CN116367139A

CN116367139A - Communication method and device

Info

Publication number: CN116367139A
Application number: CN202210051820.8A
Authority: CN
Inventors: 金辉; 王志峰; 窦凤辉; 薛祎凡
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-12-27
Filing date: 2022-01-17
Publication date: 2023-06-30
Also published as: WO2023124991A1

Abstract

The application provides a communication method and a communication device, relates to the technical field of wireless communication, and can avoid the problem that voice service cannot be performed after terminal equipment does not support new air interface voice VoNR access to a visiting network. The method comprises the following steps: the terminal device sends first information to a core network device of the home network. The first information is used for indicating the terminal equipment to support VoNR or heterogeneous network roaming, or the first information is used for requesting to acquire public land mobile network PLMN information of the visiting network, and an operator of the visiting network is different from an operator of a home network of the terminal equipment. And then, the terminal equipment receives PLMN information of the visited network from the core network equipment.

Description

Communication method and device

The present application claims priority from the national intellectual property agency, application No. 202111618289.X, application name "a method, apparatus for registration transmission", filed on month 27 of 2021, the entire contents of which are incorporated herein by reference.

Technical Field

The embodiment of the application relates to the field of wireless communication, in particular to a communication method and device.

Background

In the early stage of fifth generation (5G) independent networking (SA) deployment, the operator network and the terminal device do not support new air interface voice (voice over new radio, voNR), and the terminal device needs to perform voice services through the evolved packet system (evolved packet system, EPS) fallback (fallback) to the fourth generation (4G) network. The execution of EPS fallback requires an interface to be opened between a core network element access and mobility management function (access and mobility management function, AMF) of 5G and a core network element mobility management entity (mobility management entity, MME) of 4G, thereby completing a fallback procedure from 5G to 4G and establishing a voice transmission channel in the 4G network.

However, in the 5G core network heterogeneous roaming scenario, an interface is not opened between the AMF of the visited network side and the MME of the home network side, so that the terminal device of the unsupported VONR cannot establish a voice transmission channel by executing the EPS fallback procedure to 4G, and thus cannot perform voice service, and the user experience is poor.

Disclosure of Invention

The embodiment of the application provides a communication method and a communication device, which can avoid the problem that voice service cannot be performed after terminal equipment does not support new air interface voice VoNR access to a visiting network.

In order to achieve the above purpose, the embodiment of the application adopts the following technical scheme:

in a first aspect, the present application provides a communication method, where the execution body of the method may be a terminal device, or may be a chip applied in the terminal device. The following describes an example in which the execution subject is a terminal device. The method comprises the following steps: the terminal device sends first information to a core network device of the home network. The first information is used for indicating the terminal equipment to support the new air interface voice VoNR or the heterogeneous network roaming. Or the first information is used for requesting to acquire public land mobile network PLMN information of the visited network, and an operator of the visited network is different from an operator of a home network of the terminal equipment. And then, the terminal equipment receives PLMN information of the visited network from the core network equipment.

In this way, the core network device sends the PLMN information of the visited network to the terminal device only when determining that the terminal device supports VoNR or the terminal device requests to acquire the PLMN information of the visited network. Even if the operator of the visiting network is different from the operator of the home network, the terminal equipment can access the visiting network, and the voice service is executed through the visiting network, so that the problem that the voice service cannot be executed after the terminal equipment does not support VoNR to access the visiting network is avoided.

In one possible design, the terminal device sends the first information to the core network device of the home network through the attach request message, so that the terminal device can send the first information to the core network device in the 4G registration process, and the core network device can know that the terminal device supports VoNR, or the terminal device requests to obtain PLMN information of the visited network, so that the core network device is prevented from sending PLMN information of the visited network to the terminal device which does not support VoNR.

In one possible design, the terminal device sends the first information to the core network device of the home network through the registration request message, so that the terminal device can send the first information to the core network device in the 5G registration process, so that the core network device knows that the terminal device supports VoNR, or the terminal device requests to obtain PLMN information of the visited network, and the core network device is prevented from sending PLMN information of the visited network to the terminal device which does not support VoNR.

In one possible design, the first information is carried in a field indicating network capabilities of the user equipment.

In one possible design, the first information is carried in a preset bit, where the preset bit includes a bit indicating a fixed bit in a field of the network capability of the user equipment, such as a bit in a standby (spark) state.

In one possible design, the first information is carried by one of: a user equipment network capability field, or a user equipment network capability field of the N1 interface.

In one possible design, the first information is carried by one of: mobility management capability field, or user equipment network capability field of the S1 interface.

In one possible design, the terminal device sends the first information to the core network device of the home network via a security mode complete message. The security mode completion message is a message protected by adopting an encryption key, so that the possibility of tampering and leakage of the first information is reduced, and the reliability of information transmission is improved.

In one possible design, the terminal device sends the first information to the core network device of the home network through the tracking area update TAU request message, so that the terminal device can send the first information to the core network device in the TAU process, so that the core network device knows that the terminal device supports VoNR, or the terminal device requests to obtain PLMN information of the visited network, so as to avoid that the core network device sends PLMN information of the visited network to the terminal device which does not support VoNR.

In a second aspect, the present application provides a communication method, where the execution body of the method may be a core network device, or may be a chip applied in the core network device. The following describes an example in which the execution body is a core network device. The method comprises the following steps: the core network device receives first information from the terminal device. The first information is used for indicating the terminal equipment to support the new air interface voice VoNR or the heterogeneous network roaming. Or the first information is used for requesting to acquire public land mobile network PLMN information of the visiting network, the operator of the visiting network is different from the operator of the terminal equipment home network, and the core network equipment is core network equipment of the terminal equipment home network. And then, the core network equipment sends PLMN information of the visited network to the terminal equipment according to the first information.

In one possible design, the core network device receives the first information from the terminal device via an attach request message.

In one possible design, the core network device receives the first information from the terminal device via a registration request message.

In one possible design, the first information is carried in a predetermined bit including a bit indicating a fixed bit in a field of the network capability of the user equipment.

In one possible design, the core network device receives the first information from the terminal device via a secure mode complete message.

In one possible design, the core network device receives the first information from the terminal device via a tracking area update TAU request message.

In a third aspect, the present application provides a communication method, where an execution body of the method may be a core network device, or may be a chip applied in the core network device. The following describes an example in which the execution body is a core network device. The method comprises the following steps: the core network device determines that the terminal device supports the new air interface voice VoNR, wherein the core network device is the core network device of the home network of the terminal device. And then, the core network equipment sends Public Land Mobile Network (PLMN) information of the visiting network to the terminal equipment, wherein the operator of the visiting network is different from the operator of the home network of the terminal equipment.

In this way, the core network device sends PLMN information of the visited network to the terminal device only when determining that the terminal device supports the VoNR function. Even if the operator of the visiting network is different from the operator of the home network, the terminal equipment can access the visiting network, and the voice service is executed through the visiting network, so that the problem that the voice service cannot be executed after the terminal equipment does not support VoNR to access the visiting network is avoided.

In one possible design, the communication method of the embodiment of the application further includes: the core network device receives radio capability information from the access network device. Wherein the wireless capability information indicates the wireless capability of the terminal device. The core network device determines that the terminal device supports VoNR, including: and the core network equipment determines that the terminal equipment supports VoNR according to the wireless capability information.

In this way, the core network device can determine that the terminal device supports the VoNR function based on the radio capability information.

In one possible design, the communication method of the embodiment of the application further includes: when the core network device does not store the wireless capability information, the core network device sends an initial context establishment request to the access network device, wherein the initial context establishment request does not carry the wireless capability information, so that the access network device provides the wireless capability information to the core network device.

In one possible design, the communication method of the embodiment of the application further includes: the core network device receives indication information from the access network device, wherein the indication information indicates that the terminal device supports VoNR. The core network device determines that the terminal device supports VoNR, including: and the core network equipment determines that the terminal equipment supports VoNR according to the indication information.

Thus, the access network device determines that the terminal device supports the VoNR function, and then informs the core network device, so that the core network device can know that the terminal device supports the VoNR function.

In one possible design, the core network device receives the indication information from the access network device through a wireless capability matching response message. That is, the wireless capability matching response message carries the above indication information, so that the core network device obtains the above indication information.

In one possible design, the communication method of the embodiment of the application further includes: the core network device sends a first request message to the access network device. Wherein the first request message requests to obtain the indication information, so that the access network device provides the indication information to the core network device in response to the first request message.

In one possible design, the core network device sends the first request message to the access network device via a terminal device capability information indication message. That is, the capability information indication message carries the first request message, so as to send the indication information to the access network device.

In one possible design, the core network device sends the PLMN information of the visited network to the terminal device through the registration acceptance message, so that the terminal device obtains the PLMN information of the visited network through the registration process, and the terminal device which does not support VoNR is effectively prevented from receiving the PLMN information of the visited network.

In one possible design, the core network device comprises a mobility management entity MME, or a mobility management function AMF network element.

In a fourth aspect, the present application provides a communication device, which may be a terminal device in the above first aspect or any one of the possible designs of the first aspect, or a chip for implementing the functions of the above terminal device; the communication device comprises corresponding modules, units or means (means) for realizing the method, and the modules, units or means can be realized by hardware, software or realized by executing corresponding software by hardware. The hardware or software includes one or more modules or units corresponding to the functions described above.

The communication device includes a processing unit, a transmitting unit, and a receiving unit. The processing unit is configured to control the sending unit to send first information to a core network device of the home network, where the first information is used to instruct the communication device to support new air interface voice VoNR or heterogeneous network roaming, or the first information is used to request to obtain public land mobile network PLMN information of the visited network, and an operator of the visited network is different from an operator of the home network of the communication device. The processing unit is further configured to control the receiving unit to receive PLMN information of the visited network from the core network device.

