CN110661753A

CN110661753A - Network registration method, device and system

Info

Publication number: CN110661753A
Application number: CN201810703784.2A
Authority: CN
Inventors: 汪红星; 练仑; 舒续祖; 谢潜
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-06-30
Filing date: 2018-06-30
Publication date: 2020-01-07
Anticipated expiration: 2038-06-30
Also published as: WO2020001609A1; CN110661753B

Abstract

A network registration method, device and system are used for solving the problem that in the prior art, a terminal device with only one SIM card cannot establish connection with IMS of a plurality of networks. In this application, after sending a registration request to an access processing network element, a terminal device may send a first registration request to the registration processing network element in a first network by the access processing network element, then the access processing network element obtains a public identifier of the terminal device in the first network and signed network identifier information of the terminal device through a first registration response message from the registration processing network element in the first network, and sends a second registration request to the registration processing network elements in one or more target networks, and then sends a public identifier of the terminal device in the first network and a public identifier in the one or more target networks to the terminal device, so that the terminal device may register in the first network and the one or more target networks, and further, the terminal device communicates with the terminal devices in the plurality of networks.

Description

Network registration method, device and system

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method, an apparatus, and a system for registering a network.

Background

An IP Multimedia Subsystem (IMS) is a network system for providing multimedia services based on an Internet Protocol (IP) network, and can provide various multimedia services, such as voice call, video call, and the like, for a terminal device through the IMS.

Generally, one network corresponds to one IMS, for regional networks of some parks, such as factories, enterprises, industrial areas, and the like, an IMS corresponding to the regional network may be set, and when a terminal device enters the regional network, the IMS of the regional network may communicate with other terminal devices in the regional network, so that communication in the regional network is more convenient.

However, based on the prior art, one Subscriber Identity Module (SIM) in the terminal device corresponds to one IP Multimedia Private Identity (IMPI), and for a terminal device with only one SIM, the terminal device can only be registered in one network, that is, only can access the IMS of one network, for example, if the terminal device has already established a connection with the IMS in the local area network, the terminal device cannot establish a connection with the IMS in the public network outside the local area network.

Disclosure of Invention

The application provides a network registration method, device and system, which are used for solving the problem that in the prior art, a terminal device with only one SIM card cannot be connected with IMS (IP multimedia subsystem) of a plurality of networks.

In a first aspect, an embodiment of the present application provides a method for registering a network, where the method includes: firstly, after forwarding a first registration request from a terminal device to a first network, an access processing network element receives first registration response information from the registration processing network element of the first network, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device, and the signed network identifier information includes network identifiers of one or more signed networks of the terminal device; then, the access processing network element sends a second registration request to one or more target networks, where the one or more target networks are determined by the subscribed network identification information. Then, the access processing network element may receive second registration response information from the one or more target networks, where the second registration response information includes a public identifier of the terminal device in the corresponding target network, and after the access processing network element receives the second registration request, the access processing network element may send third registration response information to the terminal device, where the third registration response information includes the public identifier of the terminal device in the first network and the public identifier of the terminal device in the one or more target networks.

By the above method, after receiving the first registration request of the terminal device, the access processing network element may complete registration of the terminal device in the first network, and may also complete registration in the one or more target networks, thereby ensuring that the terminal device may simultaneously register in multiple networks.

In a possible design, the access processing network element further needs to confirm that the second registration reply information of each of the one or more target networks is received before sending the third registration reply information to the terminal device.

By the above method, the access processing network element sends the second registration request to the registration processing network element in each target network, and receives the second registration response message sent by the registration processing network element in each target network, so that the terminal device can be registered in the one or more target networks, and further, the terminal device can be ensured to communicate with the terminal device in the one or more target networks.

In a possible design, when determining the one or more target networks according to the signed network identifier information, the access processing network element may further determine the one or more target networks according to preset configuration information and the signed network identifier information, where the preset configuration information includes information used for determining whether the access processing network element is reachable to each network, and each network to which the access processing network element is capable of forwarding a message may be determined according to the preset configuration information.

By the method, the access processing network element can take the reachable signed network in the signed network of the terminal equipment as the target network, so that the network registration method of the embodiment of the application can be suitable for the scene that the terminal equipment has a plurality of signed networks, the application scene is wider, and the registration method is more flexible. When the position of the terminal equipment is inaccessible to the signed network, the terminal equipment does not need to register in the network, and time delay caused by registration failure is effectively avoided.

In a possible design, when the second registration response information further includes service routing information of the terminal device in the corresponding target network, where the service routing information is used to indicate an address of a registration processing network element in the corresponding target network, and after the access processing network element receives the second registration response information from the registration processing network element in the target network, the access processing network element may store the public identifier and the service routing information of the terminal device in the corresponding target network in an associated manner.

By the method, the public identification and the service routing information of the terminal equipment in the corresponding target network are stored in an associated manner, so that the access processing network element can forward the message according to the stored service routing information of the terminal equipment in the target network when the terminal equipment initiates a call flow, and further, the terminal equipment can be ensured to be capable of communicating with the terminal equipment in a plurality of target networks.

In a possible design, after the access processing network element sends the third registration response information to the terminal device, the terminal device may initiate a call flow, and the specific process is as follows:

firstly, the access processing network element receives a call request from the terminal equipment, wherein the call request comprises a public identifier of the terminal equipment in a first network; then, the access processing network element may determine, according to the public identifier of the terminal device in the first network, service routing information of the terminal device in the first network; the access processing network element may forward the call request of the terminal device according to the service routing information.

The access processing network element receives a call request from the terminal equipment, wherein the call request comprises a public identifier of the terminal equipment in any target network; then, the access processing network element may determine corresponding service routing information by using the public identifier included in the call request; the access processing network element may forward the call request of the terminal device according to the corresponding service routing information.

By the method, the access processing network element forwards the call request according to the public identifier stored before and the corresponding service routing information, so that the terminal equipment can initiate the call request to the corresponding network, and the terminal equipment can communicate with the terminal equipment in the corresponding network.

In one possible design, the first registration reply information, the second registration reply information, and the third registration reply information are all 200OK messages.

Through the method, the first registration response message, the second registration response message and the third registration response message are 200OK messages in the existing registration process, so that signaling resources can be saved, and the registration method is more efficient.

In a second aspect, an embodiment of the present application provides a method for registering a network, where the method includes: firstly, a registration processing network element in a first network sends a first message to a first server after authenticating a terminal device according to a registration request from the terminal device, wherein the first message is used for requesting subscription information of the terminal device and comprises a private identity of the terminal device; then, a registration processing network element in the first network receives a second message from the first server, where the second message includes subscription information of the terminal device, and the subscription information includes a public identifier of the terminal device in the first network and subscription network identifier information of the terminal device; after receiving the second message, the registration processing network element in the first network sends first registration response information to the access processing network element, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device.

By the method, after receiving the registration request from the terminal device, the registration processing network element in the first network can complete the registration of the terminal device in the first network, and also can obtain the signing network identification information of the terminal device from the first server, thereby ensuring that the terminal device is registered in other networks, and further ensuring that the terminal device can be simultaneously registered in the first network and other networks.

In a third aspect, an embodiment of the present application provides a method for registering a network, where the method includes: first, a first server receives a first message from a registration processing network element in a first network, where the first message is used to request subscription information of a terminal device, and the first message includes a private identity of the terminal device; then, the first server may determine subscription information of the terminal device according to the private identity of the terminal device, where the subscription information includes a public identity of the terminal device in a first network and subscription network identity information of the terminal device; after determining the subscription information, the first server sends a second message to a registration processing network element in the first network, where the second message includes the subscription information of the terminal device.

By the method, after receiving the first message from the registration processing network element in the first network, the first server feeds back the public identifier of the terminal device in the first network and the signing network identifier information of the terminal device, so that the terminal device can be ensured to be registered in the first network and other networks.

In a possible design, before the first server determines the subscription information of the terminal device according to the private identity of the terminal device, the first server obtains the subscription network identifier information of the terminal device, and specifically, the first server may obtain the subscription network identifier information from a server in the subscription network of the terminal device.

By the method, the first server can acquire the signed network identification information of the terminal device before the terminal device is registered, so that the terminal device can be registered in other networks while being registered in the first network.

In a fourth aspect, an embodiment of the present application provides a method for registering a network, where the method includes: the terminal equipment sends a registration request to an access processing network element; and then, the terminal device receives registration response information from the access processing network element, wherein the registration response information comprises a public identifier of the terminal device in the first network and a public identifier of the terminal device in one or more target networks.

By the method, the terminal device can receive the public identification of the terminal device in the first network and the public identification of the terminal device in one or more target networks by sending a registration request once, namely, the registration of the terminal device in the first network and the one or more target networks is completed, so that the terminal device can be simultaneously registered to a plurality of networks.

In a possible design, after the terminal device receives the registration response information from the access processing network element, the terminal device may initiate a call flow, which includes the following specific processes: the terminal equipment receives a network selection command firstly, wherein the network selection command is used for determining a network to which a call request is accessed; then the terminal equipment selects a public identification from the public identification of the terminal equipment in the first network and the public identification of the terminal equipment in one or more target networks according to the network selection command; and then, the terminal equipment sends a call request to the access processing network element, wherein the call request comprises the public identification selected by the terminal equipment.

