Channel establishment method and device and session management function network element

Abstract

The invention relates to the technical field of communication, in particular to a channel establishment method and device and a session management function network element. The method comprises the following steps: acquiring a call request initiated by a proxy call session control function (P-CSCF) network element; wherein the call request is initiated by the P-CSCF network element under the condition that the P-CSCF network element determines that a policy control function (PCF) network element has a fault; determining a policy and a charging control PCC policy corresponding to the user terminal according to user identification information of the user terminal carried in the call request; and sending the PCC strategy to the user terminal, so that the user terminal constructs a communication channel between the user terminal and other user terminals according to the PCC strategy.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a channel establishment method, device and session management function network element. Background Art

[0002] As a core component in the network architecture, the Policy Control Function (PCF) network element plays a vital role. It is not only responsible for implementing the Quality of Service (QoS) strategy, but also bears the responsibility of billing control. In order to ensure high network availability and service continuity, according to industry best practices, at least two PCF network element devices are usually deployed in the network to achieve redundancy and load balancing.

[0003] Under normal operation, these PCF network elements work together to provide stable and efficient services to user equipment (UE). However, once one of the PCF network elements fails, according to the specifications of the 3rd Generation Partnership Project (3GPP), the network can respond quickly and perform fault recovery procedures.

[0004] However, when all PCF network element devices in the network fail, due to the lack of effective policy control and resource allocation, a large number of users' voice dedicated bearer establishment requests will not be met, and voice connection between the caller and the called party will not be possible, which will affect the user experience. Therefore, improvement is urgently needed. Summary of the invention

[0005] Based on this, it is necessary to provide a channel establishment method, device and session management function network element that can optimize the user communication process in response to the above technical problems.

[0006] In a first aspect, the present application provides a channel establishment method, which is applied to a session management function SMF network element, and the method includes:

[0007] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0008] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0009] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0010] In one embodiment, sending the PCC policy to the user terminal includes:

[0011] Send a session update request to the user plane control UPF network element; wherein the session update request includes the service quality requirements and service description information in the PCC policy; the session update request is used to instruct the UPF network element to update the data packet identification mechanism corresponding to the user terminal according to the service description information, and update the data packet processing mechanism corresponding to the user terminal according to the service quality requirements, and feedback the update response message after the update is successful;

[0012] When the update response message fed back by the UPF network element is obtained, the session configuration modification indication in the PCC policy is sent to the user terminal.

[0013] In one of the embodiments, sending a session configuration modification indication in a PCC policy to a user terminal includes:

[0014] The session configuration modification indication in the PCC policy is sent to the access and mobility management function AMF network element, so that the AMF network element forwards the session configuration modification indication in the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy.

[0015] In one of the embodiments, the call request is a request initiated by the P-CSCF network element when it determines that the PCF network element has a fault based on the communication request initiated by the calling terminal, the communication response message fed back by the called terminal for the communication request, and the answer failure message fed back by the PCF network element for the communication request.

[0016] In one of the embodiments, obtaining a call request initiated by a proxy call session control function P-CSCF network element includes:

[0017] Obtaining a call request initiated by the P-CSCF network element based on the target communication port;

[0018] Among them, the target communication port corresponds to the communication address of the SMF network element, and the communication address of the SMF network element is obtained by parsing the communication response message fed back by the called terminal in response to the communication request.

[0019] In one of the embodiments, the method further includes: obtaining a communication indication sent by an AMF network element; the communication indication is generated by the AMF network element when receiving a channel establishment success message sent by a user terminal; the channel establishment success message is generated by the user terminal when a communication channel between the user terminal and other user terminals is successfully established according to a session configuration modification indication in a PCC policy;

[0020] The communication instruction is sent to the P-CSCF network element.