In one possible design, the sending unit is specifically configured to send the first information to the core network device of the home network through an attach request message.

In one possible design, the sending unit is specifically configured to send the first information to the core network device of the home network through a registration request message.

In one possible design, the first information is carried in a preset bit, wherein the preset bit comprises a bit indicating a fixed bit in a field of the network capability of the user equipment.

In one possible design, the sending unit is specifically configured to send the first information to the core network device of the home network through a security mode complete message.

In one possible design, the sending unit is specifically configured to send the first information to the core network device of the home network through a tracking area update TAU request message.

In a fifth aspect, the present application provides a communication apparatus, which may be the core network device in the second aspect or any one of the possible designs of the second aspect, or a chip implementing the functions of the core network device; the communication device comprises corresponding modules, units or means (means) for realizing the method, and the modules, units or means can be realized by hardware, software or realized by executing corresponding software by hardware. The hardware or software includes one or more modules or units corresponding to the functions described above.

The communication device includes a processing unit, a transmitting unit, and a receiving unit. The processing unit is configured to control the receiving unit to receive first information from the terminal device, where the first information is used to instruct the terminal device to support new air interface voice VoNR or foreign network roaming, or the first information is used to request to obtain public land mobile network PLMN information of a visited network, an operator of the visited network is different from an operator of a home network of the terminal device, and the communication apparatus is core network equipment of the home network of the terminal device. The processing unit is further configured to control the sending unit to send PLMN information of the visited network to the terminal device according to the first information.

In one possible design, the receiving unit is specifically configured to receive the first information from the terminal device via an attach request message.

In one possible design, the receiving unit is specifically configured to receive the first information from the terminal device via a registration request message.

In one possible design, the receiving unit is specifically configured to receive the first information from the terminal device via a secure mode complete message.

In one possible design, the receiving unit is specifically configured to receive the first information from the terminal device through a tracking area update TAU request message.

In a sixth aspect, the present application provides a communication apparatus, which may be a core network device in any one of the above-mentioned third aspect or any one of the possible designs of the third aspect, or a chip for implementing the function of the core network device; the communication device comprises corresponding modules, units or means (means) for realizing the method, and the modules, units or means can be realized by hardware, software or realized by executing corresponding software by hardware. The hardware or software includes one or more modules or units corresponding to the functions described above.

The communication device includes a processing unit, a transmitting unit, and a receiving unit. The processing unit is configured to determine that the terminal device supports new air interface voice VoNR, where the communication device is a core network device of a home network of the terminal device. And the sending unit is used for sending the Public Land Mobile Network (PLMN) information of the visiting network to the terminal equipment, wherein the operator of the visiting network is different from the operator of the home network of the terminal equipment.

In one possible design, the receiving unit is further configured to receive radio capability information from the access network device, where the radio capability information indicates the radio capability of the terminal device. A processing unit, configured to determine that a terminal device supports VoNR, includes: and determining that the terminal equipment supports VoNR according to the wireless capability information.

In one possible design, the sending unit is further configured to send an initial context establishment request to the access network device when the communication device does not save the wireless capability information, where the initial context establishment request does not carry the wireless capability information.

In a possible design, the receiving unit is further configured to receive indication information from the access network device, where the indication information indicates that the terminal device supports VoNR. A processing unit, configured to determine that a terminal device supports VoNR, includes: and determining that the terminal equipment supports VoNR according to the indication information.

In one possible design, the receiving unit is specifically configured to receive the indication information from the access network device through a radio capability matching response message.

In one possible design, the sending unit is further configured to send a first request message to the access network device, where the first request message requests to obtain the indication information.

In one possible design, the sending unit is specifically configured to send the first request message to the access network device through a terminal device capability information indication message.

In one possible design, the sending unit is specifically configured to send PLMN information of the visited network to the terminal equipment through a registration accept message.

In one possible design, the communication device comprises a mobility management entity MME, or a mobility management function AMF network element.

In a seventh aspect, embodiments of the present application provide a communication apparatus, including: a processor and a memory; the memory is for storing computer instructions which, when executed by the processor, cause the communications apparatus to perform the method performed by the terminal device in any one of the above aspects or any one of the possible designs of any one of the aspects. The communication means may be a terminal device in the above first aspect or any of the possible designs of the first aspect, or a chip implementing the functions of the above terminal device.

In an eighth aspect, embodiments of the present application provide a communication apparatus, including: a processor; the processor is coupled to the memory for reading the instructions in the memory and executing the instructions to cause the communication device to perform the method performed by the terminal device as in any one of the above aspects or any one of the possible designs of the aspect. The communication means may be a terminal device in the above first aspect or any of the possible designs of the first aspect, or a chip implementing the functions of the above terminal device.

In a ninth aspect, embodiments of the present application provide a chip including a processing circuit and an input-output interface. The input-output interface is used for communicating with a module outside the chip, for example, the chip may be a chip implementing the terminal device function in the first aspect or any of the possible designs of the first aspect. The processing circuitry is arranged to run a computer program or instructions to implement the method of the first aspect above or any of the possible designs of the first aspect.

In a tenth aspect, embodiments of the present application provide a communication apparatus, including: a processor and a memory; the memory is configured to store computer instructions that, when executed by the processor, cause the communication apparatus to perform the method performed by the core network device in any one of the above aspects or any one of the possible designs of the aspect. The communication means may be the core network device in the second aspect or any of the possible designs of the second aspect, or the communication means may be the core network device in the third aspect or any of the possible designs of the third aspect, or a chip implementing the functions of the core network device.

In an eleventh aspect, embodiments of the present application provide a communication apparatus, including: a processor; the processor is coupled to the memory for reading the instructions in the memory and executing the instructions to cause the communication device to perform the method performed by the core network apparatus as in any one of the above aspects or any one of the possible designs of the aspect. The communication means may be the core network device in the second aspect or any of the possible designs of the second aspect, or the communication means may be the core network device in the third aspect or any of the possible designs of the third aspect, or a chip implementing the functions of the core network device.

In a twelfth aspect, embodiments of the present application provide a chip including a processing circuit and an input-output interface. Wherein the input-output interface is for communication with a module outside the chip, which may be, for example, a chip implementing the functionality of the core network device in the second aspect or any of the possible designs of the second aspect. The processing circuitry is configured to run a computer program or instructions to implement the method of the second aspect above or any of the possible designs of the second aspect. As another example, the chip may be a chip implementing the core network device function in any of the above third aspect or any of the possible designs of the third aspect. The processing circuitry is arranged to run a computer program or instructions to implement the method of any one of the above third aspects or any one of the possible designs of the third aspect.

In a thirteenth aspect, embodiments of the present application provide a computer-readable storage medium having instructions stored therein that, when run on a computer, cause the computer to perform the method of any one of the above aspects.

In a fourteenth aspect, embodiments of the present application provide a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any one of the above aspects.

In a fifteenth aspect, embodiments of the present application provide circuitry comprising processing circuitry configured to perform the method of any one of the above aspects.

In a sixteenth aspect, embodiments of the present application provide a communication system that includes a core network device and an access network device. The access network device is configured to send first information to the core network device, where the first information indicates wireless capability of the terminal device, or the first information indicates that the terminal device supports new air interface voice VoNR. And the core network equipment is used for receiving the first information from the access network equipment, wherein the core network equipment is core network equipment of a home network of the terminal equipment. The core network device is further configured to determine that the terminal device supports VoNR according to the first information. And the core network equipment is also used for sending the Public Land Mobile Network (PLMN) information of the visiting network to the terminal equipment, wherein the operator of the visiting network is different from the operator of the home network of the terminal equipment.

The technical effects of any one of the designs of the second aspect to the sixteenth aspect may refer to the advantages of the corresponding methods provided above, and are not described herein.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system applied in an embodiment of the present application;

FIG. 2 is a schematic architecture diagram of yet another communication system to which embodiments of the present application are applied;

FIG. 3 is a schematic architecture diagram of yet another communication system to which embodiments of the present application apply;

FIG. 4 is a schematic architecture diagram of yet another communication system to which embodiments of the present application apply;

FIG. 5 is a schematic diagram of an architecture of yet another communication system to which embodiments of the present application apply;

fig. 6 is a schematic flow chart of a communication method according to an embodiment of the present application;

fig. 7a is a flow chart of another communication method according to an embodiment of the present application;

fig. 7b is a flowchart of another communication method according to an embodiment of the present application;

fig. 7c is a flowchart of another communication method according to an embodiment of the present application;

fig. 7d is a flow chart of another communication method according to an embodiment of the present application;

fig. 8 is a flow chart of another communication method according to an embodiment of the present application;

fig. 9 is a flow chart of another communication method according to an embodiment of the present application;

fig. 10a is a flow chart of another communication method according to an embodiment of the present application;

Fig. 10b is a flowchart of another communication method according to an embodiment of the present application;

FIG. 10c is a flowchart illustrating another communication method according to an embodiment of the present disclosure;

fig. 11 is a flow chart of another communication method according to an embodiment of the present application;

fig. 12a is a flow chart of another communication method according to an embodiment of the present application;

fig. 12b is a flowchart of another communication method according to an embodiment of the present application;

fig. 12c is a flowchart of another communication method according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of still another communication device according to an embodiment of the present application.

Detailed Description

Fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application. As shown in fig. 1, the communication system includes a terminal device, an access network device, and a core network.