By the method, after the terminal device registers in the first network and the one or more target networks, the terminal device may initiate a call flow to the first network or any target network, so that the terminal device may communicate with the terminal device in the first network or any target network.

In a fifth aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to an access processing network element, and for beneficial effects, reference may be made to the description of the first aspect and details are not repeated here. The apparatus has the functionality to implement the actions in the method instance of the first aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In a possible design, the structure of the apparatus includes a receiving unit and a sending unit, and may further include a processing unit, where these units may perform corresponding functions in the method example of the first aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a sixth aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to a registration processing network element in a first network, and for beneficial effects, reference may be made to description of the second aspect and details are not repeated here. The apparatus has the functionality to implement the actions in the method instance of the second aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In a possible design, the structure of the apparatus includes a receiving unit, a sending unit, and a processing unit, and these units may perform corresponding functions in the method example of the second aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a seventh aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to a first server, and for beneficial effects, reference may be made to the description of the third aspect and details are not repeated here. The apparatus has the function of implementing the actions in the method instance of the third aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In a possible design, the structure of the apparatus includes a processing unit and a transceiver unit, and these units may perform corresponding functions in the method example of the third aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In an eighth aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to a terminal device, and for beneficial effects, reference may be made to the description of the fourth aspect and details are not repeated here. The apparatus has the functionality to implement the actions in the method instance of the fourth aspect described above. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In a possible design, the structure of the apparatus includes a sending unit and a receiving unit, and may further include a processing unit, and these units may perform corresponding functions in the method example of the fourth aspect, for specific reference, detailed description in the method example is given, and details are not repeated here.

In a ninth aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to an access processing network element, and for beneficial effects, reference may be made to the description of the first aspect and details are not repeated here. The communication device has a structure including a processor and a memory, and the processor is configured to support the terminal to execute corresponding functions in the method of the first aspect. The memory is coupled to the processor and retains program instructions and data necessary for the communication device. The structure of the communication device also comprises a communication interface used for communicating with other equipment.

In a tenth aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to a registration processing network element in a first network, and for beneficial effects, reference may be made to description of the second aspect and details are not repeated here. The communication device has a structure including a processor and a memory, and the processor is configured to support the terminal to execute the corresponding functions in the method of the second aspect. The memory is coupled to the processor and retains program instructions and data necessary for the communication device. The structure of the communication device also comprises a communication interface used for communicating with other equipment.

In an eleventh aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to a first server, and for beneficial effects, reference may be made to the description of the third aspect, which is not described herein again. The communication device has a structure including a processor and a memory, and the processor is configured to support the terminal to execute corresponding functions in the method of the third aspect. The memory is coupled to the processor and retains program instructions and data necessary for the communication device. The structure of the communication device also comprises a communication interface used for communicating with other equipment.

In a twelfth aspect, an embodiment of the present application further provides a communication apparatus, where the communication apparatus is applied to a terminal device, and for beneficial effects, reference may be made to the description of the fourth aspect and details are not repeated here. The communication device has a structure including a processor and a memory, and the processor is configured to support the terminal to execute the corresponding functions in the method of the fourth aspect. The memory is coupled to the processor and retains program instructions and data necessary for the communication device. The structure of the communication device also comprises a transceiver used for communicating with other equipment.

In a thirteenth aspect, an embodiment of the present application further provides a communication system, which is not described herein again with reference to the description of the foregoing aspects, where the communication system includes an access processing network element and a registration processing network element in a first network;

the access processing network element is configured to forward a first registration request from a terminal device to a registration processing network element in the first network; receiving first registration response information from a registration processing network element in the first network, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device, where the signed network identifier information includes network identifiers of one or more signed networks of the terminal device;

and the registration processing network element in the first network is configured to authenticate the terminal device according to the first registration request from the terminal device, and send the first registration response information to the access processing network element.

In one possible design, the communication system may further include a first server; the registration processing network element in the first network may further send a first message to the first server after the authentication of the terminal device is passed according to a first registration request from the terminal device, where the first message is used to request subscription information of the terminal device, and the first message includes a private identity of the terminal device; the first server receives the first message from the registration processing network element in the first network, and then the first server determines the subscription information of the terminal device according to the private identity of the terminal device, where the subscription information includes the public identity of the terminal device in the first network and the subscription network identity information of the terminal device, and then the first server may send a second message to the registration processing network element in the first network, where the second message includes the subscription information of the terminal device; a registration processing network element in the first network may receive the second message from the first server.

In one possible design, the communication system further includes at least one registration processing network element in the target network; after receiving the first registration response message, the access processing network element may send a second registration request to a registration processing network element in the at least one target network, where the at least one target network is determined by the signed network identifier information; a registration processing network element in the at least one target network receives the second registration request from the access processing network element, where the second registration request may include a private identity of the terminal device; then, for a registration processing network element in any target network, the registration processing network element in the target network acquires subscription information of the terminal device in the target network from a second server in the target network, wherein the subscription information of the terminal device in the target network includes a public identifier of the terminal device in the target network; then, sending a second registration response message to the access processing network element, where the second registration response message includes a public identifier of the terminal device in the target network; and the access processing network element receives second registration response information from the registration processing network element in the at least one target network.

In one possible design, the communication system may further include a terminal device; the terminal device may send a first registration request to the access processing network element, where the first registration request may include a private identity of the terminal device in the first network; then, the access processing network element may receive a first registration request from the terminal device, and when the access processing network element receives a first registration response message from a registration processing network element in the first network and a second registration response message from a registration processing network element in the at least one target network, the access processing network element may send third registration response information to the terminal device, where the third registration response information includes a public identifier of the terminal device in the first network and a public identifier of the terminal device in the at least one target network, and then the terminal device receives the third registration response information from the access processing network element.

In a fourteenth aspect, the present application also provides a computer-readable storage medium having stored therein instructions, which, when run on a computer, cause the computer to perform the method of the above-described aspects.

In a fifteenth aspect, the present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the above aspects.

In a sixteenth aspect, the present application further provides a computer chip, where the computer chip is connected to a memory, and the computer chip is configured to read and execute a software program stored in the memory, and execute the method in the above aspects.

Drawings

FIG. 1 is a schematic diagram of an IMS architecture;

fig. 2 is a schematic architecture diagram of a network system provided in the present application;

FIG. 3 is a schematic diagram of another network system architecture provided in the present application;

fig. 4 is a schematic diagram illustrating a network registration method provided in the present application;

fig. 5 is a flowchart of a network registration method provided in the present application;

fig. 6 to 11 are schematic structural diagrams of a communication device according to the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a network framework of an IMS, including: a terminal device, a proxy-call-state control function (P-CSCF) network element, a serving-call-state control function (S-CSCF) network element, a Home Subscriber Server (HSS), and an Application Server (AS).

Wherein the terminal device: the system comprises a P-CSCF network element used for generating a registration request and sending the generated registration request to the IMS; and receiving registration reply information returned from the IMS system.

The P-CSCF network element: the first connection point from the access network to the IMS is the first contact point of the terminal device in the IMS, the P-CSCF network element functions in the IMS system similarly to performing proxy services, and all information, whether coming from the terminal device or sent to the terminal device, must be forwarded through the P-CSCF network element. The P-CSCF network element is responsible for verifying the request in the IMS, forwarding the verified request to a specified target, and processing and forwarding response information, and the IMS of different networks can have the same P-CSCF network element.

Specifically, the P-CSCF network element is configured to forward a registration request and response information from a terminal device to the S-CSCF network element; and forwarding the registration request and the response information to the terminal equipment.

The S-CSCF network element: and the method provides session control and registration for the terminal equipment for the control core of the IMS. The S-CSCF network element is used for receiving the registration request of the terminal equipment forwarded by the P-CSCF network element; authenticating the terminal equipment; after the authentication is determined to pass, acquiring subscription information of the terminal equipment from the HSS through a CX interface of a Diameter protocol, wherein the subscription information comprises IMPU of the terminal equipment in a network; and the S-CSCF network element is also used for connecting with each application server based on the ISC interface, and triggering the application servers to execute operation, and routing the request message of the terminal equipment to the corresponding application servers.

The HSS is used for: is the main data storage in the IMS that stores all user and service related data. The data stored in the HSS mainly includes user identities, subscription information, access parameters, etc.

The AS: at the user's home network or third party location. Where a third party location refers to a network or a separate application server. The main functions of the AS are: processing a request message sent from the S-CSCF network element; and sending the processed request message to the S-CSCF network element.

Although not shown, an interrogating-call session control function (I-CSCF) network element may be further included in the IMS, and the I-CSCF network element may connect the S-CSCF network element and the P-CSCF network element, and is configured to provide an entry to a home network for a user; when the terminal equipment roams to other networks, sending a message to the P-CSCF network element, wherein the P-CSCF network element can forward the message from the terminal equipment to the I-CSCF network element and send the message from the terminal equipment to the S-CSCF network element through the I-CSCF network element; specifically, the I-CSCF network element needs to query a corresponding S-CSCF network element through an HSS in the IMS, and then forward the message from the terminal device to the corresponding S-CSCF network element.

