is an urgent problem that the terminal device chooses which core network to access for registration to increase the probability of successful registration.

Summary of the invention

The embodiments of the present application provide a wireless communication method, terminal device and network device, which are beneficial to improving the probability of successful core network registration.

In a first aspect, a method for wireless communication is provided, comprising: a terminal device determines a preferred core network type based on first information or second information, wherein the first information is information configured by a network device for core network selection, and the second information is historical information of core network selection of the terminal device; the terminal device preferentially chooses to initiate a registration process with a core network of the preferred core network type.

In a second aspect, a method for wireless communication is provided, comprising: a network device sends first information to a terminal device, the first information is used by the terminal device to determine a preferred core network type, and the first information is information configured by the network device for core network selection.

In a third aspect, a terminal device is provided, which is used to execute the method in the first aspect or any possible implementation of the first aspect. Specifically, the terminal device includes a unit for executing the method in the first aspect or any possible implementation of the first aspect.

In a fourth aspect, a network device is provided, which is used to execute the method in the second aspect or any possible implementation of the second aspect. Specifically, the network device includes a unit for executing the method in the second aspect or any possible implementation of the second aspect.

In a fifth aspect, a terminal device is provided, the terminal device comprising: a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method in the first aspect or its implementation manners.

In a sixth aspect, a network device is provided, the network device comprising: a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method in the second aspect or its implementation manner.

In a seventh aspect, a chip is provided for implementing the method in any one of the first to second aspects or in each of their implementations.

Specifically, the chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes a method as described in any one of the first to second aspects or in each of their implementations.

In an eighth aspect, a computer-readable storage medium is provided for storing a computer program, wherein the computer program enables a computer to execute the method of any one of the first to second aspects or any of their implementations.

In a ninth aspect, a computer program product is provided, comprising computer program instructions, which enable a computer to execute the method in any one of the first to second aspects or their respective implementations.

In a tenth aspect, a computer program is provided, which, when executed on a computer, enables the computer to execute the method in any one of the first to second aspects or in each of their implementations.

Based on the above technical solution, the terminal device can register with the core network according to the network device configuration or the historical information selected by the core network, which is helpful to reduce the probability of core network registration failure and improve the user experience.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of an application scenario provided by an embodiment of the present application.

FIG. 2 is a schematic diagram of a connection method of SA and NAS networking.

FIG3 is a schematic flow chart of a terminal device registering with a core network.

FIG4 is a schematic diagram of a wireless communication method provided in an embodiment of the present application.

FIG5 is a schematic diagram of another wireless communication method provided in an embodiment of the present application.

FIG6 is a schematic block diagram of a terminal device provided in an embodiment of the present application.

FIG. 7 is a schematic block diagram of a network device provided in an embodiment of the present application.

FIG8 is a schematic block diagram of a communication device provided by another embodiment of the present application.

FIG. 9 is a schematic block diagram of a chip provided in an embodiment of the present application.

FIG10 is a schematic block diagram of a communication system according to an embodiment of the present application.

Detailed ways

The following will describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system or 5G system, etc.

Exemplarily, a communication system 100 used in an embodiment of the present application is shown in FIG1. The communication system 100 may include an access network device 110, and the access network device 110 may be a device that communicates with a terminal device 120 (or referred to as a communication terminal or terminal). The access network device 110 may provide communication coverage for a specific geographical area, and may communicate with a terminal device located in the coverage area. Optionally, the access network device 110 may be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, or a base station (NodeB, NB) in a WCDMA system, or an evolved base station (Evolutional Node B, eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (Cloud Radio Access Network, CRAN), or the network device may be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network side device in a 5G network, or a network device in a future evolved public land mobile network (Public Land Mobile Network, PLMN), etc.

The communication system 100 also includes at least one terminal device 120 located within the coverage of the access network device 110. As used herein, "terminal device" includes but is not limited to connection via a wired line, such as via a Public Switched Telephone Networks (PSTN), a Digital Subscriber Line (DSL), a digital cable, a direct cable connection; and/or another data connection/network; and/or via a wireless interface, such as, for a cellular network, a wireless local area network (WLAN), a digital television network such as a DVB-H network, a satellite network, an AM-FM broadcast transmitter; and/or a device of another terminal device configured to receive/send communication signals; and/or an Internet of Things (IoT) device. A terminal device configured to communicate via a wireless interface may be referred to as a "wireless communication terminal", "wireless terminal" or "mobile terminal". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; Personal Communications System (PCS) terminals that may combine cellular radiotelephones with data processing, fax, and data communications capabilities; PDAs that may include radiotelephones, pagers, Internet/intranet access, web browsers, notepads, calendars, and/or Global Positioning System (GPS) receivers; and conventional laptop and/or palmtop receivers or other electronic devices that include radiotelephone transceivers. A terminal device may refer to an access terminal, user equipment (UE), a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The access terminal can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved PLMN, etc.

Optionally, terminal devices 120 may perform device-to-device (D2D) communication with each other.

Optionally, the 5G system or 5G network may also be referred to as a New Radio (NR) system or NR network.

Optionally, in some scenarios, the communication system 100 may also include an access network device 130, and the access network device 130 may also provide network services for the terminal device 120. For example, the access network device 120 and the access network device 130 may provide services for the terminal device through dual connection (DC). As an example, the access network device 120 may be a primary access network device, and the access network device 130 may be an auxiliary access network device. Optionally, the communication system may also include more auxiliary access network devices. The terminal device may establish connections with the primary access network device and the auxiliary access network device at the same time. The connection established between the terminal device and the primary access network device is the primary connection, and the connection established between the terminal device and the auxiliary access network device is the auxiliary connection. The control signaling of the terminal device may be transmitted through the primary connection, and the data of the terminal device may be transmitted through the primary connection and the auxiliary connection at the same time, or may be transmitted only through the auxiliary connection.

