WO2021120744A1

WO2021120744A1 - Method and apparatus for recovering ims service

Info

Publication number: WO2021120744A1
Application number: PCT/CN2020/116602
Authority: WO
Inventors: 陈靖; 秦存秀
Original assignee: 华为技术有限公司
Priority date: 2019-12-20
Filing date: 2020-09-21
Publication date: 2021-06-24
Also published as: CN113098822A; CN113098822B; CN114915614B; CN114915614A

Abstract

The present application relates to the technical field of communications. Disclosed are a method and apparatus for recovering an IMS service. The method comprises: if it is determined that the IMS session of a terminal device is failed, a user data management network node transmits first indication information to a mobility management network node and/or a session management network node, wherein the first indication information is used for indicating that the IMS session of the terminal device is failed, and thus, the mobility management network node and/or the session management network node can re-establish an IMS session for the terminal device, so as to recover an IMS service of the terminal device. According to the solution, by triggering, by means of the user data management network node, the mobility management network node and/or the session management network node to re-establish the IMS session of the terminal device so as to recover the IMS service of the terminal device in a timely mode, the present invention can re-establish the IMS session of the terminal device in a more targeted mode, and effectively reduces the delay of recovering the IMS service.

Description

Method and device for restoring IMS service

Cross-references to related applications

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201911330900.1, and the application name is "A method and device for restoring IMS services" on December 20, 2019, the entire content of which is incorporated herein by reference. Applying.

Technical field

This application relates to the field of communication technology, and in particular to a method and device for restoring IMS services.

Background technique

Internet Protocol (IP) Multimedia Subsystem (IP Multimedia Subsystem, IMS) is a network system of IP network used to provide multimedia services. Through IMS, it can provide a variety of multimedia services for terminal equipment, such as voice calls and video. Call etc.

Taking voice calls as an example, the calling terminal device can initiate a call request to the called terminal device through a packet switched (PS) network. After the called terminal device receives the call request, if it successfully responds to the call request, the calling terminal device The terminal device and the called terminal device can make a voice call. However, some failure scenarios (such as a failure of a certain network entity in the PS network or a network failure between two network entities that need to communicate) may cause the processing of the called process to fail, thereby causing the IMS service to fail. Therefore, how to restore the IMS service of the terminal equipment in a timely manner to avoid a long interruption of the IMS service and affect the user experience requires further research.

Summary of the invention

This application provides a method and device for restoring the IMS service, which can restore the IMS service of the terminal equipment in a timely manner to prevent the IMS service from being interrupted for a long time and affecting user experience.

In the first aspect, an embodiment of the present application provides a method for restoring an IMS service. The method may be applicable to a device for restoring an IMS service. The device may be an SDMN or a chip set in the SDMN. Taking this method for SDMN as an example, in this method, the SDMN determines that the IMS session of the terminal device has failed, and then sends first indication information to the MMN and/or SMN. The first indication information is used to indicate that the IMS session of the terminal device has failed. The IMS session is used to carry the IMS service of the terminal device.

Using this solution, the SDMN triggers the MMN and/or SMN to re-establish the IMS session of the terminal device, and then restores the IMS service of the terminal device in time, which can re-establish the IMS session of the terminal device in a more targeted manner and effectively reduce the recovery of IMS. The latency of the business.

In a possible design, the SDMN determining that the IMS session of the terminal device has failed includes: the SDMN receives the second indication information from the S-CSCF entity, and the second indication information is used to indicate that the IMS session of the terminal device has failed.

With this solution, after the P-CSCF entity determines that the called process has failed, it can return a failure response (indicating that the IMS session of the terminal device has failed) to the S-CSCF entity, and the S-CSCF entity will notify the SDMN so that the SDMN can It is learned in time that the IMS session of the terminal device has failed.

In a possible design, the second indication information is included in the registration notification request or de-registration notification request received by the SDMN from the S-CSCF entity.

In a possible design, the SDMN sending the first indication information to the MMN includes: if the SDMN determines that the SMN has not successfully restored the IMS session of the terminal device, sending the first indication information to the MMN.

With this method, the SDMN sends the first indication information to the MMN when the SMN fails to restore the IMS session of the terminal device, and when the SMN successfully restores the IMS session of the terminal device, it may no longer send the first indication to the MMN Information, which can effectively save signaling overhead.

In a possible design, the SDMN determining that the SMN has not successfully restored the IMS session of the terminal device includes: the SDMN determining that the SMN has failed; or, the SDMN sends the first indication information to the SMN, and the SMN is not received within a preset time period Or, the SDMN sends the first indication information to the SMN, and receives a response message from the SMN, the response message carries the value of the reason for the unsuccessful restoration of the IMS session.

In a possible design, the method further includes: the SDMN receives the first information sent by the MMN, and the first information is used to request to subscribe to the IMS session failure event of the terminal device.

In a possible design, the SDMN receiving the first information from the MMN includes: the SDMN receives the first user context management registration request from the MMN, and the first user context management registration request includes the first information.

With this method, the MMN can request to subscribe to the IMS session failure event of the terminal device when the terminal device registers with the MMN.

In a possible design, the method further includes: the SDMN receives second information from the SMN, and the second information is used to request to subscribe to the IMS session failure event of the terminal device.

In a possible design, the SDMN receiving the second information from the SMN includes: the SDMN receiving the second user context management registration request from the SMN, and the second user context management registration request includes the second information.

With this method, the SMN can request to subscribe to the IMS session failure event of the terminal device when the terminal device requests the SMN to establish a session.

In the second aspect, an embodiment of the present application provides a method for restoring an IMS service. The method may be applicable to a device for restoring an IMS service. The device may be an MMN or a chip set in the MMN. Taking this method for MMN as an example, in this method, if the MMN determines that the IMS session of the terminal device fails, the IMS session is re-established for the terminal device, and the IMS session is used to carry the IMS service of the terminal device.

In a possible design, the MMN determining that the IMS session of the terminal device has failed includes: MMN determining that the SMN associated with the IMS session is faulty; or, the MMN receives first indication information from the SDMN, and the first indication information is used to indicate the terminal device The IMS session failed.

In a possible design, the method further includes: the MMN sends first information to the SDMN, where the first information is used to request to subscribe to the IMS session failure event of the terminal device.

In a possible design, the MMN sending the first information to the SDMN includes: the MMN sends a first user context management registration request to the SDMN, and the first user context management registration request includes the first information.

In a possible design, the MMN re-establishing the IMS session for the terminal device includes: the MMN sends third indication information to the terminal device, and the third indication information is used to instruct the terminal device to re-establish the IMS session.

In a possible design, the third indication information includes state information of the IMS session, and the state information of the IMS session is used to indicate that the state of the IMS session is in an inactive state.

In a possible design, the MMN sending the third indication information to the terminal device includes: the MMN sends a configuration update command to the terminal device, and the configuration update command includes the third indication information.

In the third aspect, an embodiment of the present application provides a method for restoring an IMS service. The method may be applicable to a device for restoring an IMS service, and the device may be an SMN or a chip set in the SMN. Take this method for SMN as an example. In this method, the SMN receives the first indication information from SDMN. The first indication information is used to indicate that the IMS session of the terminal device fails, and the IMS session is re-established for the terminal device. IMS services for carrying terminal equipment;

In a possible design, the method further includes: the SMN sends second information to the SDMN, where the second information is used to request to subscribe to the IMS session failure event of the terminal device.

In a possible design, the SMN sending the second information to the SDMN includes: the SMN sending a second user context management registration request to the SDMN, and the second user context management registration request includes the second information.

In a fourth aspect, the embodiments of the present application provide a method for restoring IMS services. The method may be applicable to a device for restoring IMS services. The device may be a terminal device or a chip set in the terminal device. Take this method for terminal equipment as an example. In this method, the terminal equipment receives the third indication information from the MMN. The third indication information is used to instruct the terminal equipment to re-establish the IMS session, and then re-establish the IMS session according to the third indication information. .

In a possible design, the terminal device receiving the third indication information from the MMN includes: the terminal device receives a configuration update command from the MMN, and the configuration update command includes the third indication information.