The terminal device in the present application, which may also be referred to as a User Equipment (UE), may be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (pad), a computer with wireless transceiving function, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless device in industrial control (industrial control), a wireless device in unmanned driving (self driving), a wireless device in remote medical treatment (remote medical), a wireless device in smart grid (smart grid), a wireless device in transportation safety (transportation safety), a wireless device in smart city (smart city), a wireless device in smart home (smart home), and the like.

Based on the network framework shown in fig. 1, the process of registering the terminal device to the first network is as follows:

after a terminal device initiates a registration request to an IMS system of a first network, a P-CSCF network element receives a registration request carrying IMPI of the terminal device from the terminal device, the P-CSCF network element forwards the registration request to an S-CSCF network element, the S-CSCF network element performs authentication, after the authentication is passed, the P-CSCF network element sends a Server Assignment Request (SAR) message to an HSS in the first network, the HSS in the first network feeds back an SAA message to the S-CSCF network element after receiving the SAR message, the server assignment response (SAA) message includes subscription information of the terminal device, for example, an IP multimedia public Identity (IMPU) of the terminal device in the first network, the S-CSCF network element receives the SAA message, obtaining an IMPU of the terminal device in a first network, and sending a 200OK message to the P-CSCF network element, wherein the 200OK message includes the IMPU of the terminal device in the first network and service route (service route) information of the terminal device in the first network, and the service route information carries information for indicating an address of the S-CSCF network element in the first network, so that the P-CSCF network element forwards a call request to the S-CSCF network element according to the stored service route information after receiving the call request carrying the IMPU of the terminal device in the first network. And after receiving the 200OK message, the P-CSCF network element deletes the service routing information in the 200OK message and sends the 200OK message with the deleted service routing information to the terminal equipment. To this end, the terminal device registers with the first network and establishes a connection with the IMS of the first network.

After receiving the 200OK message, the terminal device may initiate a call request based on the IMPU of the terminal device in the first network included in the 200OK message, establish a connection with a network element in the IMS of the first network, and communicate with other terminal devices in the first network; however, when the terminal device is registered in the first network, that is, when the terminal device has established a connection with the IMS of the first network, the terminal device cannot be registered in another network, that is, cannot establish a connection with the IMS of another network, so that the terminal device cannot communicate with the terminal device in another network.

Therefore, the embodiment of the present application provides a network registration method, so as to solve the problem that in the prior art, a terminal device cannot establish a connection with IMS in multiple networks.

Fig. 2 is a schematic structural diagram of a network system applied in the embodiment of the present application, where the network system includes: the system comprises terminal equipment, an access processing network element, a registration processing network element in a first network, a first server and a registration processing network element in a target network. Optionally, the network system may further include a second server, and in this embodiment, the number of target networks is not limited, that is, the terminal device may register to one target network, or may register to multiple target networks, and accordingly, the network system may include a registration processing network element and a second server in each target network.

It is to be understood that the terms "first," "second," "third," and the like in the description of the present application are used for descriptive purposes only and not for purposes of indicating or implying relative importance, nor order; plural in the present embodiment means two or more; in the embodiment of the present application, the network attributes of the first network and the target network are not limited, for example, the first network may be a public network, and the second network may be a regional network; also for example, the first network and the second network may both be area networks.

It should be noted that the public network may be a network owned by an operator, and the local area network may refer to a network owned by a specific user, such as a cell network, a campus network, and so on.

The terminal device may send a registration request to a registration processing network element in the first network (in this embodiment, the registration request sent by the terminal device is a first registration request), and may also receive a registration response message from the registration processing network element in the first network (in this embodiment, the registration response message received by the terminal device from the registration processing network element in the first network is a third registration response message), where the public identity of the terminal device in the first network may be included in the registration response message received from the registration processing network element in the first network, and may also include a public identity of the terminal device in one or more target networks; the terminal device may initiate a call flow based on the plurality of public identities included in the registration response message received from the registration processing network element in the first network.

The access processing network element is a first contact point between the terminal device and the first network or the target network, and the access processing network element may forward a registration request (e.g., a first registration request) from the terminal device to the registration processing network element in the first network or the target network, where the registration request from the terminal device includes a private identity of the terminal device, and may also actively send a second registration request carrying the private identity of the terminal device to the registration processing network element in the target network when receiving the signed network identity information of the terminal device; a third registration reply message may also be sent to the terminal device.

Optionally, the access processing network element may be a P-CSCF network element in the IMS system.

The private identity of the terminal device is an identity used for identifying the terminal device, and is an identity which is private to the terminal device and invisible to other terminal devices, the number of the private identities of the terminal device is not limited in the application, and the type of the private identity of the terminal device is not limited in the application, for example, the private identity of the terminal device may be an IMPI, or may be other identities.

The registration processing network element (e.g., the registration processing network element in the first network or the registration processing network element in the target network) may receive a registration request from the terminal device, authenticate the terminal device according to the registration request from the terminal device, and obtain subscription information of the terminal device through a server in the network after the authentication is passed, where the subscription information includes a public identifier of the terminal device in the network, and then send a registration response message (e.g., a first registration response message or a second registration response message) carrying the subscription information to the access processing network element.

The public identifier of the terminal device in a network is information for identifying the terminal device in the network, and is an identifier that is visible to other terminal devices, for example, the public identifier of the terminal device in the network may represent identity information of the terminal device in the network, and a terminal device in the network may have a plurality of different public identifiers for representing different identity information. The present application does not limit the type of the public identifier of the terminal device in the network, for example, the public identifier may be an IMPU, or may be another identifier, and the present application is not limited thereto.

It should be noted that, in this embodiment of the present application, the registration processing network element in the first network may be configured as a registration processing network element that needs to authenticate the terminal device, and the registration processing network element in the target network may be configured as a registration processing network element that needs to authenticate the terminal device. The above configuration manner is merely an example, and in fact, the registration processing network element in each network (e.g., the first network or the target network) may be configured according to a scenario.

The registration processing network element in the first network or the target network may be an S-CSCF network element in the IMS, for example, the registration processing network element in the first network is an S-CSCF network element in the first network; and the registration processing network element in the target network is an S-CSCF network element in the target network.

The first server is a data memory for storing subscription information and service related data of the terminal equipment in a first network; and the second server is used for storing the data memory of the signing data and the service related data of the terminal equipment in the target network.

The first server or the second server may be an HSS, e.g., the first server is a first HSS and the second server is a second HSS.

In the application embodiment, the terminal device may send, after sending the first registration request to the access processing network element, the access processing network element sends the first registration request to the registration processing network element in the first network, then obtains, through a first registration response message received from the registration processing network element in the first network, the public identifier of the terminal device in the first network and the subscription network identifier information of the terminal device, and sends, to the registration processing network element in the one or more target networks, the second registration request, and then obtains, through a second registration response message received from the registration processing network element in the one or more target networks, the public identifier of the terminal device in the one or more target networks, and then the access processing network sends, to the terminal device, a third note carrying the public identifier that the terminal device can have in the first network and the one or more target networks And registering the response message so that the terminal equipment can be simultaneously registered to the first network and the one or more target networks, and further, the terminal equipment is communicated with the terminal equipment in a plurality of networks.

Fig. 3 is a schematic diagram of a framework of another network system applicable to the embodiment of the present application, where the network system includes a UE, a P-CSCF network element, an S-CSCF network element in a first network, a first HSS, and an S-CSCF network element in a target network, and the network system may further include a second HSS, wherein the P-CSCF network element corresponds to the access processing network element shown in fig. 2, the S-CSCF network element in the first network corresponds to the registration processing network element in the first network as shown in figure 2, the S-CSCF network element in the target network corresponds to the registration processing network element in the target network as shown in figure 2, the first HSS corresponding to the first server as shown in FIG. 2, the second HSS corresponding to the second server as shown in FIG. 2, the functions of the network elements shown in fig. 3 are not described herein again with reference to the related descriptions shown in fig. 1-2.

It should be understood that, although only the S-CSCF network element and the second HSS in one target network are shown in fig. 3, the network system shown in fig. 3 may include the S-CSCF network element and the second HSS in a plurality of target networks, and the number of target networks is not limited in the embodiment of the present application.

In fact, the embodiment of the present application can also be applied to the network system shown in fig. 2, and because the principles are similar, only the network system shown in fig. 3 is taken as an example for description here.

Fig. 4 shows a network registration method provided in the embodiments of the present application.

S401: and the UE sends a first registration request to the P-CSCF network element.

S402: and after receiving the first registration request, the P-CSCF network element forwards the first registration request to an S-CSCF network element in the first network.

S403: and the S-CSCF network element in the first network authenticates the UE according to a first registration request from the UE, and sends a first message to the first HSS after the authentication is passed, wherein the first message is used for requesting subscription information of the UE and comprises IMPI of the UE.