[0021] In a second aspect, the present application also provides a channel establishment device, which is configured in a session management function SMF network element, including:

[0022] A request acquisition module, used to acquire a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0023] A policy acquisition module, used to determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0024] The channel establishment module is used to send the PCC policy to the user terminal so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0025] In a third aspect, the present application further provides a session management function network element, including a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program:

[0026] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0027] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0028] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0029] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the following steps are implemented:

[0030] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0031] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0032] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0033] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0034] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0035] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0036] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0037] The above-mentioned channel establishment method, device and session management function network element, the present application utilizes the interaction between the P-CSCF network element and the SMF network element, so that the P-CSCF network element sends a call request indicating a failure of the PCF network element to the SMF network element. The SMF network element stores the PCC policy corresponding to each user, so it is possible to determine the PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request. In this process, the SMF network element implements the function of bypassing the PCF network element, and then sends the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy, and completes the establishment of a dedicated voice bearer, thereby ensuring the continuity of the user's voice service and avoiding service interruption due to PCF failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A diagram of an application environment of a channel establishment method in an embodiment;

[0040] Figure 2 A schematic diagram of a flow chart of a channel establishment method in an embodiment;

[0041] Figure 3A schematic flow chart of the steps of controlling a user terminal to establish a communication channel between the user terminal and other user terminals in one embodiment;

[0042] Figure 4 A flowchart of a step of sending a PCC policy to a user terminal in one embodiment;

[0043] Figure 5 It is an interactive schematic diagram of a method for establishing a channel in a calling network in one embodiment;

[0044] Figure 6 It is an interactive schematic diagram of a method for establishing a channel in a called network in another embodiment;

[0045] Figure 7 It is a structural block diagram of a channel establishment device in one embodiment;

[0046] Figure 8 FIG. 4 is a diagram showing the internal structure of a session management function network element in an embodiment. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0048] In an exemplary embodiment, Figure 1 As shown, an application environment of a channel establishment method is provided, the application environment including a user terminal (User Terminal, UE), a proxy call session control function network element (Proxy-Call Session Control Function, P-CSCF) corresponding to the user terminal, an interrogating-Call Session Control Function network element (Interrogating-Call Session Control Function, I-CSCF), a serving call session control function network element (Serving-Call Session Control Function, S-CSCF), a policy control function network element (PCF PolicyControl Function, PCF), a user plane network element (User Plane Function, UPF), a session management function (Session Management Function, SMF) network element corresponding to the user terminal, and an access and mobility management function network element (Access and Mobility Management Function, AMF); wherein:

[0049] The P-CSCF network element is the first contact node for users in the IP Multimedia Subsystem (IMS) network. All SIP (Session Initiation Protocol) signaling from users must pass through the P-CSCF network element. It is the entry and boundary node of the IMS system, responsible for receiving requests from the outside world (such as user equipment UE, access network) to the IMS network, and forwarding them to the internal IMS network elements for processing. As a SIP proxy server, the P-CSCF is responsible for receiving, verifying, and forwarding SIP requests and responses. It forwards the UE's SIP registration request to the corresponding I-CSCF, and forwards the SIP message to the specified SIP server. Billing and recording: The P-CSCF generates relevant billing information, supports encryption processes, and performs authentication of bearer resources and quality of service (QoS) management.

[0050] The I-CSCF network element is a key network element in the IMS network. As a proxy for SIP messages, it is mainly responsible for forwarding SIP requests initiated by user terminals (UE) to the correct S-CSCF network element.

[0051] The S-CSCF network element is responsible for processing the SIP session of the user terminal, including call establishment, modification and termination. It executes call control logic and interacts with the user's subscription data and service policy to provide personalized services.

[0052] The PCF network element obtains the policy information of the user's contract from data sources such as the unified data repository (UDR). Based on this policy information, the PCF makes decisions on the user's service request, including access and mobility policies, session management policies, etc. The PCF interacts with network elements such as the access and mobility management function (AMF) and the session management function (SMF) to send these policy control decisions to the corresponding locations in the network to ensure that users use network resources in the agreed manner. The PCF network element uses policy control to ensure that users can use network resources in accordance with the agreed quality of service (QoS). In addition to policy control, the PCF network element also participates in the billing control process.