As an example, the access network device 120 may be an access network device of an LTE network, for example, an evolved UMTS terrestrial radio access network (Evolution-UMTS Terrestrial Radio Access Network, E-UTRAN), and the access network device 130 may be an access network device of an NR network. As another example, the access network device 120 may be an access network device of an NR network, and the access network device 130 may be an access network device of an LTE network. Alternatively, both the access network device 120 and the access network device 130 may be access network devices of an NR network, or may be access network devices of an LTE network, etc.

In other embodiments, the access network device 120 and the access network device 130 may also be access network devices in a 2G or 3G network. For example, the access network device 120 may be an access network device of a GSM network, an access network device of a CDMA network, etc., and the access network device 130 may also be an access network device of a GSM network, an access network device of a CDMA network, etc.

In some embodiments, the communication system may further include a core network device 140, which may be, for example, a core network of an LTE network, namely an Evolved Packet Core (EPC), for example, a Mobility Management Entity (MME), or for example, a Serving Gateway (SGW), etc.

In some embodiments, the communication system may further include a core network device 150, which may be, for example, a 5G core network (5G Core Network, 5GC), for example, an access and mobility management function (Access and Mobility Management Function, AMF), for example, an authentication server function (Authentication Server Function, AUSF), for example, a user plane function (User Plane Function, UPF), etc.

FIG1 exemplarily shows four network devices and one terminal device. Optionally, the communication system 100 may include more network devices and each network device may include another number of terminal devices within its coverage area, which is not limited in the embodiments of the present application.

In some scenarios, network deployment may include standalone (SA) networking and non-standalone (NSA) networking. FIG2 shows a schematic diagram of a connection method between SA networking and NAS networking.

For SA networking, as an example, the next generation access network (NG-RAN) is connected to the core network of the 5G network, i.e., 5GC. The NR-RAN may include, for example, E-UTRAN (i.e., the access network equipment of the LTE network) and the access network equipment of the NR network. The E-UTRAN and 5GC may communicate via N2/N3 messages, and the NR and 5GC may communicate via N2/N3 messages. The terminal device may initiate a registration process to the 5GC using the N1 Non-Access Stratum (NAS) message.

In the SA network, the terminal device using the 5GC network can be called N1 UE. The N1 UE can transmit control information or data only through the E-UTRAN, or only through the NR access network, or through both the E-UTRAN and NR access networks.

For NSA networking, as an example, E-UTRAN can be connected to EPC as the primary access network device (or anchor node), and the access network device of the NR network can be used as the auxiliary access network device to provide air interface data transmission. E-UTRAN and EPC can communicate through S1 messages, and NR and E-UTRAN can communicate through the X2 interface. The terminal device can use the EPC NAS message to initiate the registration process to the EPC.

In an NSA network, a terminal device using an EPC network may be referred to as an EPC UE. The EPC UE may transmit control plane and user plane data only through E-UTRAN, or may transmit user plane data through E-UTRAN and an NR access network.

Optionally, in the SA network and NSA network, the EPC and 5GC can also be connected to a jointly-established network element of a Home Subscriber Server (HSS) and a Unified Data Management (UDM), that is, the jointly-established network element has the functions of both HSS and UDM, and the jointly-established network element of HSS and UDM can be used to authenticate user identities and store and manage user authentication data.

For different operators, there are differences in network deployment. For example, in the early stage of 5G network deployment, different networks may support different services. For example, some services are not supported in SA networks, and terminal devices still need to perform these services on LTE networks. For example, 5G SA networks may only support enhanced mobile ultra-wideband (Enhance Mobile Broadband, eMBB) services, while other services, such as cellular Internet of Things (CIoT), vehicle to everything (V2X), and device to device (D2D) services, still need to be executed under the EPC network.

When the area where the terminal device is located includes both SA and NSA networks, that is, the network device is covered by 5GC and EPC, the terminal device can initiate a registration process with 5GC or an attachment process with EPC, but any core network selected for access may result in access failure. Figure 3 is a schematic flowchart of a scenario in which a terminal device registers with a core network.

Step 21: The UE selects a core network to register. For example, the terminal device chooses to send a registration request to the 5GC.

Correspondingly, 5GC receives the registration request and determines that the terminal device is not allowed to use 5GC.

Further in step 22, 5GC sends a registration request reject message to the UE, and the registration request reject message includes a specific cause value, for example, 5GC should not be used.

In step 23, after receiving the specific cause value, the UE initiates a registration request to another core network. For example, the terminal device can initiate a registration request to the EPC. For the EPC network, the registration request can also be called an attachment request.

In step 24, the EPC sends an attach request reply message to the UE, where the attach request reply message indicates that the UE is successfully attached to the EPC.

In other embodiments, the UE may also first choose to initiate a registration request to the EPC. If the registration fails, it may further initiate a registration request to the 5GC. If the registration is successful, the terminal device may use the 5GC for communication.

Failure of core network registration may result in multiple interactions, unnecessary signaling overhead, increase the time it takes for UE to access the network, and affect user experience.

In view of this, an embodiment of the present application provides a method for wireless communication, in which a terminal device can register with the core network based on the network device configuration or historical information selected by the core network, which is beneficial to reducing the probability of core network registration failure and improving user experience.