The terminal device comprises a device for providing voice and/or data connectivity to a user, specifically, a device for providing voice to a user, a device for providing data connectivity to a user, or a device for providing voice and data connectivity to a user. For example, may include a handheld device having wireless connectivity, or a processing device connected to a wireless modem. The terminal device may communicate with the core network via a radio access network (radio access network, RAN), exchange voice or data with the RAN, or interact voice and data with the RAN. The terminal device may include a User Equipment (UE), a wireless terminal device, a mobile terminal device, a device-to-device (D2D) terminal device, a vehicle-to-device (V2X) terminal device, a machine-to-machine/machine-type communication (M2M/MTC) terminal device, an internet of things (internet of things, ioT) terminal device, a subscription unit (subscriber unit), a subscription station (subscriber station), a mobile station (mobile station), a remote station, an Access Point (AP), a remote terminal (remote terminal), an access terminal (access terminal), a user terminal (user terminal), a user agent (user agent), or a user equipment (user device), etc. For example, mobile telephones (or "cellular" telephones) computers with mobile terminal devices, portable, pocket, hand-held, computer-built mobile devices, and the like may be included. Such as personal communication services (personal communication service, PCS) phones, cordless phones, session initiation protocol (session initiation protocol, SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal digital assistant, PDAs), and the like. But also limited devices such as devices with lower power consumption, or devices with limited memory capabilities, or devices with limited computing capabilities, etc. Examples include bar codes, radio frequency identification (radio frequency identification, RFID), sensors, global positioning systems (global positioning system, GPS), laser scanners, and other information sensing devices.

While the various terminal devices described above, if located on a vehicle (e.g., placed in a vehicle or mounted in a vehicle), may be considered as in-vehicle terminal devices, for example, also referred to as in-vehicle units (OBUs).

In the embodiment of the application, the terminal device may further include a relay (relay). Or it is understood that all that is capable of data communication with a base station can be seen as a terminal device.

In the embodiment of the present application, the device for implementing the function of the terminal device may be the terminal device, or may be a device capable of supporting the terminal device to implement the function, for example, a chip system, and the device may be installed in the terminal device. In the embodiment of the application, the chip system may be formed by a chip, and may also include a chip and other discrete devices. In the technical solution provided in the embodiment of the present application, an apparatus for implementing a function of a terminal is taken as an example of a terminal device, and description is made.

The access network device may be an access point for wireless communication or wired communication, such as a base station or a base station controller, a wireless-fidelity (wifi) access point or a wifi controller, or a fixed network access point, etc. The base stations may include various types of base stations, for example: micro base stations (also referred to as small stations), macro base stations, relay stations, access points, etc., as embodiments of the present application are not specifically limited. In the embodiment of the present application, the base station may be a base station (base transceiver station, BTS) in a global system for mobile communications (global system for mobile communication, GSM), a base station (base transceiver station, BTS) in a code division multiple access (code division multiple access, CDMA), a base station (node B) in a wideband code division multiple access (wideband code division multiple access, WCDMA), an evolved base station (evolutional node B, eNB or e-NodeB) in a long term evolution (long term evolution, LTE), an eNB in the internet of things (internet of things, ioT) or a narrowband internet of things (narrow band-internet of things, NB-IoT), a base station in a fifth generation (the fifth generation, 5G) mobile communication network or a public land mobile network (public land mobile network, PLMN) of future evolution, which is not limited in any way by the embodiments of the present application.

The core network includes various core network devices. For example, the core network device may comprise a mobility management entity (mobility management entity, MME), in particular see the description of fig. 2. As another example, the core network device may also include an access and mobility management function (core access and mobility management function, AMF) network element, see in particular the description of fig. 3. It should be understood that the core network device may also include other network elements, such as a user plane function (user plane function, UPF) network element, a session management function (session management function, SMF) network element, etc., which are not described herein.

By way of example, fig. 2 shows a schematic architecture of a fourth generation (the fourth generation, 4G) communication system. The 4G communication system includes network elements or devices such as evolved universal mobile telecommunications system (universal mobile telecommunications system, UMTS) terrestrial radio access network (evolved UMTS territorial radio access network, E-UTRAN) devices, MME, serving Gateway (SGW), packet data network (packet data network, PDN) Gateway (PGW), policy and charging rules function (policy and charging rules function, PCRF) network elements, and home subscriber server (home subscriber server, HSS).

The terminal equipment accesses the E-UTRAN equipment through LTE-Uu, the E-UTRAN equipment communicates with MME through S1-MME, the E-UTRAN equipment communicates with SGW through S1-U, different MME communicates with HSS through S10 (only one MME is shown in the example in fig. 1), MME communicates with HSS through S6a, MME communicates with SGW through S11, PGW communicates with PCRF network element through Gx, PCRF network element communicates with server through Rx, SGW communicates with PGW through S5, and PGW accesses server through SGi.

Wherein the E-UTRAN equipment is used for realizing the functions related to the evolution network wireless. The MME is responsible for mobility management of a control plane, including user context and mobility state management, allocation of user temporary identity, and the like. SGW is a third generation partnership project (3rd generation partnership project,3GPP) inter-access network user plane anchor and is an interface to terminate E-TURAN. PGW is a user plane anchor point between 3GPP access network and non-3 GPP access network, and is an interface for termination and external PDN. The PCRF network element is used for policy control decision and flow charging control functions. The HSS is used to store subscriber subscription information. The server is used to provide internet protocol (internet protocol, IP) services such as voice/video services based on internet protocol multimedia subsystem (internet protocol multimediasubsystem, IMS), packet switched streaming services (packet switched streaming service, PSS), etc.

By way of example, fig. 3 shows a schematic architecture of a fifth generation (the fifth generation, 5G) communication system. The 5G communication system includes a radio access network (radio access network, RAN) device, a UPF network element, an AMF network element, an SMF network element, an authentication server function (authentication server function, AUSF) network element, a network slice selection function (network slice selection function, NSSF) network element, a network opening function (network exposure function, NEF) network element, a network function storage function (network exposure function repository function, NRF) network element, a policy control function (policy control function, PCF) network element, a unified data management (unified data management, UDM) network element, a unified data storage (unified data repository, UDR) network element, an application function (application function, AF) network element, or a billing function (charging function, CHF) network element, etc.

It should be noted that fig. 3 is only an example given as to some network elements or entities in the 5G communication system, and the 5G communication system may further include some network elements or entities not shown in fig. 3, such as network data analysis function (network data analytics function, NWDAF) network elements, which are not specifically limited in this embodiment of the present application.

As shown in fig. 3, the terminal device accesses the 5G network through the RAN device, and the terminal device communicates with the AMF through an N1 interface (abbreviated as N1); the RAN equipment communicates with an AMF network element through an N2 interface (N2 for short); the RAN equipment communicates with UPF network elements through an N3 interface (N3 for short); the SMF network element communicates with the UPF network element through an N4 interface (abbreviated as N4), and the UPF network element accesses a Data Network (DN) through an N6 interface (abbreviated as N6). In the architecture shown in fig. 3, N1, N2, N3, N4 and N6 represent reference points (reference points) between related network elements/network functions, respectively.

In addition, control plane functions such as an AUSF network element, an AMF network element, an SMF network element, an NSSF network element, a NEF network element, an NRF network element, a PCF network element, a UDM network element, a UDR network element, a CHF network element, or an AF network element shown in fig. 3 use a service interface to perform interaction. For example, the server interface provided by the AUSF network element is Nausf; the AMF network element provides a service interface as Namf; the SMF network element provides a serving interface as Nsmf; the NSSF network element provides a service interface for the outside as Nnssf; the network element of NEF provides a service interface for the outside as Nnef; the service interface externally provided by the NRF network element is Nnrf; the service interface externally provided by the PCF network element is an Npcf; the service interface externally provided by the UDM network element is Nudm; the server interface externally provided by the UDR network element is Nudr; the service interface externally provided by the CHF network element is Nchf; the service interface provided by the AF network element is Naf. The related functional descriptions and interface descriptions may refer to the 5G system architecture (5G system architecture) in the 23501 standard, and are not described herein.

It should be understood that the names of the core network devices, such as MME and AMF, are just one name, and the device itself is not limited. It will be appreciated that other names may be used in 5G networks and other networks in the future, and embodiments of the present application are not specifically limited thereto. For example, the AMF network element may also be referred to as an AMF or an AMF entity, which is generally described herein, and will not be described in detail herein.

Alternatively, the core network device may be implemented by one device, or may be implemented by a plurality of devices together, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application. It will be appreciated that the functional modules described above may be either network elements in a hardware device, software functional modules running on dedicated hardware, or virtualized functional modules instantiated on a platform (e.g., a cloud platform).

In order to facilitate understanding of the embodiments of the present application, the following description will be given for the terms involved in the embodiments of the present application. It should be understood that these descriptions are merely for the purpose of facilitating understanding of the embodiments of the present application and should not be construed as limiting the application in any way.

1. Visiting network party (visited network operator)

The visiting network side refers to an operator providing heterogeneous roaming service to terminal equipment of other operators in a roaming area. The network that provides the heterogeneous roaming service to the terminal device of the other operator is described as a visited network (visited network). The foreign network roaming service may be a 5G core network foreign network roaming service.

2. Home network side (home network operator)

The home network side is an operator that provides a foreign network roaming service to a terminal device of the home network through other operator networks in the roaming area. Among them, a network providing a foreign network roaming service to a terminal device of a home network through other operator networks is described as a home network (home network). The foreign network roaming service may be a 5G core network foreign network roaming service.

3. Heterogeneous network roaming

The foreign network roaming means that the terminal equipment can use the service provided by the home network by accessing to the visited network. Wherein the operator of the visited network is different from the operator of the home network of the terminal equipment, but belongs to the same country. Among them, the foreign network roaming may also be called national roaming (national roaming). In the embodiment of the present application, description will be made only taking the case of heterogeneous network roaming as an example.