[0053] The SMF network element is responsible for managing the establishment, modification, and termination of user sessions. It works in conjunction with the UPF network element to ensure the continuity and stability of user sessions. The SMF network element is also responsible for handling session-related policy control, such as QoS assurance and charging policies.

[0054] The UPF network element is responsible for handling the transmission and forwarding of user data. It is usually located at the edge of the network, interacting directly with the user terminal, and is responsible for encapsulating user data into IP packets and sending them to the destination. The UPF network element also supports functions such as traffic management and congestion control.

[0055] The AMF network element is responsible for managing user access and mobility. It handles user registration, authentication, certification, and location update processes to ensure that users can access the network securely and reliably and enjoy mobile services.

[0056] In an exemplary embodiment, Figure 2 As shown, a channel establishment method is provided, which is applied to Figure 1 The SMF network element in the example is used to illustrate, including:

[0057] S201: Obtain a call request initiated by a proxy call session control function P-CSCF network element.

[0058] It can be understood that, when the user terminal is the calling terminal, when the user terminal makes a voice call, an INVITE request is initiated to the called terminal through the P-CSCF network element, ICSCF network element and S-CSCF network element. In this embodiment, the INVITE request is a PDU session establishment request.

[0059] Optionally, after receiving the INVITE request, the called terminal returns a 183 message to the P-CSCF network element through the ICSCF network element and the S-CSCF network element, wherein the 183 message is a SIP response message, indicating that the session is in progress.

[0060] The calling request is initiated by the P-CSCF network element when it is determined that the policy control function PCF network element fails.

[0061] It can be understood that after receiving the 183 message, the P-CSCF network element will send an AAR (AAA Request, authentication, authorization and accounting request) request to the PCF network element based on the information in the 183 message, in order to obtain the policies and rules required to establish a voice-dedicated bearer. Therefore, the AAR request is also called a voice-dedicated bearer establishment request.

[0062] In an implementable manner, if the P-CSCF network element receives a successful response from the PCF network element, it continues to establish the voice-dedicated bearer according to the policy and rules provided by the PCF network element.

[0063] In another possible implementation, if the P-CSCF network element does not receive responses from all PCF network elements, or receives a failure code (such as due to network problems, PCF failures, or policy mismatches), it is determined that the PCF network element fails. It can be understood that a PCF network element failure refers to a state in which the PCF network element is completely unable to work properly, resulting in the complete failure of all policy control functions it is responsible for. This total failure may be caused by a variety of reasons, such as hardware failure, software error, network interruption, or malicious attack.

[0064] In this case, in order to ensure the normal operation of voice services, the P-CSCF network element will initiate a call request when it is confirmed that the PCF network element has a complete failure.

[0065] Optionally, the call request contains key information of the user terminal, such as user identity, terminal type, and current session identifier, to ensure that subsequent processes can correctly identify and process the voice service of the user terminal. Specifically, the call request may include the IP address of the user terminal; the IP address of the user terminal can be obtained through the Call-ID header field in the 183 message.

[0066] S202: Determine a policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request.

[0067] Optionally, when initiating a call request, the P-CSCF network element queries a locally stored database table, wherein the database table stores the association between the IP address of the candidate UE and the IP address and port number of the candidate SMF network element. Based on the IP address of the user terminal (also called the UE IP address) carried in the call request, the P-CSCF network element can find the SMF network element corresponding to the user terminal among the candidate SMF network elements in the database table, and determine the IP address and port number information of the SMF network element corresponding to the user terminal.

[0068] In order to distinguish it from the candidate SMF network elements, in this embodiment, the SMF network element corresponding to the user terminal is recorded as the target SMF network element. The P-CSCF network element will initiate a voice dedicated bearer establishment request to the target SMF network element and carry the user identification information of the user terminal.