It should be understood that the embodiments of the present application do not limit the application scenarios of the technical solution, and can be applied to scenarios where multiple networking modes coexist, including but not limited to the networking mode shown in Figure 2, or can also be applied to other scenarios where multiple core networks coexist and core network selection is required, for example, scenarios where the core network is selected to establish a session connection, etc.

It should be understood that the device with communication function in the network/system in the embodiment of the present application can be referred to as a communication device. Taking the communication system 100 shown in FIG1 as an example, the communication device may include an access network device, a terminal device and a core network device with communication function, and the access network device, the terminal device and the core network device may be the specific devices described above, which will not be repeated here.

It should be understood that the terms "system" and "network" are often used interchangeably in this article. The term "and/or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

FIG4 is a schematic flow chart of a wireless communication method provided in an embodiment of the present application. The method 200 may be executed by a terminal device in the communication system shown in FIG1 . As shown in FIG4 , the method 200 may include at least part of the following contents:

S210, the terminal device determines a preferred core network type according to first information or second information, where the first information is information configured by the network device for core network selection, and the second information is historical information of the core network selection of the terminal device;

S220, the terminal device preferentially chooses to initiate a registration process with the core network of the preferred core network type.

It should be understood that the embodiments of the present application can be applicable to core network selection during core network registration, or can also be applied to other scenarios that require core network selection, such as session establishment scenarios. It should be understood that session establishment in a 5G network can also be referred to as protocol data unit (PDU) connection establishment, or PDU session establishment, etc.

Therefore, in an embodiment of the present application, after determining the preferred core network type, the terminal device may preferably perform subsequent NAS behaviors with the core network of the preferred core network type. For example, a registration process may be initiated with the core network of the preferred core network type, or a session establishment process may be initiated with the core network of the preferred core network type, etc. The following is explained using the core network registration scenario as an example, but the present application is not limited to this.

It should be understood that in the embodiments of the present application, there may be multiple core network types, and the multiple core network types may include core networks of different networks, such as at least two of the following: a core network in an LTE network (ie, EPC), a core network in an NR network (ie, 5GC), a core network in a 2G or 3G network, a core network in an SA network (ie, EPC), and a core network in an NSA network (5GC), which is not limited to the embodiments of the present application.

It should be noted that in the embodiment of the present application, the EPC can be the core network in a single LTE network or the core network in NSA. The EPC can be connected only to an LTE base station, or an LTE base station and an NR base station can be connected to the EPC in a dual connection manner.

Optionally, in the embodiment of the present application, giving priority to initiating a registration process with a core network of the preferred core network type may refer to giving priority to initiating a registration process with a core network of the preferred core network type, and in the event that registration with the core network of the preferred core network type fails, a registration process may be initiated with a core network of another core network type. Alternatively, giving priority to initiating a registration process with a core network of the preferred core network type may also refer to initiating a registration process only with a core network of the preferred core network type.

It should be noted that in an embodiment of the present application, the terminal device can also determine the NAS message type that is preferably used for core network registration based on the first information or the second information. Furthermore, the NAS message type can be preferably used to initiate the core network registration process. In the event of registration failure, other NAS message types can be used to initiate the core network registration process. The method for determining the NAS message type can refer to the specific implementation of determining the preferred core network type below.

The following describes the method for determining the preferred core network type in conjunction with a specific embodiment.

Embodiment 1: A terminal device may determine a preferred core network type among multiple core networks according to first information configured by a network device.

Optionally, in some embodiments, the first information is used to indicate at least one of the following:

1. Priority sorting of core network types, or in other words, priority sorting of core network types, that is, which core network type is used first, or it can also be priority information of core network types.

Taking the core network types including 5GC and EPC as an example, the priority sorting of the core network type can be arranged in descending order, for example, it can be 5GC, EPC, indicating that the priority of 5GC is higher than that of EPC. For another example, it can be EPC, 5GC, indicating that the priority of EPC is higher than that of 5GC. Or it can also be arranged in descending order, which will not be repeated here.

As an example, the priority information of the core network type may be that the priority of 5GC is the first priority and the priority of EPC is the second priority, wherein the first priority may be higher than the second priority, or the first priority may be lower than the second priority;

2. The priority ranking of non-access layer NAS message types, or the priority ranking of NAS message types, that is, which NAS message type is used first, or it can also be the priority information of the NAS message type.

Taking the NAS message type including N1 NAS message and EPC NAS message as an example, the priority sorting of the NAS message type can be arranged in descending order, for example, it can be N1 NAS message and EPC NAS message, indicating that the priority of N1 NAS message is higher than that of EPC NAS message, and for another example, it can be EPC NAS message and N1 NAS message, indicating that the priority of EPC NAS message is higher than that of N1 NAS message; or it can be arranged in descending order, which will not be repeated here.

As an example, the priority information of the NAS message type may be that the priority of the N1 NAS message is the first priority, and the priority of the EPC NAS message is the second priority, wherein the first priority may be higher than the second priority, or the first priority may be lower than the second priority.

3. Priority sorting for accessing SA networks and NSA networks, or in other words, priority sorting for using different networking modes, that is, which networking mode's core network is used first, or it can also be priority information of the networking mode.

The priority of accessing the SA network and the NSA network can be arranged in order from high to low. For example, it can be SA network and NSA network, indicating that the priority of accessing the SA network is higher than that of the NSA network. For another example, it can be NSA network and SA network, indicating that the priority of accessing the NSA network is higher than that of the SA network. Or it can also be arranged in order from low to high, which will not be repeated here.