The first registration request includes IMPI of the UE and related authentication information, where the IMPI of the UE is a private identity of the UE and is used to identify the UE, and one UE may have one IMPI or multiple IMPIs, and in this embodiment, an example of an IMPI of a UE is described, the IMPI of the UE may enable a P-CSCF network element to send a first registration request to a corresponding first network according to the IMPI of the UE after receiving the first registration request, for example, the first registration request message may be sent to an I-CSCF network element in the first network, and then the I-CSCF forwards the first registration request to an S-CSCF network element in the first network, and then after the S-CSCF network element in the first network authenticates the UE, the IMPI of the UE may be carried in the first message and sent to the first HSS, obtaining subscription information of the UE from the first HSS, wherein the first message may be an SAR message.

S404: the first HSS receives a first message from an S-CSCF network element in a first network, and determines subscription information of the UE according to IMPI of the UE, wherein the subscription information comprises IMPU of the UE in the first network and subscription network identification information of the UE.

The first HSS stores IMPU of the UE in the first network and signed network identification information of the UE; the IMPU of the UE in the first network is a public identity of the UE in the first network, and is visible to a network element in an IMS of the first network and other UEs in the first network, and based on the IMPU of the UE in the first network, the UE may establish a connection with the network element in the IMS of the first network and communicate with other UEs in the first network. The number of IMPUs of the UE in the first network is not limited in this application.

The signed network identifier information of the UE is used to represent identifier information of the UE signed network, where the identifier information includes network identifiers of one or more signed networks, and the identifier information may be domain name information of a network or an Identity (ID) of the network, and all information capable of identifying a network is suitable for the embodiment of the present application.

One or more of the UE subscribed networks may be indicated in the subscribed network identification information of the UE. Before the first HSS determines the subscription information of the UE according to the IMPI of the UE, the first HSS needs to acquire the subscription network identification information of the UE.

Specifically, the first HSS may obtain the subscription network identifier information of the UE from an HSS in a subscription network.

When the UE signs up with a network, the network is a subscription network, and an HSS in the subscription network may store subscription information of the UE in the subscription network, where the subscription information includes an IMPI of the UE and an IMPU of the UE in the subscription network, where a correspondence exists between the IMPI of the UE and the IMPU of the UE in the subscription network, and the HSS in the subscription network may send, to the first HSS, a network identifier of the subscription network as subscription network identifier information of the UE to the first HSS; when the UE signs a contract with a plurality of networks, the UE corresponds to the plurality of signed networks, and the HSS in each signed network stores the IMPI of the UE and the IMPU of the UE in the signed network and sends the network identification of the signed network to the first HSS; the first HSS receives network identifications of a plurality of signed networks, and stores the identification information of the plurality of signed networks as signed network identification information of the UE.

It should be noted that, in the above example, taking an example that the HSS in the subscribed network actively sends the subscribed network identifier of the UE to the first HSS, a manner in which the HSS in the subscribed network sends the subscribed network identifier of the UE is not limited in the embodiment of the present application, and any manner that the subscribed network identifier of the UE may be sent to the first HSS is applicable to the embodiment of the present application. In fact, there are many ways for the first HSS to obtain the subscribed network identification information of the UE, and the way is not limited to the way for the HSS in the subscribed network to actively send the subscribed network identification information of the UE to the first HSS, for example, the first HSS may send a request message to the HSS in another network to determine the subscribed network of the UE and request to obtain the subscribed network identification information of the UE, and then the HSS in the subscribed network of the UE sends the subscribed network identification information of the UE to the first HSS.

S405: the first HSS sends a second message to an S-CSCF network element in the first network, where the second message includes subscription information of the UE, and the second message may be, for example, an SAA message.

S406: and the S-CSCF network element in the first network receives the second message from the first HSS, and then the S-CSCF network element in the first network sends first registration response information to the P-CSCF network element, wherein the first registration response information comprises the IMPU of the UE in the first network and the signed network identification information of the UE.

After receiving the second message from the first HSS, the S-CSCF network element in the first network acquires the IMPU of the UE in the first network and the signed network identity information of the UE, carries the IMPU of the UE in the first network and the signed network identity information of the UE in the first registration response information, and then sends the first registration response message to the P-CSCF network element, where the first registration response message has many forms, for example, the first registration response message may be a 200OK message, which is not limited in the embodiment of the present application.

The first registration response message further includes service routing information of the UE in the first network, where the service routing information is used to indicate an address of an S-CSCF network element in the first network.

The service routing information of the UE in the first network is used to enable the P-CSCF network element to determine an S-CSCF network element to which the UE needs to forward the information when forwarding the information, the service routing information of the UE in the first network may indicate addresses of the S-CSCF network elements in the first network, when the first network has a plurality of S-CSCF network elements, the service routing information of the UE in the first network may indicate addresses of the plurality of S-CSCF network elements in the first network, when the service routing information of the UE in the first network indicates the addresses of the plurality of S-CSCF network elements in the first network, and when the P-CSCF network element forwards the information, the P-CSCF network element only needs to forward the information to any one of the indicated S-CSCF network elements.

Specifically, there are many ways in which the service routing information of the UE in the first network indicates the address of the S-CSCF network element in the first network, for example, the service routing information of the UE in the first network may be directly displayed as the address of the S-CSCF network element in the first network, or may be interface information pointing to the S-CSCF network element in the first network, and the above ways are merely examples, and all the ways that the address of the S-CSCF network element in the first network may be indicated are applicable to the embodiment of the present application. The present application does not limit the form of the service routing information of the UE in the first network, and for example, the service routing information may be carried by a service-route header field, or other manners may also be adopted.

S407: and the P-CSCF network element receives first registration response information from an S-CSCF network element in the first network, and the P-CSCF network element sends a second registration request to the S-CSCF network element in one or more target networks, wherein the one or more target networks are determined by the signed network identification information.

And after receiving the first registration response information from the S-CSCF network element in the first network, the P-CSCF network element acquires the signed network identification information of the UE.

The P-CSCF network element stores preset configuration information, and the preset configuration information comprises information used for judging whether the P-CSCF network element can reach each network or not. For example, the preset configuration information may include information of a next hop from the P-CSCF network element to each network (for example, information indicating a next hop from the P-CSCF network element to each network by configuring a domain name), and if the preset configuration information includes information of a next hop from the P-CSCF network element to the subscribed network for the UE, the signed network is the network which can be reached by the P-CSCF network element, otherwise, the network can not be reached, the above information for determining whether the P-CSCF network element is reachable to each network is only an example, and it should be understood that, the types of the information for determining whether the P-CSCF network element can reach each network are many, and the information that can be used for determining whether the P-CSCF network element can reach each network is applicable to the embodiment of the present application.

When determining the one or more target networks, the P-CSCF network element may determine, based on the preset configuration information and according to the contracted network identification information, a network that the P-CSCF network element can reach from the contracted network indicated by the contracted network identification information as a target network, where the number of the determined target networks may be one or multiple; if one network that the P-CSCF network element can reach exists in the contracted network indicated by the contracted network identification information, the network that the P-CSCF network element can reach is the target network, and if multiple networks that the P-CSCF network element can reach exist in the contracted network indicated by the contracted network identification information, each network that the P-CSCF network element can reach is a target network, in which case, multiple target networks exist; in another possible implementation manner, a plurality of networks that can be reached by the P-CSCF network element exist in the contracted network indicated by the contracted network identification information, and a part of the networks that can be reached by the P-CSCF network elements may also be determined as target networks. The above manner is merely illustrative, and in a specific implementation, the number of the target networks and the corresponding target networks may be determined according to a specific scenario, which is not limited in the present application.

It should be noted that the preset configuration information is pre-stored in the P-CSCF network element, the preset configuration information may be updated in real time, and a specific storage manner and an update manner are not limited in this application embodiment; because the geographic location and the network attribute of each network are different, the P-CSCF network element may only be routed to some specific networks, and the preset configuration information may only include information for determining whether the P-CSCF network element is reachable to a part of the networks.

After the one or more target networks are determined from the contracted networks indicated by the contracted network identification information, the P-CSCF network element sends a second registration request to an S-CSCF network element in the one or more target networks, that is, the P-CSCF network element sends a second registration request to an S-CSCF network element in each target network. The second registration request includes an IMPI of the UE.

For each target network, after receiving the second registration request, the S-CSCF network element in the target network may authenticate the UE, or may not authenticate the UE, and the embodiment of the present application is not limited as to whether authentication is required in the second network. The authentication operation of the S-CSCF network element in the target network on the UE may be set according to a specific scenario.

Then, the S-CSCF network element in the target network sends a first message carrying the IMPI of the UE to a second HSS in the target network to acquire the subscription information of the UE in the target network, and after receiving the first message, the second HSS in the target network determines the subscription information of the UE in the target network according to the IMPI of the UE and feeds back a second message to the S-CSCF network element in the target network, wherein the subscription information of the UE in the target network comprises the IMPU of the UE in the target network; for example, the first message may be a SAR message and the second message may be a SAA message.

And after receiving a second message from the second HSS, the S-CSCF network element in the target network sends second registration response information to the P-CSCF network element, wherein the second registration response information comprises the IMPU of the UE in the target network.

Optionally, the second registration response message may have many forms, for example, the second registration response message may be a 200OK message, which is not limited in this application.