[0069] For example, user identification information may include: (1) International Mobile Subscriber Identity (IMSI); (2) Mobile Subscriber ISDN Number (MSISDN), also known as mobile phone number; (3) User Equipment IP Address; Data Network Name (DNN), which is often used in 5G to specify the specific data network to which the user equipment should be connected; (4) m-line information in the SDP session description protocol: In SDP, the m-line (media line) is used to describe the media type and its related parameters in the session; (5) The end real-time transport protocol port number (RTP) in the SDP session description protocol is used to specify the port for media stream transmission; (6) Media type in the SDP session description protocol: such as audio, video, etc., specifies the type of media used in the session.

[0070] Furthermore, after receiving this information, the target SMF network element will associate the corresponding session ID according to the IMSI and UE IP address of the user terminal, and call the Policy and Charging Control (PCC) policy configured locally in the target SMF network element. This PCC policy defines information such as the quality of service and charging rules subscribed by the user terminal.

[0071] It is understandable that the PCC policy can set different priorities for the data traffic of the user terminal. For example, for applications with high real-time requirements (such as video calls, online games, etc.), their traffic priority can be set to a higher level to ensure low latency and high throughput. The PCC policy can also define a series of service quality parameters, such as bandwidth, latency, jitter, etc. These parameters can be dynamically adjusted according to the user's subscription level, business requirements and network conditions to provide the best user experience. The PCC policy can also support multiple billing modes, such as flow-based billing, time-based billing, session-based billing, etc. These billing modes can be flexibly configured according to the user's subscription information and business requirements. In addition to the billing mode, the PCC policy can also define specific billing strategies, such as traffic capping, package discounts, and additional charges after exceeding the package. These strategies help network operators achieve refined billing management, increase revenue and enhance user satisfaction.

[0072] Exemplarily, the PCC policy may specifically include voice QoS flow information, session configuration parameters, and network resource configuration parameters that the user terminal needs to configure; wherein:

[0073] Voice QoS flow information includes: (1) QoS parameters: such as bandwidth, latency, jitter, packet loss rate, etc. These parameters define the service quality standards required for voice communication; (2) QoS flow identifier: used to uniquely identify a QoS flow so that the network can distinguish and prioritize it; (3) Priority: specifies the priority of voice communication in the network to ensure that it can be given priority when resources are tight.

[0074] Session configuration parameters include: (1) Security policies: such as encryption algorithms and authentication mechanisms, which are used to ensure data security and user privacy during communication; (2) Traffic control policies: such as rate limiting and shaping, which are used to prevent network congestion and ensure the communication quality of other users; (3) Session management policies: such as session establishment, maintenance, and release rules, which are used to manage communication sessions between user terminals and other terminals.

[0075] Network resource configuration parameters include: (1) IP address and port allocation: assigning specific IP addresses and ports to user terminals so that the network can correctly route and forward voice communication data packets; (2) bearer channel setting: establishing a dedicated bearer channel for user terminals in the network to ensure the real-time and reliability of voice communication.

[0076] S203: Send the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0077] Specifically, after receiving the PCC policy, the user terminal will parse the session configuration parameters and network resource configuration parameters in the PCC policy, configure the session parameters of the user terminal according to the session configuration parameters, and configure the network interface of the user terminal according to the network resource configuration parameters.

[0078] After the configuration is completed, the user terminal will send a PDU session establishment confirmation message to the target SMF network element to indicate that the PDU session has been successfully established. At this point, the PDU session channel between the user terminal and other user terminals has been established, and the two parties can communicate through the channel.

[0079] In the above-mentioned channel establishment method, the present application utilizes the interaction between the P-CSCF network element and the SMF network element, so that the P-CSCF network element sends a call request indicating a failure of the PCF network element to the SMF network element. The SMF network element stores the PCC policy corresponding to each user. Therefore, it is possible to determine the PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request. In this process, the SMF network element implements the function of bypassing the PCF network element, and then sends the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy, and completes the establishment of a dedicated voice bearer, thereby ensuring the continuity of the user's voice service and avoiding service interruption due to PCF failure.