The access network and the core network of the two parties of the different network roaming operators are independently constructed and managed, and the mobile users are independently managed. The two operators providing the different network roaming service provide corresponding services for the roaming terminal equipment based on the inter-network roaming agreement. The different network roaming is realized by adopting a home routing mode, namely roaming user data returns to a home network, and the service is provided to the terminal equipment by the home network.

In the 5G SA scenario, the terminal device cannot access the home network in the roaming area, and uses the 5G service by accessing the visited network, such as a data service, an IMS-based voice/video service, and a short message service. In this case, the heterogeneous network roaming may also be described as 5G core network heterogeneous network roaming or 5G core network roaming. In the embodiment of the present application, only 5G core network foreign network roaming is taken as an example for description.

4. The scene is diffused out and the scene is diffused back

The roaming scene means that the terminal equipment enters a roaming area, accesses a visiting network, is connected with a home network through a roaming intercommunication interface, and then provides service by the home network. Illustratively, the visited network may be a 5G network of the visited operator and the home network may be a 5G network of the home operator. As shown in fig. 4, in the 5G independent networking mode, the visited network and the home network are connected through an edge gateway (BG). Illustratively, the network element in the visited network and the network element in the home network are connected as shown in fig. 5.

In addition, the 4G network of the visiting operator does not provide a 5G core network foreign network roaming service, and voice fallback to the 4G network of the visiting operator is not supported.

The diffuse back scene is that the terminal equipment leaves the roaming area and accesses to the home network when searching the signal of the home network.

As a possible implementation, the terminal device is configured with a subscriber identity module (subscriber identity module, SIM) card. The SIM card may be used as an identifier of the mobile subscriber's network identity. The SIM card is used for storing user data and completing user identity authentication. One SIM card corresponds to one mobile subscriber. It should be noted that the SIM card may store a user identification. For example, the user identification may be: an international mobile subscriber identity (international mobile subscriber identification number, IMSI) or a subscription permanent identity (subscription permanent identifier, SUPI). The SIM card may be implemented in the form of a physical card such as a standard SIM card, a Mini-SIM card, a Micro SIM card, and a Nano SIM card. This type of SIM card may also be referred to as a universal subscriber identity (universal subscriber identity module, USIM) card. The SIM card may also be implemented in the form of a built-in chip, such as an embedded subscriber identity module (eSIM) card. The SIM card may also be implemented in software, which is not limited in this embodiment of the present application.

The SIM card stores therein an Identity (ID) of the home operator PLMN. And the terminal equipment preferentially selects PLMN of the home operator to carry out residence and execution service under the starting state. The terminal device receives the system broadcast message of the access network device. Wherein the system broadcast message includes a PLMN ID. When the terminal equipment selects the network, the operator is determined by analyzing the PLMN ID in the system broadcast message, and the PLMN of the home operator is preferentially selected for residence.

After the PLMN of the home operator resides, the terminal device sends a registration (attach or registration) request message to the core network device of the home operator, and then the core network device sends equivalent public land mobile network (equivalent public land mobile network, EPLMN) information to the terminal device. Wherein the EPLMN information includes 1 or more PLMN IDs. The PLMN ID in the EPLMN information may be a PLMN ID of the visited network side operator. And the terminal equipment stores the received EPLMN information, and treats the PLMN contained in the EPLMN information and the PLMN of the home operator equally when the network is selected later, namely the PLMN is considered to have the same network selecting priority. For example, when the terminal device moves to the coverage area of the visited network, the PLMN ID of the operator of the visited network is obtained by parsing the system broadcast message of the access network device. And then, when the terminal equipment determines that the PLMN ID is the same as the PLMN ID obtained in the registration acceptance message, the terminal equipment resides in the base station of the visiting network side operator and initiates a registration request to the core network equipment of the visiting network side operator so as to access the visiting network.

For the terminal device, in the 5G independent networking mode, there are 2 modes for executing the voice service:

mode 1, new air interface speech (voice over new radio, voNR)

VoNR means that a voice transmission channel is established in an NR network to implement a VoNR function.

Mode 2, evolved packet system (evolved packet system, EPS) fallback (fallback)

Mode 2 cannot establish a voice transmission channel through the NR network, and the terminal device needs to fall back to the 4G network, and establish the voice transmission channel through the 4G network to execute the voice service. In this case, an interface needs to be opened between the AMF network element of the 5G core network and the MME network element of the 4G core network.

Both mode 1 and mode 2 are based on IMS to realize voice services.

In the early stage of 5G SA network deployment, the operator's network does not support VoNR. Correspondingly, the terminal equipment supporting 5G SA does not support the VoNR function, and the voice service is carried out through the EPS fallback function.

However, in the roaming scenario of the 5G core network, an interface between the AMF network element and the home network is opened between the visited network and the MME network element of the home network is not opened between the AMF network element of the visited network. Therefore, the terminal equipment cannot perform voice service through the EPS fallback, so that the user cannot answer the incoming call, and the user experience is affected.

In view of this, the embodiments of the present application provide two communication methods, and the communication method (such as the first communication method or the second communication method) of the embodiments of the present application may be applied to the communication systems shown in fig. 1 to 5.

In the first communication method provided in the embodiment of the present application, the terminal device sends first information to a core network device of a home network. The first information is used for indicating the terminal equipment to support VoNR or heterogeneous network roaming. Or the first information is used for requesting to acquire PLMN information of the visiting network, and an operator of the visiting network is different from an operator of a home network of the terminal equipment. The terminal device then receives PLMN information of the visited network from the core network device. In this way, the core network device determines that the terminal device supports VoNR, or the terminal device sends PLMN information of the visited network to the terminal device when the terminal device requests to obtain PLMN information of the visited network. Even if the operator of the visiting network is different from the operator of the home network, the terminal equipment can access the visiting network, and the voice service is executed through the visiting network, so that the problem that the voice service cannot be executed after the terminal equipment does not support VoNR to access the visiting network is avoided.

As shown in fig. 6, a first communication method 600 provided in an embodiment of the present application includes the following steps:

S601, the terminal equipment sends first information to core network equipment of a home network. Correspondingly, the core network device of the home network receives the first information from the terminal device.

The core network device may be an MME shown in fig. 2 or an AMF shown in fig. 3, for example. It should be understood that, as the communication technology evolves, the core network device may also have other names, which are not limited in this embodiment of the present application.

There are two possible implementations of the first information (i.e., the following modes 1 and 2), which are specifically described as follows:

mode 1, the first information is used to indicate that the terminal device supports VoNR or heterogeneous roaming. Where VoNR and heterogeneous roaming may refer to the noun interpretation section, and are not described in detail herein.

It should be noted that, in the embodiment of the present application, if the terminal device supports heterogeneous network roaming, the terminal device also supports the VoNR function. Because the terminal equipment which does not support VoNR cannot carry out voice service in the visiting network, the terminal equipment of the type cannot reside in the visiting network and only resides in the home network, and the terminal equipment can be considered to not support heterogeneous roaming; otherwise, the terminal equipment supporting VoNR can reside in the visiting network to carry out voice service through the VoNR, and the terminal can be considered to support heterogeneous network roaming. Thus, supporting heterogeneous network roaming and supporting VoNR can be considered equivalent.

For example, the first information may indicate that the terminal device supports VoNR or heterogeneous network roaming in a direct indication manner. Alternatively, the first information may also indicate that the terminal device supports VoNR or heterogeneous roaming by using an indirect indication manner. By way of example, table 1a illustrates one possible mapping relationship.

TABLE 1a

Character(s)	Characteristics of
		A1	Supporting heterogeneous network roaming
A2	Supporting VoNR

In table 1a, support heterogeneous network roaming corresponds to A1, and support VoNR corresponds to A2. In some embodiments, if the first information includes A1, it may be understood that the first information is used to indicate that the terminal device supports heterogeneous roaming. If the first information includes A2, it can be understood that the first information is used to indicate that the terminal device supports VoNR.

It should be understood that the first information may also be indicated in other forms, which are not limited in this embodiment of the present application. The above description will be given by taking the terminal device supporting VoNR or heterogeneous network roaming as an example. Otherwise, the first information may also perform a corresponding indication in case the terminal device does not support VoNR and heterogeneous network roaming. For example, if the terminal device does not support heterogeneous roaming, the first information indicates that the terminal device does not support heterogeneous roaming. For another example, if the terminal device does not support VoNR, the first information indicates that the terminal device does not support VoNR. Similarly, the first information may indicate that the terminal device does not support VoNR or does not support heterogeneous roaming in a direct indication manner. Alternatively, the first information may also indicate that the terminal device does not support VoNR or does not support heterogeneous roaming in an indirect indication manner. By way of example, table 1b illustrates one possible mapping relationship.

TABLE 1b

Character(s)	Characteristics of
		B1	Not supporting heterogeneous network roaming
B2	Not supporting VoNR

In table 1B, heterogeneous network roaming is not supported to correspond to B1, and VoNR is not supported to correspond to B2. In some embodiments, if the first information includes B1, it may be understood that the first information is used to indicate that the terminal device does not support heterogeneous roaming. If the first information includes B2, it may be understood that the first information is used to indicate that the terminal device does not support VoNR.

Mode 2, the first information is used to request to obtain PLMN information of the visited network. Wherein the operator of the visited network is different from the operator of the home network of the terminal device. Illustratively, the PLMN information includes a PLMN ID.

The first information may indicate directly that the PLMN information of the visited network is requested to be acquired, or may indicate indirectly that the PLMN information of the visited network is requested to be acquired, for example, the first information is indicated by 1 bit (bit). For example, the bit has a value of 1, which indicates that the PLMN information of the visited network is requested to be acquired. Correspondingly, the bit has a value of 0, which means that PLMN information of the visited network does not need to be acquired. Or otherwise, the bit takes a value of 0, which indicates that the PLMN information of the visited network is requested to be acquired. Correspondingly, the bit has a value of 1, which means that PLMN information of the visited network does not need to be acquired. Or, in case the first information is sent, it indicates that acquisition of PLMN information of the visited network is requested. In the case that the first information is not sent, this indicates that the PLMN information of the visited network does not need to be acquired, which is not limited in the embodiment of the present application.