S408: and the P-CSCF network element receives second registration response information from an S-CSCF network element in the one or more target networks, wherein the second registration response information comprises IMPU of the UE in the corresponding target network.

In a possible implementation manner, the second registration reply message further includes service routing information of the UE in the corresponding target network. And after receiving the second registration response message, the P-CSCF network element associates and stores the IMPU and the service routing information of the UE in the corresponding target network. The service routing information is used for indicating the address of the S-CSCF network element in the corresponding target network.

For an S-CSCF network element in any one of the one or more target networks, the P-CSCF network element receives second registration response information from the S-CSCF network element in the target network, where the second registration response information may include service routing information of the terminal device in the target network, where the service routing information is used to indicate an address of the S-CSCF network element in the target network, where the service routing information of the UE in the target network is used to enable the P-CSCF network element to determine the S-CSCF network element to which forwarding information needs to be forwarded, the service routing information of the UE in the target network may indicate the address of the S-CSCF network element in the target network, and when there are multiple S-CSCF network elements in the target network, the service routing information of the UE in the target network may indicate the multiple S-CSCF network elements in the target network And when the service routing information of the UE in the target network can indicate the addresses of a plurality of S-CSCF network elements in the target network, and the P-CSCF network element only needs to forward the information to any one of the indicated S-CSCF network elements when forwarding the information.

A manner in which the service routing information of the UE in the target network indicates the address of the S-CSCF network element in the target network is similar to a manner in which the service routing information of the UE in the first network indicates the address of the S-CSCF network element in the first network, which may specifically refer to the related description of the service routing information of the UE in the first network, and is not described herein again.

The present application does not limit the form of the service routing information of the UE in the target network, and for example, the service routing information may be carried by a service-route header field, or other manners may also be adopted.

Optionally, in the case that the second registration response message includes the service routing information of the UE in the target network, the P-CSCF network element may delete the second registration response message after saving the IMPU of the UE in the target network and the service routing information of the UE in the target network.

After the P-CSCF network element receives second registration response information from the one or more target networks, the P-CSCF network element obtains an IMPU of the UE in the corresponding target network from each second registration response message, adds the IMPU of the UE in the one or more target networks to the first registration response information, and sends the first registration response information, to which the IMPU of the UE in the one or more target networks is added, as third registration response information to the UE. The P-CSCF network element may also obtain, after the IMPU of the UE in the corresponding target network in each second registration reply message and the IMPU of the UE in the first network in the first registration reply message, carry, in the third registration reply information, the IMPU of the UE in the one or more target networks and the IMPU of the UE in the first network, and send the third registration reply information to the UE.

Optionally, the third registration response message may have many forms, for example, the third registration response message may be a 200OK message, which is not limited in this application.

S409: and the P-CSCF network element sends third registration response information to the UE, wherein the third registration response information comprises the IMPU of the UE in the first network and the IMPU of the UE in the one or more target networks.

The IMPU of the UE in the one or more target networks included in the third registration reply information may be an IMPU sent by an S-CSCF network element in each of the target networks.

Specifically, before the P-CSCF network element sends the third registration reply information to the UE, the P-CSCF network element may determine that the second registration reply information of the S-CSCF network element in each of the one or more target networks has been received.

After receiving the third registration response message, the UE determines that the registration is successful, and if the UE receives a network selection command, the network selection command is used to determine a network to which the call request is accessed; then, the UE may select one IMPU from the IMPUs of the UE in the first network and the IMPUs of the UE in the one or more target networks to initiate a call flow according to the network selection command, for example, when a user needs to communicate with the UE in the first network, an indication may be sent to the UE, for example, an indication may be sent by dialing, shortcut key, and the UE may receive the network selection command; in this case, the network selection command is used to determine that the network to which the call requests to access is the first network, and the UE selects an IMPU in the first network to initiate a call flow according to the network selection command; when a user needs to communicate with a UE in a target network, an instruction may be sent to the UE, for example, the instruction is sent by dialing, shortcut key, and the like, and the UE may receive a network selection command; in this case, the network selection command is used to determine that the network to which the call request is accessed is the target network, and the UE selects the IMPU of the UE in the target network to initiate a call flow according to the network selection command; that is, the UE sends a call request to the P-CSCF network element, where the call request includes the IMPU selected by the UE.

Accordingly, there are two cases:

in case one, the UE may send a call request to the P-CSCF network element, where the call request includes an IMPU of the UE in the first network;

the P-CSCF network element determines service routing information of the UE in the first network according to the IMPU of the UE in the first network; and then forwarding the call request to an S-CSCF network element in the first network according to the service routing information of the UE in the first network.

In case two, the UE may send a call request to the P-CSCF network element, where the call request includes an IMPU of the UE in any target network;

the P-CSCF network element determines corresponding service routing information according to the IMPU included in the call request; and then, forwarding the call request to an S-CSCF network element in a corresponding target network according to the corresponding service routing information.

The network registration method provided in the embodiment of the present application is further described below with application of the network registration method shown in fig. 4 to a specific scenario.

As shown in fig. 5, a network registration method provided in this embodiment of the present application is implemented, where the first network is a public network, the target network is a local area network, and the signing network identifier information of the terminal device is domain name information of the local area network.

S501: the UE signs up with a local area network, and the second HSS stores subscription information, wherein the subscription information comprises an IMPI of the UE and an IMPU of the UE in the local area network.

The second HSS may acquire, when acquiring the IMPI of the UE, the IMPI of the UE from the first HSS of the public network in the local network based on the IMPU of the UE in the local network.

S502: and the second HSS registers the domain name information of the regional network in the first HSS of the public network.

Specifically, there are many ways for the second HSS to register the domain name information of the area network, for example, the domain name information of the area network may be sent to the first HSS through an interface, or the domain name information of the area network may be sent to the first HSS through a signaling method.

There are many ways for the first HSS to store the domain name information of the local area network, for example, the first HSS may add an extended domain name list after the IMPI of the UE, and store the domain name information of the local area network in the extended domain name list; or setting a mapping relationship, and establishing the mapping relationship between the IMPI of the UE and the domain name information of the area network.

S503: and the UE sends a registration request carrying IMPI of the UE to the P-CSCF network element, the S-CSCF network element in the public network authenticates the UE, and after the authentication is passed, the SAR message is sent to the first HSS to acquire subscription information of the UE.

S504: and the first HSS sends an SAA message to an S-CSCF network element in the public network, wherein the SAA message carries subscription information of the UE.

And the subscription information of the UE comprises IMPU of the UE in the public network, and if the domain name information of the local area network of the UE is stored in the first HSS, the domain name information of the local area network is carried in SAA information and is sent to an S-CSCF network element in the public network.

S505: after receiving the SAA message, an S-CSCF network element in the public network sends a first 200OK message of successful registration to the P-CSCF network element, wherein the first 200OK message comprises an IMPU (advanced peripheral unit) of the UE in the public network and a corresponding service-route header domain, the service-route header domain carries service routing information of the UE in the public network, and the service routing information is used for indicating an address of the S-CSCF network element in the public network; and if the SAA message comprises the domain name information of the area network, carrying the domain name information of the area network in the first 200OK message.

S506: after the P-CSCF network element receives a first 200OK message, if the first 200OK message comprises domain name information of the local area network, the domain name information of the local area network needs to be stored; the domain name information of the area network in the first 200OK message may be deleted later.

And aiming at the area networks indicated in the domain name information of the area networks, the P-CSCF network elements initiate registration processes to the indicated IMS in each area network one by one, namely, second registration requests are sent to the S-CSCF network elements in each area network, and the second registration requests comprise IMPIs of the UE.

When the P-CSCF network element sends the second registration request to the S-CSCF network element in one of the regional networks, in fact, the second registration request may be sent to an S-CSCF network element in the area network by an I-CSCF network element in the area network, and, in particular, the P-CSCF network element sends the second registration request to an I-CSCF network element in the area network, an I-CSCF network element in the regional network sends a request message to a second HSS in the regional network, for obtaining from said second HSS an address of an S-CSCF network element in the area network, after the I-CSCF network element in the regional network acquires the address of the S-CSCF network element in the regional network, and sending the second registration request to the S-CSCF network element in the area network according to the address of the S-CSCF network element in the area network.

S507: after receiving the second registration request, the S-CSCF network element in the local area network may not authenticate the UE, and interact with the second HSS of the local area network to acquire the subscription information of the UE in the local area network, for example, the S-CSCF network element in the local area network sends an SAR message to the second HSS, and the second HSS returns an SAA message, where the SAA message carries the subscription information of the UE in the local area network.

S508: and the S-CSCF network element in the local area network sends a second 200OK message to the P-CSCF network element, wherein the second 200OK message comprises an IMPU (implementation Unit) of the UE in the local area network and a corresponding service-route header field, the service-route header field carries service routing information of the UE in the local area network, and the service routing information is used for indicating the address of the S-CSCF network element in the local area network.

Correspondingly, when the S-CSCF network element in the regional network sends the second 200OK message to the P-CSCF network element, the second 200OK message may also be sent to the P-CSCF network element through the I-CSCF network element in the regional network.