[0080] In an exemplary embodiment, Figure 3 As shown, the PCC policy is sent to the user terminal, including:

[0081] S301, sending a session update request to the user plane control UPF network element.

[0082] The session update request includes the service quality requirement and service description information in the PCC policy.

[0083] It can be understood that the session update request is used to instruct the UPF network element to update the data packet identification mechanism corresponding to the user terminal according to the service description information, and to update the data packet processing mechanism corresponding to the user terminal according to the service quality requirements, and to feedback the update response message after the update is successful.

[0084] In this embodiment, the session update request is an N4 session update request, and the service quality requirements (such as bandwidth, delay, jitter, etc.) are added to the QoS enforcement rule (QoS Enforcement Rule, QER) in the N4 session update request, and the service description information (such as media type, port number, etc.) is added to the packet detection rule (Packet Detection Rule, PDR) in the N4 session update request, and the added QER and PDR are sent to the UPF network element.

[0085] After receiving this information, the UPF network element will perform a session update operation to ensure that the voice data of the user terminal can be transmitted according to the specified QoS. Specifically, after receiving this session update request, the UPF network element will update the data packet identification mechanism corresponding to the user terminal according to the service description information, which specifically involves modifying or adding corresponding message detection rules (PDR) to ensure that only data packets that meet specific conditions will be further processed. At the same time, the UPF network element will also update the data packet processing mechanism corresponding to the user terminal according to the service quality requirements, specifically including adjusting the QoS execution rules (QER) to ensure that the data packets can be transmitted according to the specified QoS.

[0086] Exemplarily, the UPF network element performs the following session update operation process: First, the UPF network element parses the N4 session update request and extracts key information from the QER and PDR, including QoS parameters (such as bandwidth, delay, jitter, etc.) and service characteristics (such as voice coding type, data packet size, etc.). Based on the parsed information, the UPF network element will update its internally maintained session state table or database to ensure that subsequent data packet processing can meet the new QoS requirements, such as adjusting data packet forwarding rules, priority settings, flow control policies, etc. Then, the UPF network element monitors and dynamically adjusts the voice data packets sent or received by the user terminal in real time according to the instructions in the QER. For example, according to QoS requirements, the UPF may limit the speed, shape, discard or retransmit the data packets to ensure the continuity and quality of voice communication. At the same time, the UPF network element will also identify and classify the data packets of the user terminal according to the message feature information in the PDR. This helps to distinguish different types of service traffic and apply appropriate QoS policies to each service traffic.

[0087] Finally, the UPF network element may feedback the results of the session update to the target SMF network element, including whether the update is successful, the current session status, etc. For example, when the update is completed, the UPF network element will feedback an update response message to the SMF network element, indicating that the session update request has been successfully processed.

[0088] S302: When an update response message fed back by the UPF network element is obtained, the session modification indication in the PCC policy is sent to the user terminal.

[0089] It can be understood that the update response message fed back by the UPF network element indicates that the UPF network element has made corresponding modifications according to the PCC policy, and then, according to the PCC policy, the configuration on the user terminal side is modified, that is, the session modification indication in the PCC policy is sent to the user terminal.

[0090] In one implementable manner, sending a session modification indication in a PCC policy to a user terminal includes: sending a session configuration modification indication in a PCC policy to an access and mobility management function AMF network element, so that the AMF network element forwards the session configuration modification indication in the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy.

[0091] The session modification indication in the PCC policy is a PDU session modification command.

[0092] Optionally, the PDU session modification command is an instruction generated according to the voice QoS flow information, session configuration parameters and network resource configuration parameters that the user terminal needs to configure in the above PCC policy.

[0093] In this embodiment, the PDU session modification command is an N1 message. The target SMF network element will call the network element service of the AMF network element and request that the N1 message containing the PDU session modification command be transparently transmitted to the user terminal. After receiving the N1 message, the AMF network element will transmit the N1 message to the user terminal through an appropriate communication interface (such as generation NodeB, gNB).