It should be noted that, since the methods for restoring IMS services described in the second, third, and fourth aspects above correspond to the methods for restoring IMS services described in the first aspect, the second, third, and The related beneficial effects of the method for restoring the IMS service described in the fourth aspect can be referred to the first aspect, which is not repeated here.

In a fifth aspect, this application provides a device for restoring an IMS service. The device has the function of realizing any one of the possible designs of the first aspect to the fourth aspect. For example, the device includes performing the first aspect to the fourth aspect. The module or unit or means corresponding to the steps involved in any possible design of the fourth aspect. The function or unit or means can be realized by software, or by hardware, or the corresponding software can be executed by hardware. achieve.

In a possible design, the device for restoring IMS services includes a processing unit and a communication unit, where the communication unit can be used to send and receive signals to achieve communication between the device and other devices; the processing unit can be used to execute Some internal operations of the device. The functions performed by the processing unit and the communication unit may correspond to the steps involved in any possible design of the first aspect to the fourth aspect.

In a possible design, the device for restoring IMS services includes a processor, and may also include a transceiver. The transceiver is used to send and receive signals, and the processor executes program instructions to complete the first to fourth aspects described above. Any possible design or implementation method in the aspect. Wherein, the device may further include one or more memories, and the memories are used for coupling with the processor. The one or more memories may be integrated with the processor, or may be provided separately from the processor, which is not limited in this application. The memory can store necessary computer programs or instructions to realize the functions related to the first to fourth aspects. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the device implements any possible design or implementation method of the first aspect to the fourth aspect. .

In a possible design, the device for restoring an IMS service includes a processor and a memory, and the memory can store necessary computer programs or instructions for realizing the functions involved in the first to fourth aspects. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the device implements any possible design or implementation method of the first aspect to the fourth aspect. .

In a possible design, the device for restoring IMS services includes at least one processor and an interface circuit, where at least one processor is used to communicate with other devices through the interface circuit and execute the first to fourth aspects described above. In any possible design or implementation method.

In a sixth aspect, an embodiment of the present application also provides a computer storage medium, the storage medium stores a software program, and the software program can implement the first to fourth aspects when read and executed by one or more processors Any of the possible designs provided.

In a seventh aspect, the embodiments of the present application also provide a computer program, which when the computer program runs on a computer, causes the computer to execute the method provided by any one of the above-mentioned first to fourth aspects. .

In an eighth aspect, an embodiment of the present application also provides a chip, which is used to read a computer program stored in a memory and execute the method provided by any one of the possible designs from the first aspect to the fourth aspect.

In a ninth aspect, an embodiment of the present application provides a chip system, the chip system includes a processor, and an apparatus for supporting the restoration of an IMS service realizes the functions involved in the foregoing aspects. In a possible design, the chip system further includes a memory, and the memory is used to store the necessary program instructions and data of the management device. The chip system can be composed of chips, or include chips and other discrete devices.

Description of the drawings

FIG. 1 is a schematic diagram of a network architecture to which an embodiment of the application is applicable;

FIG. 2a is a schematic diagram of another network architecture to which an embodiment of this application is applicable;

FIG. 2b is a schematic diagram of another network architecture to which the embodiments of this application are applicable;

Figure 3a is a schematic diagram of a service processing flow of a called terminal device;

Figure 3b is a schematic diagram of another service processing flow of the called terminal device;

Figure 4a is a schematic diagram of a PDU session establishment process provided by an embodiment of the application;

Figure 4b is a schematic diagram of a PDU session release process provided by an embodiment of the application;

FIG. 5 is a schematic diagram of the format of a PDU session state information element provided by an embodiment of the application;

FIG. 6 is a schematic diagram of the process corresponding to the method for restoring IMS services provided in the first embodiment of the application; FIG.

FIG. 7 is a schematic diagram of a process corresponding to the method for restoring an IMS service provided by the second embodiment of the application; FIG.

FIG. 8 is a possible exemplary block diagram of a device involved in an embodiment of this application;

Fig. 9 is a schematic diagram of a device for restoring an IMS service provided by an embodiment of the application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

FIG. 1 is a schematic diagram of a network architecture to which an embodiment of this application is applicable. As shown in Figure 1, the network architecture can include terminal equipment, PS network and IMS. IMS can provide various multimedia services such as audio, video, text and data for terminal equipment based on the PS network. It can be understood as completing the services carried by the previous circuit switched (CS) network based on the PS network, such as voice calls, video calls, and These services, such as short messages, can be collectively referred to as IMS services.

The terminal equipment, IMS and PS network are respectively introduced below.

(1) Terminal equipment

Terminal equipment can also be called user equipment (UE), which can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; it can also be deployed on water (such as ships, etc.); it can also be deployed in the air (such as airplanes). , Balloons and satellites etc.). Terminal devices can be mobile phones, tablets, computers with wireless transceiver functions, virtual reality (VR) equipment, augmented reality (AR) equipment, industrial control (industrial control) Wireless devices in unmanned driving (self-driving), wireless devices in remote medical (remote medical), wireless devices in smart grid (smart grid), wireless devices in transportation safety, and smart devices Wireless devices in the city (smart city), wireless devices in the smart home (smart home), etc.

(2)IMS

The IMS may include a proxy-call session control function (P-CSCF) entity and a serving-call session control function (S-CSCF) entity.

The P-CSCF entity is an edge network node between the PS network and the IMS, and interacts with terminal equipment through the user plane of the PS network. Further, the P-CSCF entity is the first connection point from the PS network to the IMS, that is, the first contact point of the terminal device in the IMS. The role of the P-CSCF entity in the IMS is similar to the execution of proxy services. Whether it is information from a terminal device or information sent to a terminal device, it needs to be forwarded by the P-CSCF entity. The P-CSCF entity is responsible for sending verification requests in the IMS, forwarding the verified requests to the designated target, and processing and forwarding response information.

The S-CSCF entity is the service processing node of the IMS, responsible for the IMS registration of terminal equipment and related calling and called service processing.

Although not shown, IMS may also include other possible entities, such as interrogating-call session control function (I-CSCF) entity, I-CSCF entity can connect S-CSCF entity and P-CSCF The entity is used to provide users with the entrance to the home network; when the terminal device roams to other networks, it sends a message to the P-CSCF entity. The P-CSCF entity can forward the message from the terminal device to the I-CSCF entity through the I-CSCF entity. -The CSCF entity sends the message from the terminal device to the S-CSCF entity.

(3) PS network

The PS network may include user data management network nodes (subscriber data management node, SDMN), policy management network nodes (policy management node, PMN), session management network nodes (session management node, SMN), and user plane network nodes (user plane). node, UPN), and mobile management network node (mobile management node, MMN). Although not shown, other possible nodes may be included in the PS network.

Exemplarily, the PS network may also be referred to as an operator network or a mobile communication network, and is mainly a network through which mobile network operators (mobile network operators, MNOs) provide users with mobile broadband access services. The operator network described in the embodiment of the application may be a network that meets the requirements of the 3rd generation partnership project (3rd generation partnership project, 3GPP) standard, referred to as the 3GPP network. Generally, 3GPP networks are operated by operators, including but not limited to fifth-generation mobile communication technology (5th-generation, 5G) networks, fourth-generation mobile communication technology (4th-generation, 4G) networks, and so on. Among them, the 5G network may also be called a new radio (NR) network, and the 4G network may also be called a long term evolution (LTE) network.

If the PS network is a 4G network, as shown in Figure 2a, the function of the SDMN can be implemented by the home subscriber server (HSS), and the function of the PMN can be implemented by the policy and charging rules function (policy and charging rules). , PCRF) entity, SMN functions can be implemented by the packet data network gateway control plane function (PGW-C) entity and the serving gateway control plane function (serving gateway control plane function, SGW-C) The function of UPN can be realized by the user plane function of packet data network gateway (PGW-U) entity and the user plane function of serving gateway (serving gateway user plane function, SGW-U) entity. , The function of MMN can be implemented by a mobility management entity (mobility management entity, MME).

If the PS network is a 5G network, as shown in Figure 2b, the function of SDMN can be implemented by a unified data management (UDM) entity, and the function of PMN can be implemented by a policy control function (PCF) entity. Realization, SMN function can be realized by session management function (SMF) entity, UPN function can be realized by user plane function (UPF) entity, MMN function can be realized by access and mobility The management function (access and mobility management function, AMF) entity is implemented.