S509: after receiving the second 200OK message, the P-CSCF network element stores the IMPU of the UE in the area network and the corresponding service-route header field, adds the IMPU of the UE in the area network to the first 200OK message, and then sends the first 200OK message to which the IMPU of the UE in the area network is added to the UE.

S510: the UE selects an IMPU (for example, selects an IMPU of the UE in the public network or selects an IMPU of the UE in the local network), and initiates a call request to the P-CSCF network element, where the call request includes the selected IMPU.

S511: and after receiving the call request, the P-CSCF network element queries a corresponding service-route header domain according to the IMPU included in the call request, and forwards the call request according to the corresponding service-route header domain.

Based on the same inventive concept as the method embodiment, an embodiment of the present application further provides a communication apparatus for executing the method executed by the access processing network element in the foregoing method embodiment, and related features may refer to the foregoing method embodiment, which is not described herein again, and as shown in fig. 6, the apparatus includes a sending unit 601 and a receiving unit 602;

the sending unit 601 is configured to forward the first registration request from the terminal device to the first network;

the receiving unit 602 is configured to receive first registration response information from a first network after the sending unit 601 forwards a first registration request from a terminal device to the first network, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device, where the signed network identifier information includes network identifiers of one or more signed networks of the terminal device;

the sending unit 601 is further configured to send a second registration request to one or more target networks, where the one or more target networks are determined by the subscription network identification information;

the receiving unit 602 is further configured to receive second registration response information from the one or more target networks, where the second registration response information includes a public identifier of the terminal device in the corresponding target network;

the sending unit 601 is further configured to send third registration response information to the terminal device, where the third registration response information includes a public identifier of the terminal device in the first network and a public identifier of the terminal device in the one or more target networks.

In a possible implementation manner, the first registration request and the second registration request include a private identity of the terminal device.

Optionally, the communication apparatus further includes a processing unit 603, and the processing unit 603 may determine that the second registration response information of each of the one or more target networks is received before the sending unit 601 sends the third registration response information to the terminal device.

After determining that the second registration response information of each of the one or more target networks is received, the sending unit 601 sends third registration response information to the terminal device.

The processing unit 603 may further be configured to determine the one or more target networks, specifically, the one or more target networks are determined by preset configuration information and the subscription network identifier information; the preset configuration information includes information for judging whether the access processing network element is reachable to each network.

After the receiving unit 602 receives the second registration response information from the registration processing network element in the one or more target networks, if the second registration response information further includes the service routing information of the terminal device in the corresponding target network, where the service routing information is used to indicate an address of the registration processing network element in the corresponding target network, and the processing unit 603 stores the public identifier and the service routing information of the terminal device in the corresponding target network in an associated manner.

After the sending unit 601 sends the third registration response message to the terminal device, the terminal device may send a call request based on the public identifier in the third registration response message.

The receiving unit 602 receives a call request from the terminal device, where the call request includes a public identifier of the terminal device in a first network or a public identifier of the terminal device in any target network.

Then, the processing unit 603 determines corresponding service routing information according to the public identifier included in the call request.

Finally, the sending unit 601 forwards the call request of the terminal device according to the corresponding service routing information.

Optionally, the first registration reply information, the second registration reply information, and the third registration reply information are all 200OK messages.

Based on the same inventive concept as the method embodiment, an embodiment of the present application further provides a communication apparatus for executing the method executed by the registration processing network element in the first network in the foregoing method embodiment, and related features may refer to the foregoing method embodiment, which are not described herein again, and as shown in fig. 7, the apparatus includes a sending unit 701, a receiving unit 702, and a processing unit 703:

the processing unit 703 is configured to authenticate the terminal device according to a registration request from the terminal device;

the sending unit 701 is configured to send a first message to a first server after the processing unit 703 authenticates the terminal device according to a registration request from the terminal device, where the first message is used to request subscription information of the terminal device, and the first message includes a private identity of the terminal device;

the receiving unit 702 is configured to receive a second message from the first server, where the second message includes subscription information of the terminal device, and the subscription information includes a public identifier of the terminal device in a first network and subscription network identifier information of the terminal device, where the subscription network identifier information includes network identifiers of one or more subscription networks of the terminal device.

The sending unit 701 is further configured to send first registration response information to an access processing network element, where the first registration response information includes a public identifier of the terminal device in a first network and signed network identifier information of the terminal device;

based on the same inventive concept as the method embodiment, an embodiment of the present application further provides a communication apparatus for executing the method executed by the first server in the method embodiment, and related features may refer to the method embodiment described above, which are not described herein again, and as shown in fig. 8, the apparatus includes a transceiver unit 801 and a processing unit 802:

the transceiver 801 is configured to receive a first message from a registration processing network element in a first network, where the first message is used to request subscription information of a terminal device, and the first request message includes a private identity of the terminal device.

The processing unit 802 is configured to determine, according to a private identity of the terminal device, subscription information of the terminal device, where the subscription information includes a public identity of the terminal device in a first network and subscription network identity information of the terminal device, where the subscription network identity information includes network identities of one or more subscription networks of the terminal device;

the transceiver 801 is further configured to send a second message to a registration processing network element in the first network, where the second message includes subscription information of the terminal device.

Specifically, the processing unit 802 obtains the subscription network identifier information of the terminal device before determining the subscription information of the terminal device according to the private identifier of the terminal device.

Based on the same inventive concept as the method embodiment, an embodiment of the present application further provides a communication apparatus for executing the method executed by the terminal device in the foregoing method embodiment, and related features may refer to the foregoing method embodiment, which is not described herein again, and as shown in fig. 9, the apparatus includes a sending unit 901 and a receiving unit 902:

the sending unit 901 is configured to send a registration request to an access processing network element;

the receiving unit 902 is configured to receive registration response information from the access processing network element, where the registration response information includes a public identifier of a terminal device in a first network and a public identifier of the terminal device in one or more target networks.

Optionally, the communication apparatus may further include a processing unit 903, and after the receiving unit 903 receives the registration response information from the access processing network element, the terminal device may initiate a call flow, first, the receiving unit 903 receives a network selection command, where the network selection command is used to determine a network to which the call request is accessed; then, the processing unit 903 may select a public identity from the public identity of the terminal device in the first network and the public identity of the terminal device in one or more target networks according to the network selection command; then, the sending unit 901 sends a call request to the access processing network element, where the call request includes the public identifier selected by the terminal device.

The division of the units in the embodiments of the present application is schematic, and only one logic function division is used, and there may be another division manner in actual implementation, and in addition, each functional unit in each embodiment of the present application may be integrated in one processor, may also exist alone physically, or may also be integrated in one module by two or more units. The integrated unit can be realized in a form of hardware or a form of a software functional module.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a terminal device (which may be a personal computer, a mobile phone, or a network device) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

In this embodiment of the present application, the access processing network element, the registration processing network element in the first network, the first server, and the terminal device may all be presented in a form of dividing each functional module in an integrated manner. A "module" herein may refer to a particular ASIC, a circuit, a processor and memory that execute one or more software or firmware programs, an integrated logic circuit, and/or other device that provides the described functionality.

In a simple embodiment, it is conceivable for those skilled in the art that the access processing network element, the registration processing network element in the first network, and the first server may all take the form shown in fig. 10.

The communication device 1000 shown in fig. 10 includes at least one processor 1001, a memory 1002, and optionally a communication interface 1003.

Memory 1002 can be volatile memory, such as random access memory; the memory may also be a non-volatile memory such as, but not limited to, a read-only memory, a flash memory, a Hard Disk Drive (HDD) or solid-state drive (SSD), or the memory 1002 may be any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory 1002 may be a combination of the above.

The embodiment of the present application does not limit the specific connection medium between the processor 1001 and the memory 1002. In the embodiment of the present application, the memory 1002 and the processor 1001 are connected by a bus 1004, the bus 1004 is represented by a thick line in the figure, and the connection manner between other components is merely illustrative and is not limited thereto. The bus 1004 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 10, but this is not intended to represent only one bus or type of bus.

The processor 1001 may have a data transceiving function, and may be capable of communicating with other devices, and in the apparatus as shown in fig. 10, a separate data transceiving module, such as a communication interface 1003, may also be provided for transceiving data; the processor 1001 can perform data transmission through the communication interface 1003 when communicating with other apparatuses.

When the access processing network element takes the form shown in fig. 10, the processor 1001 in fig. 10 may make the access processing network element perform the method performed by the access processing network element in any of the above method embodiments by calling a computer stored in the memory 1002 to execute the instructions.

Specifically, the functions/implementation processes of the sending unit, the receiving unit and the processing unit in fig. 6 can be implemented by the processor 1001 in fig. 10 calling a computer executing instruction stored in the memory 1002. Alternatively, the functions/implementation procedures of the processing unit in fig. 6 may be implemented by the processor 1001 in fig. 10 calling a computer executing instruction stored in the memory 1002, and the functions/implementation procedures of the transmitting unit and the receiving unit in fig. 6 may be implemented by the communication interface 1003 in fig. 10.

When the registration processing network element in the first network adopts the form shown in fig. 10, the processor 1001 in fig. 10 may execute the instructions by calling a computer stored in the memory 1002, so that the access processing network element may execute the method executed by the access processing network element in any of the above method embodiments.