As an example, the priority information of the networking mode may be that the priority of the SA network is the first priority, and the priority of the NSA network is the second priority, wherein the first priority may be higher than the second priority, or the first priority may be lower than the second priority.

4. Specific core network type, for example, 5GC or EPC;

Optionally, the specific core network type may be a core network type that allows the terminal device to register, or a core network type that the terminal device is expected to access, or a core network type that the terminal device can access, or a core network type that the terminal device can only access or must access.

5. Specific NAS message types, for example, N1 NAS or EPC NAS;

Optionally, the specific NAS message type may be a NAS message type that the terminal device is allowed to use, a NAS message type that the terminal device is expected to use, or a NAS message type that the terminal device can use, or a NAS message type that the terminal device can only use or must use, etc.

6. Specific networking mode, such as SA or NSA.

Optionally, the specific networking mode may be a networking mode that the terminal device is allowed to use, a networking mode that the terminal device is expected to use, a networking mode that the terminal device can use, or a networking mode that the terminal device can only use or must use, etc.

It should be understood that in the embodiment of the present application, the NAS message type may have a corresponding relationship with the core network type. For example, the core network type corresponding to the N1 NAS message may be 5GC, and the core network type corresponding to the EPC NAS may be EPC.

Optionally, in some embodiments, the network device determines the first information based on information such as services supported by the core network, contract information of the terminal device, service information supported by the terminal device, current network congestion, and the number of users supported by the core network.

A specific description is given by taking determining a preferred core network type between the first core network type and the second core network type as an example.

For example, if the terminal device is not subscribed to the first core network type, and is subscribed to the second core network type, the first information may indicate that the priority of the second core network type is higher than that of the first core network type, or that the priority of the NAS message of the second core network type is higher than that of the NAS message of the first core network type.

For another example, if the terminal device supports the first service, the first core network type supports the first service, and the second core network type does not support the first service, the first information may indicate that the priority of the first core network type is higher than that of the second core network type, or that the priority of the NAS message type corresponding to the first core network type is higher than that of the NAS message type corresponding to the second core network type.

For another example, if the first core network type supports a larger number of users and the second core network type supports a smaller number of users, that is, the first core network type supports access of more terminal devices, the first information may indicate that the priority of the first core network type is higher than that of the second core network type, or that the priority of the NAS message type corresponding to the first core network type is higher than that of the NAS message type corresponding to the second core network type.

As an embodiment, if the first information indicates a usage priority ranking of core network types, the terminal device may determine the core network type with the highest priority as the preferred core network type according to the usage priority ranking of the core network types.

For example, if the first information indicates that 5GC has a higher priority than EPC, the terminal device can determine that 5GC is the target core network type.

As another embodiment, if the first information indicates a usage priority ranking of NAS message types, the terminal device may determine the core network type corresponding to the highest priority NAS message type as the preferred core network type according to the usage priority ranking of the NAS message types.

For example, if the first information indicates that the priority of the N1 NAS message is higher than that of the EPC NAS message, the terminal device can determine that the core network type corresponding to the N1 NAS message is the preferred core network type. Or if the first information indicates that the priority of the N1NAS message is higher than that of the EPC NAS message, the terminal device can directly use the N1 NAS message to initiate a registration process to the 5GC.

As another embodiment, if the first information indicates the priority ranking of accessing the SA network and the NAS network, the terminal device may determine the core network type corresponding to the networking mode with the highest priority as the preferred core network type.

For example, if the priority of accessing the SA network is higher than the priority of accessing the NSA network, the terminal device determines the core network type of the SA network as the preferred core network type; for another example, if the priority of accessing the SA network is lower than the priority of accessing the NSA network, the terminal device determines the core network type of the NSA network as the preferred core network type.

As another embodiment, if the first information indicates the core network type that allows the terminal device to register, the terminal device may determine the core network type that allows the terminal device to register as the preferred core network type.

As another embodiment, if the first information indicates the NAS message type allowed to be used by the terminal device, the terminal device may determine the core network type corresponding to the NAS message type allowed to be used by the terminal device as the preferred core network type. Alternatively, the terminal device may directly use the NAS message type to initiate a registration process.

As another embodiment, if the first information indicates a networking mode that the terminal device is allowed to access, the terminal device may determine the core network type corresponding to the networking mode that the terminal device is allowed to access as the preferred core network type.

For example, if the terminal device is allowed to access the SA network, the terminal device may determine the core network type of the SA network as the preferred core network type; for another example, if the terminal device is allowed to access the NSA network, the terminal device may determine the core network type of the NSA network as the preferred core network type.

The following describes the configuration method of the first information in conjunction with a specific embodiment.

As an embodiment, the first information may be sent by a core network device, for example, the core network device may send the first information to the terminal device via a downlink NAS message. Specifically, the NAS of the terminal device may receive a NAS message sent by the NAS of the core network device, and the NAS message may include the first information.

Optionally, the core network device is a core network device with which the terminal device is registered. As an example, the core network device may be a core network device with which the terminal device was last registered.

For example, the core network device may send the first information to the terminal device during the registration process of the terminal device, and the registration process may be an initial registration process, or may be a registration process caused by a location update of the terminal device. For example, the core network device may carry the first information via a registration request reply message or a location update request reply message.

For another example, the core network device may send a first message to the terminal device after the terminal device is successfully registered. In this case, the first message may be transmitted via any downlink NAS message.