It should be noted that, in the embodiment of the present application, the terminal device sends the first information to the core network device, which means that the terminal device sends the first information to the access network device, and then the access network device sends the first information to the core network device.

Optionally, in conjunction with fig. 2 or fig. 3, an exemplary description is given of a transmission procedure of the first information:

taking fig. 2 as an example, in the case where the core network device is implemented as MME in fig. 2, as a possible implementation, S601 may be implemented as S601a as shown in fig. 7 a:

s601a, the terminal device sends first information to MME of home network through attach request (attach request) message. Accordingly, the MME of the home network receives the first information from the terminal device through the attach request message.

That is, the attach request message carries the first information. In this way, the terminal device can send the first information to the MME during the 4G registration process, so that the MME knows that the terminal device supports VoNR, or the terminal device requests to obtain PLMN information of the visited network, so as to avoid the MME sending PLMN information of the visited network to the terminal device that does not support VoNR.

Alternatively, the first information may be carried in a field in the attach request message indicating network capabilities of the user equipment. For example, the first information may be carried in a field indicating 4G network capabilities of the user equipment, such as a field indicating user equipment network capabilities (UE network capability), or in a field indicating 5G network capabilities of the user equipment, such as a field indicating user equipment network capabilities of an N1 interface (N1 UE network capability). The N1 interface is an interface for performing communication connection between the terminal device and the AMF network element, and specifically, reference may be made to description of fig. 3, which is not repeated herein. It should be understood that the first information may also be carried in other fields in the attach request message, which is not limited in this embodiment of the present application.

Illustratively, a field indicating network capabilities of the user equipment (e.g., UE network capability, or N1 UE network capability field) may carry the first information by a number of preset bits. The preset bits may include bits indicating fixed bits in a field of the network capability of the user equipment, such as bits in a standby (spare) state.

Referring to table 2, table 2 shows one possible UE network capability field. The bits in the UE network capability field that can carry the first information are shown as circles.

TABLE 2

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As shown in table 2, byte 1 indicates the information element identity (information element identifier, IEI), i.e., UE network capability IEI. Byte 2 indicates the UE network capability content length (length of UE network capability contents). Byte 3 carries information of a general mobile communication system (evolved packet system, EPS) encryption algorithm, byte 4 carries information of an EPS integrity algorithm, byte 5 carries information of a general mobile communication system (universal mobile telecommunications system, UMTS) encryption algorithm, and byte 6 carries information of a UMTS integrity algorithm and information of a general multi-octet encoding character set (universal multiple-octet coded character set, UCS). In bytes 7 through 10 (e.g., bits 1 through 5 of byte 10), information of characteristics 1 through 29 may be included. Here, the characteristics 1 to 29 may be referred to the description in the related art, and will not be described here. In bytes 10 (e.g., bits 6, 7, and 8 of byte 10) through 15, bits in standby state are included. In this case, the bits of the fixed bit include at least one of the following bits: some of the bits in byte 10 (e.g., bit 6, bit 7, and bit 8 in byte 10), all of the bits in byte 11, byte 12, byte 13, byte 14, and byte 15.

Referring to Table 3, table 3 shows one possible N1 UE network capability field. Bits in the N1 UE network capability field that can carry the first information are shown as circles.

TABLE 3 Table 3

As shown in table 3, byte 1 indicates IEI, i.e., N1 UE network capability IEI. Byte 2 indicates an N1 UE network capability content length (length of N1 UE network capability contents). In bits 1 to 6 of byte 3, information of characteristics 1 to 5 may be included. Here, the characteristics 1 to 5 may be referred to the description in the related art, and will not be described here. In bytes 3 (e.g., bits 7 and 8 of byte 3) to 4, bits in standby state are included. In this case, the bits of the fixed bit include at least one of the following bits: some bits in byte 3 (e.g., bit 7 and bit 8 in byte 3), all bits in byte 4.

In tables 2 and 3, a bit indicated by a circle is given a value of 0, which indicates that the first information is carried, and a bit indicated by a value of 1, which indicates that the first information is not carried. Or conversely, when the bit value is 1, it indicates that the first information is carried, and when the bit value is 0, it indicates that the first information is not carried, which is not limited in this embodiment of the present application.

Taking fig. 2 as an example, in the case where the core network device is implemented as the MME in fig. 2, as another possible implementation, S601 may be implemented as S601b as shown in fig. 7 b:

s601b, the terminal device sends the first information to the MME of the home network through a tracking area update (tracking area update, TAU) request message. Correspondingly, the MME of the home network receives the first information from the terminal device through the TAU request message.

That is, the TAU request message carries the first information. In this way, the terminal device can send the first information to the MME during the TAU process, so that the MME knows that the terminal device supports VoNR, or the terminal device requests to obtain PLMN information of the visited network, so as to avoid the MME sending PLMN information of the visited network to the terminal device that does not support VoNR.

Illustratively, the mobile network tracks the location of the terminal device by means of a Tracking Area (TA) in order to facilitate location management and paging of the terminal device. Specifically, the core network device configures a tracking area list (tracking area list, TA list) for the terminal device. Typically, one TA list contains one or more tracking area codes (tracking area code, TAC), one TAC identifying one TA. A TA may contain one or more cells. Subsequently, if the terminal device moves in the cell indicated by the configured TA list, the TAU does not need to be executed. Correspondingly, after the service arrives, the core network device pages the terminal device in the area corresponding to the configured TA list. Otherwise, if the terminal equipment moves out of the cell indicated by the TA list, the core network equipment does not know the latest position of the terminal equipment, the terminal equipment needs to execute TAU, and a TAU request message is sent to the core network equipment, so that the core network equipment knows the TA where the terminal equipment is currently located, and the core network equipment can update the TA list of the terminal equipment.

Alternatively, the first information may be carried in a spare field, or other fields, in the TAU request message, which is not limited in the embodiments of the present application.

Taking fig. 3 as an example, in a case where the core network device is implemented as the AMF in fig. 3, as a possible implementation manner, as shown in fig. 7c, S601 may be implemented as S601c:

s601c, the terminal device sends the first information to the AMF of the home network through a registration request (registration request) message. Accordingly, the AMF of the home network receives the first information from the terminal device through the registration request message.

That is, the registration request message carries the first information. In this way, the terminal device can send the first information to the AMF in the 5G registration process, so that the AMF knows that the terminal device supports VoNR, or the terminal device requests to obtain PLMN information of the visited network, thereby avoiding the AMF from sending PLMN information of the visited network to the terminal device that does not support VoNR.

Alternatively, the first information may also be carried in a field in the registration request message indicating the network capabilities of the terminal device. For example, the first information may be carried in a field indicating 4G network capabilities of the terminal device, such as user equipment network capabilities of the S1 interface (S1 UE network capability). Wherein the S1 interface is an interface between an eNB in the E-UTRAN device and a core network device. The S1 interface comprises an S1-MME interface and an S1-U interface, and as shown in figure 2, the S1-MME interface is a control plane interface and is an interface for communication connection between E-UTRAN equipment and MME; the S1-U interface is a user interface, and is an interface for communication connection between E-UTRAN equipment and SGW. The first information may also be carried in a field indicating 5G network capabilities of the terminal device, such as a mobility management capability field, which may specifically include 5G mobility management capabilities (5G mobility management,5GMM capability). It should be understood that the first information may also be carried in other fields in the registration request message, which is not limited in this embodiment of the present application.

Illustratively, the above-mentioned field indicating the network capability of the terminal device (e.g. S1 UE network capability, or 5GMM capability field) may carry the first information by a certain number of preset bits. The preset bits may include bits indicating fixed bits in a field of the network capability of the user equipment, such as bits in a standby (spare) state.

Referring to table 4, table 4 shows one possible 5GMM capability field. Bits in the 5GMM capability field that may carry the first information are shown as circles.

TABLE 4 Table 4

As shown in table 4, byte 1 indicates IEI, i.e., 5GMM capability IEI. Byte 2 indicates a 5GMM capability content length (length of 5GMM capability contents). In bytes 3 through 6 (e.g., bits 1 through 3 in byte 6), information of characteristics 1 through 27 may be included. Here, the characteristics 1 to 27 may be referred to the description in the related art, and will not be described here. Bits in the spare state are included in bytes 6 (e.g., bits 4 to 8 in byte 6) to 15. In this case, the bits of the fixed bit include at least one of the following bits: some bits in byte 6 (e.g., bits 4 through 8 in byte 6), all bits in byte 7, byte 8, byte 9, byte 10, byte 11, byte 12, byte 13, byte 14, byte 15. In table 4, a bit indicated by a circle is 0, which indicates that the first information is carried, and a bit indicated by a 1, which indicates that the first information is not carried. Or conversely, when the bit value is 1, it indicates that the first information is carried, and when the bit value is 0, it indicates that the first information is not carried, which is not limited in this embodiment of the present application.

Taking fig. 3 as an example, in a case where the core network device is implemented as the AMF in fig. 3, as another possible implementation, as shown in fig. 7d, S601 may be implemented as S601d:

s601d, the terminal device sends the first information to the AMF through a security mode complete (security mode complete, SMC) message. Accordingly, the AMF receives the first information from the terminal device through the security mode completion message.

That is, the security mode complete message carries the first information. The security mode completion message is a message protected by adopting an encryption key, so that the possibility of tampering and leakage of the first information is reduced, and the reliability of information transmission is improved.