Specifically, the functions/implementation processes of the sending unit, the receiving unit and the processing unit in fig. 7 can be implemented by the processor 1001 in fig. 10 calling a computer executing instruction stored in the memory 1002. Alternatively, the functions/implementation procedures of the processing unit in fig. 7 may be implemented by the processor 1001 in fig. 10 calling a computer executing instruction stored in the memory 1002, and the functions/implementation procedures of the transmitting unit and the receiving unit in fig. 7 may be implemented by the communication interface 1003 in fig. 10.

When the first server adopts the form shown in fig. 10, the processor 1001 in fig. 10 may make the access processing network element perform the method performed by the access processing network element in any of the above method embodiments by calling a computer stored in the memory 1002 to execute the instructions.

Specifically, the functions/implementation processes of the transceiving unit and the processing unit in fig. 8 can be implemented by the processor 1001 in fig. 10 calling the computer execution instructions stored in the memory 1002. Alternatively, the functions/implementation procedures of the processing unit in fig. 8 may be implemented by the processor 1001 in fig. 10 calling a computer executing instruction stored in the memory 1002, and the functions/implementation procedures of the transceiving unit in fig. 8 may be implemented by the communication interface 1003 in fig. 10.

In a simple embodiment, the terminal device may take the form shown in fig. 11, as will be appreciated by those skilled in the art.

The communication device 1100 shown in fig. 11 includes at least one processor 1101, a memory 1102, and optionally a transceiver 1103.

Memory 1102 can be a volatile memory, such as a random access memory; the memory may also be a non-volatile memory such as, but not limited to, a read-only memory, a flash memory, a Hard Disk Drive (HDD) or a solid-state drive (SSD), or the memory 1102 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Memory 1102 may be a combination of the memories described above.

The specific connection medium between the processor 1101 and the memory 1102 is not limited in the embodiment of the present application. In the embodiment of the present application, the memory 1102 and the processor 1101 are connected by a bus 1104, the bus 1104 is shown by a thick line in the figure, and the connection manner between other components is only schematically illustrated and is not limited. The bus 1104 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 11, but this is not intended to represent only one bus or type of bus.

The processor 1101 may have a data transceiving function, and may be capable of communicating with other devices, and in the apparatus shown in fig. 11, a separate data transceiving module, such as the transceiver 1103, may be provided for transceiving data; the processor 1101 may transmit data through the transceiver 1103 when communicating with other devices.

When the terminal device adopts the form shown in fig. 11, the processor 1101 in fig. 11 may make the access processing network element execute the method executed by the access processing network element in any one of the above-described method embodiments by calling a computer stored in the memory 1102 to execute the instructions.

Specifically, the functions/implementation processes of the sending unit, the receiving unit, and the processing unit in fig. 9 can be implemented by the processor 1101 in fig. 11 calling a computer executing instruction stored in the memory 1102. Alternatively, the functions/implementation procedures of the processing unit in fig. 9 may be implemented by the processor 1101 in fig. 11 calling a computer executing instruction stored in the memory 1102, and the functions/implementation procedures of the transmitting unit and the receiving unit in fig. 9 may be implemented by the transceiver 1103 in fig. 11.

Since the apparatus provided in the embodiment of the present application can execute the communication method, the technical effects obtained by the apparatus can refer to the method embodiment, and are not described herein again.

Based on the same inventive concept as the method embodiment, the embodiment of the present application further provides a communication system for executing the method of any of the above embodiments, and related features may refer to the above method embodiment, which is not described herein again.

Fig. 2 shows a schematic structural diagram of a communication system provided in an embodiment of the present application, specifically, the communication system includes an access processing network element and a registration processing network element in a first network;

Optionally, the communication system may further include a first server; the registration processing network element in the first network may further send a first message to the first server after the authentication of the terminal device is passed according to a first registration request from the terminal device, where the first message is used to request subscription information of the terminal device, and the first message includes a private identity of the terminal device.

The first server receives the first message from the registration processing network element in the first network, and then determines the subscription information of the terminal device according to the private identifier of the terminal device, wherein the subscription information includes the public identifier of the terminal device in the first network and the subscription network identifier information of the terminal device. Then, the first server may send a second message to a registration processing network element in the first network, where the second message includes subscription information of the terminal device.

In a possible implementation manner, before the first server determines the subscription information of the terminal device according to the private identity of the terminal device, the first server may further obtain the subscription network identity information of the terminal device, for example, the first server may obtain the subscription network identity information of the terminal device from a server in each subscription network of the terminal device.

The registration processing network element in the first network may then receive the second message from the first server, and obtain the subscription information of the terminal device.

Optionally, the communication system further includes at least one registration processing network element in the target network; after the access processing network element receives the first registration response message from the registration processing network element in the first network, the access processing network element may send a second registration request to the registration processing network element in the at least one target network, where the second registration request may include the private identity of the terminal device; thereafter, a registration processing network element in the at least one target network receives the second registration request from the access processing network element.

Wherein the at least one target network is determined by the subscription network identification information. Specifically, the at least one target network may be determined by preset configuration information and the signing network identification information; the preset configuration information includes information for judging whether the access processing network element is reachable to each network.

Specifically, the communication system may further include a second server in the target network.

For a registration processing network element in any target network, after receiving the second registration request from the access processing network element, the registration processing network element in the target network acquires subscription information of the terminal device in the target network from a second server in the target network, where the subscription information of the terminal device in the target network includes a public identifier of the terminal device in the target network; and then, sending second registration response information to the access processing network element, wherein the second registration response information comprises the public identification of the terminal equipment in the target network.

The access processing network element receives second registration reply information from a registration processing network element in the at least one target network.

In a possible implementation manner, when the second registration response information further includes service routing information of the terminal device in a corresponding target network, where the service routing information is used to indicate an address of a registration processing network element in the corresponding target network, and after the access processing network element receives the second registration response information from the at least one target network, the access processing network element may store a public identifier of the terminal device in the corresponding target network and the service routing information in an associated manner.

In a possible implementation manner, the access processing network element may first determine that the second registration response information of each of the at least one target network is received, and then, the access processing network element sends third registration response information to the terminal device.

Optionally, the communication system further includes a terminal device; the terminal device may send a first registration request to the access processing network element, where the first registration request may include a private identity of the terminal device. The access processing network element receives the first registration request from the terminal device, and forwards the first registration request from the terminal device to the registration processing network element in the first network.

In a case that the access processing network element receives a first registration response message from a registration processing network element in the first network and a second registration response message from a registration processing network element in the at least one target network, the access processing network element may send third registration response information to the terminal device, where the third registration response information includes a public identifier of the terminal device in the first network and a public identifier of the terminal device in the at least one target network.

The terminal device receives third registration response information from the access processing network element, and based on the public identifier included in the third registration response information, the terminal device may initiate a call flow, which includes the following specific processes:

the terminal equipment receives a network selection command, wherein the network selection command is used for determining a network to which a call request is accessed;

then, the terminal equipment selects a public identification from the public identification of the terminal equipment in the first network and the public identification of the terminal equipment in one or more target networks according to the network selection command;

and the terminal equipment sends a call request to the access processing network element, wherein the call request comprises the public identification selected by the terminal equipment.

The access processing network element receives a call request from the terminal equipment; determining corresponding service routing information according to the public identification included in the call request; and then, the access processing network element forwards the call request of the terminal equipment according to the corresponding service routing information.

Based on the above process, the terminal device may register in the first network and the at least one target network, and may initiate a call flow to the first network or the at least one target network, and further may communicate with the terminal device of the first network or the at least one target network.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of registering a network, the method comprising:

an access processing network element receives first registration response information from a first network after forwarding a first registration request from a terminal device to the first network, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device, and the signed network identifier information includes network identifiers of one or more signed networks of the terminal device;

the access processing network element sends a second registration request to one or more target networks, wherein the one or more target networks are determined by the signed network identification information;

the access processing network element receives second registration response information from the one or more target networks, wherein the second registration response information comprises a public identifier of the terminal equipment in the corresponding target network;

and the access processing network element sends third registration response information to the terminal equipment, wherein the third registration response information comprises the public identification of the terminal equipment in the first network and the public identification of the terminal equipment in the one or more target networks.

2. The method of claim 1, wherein before the access processing network element sends the third registration reply information to the terminal device, the method further comprises:

the access processing network element determines to receive the second registration reply information of each of the one or more target networks.

3. The method according to claim 1, wherein the one or more target networks are determined by the subscription network identification information, specifically:

the one or more target networks are determined by preset configuration information and the signing network identification information; the preset configuration information includes information for judging whether the access processing network element is reachable to each network.

4. The method according to any one of claims 1 to 3, wherein the second registration response information further includes service routing information of the terminal device in the corresponding target network, the service routing information is used to indicate an address of a registration processing network element in the corresponding target network, and after the access processing network element receives the second registration response information from the one or more target networks, the method further includes:

and the access processing network element stores the public identification and the service routing information of the terminal equipment in the corresponding target network in an associated manner.