In the following, taking the PS network as a 5G network as an example, the above entities included in the 5G network are introduced.

The UDM entity is responsible for storing information such as subscriber permanent identifier (SUPI), credential, security context, and subscription data of subscribers in the operator's network. The information stored by the UDM entity can be used for authentication and authorization of terminal equipment accessing the operator's network. Among them, the contracted users of the above-mentioned operator's network may specifically be users who use the services provided by the operator's network, such as users who use China Telecom's mobile phone core card, or users who use China Mobile's mobile phone core card. The SUPI of the aforementioned subscriber may be the number of the mobile phone core card, etc. The credential and security context of the aforementioned subscriber may be a small file stored such as the encryption key of the mobile phone core card or information related to the encryption of the mobile phone core card for authentication and/or authorization. The aforementioned security context may be data (cookie) or token (token) stored on the user's local terminal (for example, mobile phone). The contract data of the above-mentioned subscriber may be a supporting service of the mobile phone core card, such as the data package of the mobile phone core card or the use of the network.

The PCF entity is used to provide a protocol data unit (protocol data unit, PDU) session strategy to the SMF network element. Policies may include charging-related policies, quality of service (QoS)-related policies, authorization-related policies, and the like.

The SMF entity is responsible for session management (such as session establishment, modification, and release), UPF network element selection and control, service and session continuity (service and session continuity, SSC) mode selection, roaming and other session-related functions.

The UPF entity provides user-plane related functions such as data routing and forwarding, packet inspection, service usage reporting, QoS processing, lawful monitoring, upstream packet inspection, and downstream data packet storage for terminal equipment and external data networks.

The AMF entity is responsible for the access control and mobility management of terminal devices accessing the operator's network, including functions such as mobility status management, allocating user temporary identities, authenticating and authorizing users, and selecting appropriate SMF entities for terminal devices to establish related sessions.

It should be noted that: (1) Terminal equipment can access the PS network through (radio) access network ((radio) access network, (R) AN) equipment, and (R) AN equipment will be referred to as AN equipment in the following text. The equipment is not shown in Figure 1, Figure 2a and Figure 2b. AN equipment can also be called a base station or network equipment. At present, some examples of AN equipment are: new generation Node B (gNodeB), transmission reception point (TRP), evolved Node B (evolved Node B, eNB), wireless network in 5G communication system Controller (radio network controller, RNC), node B (Node B, NB), base station controller (BSC), base transceiver station (base transceiver station, BTS), home base station (for example, home evolved NodeB), Or home Node B, HNB, baseband unit (BBU), or wireless fidelity (Wi-Fi) access point (AP), etc. In addition, in a network structure, the network device may include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including a CU node and a DU node. In addition, in other possible situations, the network device may be another device that provides wireless communication functions for the terminal device.

(2) The functional entities involved in the embodiments of this application may also be referred to as network elements, which are not limited in this application. For example, the AMF entity may also be referred to as an AMF network element, and the SMF entity may also be referred to as an SMF network element. The name of each entity is not limited in this application, and those skilled in the art can change the name of the aforementioned network element to another name to perform the same function, which all fall within the protection scope of this application.

(3) The aforementioned network element or functional entity can be either a network element in a hardware device, a software function running on dedicated hardware, or a virtualization function instantiated on a platform (for example, a cloud platform). This application No restrictions.

(4) Cx, Mw, Rx, Gx, S5, S8, S11, S6a, N8, N10, N11 in Figure 2a and Figure 2b are the interface serial numbers. The meaning of these interface serial numbers can refer to the meaning defined in the 3GPP standard protocol, which is not limited here.

(5) The terms "system" and "network" in the embodiments of this application can be used interchangeably. "And/or" describes the association relationship of the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: the existence of A alone, both A and B, and B alone, where A, B can be singular or plural. The character "/" generally indicates that the associated objects before and after are in an "or" relationship. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects, and are not used to limit the order, timing, priority, or importance of multiple objects. degree. For example, the first information and the second information are only for distinguishing different information, but do not indicate the difference in priority or importance of the two types of information.

When the terminal device 1 needs to establish a connection with the terminal device 2 through the IMS, an invite message or a call request can be triggered; wherein, the terminal device 1 may be called a calling terminal device, and the terminal device 2 may be called a called terminal device. Among them, the called terminal device may be in a connected state, or may also be in an idle state or an inactive state.

Case 1: The called terminal device is in the connected state

Refer to Figure 3a, which is a schematic diagram of the service processing flow of the called terminal device. Taking the network architecture shown in Figure 2b as an example, as shown in Figure 3a, the service processing flow of the called terminal device includes the following steps:

Step 301: The P-CSCF entity receives an invite message from the calling party, and the invite message includes the identity of the called terminal device.

Step 302: The P-CSCF entity sends an invite message to the UPF entity.

Step 303: After receiving the invite message from the P-CSCF entity, the UPF entity sends an invite message to the called terminal device if it determines that the called terminal device is in the connected state.

Step 304: After receiving the invite message from the UPF entity, the called terminal device returns a response message (such as the 183 message) to the P-CSCF entity to indicate that the called terminal device has received the invite message.

Step 305: After receiving the 183 message, the P-CSCF entity sends an authentication & authorization request (AAR) message to the PCF entity.

Step 306: After receiving the AAR message from the P-CSCF entity, the PCF entity sends a re-authentication-request (RAR) message to the SMF entity.

Step 307: After receiving the RAR message from the PCF entity, the SMF entity returns a re-authentication-answer (RAA) message to the PCF entity.

Step 308: After receiving the RAA message from the SMF entity, the PCF entity returns an authentication authorization answer (AAA) message to the P-CSCF entity.

Exemplarily, the process shown in step 305 to step 308 above refers to the process of establishing a voice bearer for the called terminal device based on the IMS session of the called terminal device, where the voice bearer may be quality of service (QoS) A bearer with a QoS class identifier (QCI)=1 is used to bear voice services. After the AAA message received by the P-CSCF entity indicates that the voice bearer is successfully established, the P-CSCF entity can perform subsequent procedures to implement a voice call between the calling terminal device and the called terminal device.

Scenario 2: The called terminal device is in idle or inactive state

Refer to Figure 3b, which is a schematic diagram of the service processing flow of the called terminal device. Taking the network architecture shown in Figure 2b as an example, as shown in Figure 3b, the service processing flow of the called terminal device includes the following steps:

Step 311: The P-CSCF entity receives an invite message from the calling party, and the invite message includes the identity of the called terminal device.

Step 312: The P-CSCF entity sends an invite message to the UPF entity.

Step 313: After receiving the invite message from the P-CSCF entity, the UPF entity sends a downlink data report (downlink data report) message to the SMF if it determines that the called terminal device is in an idle state or an inactive state, requesting to re-establish an IMS session.

Step 314: After receiving the downlink data report message, the SMF entity establishes an IMS session for the terminal device.

Step 315: The UPF entity sends an invite message to the called terminal device through the IMS session.

Step 316: After receiving the invite message from the UPF entity, the called terminal device returns a 183 message to the P-CSCF entity.

Step 317: After receiving the 183 message, the P-CSCF entity sends an authentication and authorization AAR message to the PCF entity.

Step 318: After receiving the AAR message from the P-CSCF entity, the PCF entity sends the RAR message to the SMF entity.

Step 319: After receiving the RAR message from the PCF entity, the SMF entity returns an RAA message to the PCF entity.

Step 3110: After receiving the RAA message from the SMF entity, the PCF entity returns an AAA message to the P-CSCF entity.

Exemplarily, after the AAA message received by the P-CSCF entity indicates that the voice bearer is successfully established, the P-CSCF entity may perform subsequent procedures to implement a voice call between the calling terminal device and the called terminal device.

However, in the process shown in Figure 3a and Figure 3b, the called process may fail due to some failure scenarios (such as a network entity failure or a network failure between two network entities that need to communicate). In turn, the IMS service fails.

The following examples illustrate several scenarios that cause the called process to fail:

Scenario 1. In step 302 of FIG. 3a and step 312 of FIG. 3b, if the UPF entity fails or is abnormal, or the network between the P-CSCF entity and the UPF entity fails, the called terminal device cannot receive the invite message, and then As a result, the P-CSCF entity fails to receive a response from the called terminal device over time, and the called process fails.