Optionally, the first information may also be carried in a field indicating network capabilities of the terminal device in the security mode complete message. For example, the first information may be carried in a field indicating the 5G network capability of the terminal device, for example, the mobility management capability field may specifically include a 5GMM capability field, and specifically may refer to the description of table 4, which is not repeated herein. It should be understood that the first information may also be carried in other fields in the secure mode complete message, which embodiments of the present application do not limit.

Illustratively, in fig. 7d, the terminal device sends a registration request message to the AMF before executing S601 d. Accordingly, the AMF receives the registration request message from the terminal device.

Wherein the registration request message carries hidden identity information (subscriber concealed identifier, sui). The sui is generated by the terminal device. Wherein, the SUCI comprises at least one of the following information:

the first item, the user permanent identification Type (subscription permanent identifier, SUPI Type), may have 7 values for identifying the 7 types of SUPI encrypted in the SUPI. Illustratively, when the value of SUPI Type is 0, it indicates that SUPI is an international mobile subscriber identity (international mobile subscriber identification number, IMSI). The IMSI is a flag for distinguishing between terminal devices. The IMSI comprises a mobile country code (mobile country code, MCC), a mobile network code (mobile network code, MNC) and a mobile subscriber identification number (mobile subscriber identification number, MSIN). The MCC is used to uniquely identify the country to which the mobile subscriber belongs, for example, the MCC in our country is 460.MNC is used to identify to which operator the mobile subscriber belongs. MSIN is used to identify a mobile subscriber in a mobile communications network. When the value of SUPI Type is 1, SUPI is indicated as a network specific indicator (network specific identifier).

Second, home network indicator (home network identifier). For example, when the SUPI Type indicates that the SUPI is IMSI, the home network indicator may include MCC and MNC. Wherein MCC and MNC are used in combination to uniquely represent the network operator of the terminal device.

It should be understood that the above two information are only exemplary descriptions, and the sui may also include other information, which is not described in detail herein.

Note that, in contrast to the registration request message of S601c, the registration request message carrying the sui does not carry the first information described above.

After the AMF receives the registration request message carrying the SUCI, the AMF authenticates the terminal equipment based on the SUCI. The AMF then sends a secure mode command (security mode command) message to the terminal device. Accordingly, the terminal device receives the security mode command message from the AMF.

The security mode command message carries information of an encryption key, such as a key used by negotiation between the AMF and the terminal equipment. The encryption key carried in the security mode command message is used to protect the security mode complete message, see the description of S601d, which is not repeated here.

It should be understood that in fig. 7a to 7d, it is only exemplary to describe which messages the first information is sent through, and of course, the first information may also be sent through other messages, which is not limited in this embodiment of the present application.

S602, the core network equipment sends PLMN information of the visited network to the terminal equipment. Correspondingly, the terminal equipment receives PLMN information of the visited network from the core network equipment.

The PLMN information in S602 is consistent with the PLMN information in S601, which is not described herein.

Illustratively, if the PLMN ID of the operator a for foreign network roaming in the region X is 46030, the terminal device supporting VoNR of the operator B receives 46030 sent by the core network device when the operator B registers. The terminal device that received 46030 may select and register with the network of operator a. Otherwise, the terminal device that does not support VoNR cannot receive 46030 sent by the core network device, and cannot register with the network of the operator a.

Optionally, in conjunction with fig. 2 or fig. 3, an exemplary description is given of a procedure for transmitting PLMN information of the visited network:

in the case where the core network device is implemented as MME in fig. 2 as shown in fig. 2, as a possible implementation, S602 may be implemented as S602a as shown in fig. 7 a:

s602a, the MME sends PLMN information of the visited network to the terminal equipment through a registration acceptance (attach accept) message. Correspondingly, the terminal equipment receives PLMN information of the visited network from the MME through the registration acceptance message.

That is, the registration accept message carries PLMN information for the visited network. The specific implementation process of sending PLMN information of the visited network through the registration acceptance message may refer to the description of sending EPLMN through the registration acceptance message, which is not described herein.

As another possible implementation, in the case where the core network device is implemented as MME in fig. 2, as shown in fig. 2, S602 may be implemented as S602b:

s602b, the MME sends PLMN information of the visited network to the terminal equipment through the TAU receiving message. Correspondingly, the terminal equipment receives PLMN information of the visited network from the MME through the TAU receiving message.

That is, the TAU accept message carries PLMN information of the visited network. Thus, under the condition that the terminal equipment supports VoNR or the terminal equipment requests to acquire PLMN information of the visiting network, the terminal equipment can acquire the PLMN information of the visiting network in the TAU process so as to enable the terminal equipment to execute voice service through the visiting network.

Taking fig. 3 as an example, in the case where the core network device is implemented as the AMF in fig. 3, as a possible implementation manner, as shown in fig. 7c and fig. 7d, S602 may be implemented as S602c:

S602c, the AMF sends PLMN information of the visited network to the terminal equipment through the registration acceptance message. Correspondingly, the terminal equipment receives PLMN information of the visited network from the AMF through the registration acceptance message.

It should be understood that in fig. 7a to 7d, it is only exemplary to describe which messages the PLMN information of the visited network is sent through, and of course, the PLMN information of the visited network may also be sent through other messages, which is not limited in this embodiment of the present application.

In this way, the terminal device sends the first information to the core network device, so that the core network device determines that the terminal device supports the VoNR function, or requests the core network device to obtain PLMN information of the visited network, where the core network device sends the PLMN information of the visited network to the terminal device. Even if the operator of the visiting network is different from the operator of the home network, the terminal equipment can access the visiting network, and the voice service is executed through the visiting network, so that the problem that the voice service cannot be executed after the terminal equipment does not support VoNR to access the visiting network is avoided.

The embodiment of the application also provides a second communication method, in which the core network device determines that the terminal device supports VoNR. The core network equipment is core network equipment of a home network of the terminal equipment. And then, the core network equipment sends PLMN information of the visiting network to the terminal equipment, wherein the operator of the visiting network is different from the operator of the home network of the terminal equipment. In this way, the core network device sends PLMN information of the visited network to the terminal device only when determining that the terminal device supports the VoNR function. Even if the operator of the visiting network is different from the operator of the home network, the terminal equipment can access the visiting network, and the voice service is executed through the visiting network, so that the problem that the voice service cannot be executed after the terminal equipment does not support VoNR to access the visiting network is avoided.

As shown in fig. 8, a second communication method 800 provided in the embodiment of the present application includes the following steps:

s801, the core network equipment determines that the terminal equipment supports VoNR.

The core network equipment is core network equipment in a home network of the terminal equipment. The core network device may be an MME shown in fig. 2 or an AMF shown in fig. 3, for example. It should be understood that, as the communication technology evolves, the core network device may also have other names, which are not limited in this embodiment of the present application.

The description of VoNR may refer to the noun explanation, and will not be repeated here.

Optionally, the implementation procedure of S801 includes the following two examples (example 1 and example 2):

as shown by the dotted line box where "example 1" is located in fig. 9, S801 is implemented as S801a and S801b:

s801a, the access network equipment sends wireless capability information to the core network equipment. Correspondingly, the core network device receives the wireless capability information from the access network device.

Wherein the wireless capability information indicates the wireless capability of the terminal device. Illustratively, the wireless capability information may include UE radio capability info. The radio capability information may include an IMS parameter (IMS-Parameters) that may include a VoNR field that is valued as supported (supported) to indicate that the terminal device supports VoNR. Alternatively, the IMS-parameters frx-Diff field may not include a VoNR field, or the value of the VoNR field indicates that no supported is supported, to indicate that the terminal device does not support VoNR.

As a possible implementation manner, referring to fig. 10a, fig. 10a shows a schematic flow chart of transmitting wireless capability information, and specific steps are as follows:

step 11, the terminal device sends a registration request message to the core network device. Correspondingly, the core network device receives a registration request message from the terminal device.

Wherein the registration request message is used to initiate registration.

Illustratively, in case the core network device is implemented as MME in fig. 2, the registration request message is for the terminal device to register with the 4G network. The registration request message may also be described as an attach request (attach request), as shown in fig. 10 b. In case the core network device is implemented as an AMF in fig. 3, the registration request message is used for the terminal device to register to the 5G network. The registration request message may also be denoted registration equest as shown in fig. 10 c.

Step 12, the core network device sends a capability matching request message to the access network device. Accordingly, the access network device receives the capability matching request message from the core network device.

The capability matching request message is used for requesting the access network equipment to determine whether the terminal equipment supports IMS voice.

Illustratively, in case the core network device is implemented as an MME in fig. 2, the access network device may be an eNB, and the capability matching request may also be described as a user equipment capability matching request of an application protocol (application protocol, AP) of the S1 interface, as denoted by S1-AP UE Capability match request, as shown in fig. 10 b. In case the core network device is implemented as an AMF in fig. 3, the access network device may be a gNB, and the capability matching request may also be described as a user equipment capability matching request of an N2 interface, as denoted as N2 UE Capability match request, as shown in fig. 10 c.

And step 13, the access network equipment sends a capability query message to the terminal equipment. Correspondingly, the terminal device receives the capability query message from the access network device.

The capability inquiry message is used for inquiring the wireless capability of the terminal equipment.

For example, in case the core network device is implemented as an MME in fig. 2, or an AMF in fig. 3, the capability query message may comprise a capability query message of the user equipment, i.e. UE Capability enquiry.

And 14, the terminal equipment sends the capability information of the access network equipment. Accordingly, the access network device receives capability information from the terminal device.

Wherein the capability information indicates the wireless capability of the terminal device.

For example, in case the core network device is implemented as MME in fig. 2, or AMF in fig. 3, the capability information may be denoted as UE capability information.

And step 15, the access network equipment sends a capability matching response message to the core network equipment. Accordingly, the core network device receives the capability matching response message from the access network device.