As another embodiment, the first information may be sent by an access network device, for example, the access network device may send the first information to the terminal device via an RRC message or a broadcast message or other downlink message or downlink channel. Specifically, an access stratum (AS) of the terminal device may receive the first information sent by the AS of the access network device.

Optionally, the access network device is the access network device where the terminal device resides. As an example, the access network device may be the access network device where the terminal device resided last time.

For example, the access network device can send the first information to the terminal device during the radio resource control (Radio Resource Control, RRC) connection establishment process. For example, the access network device can carry the first information through an RRC connection establishment (ConnectionSetup) message. Optionally, the RRC connection establishment message can also be called an RRC establishment (Setup) message.

For another example, the access network device may send a first message to the terminal device after the RRC connection is successfully established. In this case, the first message may be transmitted via any downlink RRC message.

Furthermore, after the AS of the terminal device receives the first information sent by the access network device, the AS of the terminal device may also send the first information to the NAS of the terminal device. Further, the NAS of the terminal device may determine the preferred core network type based on the first information. For the specific determination method, please refer to the relevant description in the previous text.

Embodiment 2: The historical information of core network selection stored by the terminal device, ie, the second information, determines a preferred core network type among multiple core network types.

In some embodiments, the second information is used to indicate at least one of the following:

The core network type of successful registration or the NAS message type corresponding to the core network type;

The number of successful registrations to the core network type where the registration is successful;

The core network type for which registration failed or the NAS message type corresponding to the core network type;

The core network type for which the initial registration failed but the second registration succeeded;

The number of registration failures to the core network type for which registration failed;

The reason for the failure to register with the core network type for which the registration failed;

The network type corresponding to the core network type that is successfully registered, such as SA network or NAS network;

The network type corresponding to the core network type for which registration failed.

Optionally, in some embodiments, if the terminal device first initiates a registration process with a core network of a first core network type, if the registration fails, then initiates a registration process with a core network of a second core network type, if the registration is successful, then the core network type where the initial registration failed but the second registration succeeded may be the second core network type. For example, for the example shown in Figure 3, if the terminal device fails to register with 5GC and then successfully registers with EPC, then the second information may include information of the EPC, or if the terminal device first fails to register with EPC and then successfully registers with 5GC, then the second information may include information of the 5GC.

It should be noted that here, the core network type that successfully registers may include the core network type that successfully registers in the SA network and the NAS network, that is, the core network type that successfully registers in the scenario where multiple networking modes coexist, or it may be the core network type that successfully registers when multiple networks coexist (different networks are independent of each other). Similarly, the core network type that fails to register may also include the core network type that fails to register in the scenario where multiple networking modes coexist.

Specifically, after registering with the core network, the terminal device can save the registration result and obtain the second information. The second information may include the type information of the registered core network and the registration result of the core network type, that is, whether the registration is successful or failed. Optionally, it may also include the number of successful registrations, or the number of registration failures, and the reason for the registration failure, for example, the reason may be that the UE cannot use the core network type.

Optionally, as an embodiment, if the second information indicates that the core network type for which registration is successful is the first core network type, the terminal device determines the first core network type as the preferred core network type.

Optionally, as another embodiment, if the number of successful registrations to the first core network type indicated by the second information is greater than or equal to a first threshold, the terminal device determines the first core network type as the preferred core network type.

Optionally, as another embodiment, the terminal device may also determine the core network type for which the initial registration failed but the re-registration succeeded as the preferred core network type.

Furthermore, in some embodiments, the terminal device may also update the second information according to the registration result with the core network of the preferred core network type, that is, whether the registration is successful or failed.

In an embodiment of the present application, if the preferred core network type is Evolved Packet Core (EPC), the NAS of the terminal device may preferably use an EPC NAS message to initiate a registration request to the EPC; or

If the preferred core network type is 5GC, the NAS of the terminal device preferably uses an N1 NAS message to send a registration request to the 5GC.

In some embodiments, the terminal device uses an EPC NAS message to initiate a registration request to the EPC, which can trigger the terminal device to establish a connection only with the LTE base station. In other embodiments, the terminal device uses an EPC NAS message to initiate a registration request to the EPC, which can trigger the establishment of a dual connection between the terminal device and the LTE base station and the NR base station.

It should be understood that the above-mentioned Embodiment 1 and Embodiment 2 can be implemented separately or in combination with the embodiments. For example, when the first information indicates that the priority of EPC is higher than 5GC, but the second information indicates that the number of 5GC registration failures is high, the terminal device can determine that the preferred core network type is EPC, and further initiate a registration process to EPC.

Therefore, according to the wireless communication method of the embodiment of the present application, the terminal device can register with the core network based on the network device configuration or the historical information selected by the core network, which is beneficial to reduce the probability of core network registration failure and improve user experience.

In the above text, in conjunction with FIG. 4 , a method for wireless communication according to an embodiment of the present application is described in detail from the perspective of a terminal device. In the following text, in conjunction with FIG. 5 , a method for wireless communication according to another embodiment of the present application is described in detail from the perspective of a network device. It should be understood that the description on the network device side corresponds to the description on the terminal device side. Similar descriptions can be found above. To avoid repetition, they will not be repeated here.

FIG5 is a schematic flow chart of a wireless communication method 300 according to another embodiment of the present application. The method 300 may be executed by a network device in the communication system shown in FIG1 . As shown in FIG5 , the method 300 includes the following contents:

S310, the network device sends first information to the terminal device, where the first information is used by the terminal device to determine a preferred core network type, and the first information is information configured by the network device for core network selection.