Scenario 2: In step 313 of Figure 3b, if the SMF entity is faulty or abnormal, or the network between the UPF entity and the SMF entity is faulty, the called terminal device cannot receive the invite message, which causes the P-CSCF entity to time out and fail to receive it. In response to the called terminal device, the called process failed.

Scenario 3: In step 305 of Figure 3a and step 317 of Figure 3b, if the P-CSCF entity senses a PCF entity failure and does not send an AAR message; or, the P-CSCF entity sends an AAR message, but the PCF entity fails or A network failure between the P-CSCF entity and the PCF entity causes the P-CSCF entity to fail to receive a response from the PCF entity over time; or the PCF entity no longer has relevant information about the IMS session, which will cause the called process to fail.

Scenario 4, in step 306 of Figure 3a and step 318 of Figure 3b, if the PCF entity senses that the SMF entity is faulty and does not send the RAR message; or, the PCF entity sends the RAR message to the SMF entity, but due to the SMF entity failure or SMF A network failure with the PCF causes the PCF entity to time out and does not receive the SMF response; or, if there is no IMS session related information on the SMF entity, it will cause the called process to fail.

For some of the failure scenarios described above, such as the failure of the PCF entity or the UPF entity, one possible solution is that when the SMF entity senses the failure of the UPF entity or the PCF entity, the SMF entity triggers the related session The deletion processing requires the corresponding terminal device to re-establish the session and select a normal network node for the session in the process of re-establishing the session. However, in order to avoid impact on the network nodes of the existing network, smooth processing is performed. For example, the SMF entity may divide the terminal devices that need to re-establish a session into multiple groups, first re-establish the session of a group of terminal devices, and then re-establish the session. The session of another group of terminal devices, and so on, until all the sessions are re-established. With this method, the service of the called terminal device may be interrupted for more than 10 minutes.

Understandably, the failure scenarios described above may also appear in the calling process, but because the calling process is initiated by the calling terminal device, when the above failure occurs in the calling process (such as SMF entity perception When the UPF entity or PCF entity fails), the SMF entity can select a new UPF entity or PCF entity for the terminal device in time to restore the IMS service; however, in the called process, the IMS service cannot be delivered in time by the above methods. restore.

Based on this, the embodiments of the present application provide a method and device for restoring an IMS service, which are used to restore the IMS service of a terminal device in a timely manner, so as to prevent the IMS service from being interrupted for a long time and affecting the user experience.

Illustratively, in the method for restoring IMS services provided by the embodiments of the present application, taking the network architecture shown in FIG. 2b as an example, if the UDM entity determines that the IMS session of the terminal device has failed, the IMS session is used to carry the IMS of the terminal device. Service, the first instruction information is sent to the AMF entity and/or SMF entity, the first instruction information is used to instruct the recovery of the IMS service of the terminal device, and then the AMF entity and/or SMF entity can re-establish the IMS session for the terminal device to recover IMS service of terminal equipment. With this solution, after determining that the IMS session of the terminal device has failed, the UDM entity can trigger the AMF entity and/or the SMF entity to re-establish the IMS session of the terminal device, and then resume the IMS service of the terminal device in time. Compared with the above description As far as the smooth processing solution is concerned, this solution can re-establish the IMS session of the terminal device in a more targeted manner, effectively reducing the delay of restoring the IMS service.

The relevant technical features involved in the embodiments of the present application will be introduced below. It should be noted that these explanations are for making the embodiments of the present application easier to understand, and should not be regarded as limiting the scope of protection required by the present application.

(1) The status of the session

In the embodiment of the present application, the session may refer to a PDU session. The terminal device registers with the AMF entity in the PS network, and then establishes a PDU session for the IMS service through the SMF entity. The PDU session may be referred to as an IMS session.

Exemplarily, the terminal device may establish multiple PDU sessions, and the SMF entity corresponding to each PDU session may be different. Further, when a PDU session of the terminal device is successfully established, the AMF entity may save the identity of the SMF entity serving the PDU session, and the SMF entity may save the identity of the AMF entity serving the terminal device.

A PDU session can be in two stable states, active or inactive. A successfully established PDU session is in the active state, and a successfully released PDU session is in the inactive state. The inactive state can also be called Deactivated state. In the embodiment of the present application, releasing a session can also be understood as deleting a session. In the embodiment of the present application, releasing a session is described as an example.

(2) PDU session (or IMS session) establishment process

Refer to Figure 4a, which is a schematic diagram of a PDU session establishment process provided by an embodiment of this application. Figure 4a includes the following steps:

Step 401: The terminal device sends a PDU session establishment request (PDU session establishment request) message to the SMF entity, requesting the SMF entity to establish a PDU session for it. Exemplarily, the terminal device may send a PDU session establishment request message to the SMF entity through the AN device and the AMF entity.

Step 402a: After the SMF entity receives the PDU session establishment request message sent by the terminal device, if it determines that a PDU session can be established for the terminal device, it sends a PDU session establishment accept message to the terminal device, and the terminal device receives it. The PDU session establishment acceptance message from the SMF entity completes the establishment of the PDU session. At this time, the PDU session enters the active state. Exemplarily, the SMF entity may receive the PDU session establishment request message from the terminal device through the AN device and the AMF entity. Correspondingly, the SMF entity may send the PDU session establishment accept message to the terminal device through the AMF entity and the AN device.

Step 402b: After the SMF entity receives the PDU session establishment request message sent by the terminal device, if it determines that the PDU session cannot be established for the terminal device, it sends a PDU session establishment reject message to the terminal device, and the terminal device receives the PDU session establishment reject message from the terminal device. The PDU session establishment rejection message of the SMF entity fails to establish the PDU session, and the PDU session enters the inactive state at this time. Exemplarily, the SMF entity may send a PDU session establishment rejection message to the terminal device through the AMF entity and the AN device.

It should be noted that the above step 402a and step 402b are executed alternatively.

(3) PDU session (or IMS session) release process

Refer to Figure 4b for a schematic diagram of a PDU session release process provided by an embodiment of the application. Figure 4b shows a PDU session release process initiated by an SMF entity. Figure 4b includes the following steps:

Step 411: The SMF entity sends a PDU session release command (PDU session release command) to the terminal device. Exemplarily, the SMF entity may send a PDU session release command to the terminal device through the AMF entity and the AN device.

Step 412: The terminal device sends a PDU session release complete (PDU session release complete) message to the SMF entity. Exemplarily, the terminal device may send a PDU session release completion message to the SMF entity through the AN device and the AMF entity.

In Figure 4b, the SMF entity can directly send a PDU session release command to the terminal device to initiate the PDU session release process. After the terminal device replies to the SMF entity with a PDU session release completion message, the PDU session is released. At this time, the PDU session enters a non- Active or deactivated state.

(4) Synchronize the status of PDU session

Exemplarily, the maximum number of PDU sessions that can be established simultaneously by a terminal device in a public land mobile network (PLMN) can be defined by "Maximum Protocol Defined (16)" and "Maximum PDU Sessions Supported by PLMN" The minimum value among the three “values” and “the upper limit realized by the terminal equipment” is determined. For example, if the "Maximum Protocol Definition" is 16, the "Maximum Number of PDU Sessions Supported by the PLMN" is 12, and the "Upper Limit Realized by the Terminal Device" is 14, then the terminal device can simultaneously establish the number of PDU sessions in the PLMN The maximum value is 12. Among them, PLMN can be understood as an operator network. The "maximum number of PDU sessions supported by the PLMN" can be understood as the maximum value of the PDU sessions that the PLMN can support for the terminal device; the "upper limit realized by the terminal device" can be understood as the software and/or hardware configuration for the terminal device, This enables the terminal device to support the maximum value of the established PDU session.