Wherein the capability matching response message indicates at least whether the terminal device supports IMS voice.

For example, in case the core network device is implemented as MME in fig. 2, or AMF in fig. 3, the capability matching response message may also be described as a user equipment wireless capability matching response (UE radio capability match response).

Since the VoNR is implemented based on the IMS voice, in the case where the capability matching response message indicates that the terminal device supports the IMS voice, the core network device waits to receive the wireless capability information, that is, the core network device performs S801a first and then S801b. The wireless capability information in S801a may be determined based on the capability information in step 14, or the wireless capability information in S801a includes the capability information in step 14, which is not limited in the embodiment of the present application.

As another possible implementation manner, referring to fig. 11, fig. 11 shows a schematic flow chart of transmitting wireless capability information, and specific steps are as follows:

step 21, the terminal device sends a registration request message to the core network device. Correspondingly, the core network device receives a registration request message from the terminal device.

Step 21 may refer to the description of step 11, and will not be described herein.

Step 22, when the core network device does not save the radio capability information, the core network device sends an initial context setup request to the access network device (initial context setup request). Accordingly, the access network device receives an initial context setup request from the core network device.

Wherein the initial context establishment request does not carry wireless capability information. The wireless capability information indicates the wireless capability of the terminal device, and may be referred to the description of S801a, which is not repeated here. For example, the initial context setup request may carry security context information, which is not limited by embodiments of the present application.

In this case, the access network device learns that the core network device does not store the wireless capability information of the terminal device, and then, the access network device performs step 23, step 24, and step S801a:

step 23, the access network device sends a capability query message to the terminal device. Correspondingly, the terminal device receives the capability query message from the access network device.

Step 23 may be described in step 13, and will not be described herein.

And step 24, the terminal equipment sends the capability information of the access network equipment. Accordingly, the access network device receives capability information from the terminal device.

Step 24 may be referred to as step 14, and will not be described herein.

For the access network device, after step 24 is performed, S801a is performed. The wireless capability information in S801a may be determined based on the capability information in step 24, or the wireless capability information in S801a includes the capability information in step 24, which is not limited in the embodiment of the present application. For the core network device, the core network device first performs S801a and then performs S801b.

It should be understood that in the flow diagram shown in fig. 11, the core network device may be implemented as an MME in fig. 2, in which case the access network device may be an eNB, as shown in fig. 10 b. The core network device may also be implemented as an AMF in fig. 3, in which case the access network device may be a gNB, as shown in fig. 10c, which is not described here again.

S801b, the core network equipment determines that the terminal equipment supports VoNR according to the wireless capability information.

Illustratively, taking the example that the radio capability information includes an IMS parameter, when the IMS-parameters frx-Diff field of the parameter includes a VoNR field that is valued as supported, the core network device determines that the terminal device supports VoNR.

It should be understood that, still taking the example that the radio capability information includes an IMS-ParametersFRX-Diff field, when the IMS-ParametersFRX-Diff field does not include a field of VoNR, or when the value of the field of VoNR indicates that no support (non supported), the core network device determines that the terminal device does not support VoNR.

Thus, through S801a and S801b indicated by the dashed line boxes where "example 1" is located in fig. 9, the core network device can determine from the master that the terminal device supports the VoNR function based on the radio capability information.

As shown by the dotted line box where "example 2" is located in fig. 9, S801 is implemented as S801c and S801d:

S801c, the access network equipment sends indication information to the core network equipment. Correspondingly, the core network device receives the indication information from the access network device.

The indication information indicates that the terminal device supports VoNR, and may be specifically referred to the description of S601, which is not repeated herein.

The characteristic indicated by the indication information is illustratively determined based on capability information of the terminal device. Still taking the IMS parameter in the capability information as an example, when the IMS-parameters frx-Diff field of the parameter includes a VoNR field that is valued as supported, the access network device determines that the terminal device supports VoNR. Accordingly, the indication information indicates that the terminal device supports VoNR. When the IMS-parameters frx-Diff field does not include a field of VoNR, or the value of the field of VoNR indicates that no support (non supported), the access network device determines that the terminal device does not support VoNR. Accordingly, the indication information indicates that the terminal device does not support VoNR.

Alternatively, as shown in fig. 12a, S801c may be replaced by the following steps: the access network device sends indication information to the core network device through the wireless capability matching response message. Correspondingly, the core network equipment receives the indication information from the access network equipment through the wireless capability matching response message.

Illustratively, the wireless capability matching response message carries the indication information through a preset number of spare fields.

That is, the wireless capability matching response message carries the above indication information, so that the core network device obtains the above indication information.

It should be appreciated that the above description describes the bearer of the indication information using only the wireless capability matching response message as an example. Of course, the indication information may also be transmitted through other messages, or may be carried by a separate message, which is not limited in the embodiment of the present application.

It should be noted that, the access network device may autonomously perform S801c, or may perform S801c in response to a request from the core network device. In this case, as shown in fig. 12a, the core network device further performs S801e before performing S801 c:

s801e, the core network device sends a first request message to the access network device. Accordingly, the access network device receives a first request message from the core network device.

Wherein the first request message requests acquisition of the indication information. The indication information in S801e is identical to the indication information in S801c, and will not be described here.

Alternatively, S801e may be replaced by the following steps: the core network device sends a first request message to the access network device through the capability information indication message. Accordingly, the access network device receives the first request message from the core network device through the capability information indication message.

Illustratively, the capability information indication message carries the first request message through a preset number of spare fields.

By way of example, in connection with fig. 2 or 3, the transmission procedure of the first request message will be described: in case the core network device is implemented as MME in fig. 2, the access network device may be an eNB and the capability information indication message may comprise a user equipment capability information indication (S1-AP UE capability info indication) of an application protocol of the S1 interface, as shown in fig. 12 b. In case the core network device is implemented as an AMF in fig. 3, the access network device may be a gNB and the capability information indication message may comprise a user equipment capability information indication (N2 UE capability info indication) of the N2 interface, as shown in fig. 12 c.

That is, the capability information indication message carries the first request message, so as to send the indication information to the access network device.

It should be appreciated that the above description is presented with respect to the bearer of the first request message, taking the capability information indication message as an example only. Of course, the first request message may also be transmitted through other messages, or may be carried by a separate message, which is not limited in the embodiment of the present application.

S801d, the core network equipment determines that the terminal equipment supports VoNR according to the indication information.

For example, in the case where the indication information indicates that the terminal device supports VoNR, the core network device may determine that the terminal device supports VoNR.

It should be understood that, in case the indication information indicates that the terminal device does not support VoNR, the core network device may determine that the terminal device does not support VoNR.

In this way, through S801c and S801d shown by the dashed line box where "example 2" is located in fig. 9, the access network device determines whether the terminal device supports the VoNR function, and then informs the core network device, so that the core network device knows whether the terminal device supports the VoNR function.

For the core network device, in the case where it is determined that the terminal device supports VoNR, the core network device performs S802, whereas in the case where it is determined that the terminal device does not support VoNR, the core network device does not perform S802.

S802, the core network equipment sends PLMN information of the visited network to the terminal equipment. Correspondingly, the terminal equipment receives PLMN information of the visited network from the core network equipment.

Herein, S802 may refer to the description of S602, which is not repeated herein.

That is, the core network device sends PLMN information of the visited network to the terminal device only if it is determined that the terminal device supports the VoNR function. Even if the operator of the visiting network is different from the operator of the home network, the terminal equipment can access the visiting network, and the voice service is executed through the visiting network, so that the problem that the voice service cannot be executed after the terminal equipment does not support VoNR to access the visiting network is avoided.

The above description has been presented mainly from the point of interaction between the network elements. Correspondingly, the embodiment of the application also provides a communication device, which can be the network element in the embodiment of the method, or a device containing the network element, or a component applicable to the network element. It will be appreciated that the communication device, in order to achieve the above-described functions, comprises corresponding hardware structures and/or software modules performing the respective functions. Those of skill in the art will readily appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

By way of example, fig. 13 illustrates a schematic diagram of a communication device 1300. The communication apparatus 1300 includes a processing unit 1301, a transmitting unit 1302, and a receiving unit 1303.

In a possible example, taking the communication apparatus 1300 as an example of a terminal device, the processing unit 1301 is configured to support the terminal device to perform other processing operations that the terminal device in fig. 6 needs to perform. The sending unit 1302 is configured to support the terminal device to perform S601 in fig. 6, and/or other sending operations that the terminal device needs to perform in the embodiment of the present application. The receiving unit 1303 is configured to support the terminal device to perform S602 in fig. 6, and/or other receiving operations that the terminal device needs to perform in the embodiment of the present application.

In another possible example, taking the communication apparatus 1300 as an example of a terminal device, the processing unit 1301 is configured to support the terminal device to perform other processing operations that the terminal device in fig. 8 needs to perform. The sending unit 1302 is configured to support the terminal device to perform other sending operations that the terminal device needs to perform in fig. 8. The receiving unit 1303 is configured to support the terminal device to perform S802 in fig. 8, and/or other receiving operations that the terminal device needs to perform in the embodiment of the present application.

In a possible example, taking the communication apparatus 1300 as a core network device, the processing unit 1301 is configured to support the core network device to perform other processing operations that the core network device in fig. 6 needs to perform. The sending unit 1302 is configured to support the core network device to perform S602 in fig. 6, and/or other sending operations that the core network device needs to perform in the embodiment of the present application. The receiving unit 1303 is configured to support the core network device to perform S601 in fig. 6, and/or other receiving operations that the core network device needs to perform in the embodiment of the present application.