5. The method of claim 4, wherein after the access processing network element sends the third registration reply information to the terminal device, the method further comprises:

the access processing network element receives a call request from the terminal equipment, wherein the call request comprises a public identifier of the terminal equipment in the first network or any target network;

the access processing network element determines corresponding service routing information according to the public identification included in the call request;

and the access processing network element forwards the call request of the terminal equipment according to the corresponding service routing information.

6. The method according to any of claims 1 to 5, wherein the first registration reply information, the second registration reply information, and the third registration reply information are all 200OK messages.

7. A method of registering a network, the method comprising:

a registration processing network element in a first network sends a first message to a first server after authenticating a terminal device according to a registration request from the terminal device, wherein the first message is used for requesting subscription information of the terminal device and comprises a private identity of the terminal device;

a registration processing network element in the first network receives a second message from the first server, where the second message includes subscription information of the terminal device, and the subscription information includes a public identifier of the terminal device in the first network and subscription network identifier information of the terminal device, where the subscription network identifier information includes network identifiers of one or more subscription networks of the terminal device;

and the registration processing network element in the first network sends first registration response information to an access processing network element, wherein the first registration response information comprises a public identifier of the terminal equipment in the first network and signed network identifier information of the terminal equipment.

8. A method of registering a network, the method comprising:

a first server receives a first message from a registration processing network element in a first network, wherein the first message is used for requesting subscription information of a terminal device, and the first message comprises a private identity of the terminal device;

the first server determines subscription information of the terminal device according to a private identity of the terminal device, wherein the subscription information comprises a public identity of the terminal device in a first network and subscription network identity information of the terminal device, and the subscription network identity information comprises network identities of one or more subscription networks of the terminal device;

and the first server sends a second message to a registration processing network element in the first network, wherein the second message comprises the subscription information of the terminal equipment.

9. The method of claim 8, wherein before the first server determines the subscription information of the terminal device according to the private identity of the terminal device, the method further comprises:

and the first server acquires the signing network identification information of the terminal equipment.

10. A method of registering a network, the method comprising:

the terminal equipment sends a registration request to an access processing network element;

and the terminal equipment receives registration response information from the access processing network element, wherein the registration response information comprises a public identifier of the terminal equipment in a first network and a public identifier of the terminal equipment in one or more target networks.

11. The method of claim 10, wherein after the terminal device receives the registration reply information from the access processing network element, further comprising:

the terminal equipment selects a public identification from public identifications of the terminal equipment in a first network and public identifications of the terminal equipment in one or more target networks;

12. A communication apparatus, characterized in that the communication apparatus comprises a transmitting unit and a receiving unit;

the sending unit is used for forwarding the first registration request from the terminal equipment to the first network;

the receiving unit is configured to receive first registration response information from a first network after the sending unit forwards a first registration request from a terminal device to the first network, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device, and the signed network identifier information includes network identifiers of one or more signed networks of the terminal device;

the sending unit is further configured to send a second registration request to one or more target networks, where the one or more target networks are determined by the contracted network identification information;

the receiving unit is further configured to receive second registration response information from the one or more target networks, where the second registration response information includes a public identifier of the terminal device in the corresponding target network;

the sending unit is further configured to send third registration response information to the terminal device, where the third registration response information includes a public identifier of the terminal device in the first network and a public identifier of the terminal device in the one or more target networks.

13. The communication apparatus according to claim 12, wherein the communication apparatus further comprises a processing unit configured to, before the transmitting unit transmits the third registration reply information to the terminal device:

determining that second registration reply information for each of the one or more target networks is received.

14. The communications apparatus as claimed in claim 12, wherein the one or more target networks are determined by the subscription network identification information, specifically:

15. The communications apparatus according to any one of claims 12 to 14, wherein the second registration response information further includes service routing information of the terminal device in the corresponding target network, the service routing information is used to indicate an address of a processing network element registered in the corresponding target network, and after the receiving unit receives the second registration response information from the one or more target networks, the processing unit is further configured to:

and storing the public identification of the terminal equipment in the corresponding target network and the corresponding service routing information in an associated manner.

16. The communications apparatus of claim 15, wherein the receiving unit is further configured to:

receiving a call request from the terminal equipment, wherein the call request comprises a public identifier of the terminal equipment in the first network or any target network;

the processing unit is further configured to:

determining corresponding service routing information according to the public identification included in the call request;

the sending unit is further configured to:

and forwarding the call request of the terminal equipment according to the corresponding service routing information.

17. The communication apparatus according to any one of claims 12 to 16, wherein the first registration reply information, the second registration reply information, and the third registration reply information are all 200OK messages.

18. A communication apparatus, characterized in that the communication apparatus comprises a transmitting unit, a receiving unit, and a processing unit:

the processing unit is used for passing the authentication of the terminal equipment according to the registration request from the terminal equipment;

the sending unit is configured to send a first message to a first server after the processing unit authenticates the terminal device according to a registration request from the terminal device, where the first message is used to request subscription information of the terminal device, and the first message includes a private identity of the terminal device;

the receiving unit is configured to receive a second message from the first server, where the second message includes subscription information of the terminal device, and the subscription information includes a public identifier of the terminal device in a first network and subscription network identifier information of the terminal device, where the subscription network identifier information includes network identifiers of one or more subscription networks of the terminal device;

the sending unit is further configured to send first registration response information to an access processing network element, where the first registration response information includes a public identifier of the terminal device in a first network and signed network identifier information of the terminal device.

19. A communication apparatus, characterized in that the communication apparatus comprises a transceiving unit and a processing unit:

the receiving and sending unit is configured to receive a first message from a registration processing network element in a first network, where the first message is used to request subscription information of a terminal device, and the first request message includes a private identity of the terminal device;

the processing unit is configured to determine subscription information of the terminal device according to a private identity of the terminal device, where the subscription information includes a public identity of the terminal device in a first network and subscription network identity information of the terminal device, where the subscription network identity information includes network identities of one or more subscription networks of the terminal device;

the transceiver unit is further configured to send a second message to a registration processing network element in the first network, where the second message includes subscription information of the terminal device.

20. The communications apparatus of claim 19, wherein the processing unit, prior to determining the subscription information for the terminal device based on the private identity of the terminal device, is further configured to:

and acquiring the signing network identification information of the terminal equipment.

21. A communication apparatus, characterized in that the communication apparatus comprises a transmitting unit and a receiving unit:

the sending unit is configured to send a registration request to an access processing network element;

the receiving unit is configured to receive registration response information from the access processing network element, where the registration response information includes a public identifier of a terminal device in a first network and a public identifier of the terminal device in one or more target networks.

22. The communications apparatus of claim 21, the communications apparatus further comprising a processing unit;

the processing unit is used for selecting a public identifier from the public identifier of the terminal equipment in the first network and the public identifiers of the terminal equipment in one or more target networks;

the sending unit is further configured to send a call request to the access processing network element, where the call request includes the public identifier selected by the terminal device.

23. A communication system, comprising an access processing network element and a registration processing network element in a first network;

the access processing network element is configured to forward the first registration request from the terminal device to the registration processing network element in the first network; receiving first registration response information from a registration processing network element in the first network, where the first registration response information includes a public identifier of the terminal device in the first network and signed network identifier information of the terminal device, where the signed network identifier information includes network identifiers of one or more signed networks of the terminal device;

24. The communication system of claim 23, wherein the communication system further comprises a first server;

the registration processing network element in the first network is further configured to send a first message to the first server after the authentication of the terminal device is passed according to a first registration request from the terminal device, where the first message is used to request subscription information of the terminal device, and the first message includes a private identity of the terminal device; and receiving a second message from the first server;

the first server is configured to receive the first message from a registration processing network element in the first network, and determine subscription information of the terminal device according to a private identifier of the terminal device, where the subscription information includes a public identifier of the terminal device in the first network and subscription network identifier information of the terminal device; and sending a second message to a registration processing network element in the first network, wherein the second message comprises subscription information of the terminal equipment.

25. The communication system according to claim 23 or 24, wherein the communication system further comprises a registration processing network element in at least one target network;

the access processing network element is further configured to send a second registration request to a registration processing network element in the at least one target network, where the at least one target network is determined by the subscription network identification information; receiving second registration response information from a registration processing network element in the at least one target network, wherein the second registration response information comprises a public identifier of the terminal equipment in the corresponding target network;

a registration processing network element in the at least one target network, configured to receive the second registration request from the access processing network element; acquiring subscription information of the terminal device in the corresponding target network from a second server in the corresponding target network, wherein the subscription information of the terminal device in the corresponding target network comprises a public identifier of the terminal device in the corresponding target network; and sending second registration response information to the access processing network element.

26. The communication system according to any of claims 23 to 25, wherein the communication system further comprises a terminal device;

the terminal device is configured to send a first registration request to the access processing network element; receiving third registration response information from the access processing network element, wherein the third registration response information includes a public identifier of the terminal device in the first network and a public identifier of the terminal device in the at least one target network;

the access processing network element is further configured to receive a first registration request from the terminal device; and sending third registration response information to the terminal equipment.

27. A computer storage medium having computer-executable instructions stored thereon for causing a computer to perform the method of any one of claims 1 to 11.