In a possible example, if the terminal device 1 determines that the number of currently established PDU sessions does not exceed the "protocol defined maximum value (16)" and does not exceed the "upper limit realized by the terminal device", then the terminal device 1 can continue to use The method shown in Figure 4a initiates a PDU session establishment request. When the AMF entity receives the PDU session establishment request sent by the terminal device 1, if the number of PDU sessions established by the terminal device 1 reaches the maximum number of PDU sessions supported by the PLMN, the AMF The entity can reject the PDU session establishment request, and reply to the terminal device 1 with a message with a reason value of #65. When the reason value is #65, it indicates that the number of established PDU sessions has reached the maximum value (maximum number of PDU sessions reached). ), after receiving the message with the reason value #65 returned by the AMF entity, the terminal device 1 considers that the number of PDU sessions established at this time is "the maximum number of sessions supported by PLMN", and can determine that the terminal device is in one The maximum number of PDU sessions that can be established simultaneously in the PLMN is "the maximum number of sessions supported by the PLMN".

To ensure that the PDU session established between the terminal device and the network does not exceed the maximum value specified in the protocol, the terminal device and the network need to maintain the status of the PDU session and the number of established PDU sessions. Exemplarily, when the terminal device successfully establishes a PDU session, the terminal device sets the state of the PDU session to the active state, and adds one to the number of established PDU sessions maintained. Accordingly, the core network element (such as the AMF entity) ) Set the state of the PDU session to the active state, and add one to the number of established PDU sessions maintained by the terminal device; conversely, when the terminal device successfully releases the PDU session, the terminal device sets the state of the PDU session to Inactive state, and the number of maintained established PDU sessions is reduced by one. Correspondingly, the core network element (for example, the AMF entity) sets the state of the PDU session to inactive state, and maintains the maintained state for the terminal device. The number of established PDU sessions is reduced by one. Among them, the number of established PDU sessions maintained by the network can be understood as the number of active PDU sessions maintained by the AMF entity for each terminal device that accesses the core network through the AMF entity.

Exemplarily, the PDU session status (PDU session status) information element (IE) can be used to synchronize the PDU session status between the terminal device and the network. As shown in Figure 5, it is a schematic diagram of the format of the PDU session state information element. The value (0/1) of each bit (0/1) included in octet3 and octet4 in the IE represents the state of a PDU session, that is, each bit can Corresponding to a PDU session, specifically, when the value of the bit is 0, it means that the PDU session corresponding to the bit is in an inactive state, and vice versa, when the value of the bit is 1, it means the PDU corresponding to the bit The session is active. For example, the terminal device and the network can carry PDU session state information elements through three processes of service request (SERVICE REQUEST), registration (REGISTRATION) or notification (NOTIFICATION) to achieve the purpose of PDU session state synchronization.

Based on the foregoing description of the relevant features, the solutions of the embodiments of the present application will be described in detail below in conjunction with Embodiment 1 and Embodiment 2.

Example one

In the first embodiment, the method in the embodiment of the present application is applied to the network architecture shown in FIG. 2b as an example to describe a possible implementation process.

Refer to FIG. 6 for a schematic diagram of the process corresponding to the method for restoring an IMS service provided by the first embodiment of the application, as shown in FIG. 6, including:

Step 601: The AMF entity sends first information to the UDM entity, where the first information is used to request to subscribe to the IMS session failure event of the terminal device (Subscribe IMS Session Failure Event).

Exemplarily, when the terminal device registers with the AMF entity, the AMF entity may send message 1 to the UDM entity. Message 1 includes the first information. The first information may also be used to notify the UDM entity of the AMF entity's information when the IMS session failure event notification is performed. target address. For example, the specific form of message 1 may be a user context management registration request (Nudm_UECM_Registration Request), and the first information is the Amf3GppAccessRegistration of the user context management registration request and the newly added ImsSessionFailureCallbackUri parameter in the AmfNon3GppAccessRegistration cell.

Step 602: The SMF entity sends second information to the UDM entity, where the second information is used to request to subscribe to the IMS session failure event of the terminal device.

Exemplarily, when the terminal device requests the SMF entity to establish an IMS session, the SMF entity may send message 2 to UDM. Message 2 includes second information. The second information may also be used to notify the UDM entity of the SMF when the IMS session failure event notification is performed. The target address of the entity. For example, the specific embodiment of message 2 is a user context management registration request (Nudm_UECM_Registration Request), and the second information is the newly added ImsSessionFailure CallbackUri parameter in the SmfRegistration cell of the user context management registration request.

Step 603: The S-CSCF entity sends second indication information to the UDM entity, where the second indication information is used to indicate that the IMS session of the terminal device fails.

Exemplarily, in the procedures shown in FIGS. 3a and 3b, when the failure scenario described above occurs, the P-CSCF entity may return a failure response message to the S-CSCF entity, indicating that the IMS session of the terminal device has failed. The specific embodiment of the failure response message may be the session initiation protocol (SIP) 604, which means that the server has verified the user information in the request and does not exist anywhere (Does Not Exists Anywhere). Furthermore, after receiving the failure response message sent by the P-CSCF entity, the S-CSCF entity may send a message 3 to the UDM, and the message 3 includes the second indication information. For example, the specific manifestation of message 3 can be a registration notification request or a deregistration notification request (Registration/Deregistration Notification Request), and the second indication information can be a newly added SAR-Flags cell in the registration notification request or deregistration notification request Subscribe-IMS-Session-Failure parameter.

Step 604: The UDM entity receives the second indication information, and then determines that the IMS session of the terminal device has failed.

Step 605: The UDM entity sends first indication information to the SMF entity, where the first indication information is used to indicate that the IMS session of the terminal device fails.

Exemplarily, if the UDM entity determines that the SMF entity has subscribed to the IMS session failure event, it may send the first indication information to the SMF entity. For example, the UDM entity may send a message 4 to the SMF entity. The message 4 includes the first indication information. The first indication information may include the identification of the terminal device or other possible information, which is not specifically limited. For example, message 4 may be a newly added message, and the manifestation may be a user context management IMS session failure request (Nudm_UECM_IMSSessionFailure Request).

In step 606, the UDM entity determines whether the SMF entity successfully restores the IMS session of the terminal device, and if so, ends the process; otherwise, executes step 607.

Exemplarily, after the UDM entity sends the first indication information to the SMF entity, if the response message from the SMF entity is not received within a preset time period, it can be determined that the SMF entity has not successfully restored the IMS session of the terminal device. If the SMF response message is received within the time period, when the cause value (cause) carried in the response message indicates that the SMF entity successfully resumes the IMS session of the terminal device, it can be determined that the SMF entity successfully resumes the IMS session of the terminal device. When the response message carries The reason value of indicates that when the SMF entity fails to restore the IMS session of the terminal device, it can be determined that the SMF entity fails to restore the IMS session of the terminal device.

There are many ways for the SMF entity to successfully restore the IMS session of the terminal device. For example, the SMF entity executes the IMS session release process (see Figure 4b), and the terminal device can re-establish the IMS session (see Figure 4a) . There may be many reasons why the SMF fails to successfully restore the IMS session of the terminal device, such as the relevant information of the IMS session that has no terminal device on the SMF entity.

Exemplarily, the response message sent by the SMF entity to the UDM entity may be a newly added message, and the embodiment may be a user context management IMS session failure response (Nudm_UECM_IMSSessionFailure Response), and the response message may carry cause information elements.

It should be noted that in other possible embodiments, if the UDM entity determines that the SMF fails, it may no longer send the first indication information to the SMF, and it is determined that the SMF entity has not successfully restored the IMS session of the terminal device.

Step 607: The UDM entity sends the first indication information to the AMF entity.

Exemplarily, if the UDM entity determines that the AMF entity has subscribed to the IMS session failure event, it may send the first indication information to the AMF entity. For example, the UDM entity may send a message 5 to the AMF entity, and the message 5 includes the first indication information. Among them, the message 5 may be a newly added message, and the embodiment may be a user context management IMS session failure request (Nudm_UECM_IMSSessionFailure Request).

Step 608: The AMF entity sends a response message to the UDM entity.

Exemplarily, the response message sent by the AMF entity to the UDM entity may be a newly added message, and the embodiment may be a user context management IMS session failure response (Nudm_UECM_IMSSessionFailure Response).

Step 609: The AMF entity sends third indication information to the terminal device, where the third indication information is used to instruct the terminal device to re-establish an IMS session.

Exemplarily, the AMF entity may send a message 6 to the terminal device. The message 6 includes third indication information. The third indication information may include the status information of the IMS session. The status information of the IMS session is used to indicate that the IMS session is in an inactive state. Among them, the manifestation of message 6 may be a configuration update command (Configuration Update Command), and a PDU session state information element may be added to the configuration update command, and the PDU session state information element is used to carry state information of an IMS session.