[0094] Optionally, after receiving the N1 message, the user terminal will perform corresponding configurations and adjustments according to the PDU session modification command. These configurations and adjustments may include adjusting network resource allocation, setting QoS flows, updating media processing, etc., to ensure that the user terminal can establish a communication channel with other user terminals that meets the PCC policy requirements.

[0095] After the configuration is completed, the user terminal can start communicating according to the new PCC policy. This communication process will follow the previously determined QoS policy and charging rules to ensure the quality and security of communication.

[0096] In this embodiment, by allowing the target SMF network element to participate in the process of establishing the communication channel when the PCF network element fails, an effective alternative solution is provided, which solves the service interruption problem caused by PCF network element failure in traditional networks and improves the availability and continuity of network services.

[0097] In an exemplary embodiment, the call request is a request initiated by the P-CSCF network element when it is determined that a PCF network element fails based on a communication request initiated by a calling terminal, a communication response message fed back by the called terminal for the communication request, and a response failure message fed back by the PCF network element for the communication request. Accordingly, obtaining the call request initiated by the proxy call session control function P-CSCF network element includes: obtaining the call request initiated by the P-CSCF network element based on the target communication port.

[0098] Among them, the target communication port corresponds to the communication address of the SMF network element, and the communication address of the SMF network element is obtained by the P-CSCF network element based on the communication response message fed back by the called terminal in response to the communication request.

[0099] Optionally, the user initiates a communication request (i.e., the above-mentioned INVTIET request) through the calling terminal, such as making a voice call. This request will be sent to the P-CSCF network element through the I-CSCF network element / S-CSCF network element. After receiving this communication request, the called terminal will send a communication response message (i.e., the above-mentioned 183 message) to the P-CSCF network element through the network. In this example, it is assumed that the called terminal sends a 183 message, indicating that it has received the invitation and is ready to establish communication. Then, the P-CSCF network element will send an AAR request to the PCF network element to establish a voice-dedicated bearer. However, due to a failure of the PCF network element, it cannot correctly process the request of the P-CSCF network element and returns a response failure message.

[0100] The CSCF network element will detect this response failure message, or determine that the PCF network element has failed through other means (such as EMS indicator analysis of the network element management system). Once the P-CSCF network element determines that all PCF network elements have failed, it obtains the IP address of the user terminal from the Call-ID header field of the 183 message, and further determines the identification information of the user terminal; the P-CSCF network element queries the communication address (IP address of the target SMF network element) of the target SMF network element corresponding to the user terminal based on the previously maintained database table and the user identification information of the user terminal.

[0101] After obtaining the communication address of the target SMF network element, the P-CSCF network element will determine the target communication port used to communicate with the target SMF network element based on the communication address corresponding to the target SMF network element and initiate a call request.

[0102] Among them, this call request contains the key parameter information required to establish a voice-dedicated bearer, such as the International Mobile Subscriber Identity (IMSI), Mobile Subscriber ISDN Number (MSISDN), UE IP address, Data Network Name (DNN), and m-line information in the Session Description Protocol (SDP) (such as the Real-time Transport Protocol (RTP) port number, media type, etc.).

[0103] After receiving the call request from the P-CSCF network element, the target SMF network element will associate the received IMSI and UE IP address with the session ID corresponding to the user terminal. Then, the target SMF network element will call the locally configured PCC policy and send an N4 session update request to the UPF network element according to the PCC policy.

[0104] Among them, this N4 session update request contains the QoS (service quality information) and service description information required for voice. This information will be placed in the QoS execution rule (QER) and the message detection rule (PDR) and sent to the UPF network element.

[0105] After receiving the N4 session update request, the UPF network element will update the packet identification mechanism and processing mechanism corresponding to the user terminal according to the information in it. After completing the update, the UPF network element will send an update response message to the SMF network element, indicating that the session update has been successfully processed.