Optionally, in some embodiments, the first information is used to indicate at least one of the following:

Use priority ranking of core network types;

Usage priority of non-access stratum NAS message types;

Prioritization of access to independent SA networks and non-independent NSA networks;

The type of core network that allows the terminal device to register;

NAS message types allowed to be used by the terminal device;

Allow access to SA network or NSA network.

Optionally, in some embodiments, the network device is a core network device, and the network device sends the first information to the terminal device, including:

The core network device sends a NAS message to the terminal device, and the NAS message includes the first information.

Optionally, in some embodiments, the core network device is a core network device registered by the terminal device.

Optionally, in some embodiments, the NAS message is a registration request reply message or a location update request reply message.

Optionally, in some embodiments, the network device is an access network device, and the network device sends the first information to the terminal device, including:

The access network device sends the first information to the terminal device.

Optionally, in some embodiments, the access network device is an access network device where the terminal device resides.

Optionally, in some embodiments, the first information is included in a radio resource control RRC message or a broadcast message.

The above text, in combination with Figures 4 to 5, describes in detail the method embodiment of the present application. The following text, in combination with Figures 6 to 10, describes in detail the device embodiment of the present application. It should be understood that the device embodiment and the method embodiment correspond to each other, and similar descriptions can refer to the method embodiment.

Fig. 6 shows a schematic block diagram of a terminal device 400 according to an embodiment of the present application. As shown in Fig. 6, the terminal device 400 includes:

The processing module 410 is used to determine the preferred core network type according to the first information or the second information, wherein the first information is the information configured by the network device for core network selection, and the second information is the historical information of the core network selection of the terminal device;

The communication module 420 is used to preferentially initiate a registration process to the core network of the preferred core network type.

Optionally, in some embodiments, the first information is used to indicate at least one of the following:

Use priority ranking of core network types;

Usage priority of non-access stratum NAS message types;

Prioritization of access to independent SA networks and non-independent NSA networks;

The type of core network that allows the terminal device to register;

NAS message types allowed to be used by the terminal device;

Allow access to SA network or NSA network.

Optionally, in some embodiments, the processing module 410 is specifically used to:

According to the usage priority ranking of the core network types, the core network type with the highest priority is determined as the preferred core network type.

Optionally, in some embodiments, the processing module 410 is specifically used to:

According to the usage priority ranking of the NAS message types, the core network type corresponding to the NAS message type with the highest priority is determined as the preferred core network type.

Optionally, in some embodiments, the processing module 410 is specifically used to:

If the priority of accessing the SA network is higher than the priority of accessing the NSA network, determining the core network type of the SA network as the preferred core network type; or

If the priority of accessing the SA network is lower than the priority of accessing the NSA network, the core network type of the NSA network is determined as the preferred core network type.

Optionally, in some embodiments, the processing module 410 is specifically used to:

The core network type that allows the terminal device to register is determined as the preferred core network type.

Optionally, in some embodiments, the processing module 410 is specifically used to:

The core network type corresponding to the NAS message type allowed to be used by the terminal device is determined as the preferred core network type.

Optionally, in some embodiments, the processing module 410 is specifically used to:

If access to the SA network is permitted, determining the core network type of the SA network as the preferred core network type; or

If access to the NSA network is allowed, the core network type of the NSA network is determined as the preferred core network type.

Optionally, in some embodiments, the communication module 420 is further used to:

A NAS message sent by the NAS of the core network device is received in the NAS, where the NAS message includes the first information.

Optionally, in some embodiments, the core network device is a core network device registered by the terminal device.

Optionally, in some embodiments, the NAS message is a registration request reply message or a location update request reply message.

Optionally, in some embodiments, the communication module 420 is specifically used for:

The access layer AS receives the first information sent by the AS of the access network device.

Optionally, in some embodiments, the access network device is an access network device where the terminal device resides.

Optionally, in some embodiments, the first information is included in a radio resource control RRC message or a broadcast message.

Optionally, in some embodiments, the processing module 410 is further configured to:

The AS sends the first information to the NAS of the terminal device, and the first information is used by the NAS of the terminal device to determine the preferred core network type.

Optionally, in some embodiments, the second information is used to indicate at least one of the following:

The core network type of successful registration or the NAS message type corresponding to the core network type;

The number of successful registrations to the core network type where the registration is successful;

The core network type for which registration failed or the NAS message type corresponding to the core network type;

The core network type for which the initial registration failed but the second registration succeeded;

The number of registration failures to the core network type for which registration failed.

Optionally, in some embodiments, the processing module 410 is specifically used to:

If the second information indicates that the core network type for which the registration is successful is the first core network type, determining the first core network type as the preferred core network type; or

If the second information indicates that the number of successful registrations with the first core network type is greater than or equal to a first threshold, the first core network type is determined as the preferred core network.

Optionally, in some embodiments, the processing module 410 is further configured to:

The second information is updated according to whether registration with the target core network type is successful.

Optionally, in some embodiments, the communication module 410 is further used for:

If the target core network type is Evolved Packet Core (EPC), preferably using an EPC NAS message to initiate a registration request to the EPC; or

If the target core network is a 5G core network 5GC, it is preferred to use an N1 NAS message to send a registration request to the 5GC.

It should be understood that the terminal device 400 according to the embodiment of the present application may correspond to the terminal device in the method embodiment of the present application, and the above-mentioned and other operations and/or functions of each unit in the terminal device 400 are respectively for realizing the corresponding processes of the terminal device in the method 200 shown in Figure 2, which will not be repeated here for the sake of brevity.