Step 610: The terminal device receives the third indication information, and re-establishes the IMS session of the terminal device.

Exemplarily, after receiving the state information of the IMS session, the terminal device determines that the state of the IMS session stored by itself (that is, the active state) is inconsistent with the state of the IMS session (that is, the inactive state) indicated by the third indication information, then The IMS session of the terminal device can be re-established (see Figure 4a).

In the process described above (for ease of description, this implementation process is referred to as the first implementation process), both the AMF entity and the SMF entity subscribe to the UDM entity for the IMS session failure event of the terminal device, and the subsequent UDM entity determines the terminal device’s After the IMS session fails, the first indication information may be sent to the SMF entity first. If the SMF entity fails to resume the IMS session of the terminal device, the UDM entity may send the first indication information to the AMF entity so that the AMF entity can restore the IMS of the terminal device. Session: If the SMF entity successfully resumes the IMS session of the terminal device, the UDM entity may no longer send the first indication information to the AMF entity to save signaling overhead and transmission resource overhead.

It should be noted that the foregoing process is only one possible implementation process. In other embodiments, there may be other implementation processes, such as the second implementation process to the fifth implementation process.

The second implementation process: Both the AMF entity and the SMF entity subscribe to the UDM entity for the IMS session failure event of the terminal device. After the subsequent UDM entity determines that the IMS session of the terminal device has failed, it can first send the first indication information to the AMF entity. If the entity fails to successfully restore the IMS session of the terminal device, the UDM entity may send the first indication information to the SMF entity so that the SMF entity restores the IMS session of the terminal device; if the AMF entity successfully restores the IMS session of the terminal device, the UDM entity may not Then send the first indication information to the SMF entity.

The third implementation process: Both the AMF entity and the SMF entity subscribe to the UDM entity for the IMS session failure event of the terminal device. After the subsequent UDM entity determines that the IMS session of the terminal device fails, it can send the first indication information to the AMF entity and the SMF entity. Here, the order in which the UDM entity sends the first indication information to the AMF entity and the SMF entity may not be limited. For example, the UDM entity may send the first indication information to the AMF entity and the SMF entity at the same time. Correspondingly, after receiving the first indication information, the AMF entity and the SMF entity can re-establish an IMS session for the terminal device.

The fourth implementation process: the AMF entity subscribes the IMS session failure event of the terminal device to the UDM entity (the SMF entity does not subscribe), and the subsequent UDM entity determines that the IMS session of the terminal device fails, and can send the first indication information to the AMF entity. Correspondingly, after receiving the first indication information, the AMF entity can re-establish an IMS session for the terminal device.

The fifth implementation process: the SMF entity subscribes to the UDM entity for the IMS session failure event of the terminal device (the AMF entity does not subscribe), and the subsequent UDM entity determines that the IMS session of the terminal device fails, and can send the first indication information to the SMF entity. Correspondingly, after receiving the first indication information, the SMF entity can re-establish an IMS session for the terminal device.

In addition, in the implementation process described above, the AMF entity re-establishes the IMS session for the terminal device after receiving the first indication information sent by the UDM entity. In the embodiment of the present application, the AMF entity may also re-establish an IMS session for the terminal device after sensing the failure of the SMF entity.

For example, the terminal device 1, the terminal device 2, and the terminal device 3 all have PDU sessions established on the SMF entity, which are PDU session 1, PDU session 2, and PDU session 3, respectively. Since the AMF entity can save the identity of the SMF entity serving the PDU session of the terminal device, when the AMF entity senses the failure of the SMF entity, it learns that PDU session 1, PDU session 2, and PDU session 3 need to be re-established, and the above can be used. In the manner described in step 609, the PDU session 1, the PDU session 2, and the PDU session 3 are re-established for the terminal device 1, the terminal device 2, and the terminal device 3, respectively.

Example two

In the second embodiment, the method in the embodiment of the present application is applied to the network architecture shown in FIG. 2a as an example to describe a possible implementation process.

Refer to FIG. 7 for a schematic diagram of a process corresponding to a method for restoring an IMS service provided by the second embodiment of the application, as shown in FIG. 7, including:

Step 701: The MME sends first information to the HSS, where the first information is used to request to subscribe to the IMS session failure event of the terminal device.

Exemplarily, when the terminal device registers with the MME, the MME may send a message 1 to the HSS, and the message 1 includes the first information. For example, the specific form of the message 1 may be an update location request (Update Location Request), and the first information is the newly added Subscribe-IMS-Session-Failure parameter in the ULR-Flags cell of the update location request.

Step 702: The PGW-C entity sends second information to the HSS, where the second information is used to request to subscribe to the IMS session failure event of the terminal device.

Exemplarily, when the terminal device requests the PGW-C entity to establish an IMS session, the PGW-C entity may send a message 2 to the HSS, and the message 2 includes the second information. For example, the message 2 may be a newly added message, the embodiment may be a PGW Update Location Request (PGW Update Location Request), and the second information may be the Subscribe-IMS-Session-Failure parameter carried in the PGW Update Location Request.

Step 703: The S-CSCF entity sends second indication information to the HSS, where the second indication information is used to indicate that the IMS session of the terminal device fails.

Exemplarily, in the procedures shown in FIGS. 3a and 3b, when the failure scenario described above occurs, the P-CSCF entity may return a failure response message to the S-CSCF entity, indicating that the IMS session of the terminal device has failed. Furthermore, after the S-CSCF entity receives the failure response message sent by the P-CSCF entity, it can send message 3 to the HSS. Message 3 includes the second indication information. The specific form of message 3 can be a registration notification request or a de-registration notification. Request, the second indication information may be the newly added Subscribe-IMS-Session-Failure parameter in the SAR-Flags cell of the registration notification request or de-registration notification request.

Step 704: The HSS receives the second indication information, and then determines that the IMS session of the terminal device has failed.

Step 705: The HSS sends first indication information to the PGW-C entity, where the first indication information is used to indicate that the IMS session of the terminal device fails.

Exemplarily, if the HSS determines that the PGW-C entity has subscribed to the IMS session failure event, it may send the first indication information to the PGW-C entity. For example, the HSS may send message 4 to the PGW-C entity, and the message 4 includes the first indication information. Among them, message 4 may be a new message, such as PGW Insert Subscriber Data Request, and the first indication information may be the newly added IMS-Session-Failure in the IDR Flags cell of the PGW insert user data request. parameter.

In step 706, the HSS determines whether the PGW-C entity successfully restores the IMS session of the terminal device, and if so, ends the process; otherwise, executes step 707.

Exemplarily, after the HSS sends the first indication information to the PGW-C entity, if the response message of the PGW-C entity is not received within the preset time period, it can be determined that the PGW-C entity has not successfully restored the IMS session of the terminal device If the response message of the PGW-C entity is received within the preset time period, when the cause value (cause) carried in the response message indicates that the PGW-C entity successfully resumes the IMS session of the terminal device, the PGW-C entity can be determined The IMS session of the terminal device is successfully restored, and when the cause value carried in the response message indicates that the PGW-C entity has not successfully restored the IMS session of the terminal device, it can be determined that the PGW-C entity has not successfully restored the IMS session of the terminal device.

There are many ways for the PGW-C entity to successfully restore the IMS session of the terminal device. For example, the PGW-C entity executes the IMS session release process, and the terminal device can re-establish the IMS session. There may be many reasons why the PGW-C entity fails to restore the IMS session of the terminal device, such as the relevant information of the IMS session without the terminal device on the PGW-C entity.

Exemplarily, the response message sent by the PGW-C entity to the HSS may be a newly-added message, and the embodiment may be a PGW Insert Subscriber Data Answer, and the response message may carry cause information elements.

It should be noted that, in other possible embodiments, if the HSS determines that the PGW-C entity is faulty, it may no longer send the first indication information to the PGW-C entity, and it is determined that the PGW-C entity has not successfully recovered the terminal device. IMS session.

Step 707: The HSS sends the first indication information to the MME.