In another possible example, taking the communication apparatus 1300 as a core network device, the processing unit 1301 is configured to support the core network device to perform S801 in fig. 8 and/or other processing operations that the core network device needs to perform in the embodiment of the present application. The sending unit 1302 is configured to support the core network device to perform S802 in fig. 8, and/or other sending operations that the core network device needs to perform in the embodiment of the present application. The receiving unit 1303 is configured to support the core network device to perform other receiving operations that the core network device in fig. 8 needs to perform.

Optionally, the communication device 1300 may further include a storage unit 1304 for storing program codes and data of the communication device, and the data may include, but is not limited to, raw data or intermediate data.

The processing unit 1301 may be a processor or a controller, such as a CPU, general purpose processor, application specific integrated circuit (application specific integrated circuit, ASIC), field programmable gate array (field programmable gate array, FPGA) or other programmable logic device, transistor logic device, hardware components, or any combination thereof. Which may implement or perform the various exemplary logic blocks, modules, and circuits described in connection with this disclosure. A processor may also be a combination that performs computing functions, e.g., including one or more microprocessors, a combination of a DSP and a microprocessor, and so forth.

The transmitting unit 1302 may be a communication interface, a transmitter, or a transmitting circuit, where the communication interface is generally called, and in a specific implementation, the communication interface may include multiple interfaces, for example, may include: an interface between the terminal device and the core network device and/or other interfaces.

The receiving unit 1303 may be a communication interface, a receiver, or a receiving circuit, where the communication interface is generally called, and in a specific implementation, the communication interface may include a plurality of interfaces, for example may include: an interface between the terminal device and the core network device and/or other interfaces.

The transmitting unit 1302 and the receiving unit 1303 may be physically or logically implemented as one and the same unit.

The storage unit 1304 may be a memory.

When the processing unit 1301 is a processor, the transmitting unit 1302 and the receiving unit 1303 are communication interfaces, and the storage unit 1304 is a memory, a communication apparatus according to an embodiment of the present application may be as shown in fig. 14.

Referring to fig. 14, the communication apparatus includes: a processor 1401, a communication interface 1402, and a memory 1403. Optionally, the communication device may also include a bus 1404. Wherein the communication interface 1402, the processor 1401 and the memory 1403 may be interconnected by a bus 1404; the bus 1404 may be a peripheral component interconnect standard (peripheral component interconnect, PCI) bus or an extended industry standard architecture (extended industry standard architecture, EISA) bus, among others. The bus 1404 may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in fig. 14, but not only one bus or one type of bus.

Optionally, the embodiments of the present application further provide a computer program product carrying computer instructions that, when run on a computer, cause the computer to perform the method described in the above embodiments.

Optionally, the embodiment of the present application further provides a computer readable storage medium, where the computer readable storage medium stores computer instructions, which when executed on a computer, cause the computer to perform the method described in the above embodiment.

Optionally, an embodiment of the present application further provides a chip, including: processing circuitry and transceiver circuitry for implementing the methods described in the above embodiments. Wherein the processing circuit is used for executing the processing actions in the corresponding method, and the transceiver circuit is used for executing the receiving/transmitting actions in the corresponding method.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device including one or more servers, data centers, etc. that can be integrated with the available medium. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital video disc (digital video disc, DVD)), or a semiconductor medium (e.g., solid state disk (solid state drive, SSD)), etc.

In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, and for example, the division of the modules is merely a logical function division, and there may be additional divisions when actually implemented, for example, multiple modules or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or modules, which may be in electrical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of devices. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

From the above description of the embodiments, it will be clear to those skilled in the art that the present application may be implemented by means of software plus necessary general purpose hardware, or of course by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in contributing parts in the form of a software product stored in a readable storage medium, such as a floppy disk, a hard disk, or an optical disk of a computer, etc., including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in the embodiments of the present application.

The foregoing is merely a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and the changes or substitutions within the technical scope of the present disclosure should be covered in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, comprising:

the method comprises the steps that a terminal device sends first information to core network equipment of a home network, wherein the first information is used for indicating that the terminal device supports new air interface voice VoNR or different network roaming, or the first information is used for requesting to acquire public land mobile network PLMN information of a visiting network, and an operator of the visiting network is different from an operator of the home network of the terminal device;

and the terminal equipment receives PLMN information of the visited network from the core network equipment.

2. The method according to claim 1, wherein the terminal device sends the first information to a core network device of the home network via an attach request message.

3. The method according to claim 1, wherein the terminal device sends the first information to a core network device of the home network via a registration request message.

4. A method according to claim 2 or 3, characterized in that the first information is carried in a field indicating network capabilities of the user equipment.

5. The method of any of claims 2, 3 or 4, wherein the first information is carried in a preset bit, wherein the preset bit comprises a bit indicating a fixed bit in a field of user equipment network capabilities.

6. The method of any one of claims 1, 2, 4, or 5, wherein the first information is carried by one of:

the user equipment network capability field, or,

user equipment network capability field of the N1 interface.

7. The method of any one of claims 1, 3, 4, or 5, wherein the first information is carried by one of:

the mobility management capability field, or,

user equipment network capability field of S1 interface.

8. The method according to claim 1, wherein the terminal device sends the first information to a core network device of the home network via a security mode complete message.

9. The method according to claim 1, wherein the terminal device sends the first information to a core network device of the home network via a tracking area update TAU request message.

10. A registration method, comprising:

the method comprises the steps that core network equipment receives first information from terminal equipment, wherein the first information is used for indicating that the terminal equipment supports new air interface voice VoNR or different network roaming, or the first information is used for requesting to acquire public land mobile network PLMN information of a visiting network, an operator of the visiting network is different from an operator of a home network of the terminal equipment, and the core network equipment is core network equipment of the home network of the terminal equipment;

and the core network equipment sends PLMN information of the visited network to the terminal equipment according to the first information.

11. The method according to claim 10, wherein the core network device receives the first information from the terminal device via an attach request message.

12. The method according to claim 10, wherein the core network device receives the first information from the terminal device via a registration request message.

13. The method according to claim 11 or 12, wherein the first information is carried in a field indicating network capabilities of the user equipment.

14. The method according to any of claims 11, 12 or 13, wherein the first information is carried in a preset bit comprising a bit indicating a fixed bit in a field of the user equipment network capability.

15. The method of any one of claims 10, 11, 13 or 14, wherein the first information is carried by one of:

the user equipment network capability field, or,

user equipment network capability field of the N1 interface.

16. The method of any one of claims 10, 12, 13 or 14, wherein the first information is carried by one of:

the mobility management capability field, or,

user equipment network capability field of S1 interface.

17. The method according to claim 10, wherein the core network device receives the first information from the terminal device via a secure mode complete message.

18. The method of claim 10, wherein the core network device receives the first information from the terminal device via a tracking area update TAU request message.

19. A method of communication, comprising:

The method comprises the steps that core network equipment determines that terminal equipment supports new air interface voice VoNR, wherein the core network equipment is core network equipment of a home network of the terminal equipment;

and the core network equipment sends Public Land Mobile Network (PLMN) information of a visiting network to the terminal equipment, wherein an operator of the visiting network is different from an operator of a home network of the terminal equipment.

20. The method of claim 19, wherein the method further comprises:

the core network equipment receives wireless capability information from access network equipment, wherein the wireless capability information indicates the wireless capability of the terminal equipment;

the core network device determines that the terminal device supports VoNR, including:

and the core network equipment determines that the terminal equipment supports VoNR according to the wireless capability information.

21. The method of claim 20, wherein the method further comprises:

and when the core network equipment does not store the wireless capability information, the core network equipment sends an initial context establishment request to the access network equipment, wherein the initial context establishment request does not carry the wireless capability information.

22. The method of claim 19, wherein the method further comprises:

the core network equipment receives indication information from access network equipment, wherein the indication information indicates that the terminal equipment supports VoNR;

and the core network equipment determines that the terminal equipment supports VoNR according to the indication information.

23. The method of claim 22, wherein the core network device receives the indication information from the access network device via a wireless capability matching response message.

24. The method according to claim 22 or 23, characterized in that the method further comprises:

and the core network equipment sends a first request message to the access network equipment, wherein the first request message requests to acquire the indication information.

25. The method according to claim 24, wherein the core network device sends the first request message to the access network device via a terminal device capability information indication message.

26. The method according to any of claims 19 to 25, wherein the core network device sends PLMN information of the visited network to the terminal device via a registration accept message.

27. The method according to any of the claims 19 to 26, wherein the core network device comprises a mobility management entity, MME, or a mobility management function, AMF, network element.

28. A communication device comprising means for performing the method of any of claims 1 to 9, or means for performing the method of any of claims 10 to 18, or means for performing the method of any of claims 19 to 27.

29. A communication device comprising a processor and interface circuitry for receiving signals from other communication devices than the communication device and transmitting to the processor or sending signals from the processor to other communication devices than the communication device, the processor being configured to implement the method of any one of claims 1 to 9, or to implement the method of any one of claims 10 to 18, or to implement the method of any one of claims 19 to 27, by logic circuitry or execution of code instructions.

30. A computer readable storage medium, characterized in that the storage medium has stored therein a computer program or instructions which, when executed by a communication device, implements the method of any of claims 1 to 9, or implements the method of any of claims 10 to 18, or implements the method of any of claims 19 to 27.

31. A communication system, comprising: an access network device and a core network device; wherein, the liquid crystal display device comprises a liquid crystal display device,

the access network device is configured to send first information to the core network device, where the first information indicates wireless capability of a terminal device, or the first information indicates that the terminal device supports new air interface voice VoNR;

the core network device is configured to receive the first information from the access network device, where the core network device is a core network device of a home network of the terminal device;

the core network device is further configured to determine that the terminal device supports VoNR according to the first information;

the core network device is further configured to send public land mobile network PLMN information of a visited network to the terminal device, where an operator of the visited network is different from an operator of a home network of the terminal device.