FIG7 is a schematic block diagram of a network device according to an embodiment of the present application. The network device 500 of FIG7 includes:

The communication module 510 is used to send first information to the terminal device, where the first information is used by the terminal device to determine the preferred core network type, and the first information is information configured by the network device for core network selection.

Optionally, in some embodiments, the first information is used to indicate at least one of the following:

Use priority ranking of core network types;

Usage priority of non-access stratum NAS message types;

Prioritization of access to independent SA networks and non-independent NSA networks;

The type of core network that allows the terminal device to register;

NAS message types allowed to be used by the terminal device;

Allow access to SA network or NSA network.

Optionally, the network device is a core network device, and the communication module 510 is specifically used to: send a NAS message from the NAS to the NAS of the terminal device, wherein the NAS message includes the first information.

Optionally, in some embodiments, the core network device is a core network device registered by the terminal device.

Optionally, in some embodiments, the NAS message is a registration request reply message or a location update request reply message.

Optionally, in some embodiments, the network device is an access network device, and the communication module 510 is specifically used to: send the first information to the AS of the terminal device in the AS.

Optionally, in some embodiments, the access network device is an access network device where the terminal device resides.

Optionally, in some embodiments, the first information is included in a radio resource control RRC message or a broadcast message.

It should be understood that the network device 500 according to the embodiment of the present application may correspond to the terminal device in the method embodiment of the present application, and the above-mentioned and other operations and/or functions of each unit in the network device 500 are respectively for realizing the corresponding processes of the network device in the method 300 shown in Figure 5, which will not be repeated here for the sake of brevity.

Fig. 8 is a schematic structural diagram of a communication device 600 provided in an embodiment of the present application. The communication device 600 shown in Fig. 8 includes a processor 610, and the processor 610 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

Optionally, as shown in Fig. 8, the communication device 600 may further include a memory 620. The processor 610 may call and run a computer program from the memory 620 to implement the method in the embodiment of the present application.

The memory 620 may be a separate device independent of the processor 610 , or may be integrated into the processor 610 .

Optionally, as shown in FIG. 8 , the communication device 600 may further include a transceiver 630 , and the processor 610 may control the transceiver 630 to communicate with other devices, specifically, may send information or data to other devices, or receive information or data sent by other devices.

The transceiver 630 may include a transmitter and a receiver. The transceiver 630 may further include an antenna, and the number of the antennas may be one or more.

Optionally, the communication device 600 may specifically be a network device of an embodiment of the present application, and the communication device 600 may implement the corresponding processes implemented by the network device in each method of the embodiment of the present application, which will not be described in detail here for the sake of brevity.

Optionally, the communication device 600 may specifically be a mobile terminal/terminal device of an embodiment of the present application, and the communication device 600 may implement the corresponding processes implemented by the mobile terminal/terminal device in each method of the embodiment of the present application, which will not be described in detail here for the sake of brevity.

Fig. 9 is a schematic structural diagram of a chip according to an embodiment of the present application. The chip 700 shown in Fig. 9 includes a processor 710, and the processor 710 can call and run a computer program from a memory to implement the method according to the embodiment of the present application.

Optionally, as shown in Fig. 9, the chip 700 may further include a memory 720. The processor 710 may call and run a computer program from the memory 720 to implement the method in the embodiment of the present application.

The memory 720 may be a separate device independent of the processor 710 , or may be integrated into the processor 710 .

Optionally, the chip 700 may further include an input interface 730. The processor 710 may control the input interface 730 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

Optionally, the chip 700 may further include an output interface 740. The processor 710 may control the output interface 740 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

Optionally, the chip can be applied to the network device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the network device in each method of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

Optionally, the chip can be applied to the mobile terminal/terminal device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the mobile terminal/terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

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

Fig. 10 is a schematic block diagram of a communication system 900 provided in an embodiment of the present application. As shown in Fig. 10 , the communication system 900 includes a terminal device 910 and a network device 920 .

Among them, the terminal device 910 can be used to implement the corresponding functions implemented by the terminal device in the above method, and the network device 920 can be used to implement the corresponding functions implemented by the network device in the above method. For the sake of brevity, they are not repeated here.

It should be understood that the processor of the embodiment of the present application may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by the hardware integrated logic circuit or software instructions in the processor. The above processor can be a general processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor are combined and performed. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, and other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

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

It should be understood that the above-mentioned memory is exemplary but not restrictive. For example, the memory in the embodiments of the present application may also be static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM), etc. That is to say, the memory in the embodiments of the present application is intended to include but not limited to these and any other suitable types of memory.

An embodiment of the present application also provides a computer-readable storage medium for storing a computer program.

Optionally, the computer-readable storage medium can be applied to the network device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

Optionally, the computer-readable storage medium can be applied to the mobile terminal/terminal device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the mobile terminal/terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

An embodiment of the present application also provides a computer program product, including computer program instructions.

Optionally, the computer program product can be applied to the network device in the embodiments of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

Optionally, the computer program product can be applied to the mobile terminal/terminal device in the embodiments of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the mobile terminal/terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

The embodiment of the present application also provides a computer program.

Optionally, the computer program can be applied to the network device in the embodiments of the present application. When the computer program runs on a computer, the computer executes the corresponding processes implemented by the network device in the various methods in the embodiments of the present application. For the sake of brevity, they are not described here.