Exemplarily, if the HSS determines that the MME has subscribed to the IMS session failure event, it may send the first indication information to the MME. For example, the HSS may send a message 5 to the MME, and the message 5 includes the first indication information. Wherein, message 5 may be a newly added message, such as an insert subscriber data request (Insert Subscriber Data Request), and the first indication information may be a newly added IMS-Session-Failure parameter in the IDR Flags cell of the insert subscriber data request.

In step 708, the MME sends a response message to the HSS.

Exemplarily, the response message sent by the MME to the HSS may be a newly added message, and the embodiment may be an Insert Subscriber Data Answer (Insert Subscriber Data Answer).

Step 709: The MME sends third indication information to the terminal device, where the third indication information is used to instruct the terminal device to re-establish an IMS session.

Exemplarily, the MME may send a message 6 to the terminal device, and the message 6 includes the third indication information. Among them, message 6 may be a Deactivate EPS Bearer Context Request (Deactivate EPS Bearer Context Request). The value of the ESM cause cell value of the EPS bearer Context Request is #39, which means that the deactivation is requested. (Reactivation Requested).

Step 710: The terminal device receives the third indication information, and re-establishes the IMS session of the terminal device.

In the embodiments of this application, by adopting the solutions in the first and second embodiments, after the SDMN determines that the IMS session of the terminal device has failed, it can trigger the MMN and/or SMN to re-establish the IMS session of the terminal device, thereby recovering the terminal in time The IMS service of the device effectively reduces the delay of restoring IMS service.

It should be noted that: (1) Since the second embodiment is applicable to the system architecture shown in FIG. 2a, and the first embodiment is applicable to the system architecture shown in FIG. 2b, the name of the network entity in the second embodiment and the first embodiment is either The names of messages communicated between different network entities may be different, except for this difference, the two can refer to each other. For example, in the second embodiment, the second to fourth implementation procedures described in the first embodiment can also be used.

(2) The step numbers of the flowcharts described in the embodiments of the present application (for example, FIG. 6 and FIG. 7) are only an example of the execution process, and do not constitute a restriction on the order of execution of the steps. The embodiment of the present application There is no strict execution order between steps that do not have a timing dependency between each other.

The foregoing mainly introduces the solution provided by the embodiment of the present application from the perspective of interaction between the network device and the terminal device. It can be understood that, in order to implement the above-mentioned functions, the network device or the terminal device may include a hardware structure and/or software module corresponding to each function. Those skilled in the art should easily realize that in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software-driven hardware depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

The embodiment of the present application may divide the terminal device and the network device into functional units according to the foregoing method examples. For example, each functional unit may be divided corresponding to each function, or two or more functions may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

In the case of using an integrated unit, FIG. 8 shows a possible exemplary block diagram of a device involved in an embodiment of the present application. As shown in FIG. 8, the apparatus 800 may include: a processing unit 802 and a communication unit 803. The processing unit 802 is used to control and manage the actions of the device 800. The communication unit 803 is used to support communication between the apparatus 800 and other devices. Optionally, the communication unit 803 is also called a transceiving unit, and may include a receiving unit and/or a sending unit, which are used to perform receiving and sending operations, respectively. The device 800 may further include a storage unit 801 for storing program codes and/or data of the device 800.

The device 800 may be an SDMN (such as the UDM entity in the first embodiment above or the HSS in the second embodiment above) or a chip set in the SDMN. The processing unit 802 may support the device 800 to perform the SDMN actions in the above method examples. Alternatively, the processing unit 802 mainly executes the internal actions of the SDMN in the method example, and the communication unit 803 may support communication between the device 800 and other devices. For example, the processing unit 802 is used to perform step 605 in FIG. 6 or step 705 in FIG. 7; the communication unit 803 may be used to perform step 604, step 607, and step 608 in FIG. 6, or to perform step 704 in FIG. , Step 707, Step 708.

In one embodiment, the processing unit 802 is configured to: determine that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device; the communication unit 803 is configured to: send the first indication information to the MMN and/or SMN, first An indication information is used to indicate that the IMS session of the terminal device fails.

In a possible design, the communication unit 803 is configured to receive the second indication information from the serving call state control function S-CSCF entity, and the second indication information is used to indicate that the IMS session of the terminal device fails.

In a possible design, the communication unit 803 is configured to receive the first information sent by the MMN, and the first information is used to request to subscribe to the IMS session failure event of the terminal device.

In a possible design, the communication unit 803 is configured to receive the second information from the SMN, and the second information is used to request to subscribe to the IMS session failure event of the terminal device.

The device 800 may be an MMN (such as the AMF entity in the first embodiment above or the MME in the second embodiment above) or a chip set in the MMN. The processing unit 802 can support the device 800 to perform the MMN actions in the above method examples. Alternatively, the processing unit 802 mainly executes the internal actions of the MMN in the method example, and the communication unit 803 can support communication between the device 800 and other devices. For example, the communication unit 803 may be used to perform step 601 and step 609 in FIG. 6 or to perform step 701 and step 709 in FIG. 7.

In one embodiment, the processing unit 802 is configured to: determine that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device; and, to re-establish the IMS session for the terminal device.

In a possible design, the communication unit 803 is configured to send first information to the SDMN, and the first information is used to request to subscribe to the IMS session failure event of the terminal device.

In a possible design, the communication unit 803 is further configured to send third indication information to the terminal device, and the third indication information is used to instruct the terminal device to re-establish an IMS session.

The device 800 may be an SMN (such as the SMF entity in the first embodiment above or the PGW-C in the second embodiment above) or a chip set in the SMN. The processing unit 802 may support the device 800 to perform the SMN actions in the above method examples. Alternatively, the processing unit 802 mainly executes the internal actions of the SMN in the method example, and the communication unit 803 can support communication between the device 800 and other devices. For example, the communication unit 803 may be used to perform step 602 in FIG. 6 or step 702 in FIG. 7.

In one embodiment, the communication unit 803 is configured to: receive first indication information from the SDMN, the first indication information is used to indicate that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device; the processing unit 802 uses To re-establish an IMS session for the terminal device.

In a possible design, the communication unit 803 is further configured to send second information to the SDMN, and the second information is used to request to subscribe to the IMS session failure event of the terminal device.

The apparatus 800 may be a terminal device or a chip set in the terminal device. The processing unit 802 may support the apparatus 800 to perform the actions of the terminal device in the foregoing method examples. Alternatively, the processing unit 802 mainly executes the internal actions of the terminal device in the method example, and the communication unit 803 may support communication between the device 800 and other devices. For example, the processing unit 802 is configured to execute step 610 in FIG. 6 or execute step 710 in FIG. 7.

In one embodiment, the communication unit 803 is configured to: receive third indication information from the MMN, the third indication information is used to instruct the terminal device to re-establish an IMS session, and the IMS session is used to carry the IMS service of the terminal device; the processing unit 802 uses According to the third instruction information, the IMS session is re-established.

In a possible design, the communication unit 803 is further configured to: receive a configuration update command from the MMN, where the configuration update command includes the third indication information.

It should be understood that the division of units in the above device is only a division of logical functions, and may be fully or partially integrated into one physical entity in actual implementation, or may be physically separated. In addition, the units in the device can be all implemented in the form of software called by processing elements; they can also be implemented in the form of hardware; part of the units can be implemented in the form of software called by the processing elements, and some of the units can be implemented in the form of hardware. For example, each unit can be a separate processing element, or it can be integrated in a certain chip of the device for implementation. In addition, it can also be stored in the memory in the form of a program, which is called and executed by a certain processing element of the device. Features. In addition, all or part of these units can be integrated together or implemented independently. The processing element described here can also become a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above units may be implemented by an integrated logic circuit of hardware in a processor element or implemented in a form of being called by software through a processing element.

In an example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, for example: one or more application specific integrated circuits (ASICs), or, one or Multiple microprocessors (digital singnal processors, DSPs), or, one or more field programmable gate arrays (Field Programmable Gate Arrays, FPGAs), or a combination of at least two of these integrated circuits. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (central processing unit, CPU), or other processors that can call programs. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

The above receiving unit is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented as a chip, the receiving unit is an interface circuit used by the chip to receive signals from other chips or devices. The above unit for sending is an interface circuit of the device for sending signals to other devices. For example, when the device is implemented in the form of a chip, the sending unit is an interface circuit used by the chip to send signals to other chips or devices.