[0106] After receiving the update response message from the UPF network element, the target SMF network element will call the network element service of the AMF network element. The specific calling process is: sending the session configuration modification indication in the PCC policy to the access and mobility management function AMF network element, so that the AMF network element forwards the session configuration modification indication in the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy.

[0107] Further, such as Figure 4 As shown, the method also includes:

[0108] S401, obtain the communication indication sent by the AMF network element.

[0109] The communication indication is generated by the AMF network element when it receives a successful channel establishment message sent by the user terminal. The successful channel establishment message is generated when the user terminal successfully establishes a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy.

[0110] S402: Send the communication instruction to the P-CSCF network element.

[0111] It is understandable that the target SMF network element will send a notification indication to the P-CSCF network element, indicating that the voice dedicated bearer has been successfully established. According to the notification indication, the P-CSCF network element knows that the voice dedicated bearer has been successfully established, and then the P-CSCF network element returns a 183 message to the user terminal, indicating that communication can continue, and voice communication can begin between user terminals, and this communication process will follow the previously determined QoS policy and charging rules.

[0112] In this embodiment, through the above process, even if all PCF network elements in the network fail, voice communication between user terminals can still continue, thereby improving the disaster recovery and emergency response capabilities of the network and the user service experience.

[0113] In an exemplary embodiment, Figure 5 As shown, an interactive schematic diagram of a channel establishment method in a calling network is provided, which is applied to a calling network. The detailed process is described as follows:

[0114] S501. The calling UE A initiates an INVITE request to a P-CSCF network element in the calling network.

[0115] S502: The P-CSCF network element in the calling network forwards the INVITE request to the I-CSCF network element / S-CSCF network element in the calling network.

[0116] S503: The I-CSCF network element / S-CSCF network element in the calling network returns a 183 message to the P-CSCF network element in the calling network.

[0117] The 183 message is a message returned by the called terminal after receiving the INVITE request transmitted by the I-CSCF network element / S-CSCF network element in the calling network.

[0118] S504: After receiving the 183 message, the P-CSCF network element in the calling network sends an AAR request to the PCF network element in the calling network.

[0119] S505. When it is determined according to the AAR request that the PCF network element fails, the P-CSCF network element in the calling network determines the target SMF network element from the candidate SMF network elements according to the 183 message, and sends a call request to the target SMF network element.

[0120] Among them, the standard SMF network element in the calling network is the SMF network element corresponding to the user terminal in the calling network.

[0121] S506: The target SMF network element in the calling network determines the PCC policy corresponding to the user terminal according to the user identification information in the call request.

[0122] S507. The target SMF network element in the calling network sends an N4 session update request to the UPF network element in the calling network.

[0123] S508. The UPF network element in the calling network returns an update response message to the target SMF network element in the calling network based on the N4 session update request.

[0124] S509. Upon receiving the update response message, the target SMF network element in the calling network sends the session configuration modification indication in the PCC policy to the AMF network element in the calling network.

[0125] S5010. The AMF network element in the calling network transmits a session configuration modification indication in the form of an N1 message to the calling UE A.

[0126] S5011. The AMF network element in the calling network receives the channel establishment success message returned by the calling UE A.

[0127] S5012. The AMF network element in the calling network generates a communication indication based on the channel construction success message, and forwards the communication indication to the target SMF network element in the calling network.

[0128] Among them, the communication indication is used to notify the target SMF network element that the QoS flow of voice has been successfully established.

[0129] S5013. The target SMF network element in the calling network forwards the communication instruction to the P-CSCF network element in the calling network.

[0130] The communication indication indicates that the voice dedicated bearer has been established.

[0131] S5014. The P-CSCF network element in the calling network returns a 183 message to the terminal UE-A.

[0132] S5015. Perform calling process based on the communication channel.

[0133] Based on the communication channel, the calling process is consistent with the calling process in 3GPP TS 23.228.

[0134] In an exemplary embodiment, Figure 6 As shown, a schematic diagram of the interaction of the channel establishment method in the called network is provided, and the detailed process is described as follows:

[0135] S601. An I-CSCF network element / S-CSCF network element in a called network receives an INVITE request sent by an I-CSCF network element / S-CSCF network element in a calling network.