Optionally, the computer program can be applied to the mobile terminal/terminal device in the embodiments of the present application. When the computer program runs on the computer, the computer executes the corresponding processes implemented by the mobile terminal/terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

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

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

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

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

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

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

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (20)

1. A wireless communication method, comprising: The terminal device determines the preferred core network type according to the first information, where the first information is information for core network selection configured by the network device according to the number of users supported by the core network; The terminal device preferentially chooses to initiate a registration process with the core network of the preferred core network type; Wherein, the network device includes the core network device with which the terminal device was last registered; and the method further includes: The terminal device receives a NAS message sent by the core network device, where the NAS message includes the first information; The first information is used to indicate at least one of the following: Use priority ranking of core network types; Usage priority of non-access stratum NAS message types; Priority sorting for accessing independent SA networks and non-independent NSA networks. 2. The method according to claim 1, wherein the terminal device determines the preferred core network type according to the first information, comprising: The terminal device sorts the core network types according to their usage priorities and determines the core network type with the highest priority as the preferred core network type. 3. The method according to claim 1, wherein the terminal device determines the preferred core network type according to the first information, comprising: The terminal device sorts the NAS message types according to their usage priorities, and determines the core network type corresponding to the NAS message type with the highest priority as the preferred core network type. 4. The method according to claim 1, wherein the terminal device determines the preferred core network type according to the first information, comprising: If the priority of accessing the SA network is higher than the priority of accessing the NSA network, the terminal device determines the core network type of the SA network as the preferred core network type; or If the priority of accessing the SA network is lower than the priority of accessing the NSA network, the terminal device determines the core network type of the NSA network as the preferred core network type. 5. The method according to any one of claims 1 to 4, characterized in that the NAS message is a registration request reply message or a location update request reply message. 6. The method according to any one of claims 1 to 5, characterized in that the terminal device preferentially chooses to initiate a registration process with the core network of the preferred core network type, comprising: If the target core network type is Evolved Packet Core (EPC), the terminal device preferably uses an EPC NAS message to initiate a registration request to the EPC; or If the target core network type is a 5G core network 5GC, the terminal device preferably uses an N1 NAS message to send a registration request to the 5GC. 7. A wireless communication method, comprising: The network device sends first information to the terminal device, where the first information is used by the terminal device to determine a preferred core network type, and the first information is information for core network selection configured by the network device according to the number of users supported by the core network; The network device includes a core network device with which the terminal device last registered; and the network device sends the first information to the terminal device, including: The core network device sends a NAS message to the terminal device, where the NAS message includes the first information; The first information is used to indicate at least one of the following: Use priority ranking of core network types; Usage priority of non-access stratum NAS message types; Priority sorting for accessing independent SA networks and non-independent NSA networks. 8. The method according to claim 7, wherein the NAS message is a registration request reply message or a location update request reply message. 9. A terminal device, comprising: A processing module, configured to determine a preferred core network type according to first information, where the first information is information for core network selection configured by a network device according to the number of users supported by the core network; A communication module, configured to preferentially initiate a registration process to a core network of the preferred core network type; The network device includes a core network device with which the terminal device was last registered; the communication module is further used to: receive, at the NAS, a NAS message sent by the NAS of the core network device, wherein the NAS message includes the first information; The first information is used to indicate at least one of the following: Use priority ranking of core network types; Usage priority of non-access stratum NAS message types; Priority sorting for accessing independent SA networks and non-independent NSA networks. 10. The terminal device according to claim 9, wherein the processing module is specifically used for: According to the usage priority ranking of the core network types, the core network type with the highest priority is determined as the preferred core network type. 11. The terminal device according to claim 9, wherein the processing module is specifically used for: According to the usage priority ranking of the NAS message types, the core network type corresponding to the NAS message type with the highest priority is determined as the preferred core network type. 12. The terminal device according to claim 9, wherein the processing module is specifically used for: If the priority of accessing the SA network is higher than the priority of accessing the NSA network, determining the core network type of the SA network as the preferred core network type; or If the priority of accessing the SA network is lower than the priority of accessing the NSA network, the core network type of the NSA network is determined as the preferred core network type. 13. The terminal device according to any one of claims 9 to 12, characterized in that the NAS message is a registration request reply message or a location update request reply message. 14. The terminal device according to any one of claims 9 to 13, characterized in that the communication module is further used for: If the target core network type is Evolved Packet Core (EPC), preferably using an EPC NAS message to initiate a registration request to the EPC; or If the target core network type is a 5G core network 5GC, it is preferred to use an N1 NAS message to send a registration request to the 5GC. 15. A network device, comprising: A communication module, configured to send first information to a terminal device, wherein the first information is used by the terminal device to determine a preferred core network type, and the first information is information for core network selection configured by a network device according to the number of users supported by the core network; The network device includes a core network device with which the terminal device last registered; the communication module is specifically used to: send a NAS message to the NAS of the terminal device at the NAS, wherein the NAS message includes the first information; The first information is used to indicate at least one of the following: Use priority ranking of core network types; Usage priority of non-access stratum NAS message types; Priority sorting for accessing independent SA networks and non-independent NSA networks. 16. The network device according to claim 15, wherein the NAS message is a registration request reply message or a location update request reply message. 17. A terminal device, characterized in that it comprises: a processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 6. 18. A network device, comprising: a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to claim 7 or 8. 19. A chip, characterized in that it comprises: a processor, used to call and run a computer program from a memory, so that a device equipped with the chip executes the method according to any one of claims 1 to 6, or the method according to claim 7 or 8. 20. A computer-readable storage medium, characterized in that it is used to store a computer program, wherein the computer program enables a computer to execute the method according to any one of claims 1 to 6, or the method according to claim 7 or 8.