Refer to FIG. 9, which is a schematic diagram of a device for restoring an IMS service provided by an embodiment of this application. The device 900 may be SDMN, MMN, SMN or terminal equipment in the foregoing embodiment. The device 900 includes a processor 902, a communication interface 903, and a memory 901. Optionally, the apparatus 900 may further include a communication line 904. Among them, the communication interface 903, the processor 902, and the memory 901 may be connected to each other through a communication line 904; the communication line 904 may be a peripheral component interconnection standard (peripheral component interconnect, PCI for short) bus or an extended industry standard architecture (extended industry standard architecture) , Referred to as EISA) bus and so on. The communication line 904 can be divided into an address bus, a data bus, a control bus, and so on. For ease of representation, only one thick line is used in FIG. 9, but it does not mean that there is only one bus or one type of bus.

The processor 902 may be a CPU, a microprocessor, an ASIC, or one or more integrated circuits used to control the execution of the program of the present application. The function of the processor 902 may be the same as the function of the processing unit described in FIG. 8.

The communication interface 903 uses any device such as a transceiver to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), Wired access network, etc. The function of the communication interface 903 may be the same as the function of the communication unit described in FIG. 8.

The memory 901 may be ROM or other types of static storage devices that can store static information and instructions, RAM or other types of dynamic storage devices that can store information and instructions, or may be electrically erasable programmable read-only memory (electrically erasable programmable read-only memory). read-only memory, EEPROM), compact disc (read-only memory, CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital universal discs, Blu-ray discs, etc.), magnetic disks A storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto. The memory may exist independently, and is connected to the processor through a communication line 904. The memory can also be integrated with the processor. The memory 901 may have the same function as the storage unit described in FIG. 8.

The memory 901 is used to store computer-executable instructions for executing the solution of the present application, and the processor 902 controls the execution. The processor 902 is configured to execute computer-executable instructions stored in the memory 901, so as to implement the session processing method provided in the foregoing embodiment of the present application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, this application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, equipment (systems), and computer program products according to this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are used to generate It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, then this application is also intended to include these modifications and variations.

Claims

A method for restoring IMS services by a network protocol IP multimedia subsystem, characterized in that the method includes:

Determining that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device;

Send first indication information to the mobility management network node MMN and/or the session management network node SMN, where the first indication information is used to indicate that the IMS session of the terminal device fails.
The method according to claim 1, wherein determining that the IMS session of the terminal device has failed comprises:

Receiving second indication information from a serving call state control function S-CSCF entity, where the second indication information is used to indicate that the IMS session of the terminal device fails.
The method according to claim 1 or 2, wherein sending the first indication information to the MMN comprises:

If it is determined that the SMN has not successfully restored the IMS session of the terminal device, sending the first indication information to the MMN.
The method according to claim 3, wherein determining that the SMN has not successfully restored the IMS session of the terminal device comprises:

It is determined that the SMN is faulty; or,

Sending the first indication information to the SMN, and the SMN response message is not received within a preset time period; or,

Sending the first indication information to the SMN, and receiving a response message from the SMN, the response message carrying the value of the reason for not successfully restoring the IMS session of the terminal device.
The method according to any one of claims 1 to 4, wherein the method further comprises:

Receiving the first information sent by the MMN, where the first information is used to request to subscribe to the IMS session failure event of the terminal device.
The method according to any one of claims 1 to 5, wherein the method further comprises:

Receiving second information from the SMN, where the second information is used to request to subscribe to the IMS session failure event of the terminal device.
A method for restoring IMS services, characterized in that the method includes:

Determining that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device;

Re-establish the IMS session for the terminal device.
The method according to claim 7, wherein determining that the IMS session of the terminal device fails, comprises:

It is determined that the SMN associated with the IMS session is faulty; or,

Receiving first indication information from the SDMN, where the first indication information is used to indicate that the IMS session of the terminal device fails.
The method according to claim 7 or 8, wherein the method further comprises:

Sending first information to the SDMN, where the first information is used to request to subscribe to the IMS session failure event of the terminal device.
The method according to any one of claims 7 to 9, wherein re-establishing the IMS session for the terminal device comprises:

Sending third instruction information to the terminal device, where the third instruction information is used to instruct the terminal device to re-establish the IMS session.
The method according to claim 10, wherein the third indication information includes state information of the IMS session, and the state information of the IMS session is used to indicate that the state of the IMS session is inactive.
The method according to claim 10 or 11, wherein sending third indication information to the terminal device comprises:

Sending a configuration update command to the terminal device, where the configuration update command includes the third indication information.
A method for restoring IMS services, characterized in that the method includes:

Receiving first indication information from the SDMN, where the first indication information is used to indicate that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device;

Re-establish the IMS session for the terminal device.
The method according to claim 13, wherein the method further comprises:

Sending second information to the SDMN, where the second information is used to request to subscribe to the IMS session failure event of the terminal device.
A method for restoring IMS services, characterized in that the method includes:

Receiving third indication information from the MMN, where the third indication information is used to instruct the terminal device to re-establish an IMS session, and the IMS session is used to carry the IMS service of the terminal device;

Re-establish the IMS session according to the third instruction information.
The method according to claim 15, wherein the third indication information includes state information of the IMS session, and the state information of the IMS session is used to indicate that the state of the IMS session is in an inactive state.
The method according to claim 15 or 16, wherein receiving the third indication information from MMN comprises:

Receiving a configuration update command from the MMN, where the configuration update command includes the third indication information.
A device for restoring IMS services, characterized in that the device includes a processing unit and a communication unit;

The processing unit is configured to determine that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device;

The communication unit is configured to send first indication information to the MMN and/or SMN, where the first indication information is used to indicate that the IMS session of the terminal device fails.
The device according to claim 18, wherein the communication unit is further configured to:

Receiving second indication information from a serving call state control function S-CSCF entity, where the second indication information is used to indicate that the IMS session of the terminal device fails.
The device according to claim 18 or 19, wherein the communication unit is further configured to:

Receiving the first information sent by the MMN, where the first information is used to request to subscribe to the IMS session failure event of the terminal device.
The device according to any one of claims 18 to 20, wherein the communication unit is further configured to:

Receiving second information from the SMN, where the second information is used to request to subscribe to the IMS session failure event of the terminal device.
A device for restoring IMS services, characterized in that the device includes a processing unit and a communication unit;

The processing unit is configured to determine that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device; and, the processing unit is also configured to control the communication unit to perform: Describe the IMS session.
The apparatus according to claim 22, wherein the communication unit is further configured to send first information to the SDMN, and the first information is used to request a subscription to an IMS session failure event of the terminal device.
The device according to claim 22 or 23, wherein the communication unit is further configured to:

Sending third instruction information to the terminal device, where the third instruction information is used to instruct the terminal device to re-establish the IMS session.
A device for restoring IMS services, characterized in that the device includes a processing unit and a communication unit;

The communication unit is configured to receive first indication information from the SDMN, where the first indication information is used to indicate that the IMS session of the terminal device fails, and the IMS session is used to carry the IMS service of the terminal device;

The processing unit is configured to control the communication unit to perform: re-establish the IMS session for the terminal device.
The apparatus according to claim 25, wherein the communication unit is further configured to send second information to the SDMN, and the second information is used to request to subscribe to the IMS session failure event of the terminal device.
A device for restoring IMS services, characterized in that the device includes a processing unit and a communication unit;

The communication unit is configured to receive third indication information from the MMN, where the third indication information is used to instruct the terminal device to re-establish an IMS session, and the IMS session is used to carry the IMS service of the terminal device;

The processing unit is configured to re-establish the IMS session according to the third indication information.
The apparatus according to claim 27, wherein the communication unit is further configured to receive a configuration update command from the MMN, the configuration update command including the third indication information.
A device for restoring IMS services, characterized in that it comprises:

Communication interface, used to communicate with other devices;

Memory, used to store computer programs and data;

The processor is configured to run the computer program in the memory, read the computer program in the memory, and execute the method according to any one of claims 1-17 through the communication interface.
A computer storage medium, characterized in that a computer program is stored in the computer storage medium, and when the computer program is executed by a computer, the computer is caused to execute the method according to any one of claims 1-17.