[0136] Among them, the INVITE request is the above Figure 5 The INVITE request in .

[0137] S602: The I-CSCF network element / S-CSCF network element in the called network forwards the INVITE request to the P-CSCF network element.

[0138] S603: The P-CSCF network element in the called network routes the INVITE request to the called terminal UE B.

[0139] S604. UE B returns a 183 message to the P-CSCF network element in the called network.

[0140] Among them, the 183 message is Figure 5The 183 message in the message is the message returned by the called terminal after receiving the INVITE request transmitted by the I-CSCF network element / S-CSCF network element in the calling network.

[0141] S605: After receiving the 183 message, the P-CSCF network element in the called network sends an AAR request to the PCF network element in the called network.

[0142] S606. When it is determined according to the AAR request that the PCF network element fails, the P-CSCF network element in the called network determines the target SMF network element from the candidate SMF network elements according to the 183 message, and sends a call request to the target SMF network element.

[0143] Among them, the standard SMF network element in the called network is the SMF network element corresponding to the user terminal in the called network.

[0144] S607: The target SMF network element in the called network determines the PCC policy corresponding to the user terminal according to the user identification information in the call request.

[0145] S608. The target SMF network element in the called network sends an N4 session update request to the UPF network element in the called network.

[0146] S609. The UPF network element in the called network returns an update response message to the target SMF network element in the called network based on the N4 session update request.

[0147] S6010. The target SMF network element in the called network sends the session configuration modification indication in the PCC policy to the access and mobility management function AMF network element.

[0148] S6011. The AMF network element in the called network transmits a session configuration modification indication in the form of an N1 message to the called UE A.

[0149] S6012. The AMF network element in the called network receives the channel establishment success message returned by the called UE A.

[0150] S6013. The AMF network element in the called network generates a communication indication based on the channel establishment success message, and forwards the communication indication to the target SMF network element in the called network.

[0151] Among them, the communication indication is used to notify the target SMF network element that the QoS flow of voice has been successfully established.

[0152] S6014. The target SMF network element in the called network forwards the notification indication to the P-CSCF network element in the called network.

[0153] The communication indication indicates that the voice dedicated bearer has been established.

[0154] S6015. The P-CSCF network element in the called network returns a 183 message to the terminal UE-A.

[0155] S6016. Perform the called process based on the communication channel.

[0156] Based on the communication channel, the called process is consistent with the called process in 3GPP TS 23.228.

[0157] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0158] Based on the same inventive concept, the embodiment of the present application also provides a channel establishment device for implementing the channel establishment method involved above. The implementation solution provided by the device to solve the problem is similar to the implementation solution recorded in the above method, so the specific limitations in one or more channel establishment device embodiments provided below can refer to the limitations on the channel establishment method above, and will not be repeated here.

[0159] In an exemplary embodiment, Figure 7 As shown, a channel establishment device is provided, comprising: a request acquisition module 11, a policy acquisition module 12 and a channel establishment module 13, wherein:

[0160] The request acquisition module 11 is used to acquire a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0161] The policy acquisition module 12 is used to determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0162] The channel establishing module 13 is used to send the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0163] In one of the embodiments, the channel establishment module 13 is further used to: send a session update request to the user plane control UPF network element; wherein the session update request includes the service quality requirements and service description information in the PCC policy; the session update request is used to instruct the UPF network element to update the data packet identification mechanism corresponding to the user terminal according to the service description information, and update the data packet processing mechanism corresponding to the user terminal according to the service quality requirements, and feedback the update response message after the update is successful;

[0164] When the update response message fed back by the UPF network element is obtained, the session configuration modification indication in the PCC policy is sent to the user terminal.

[0165] In one of the embodiments, the channel establishment module 13 is also used to: send the session configuration modification indication in the PCC policy to the access and mobility management function AMF network element, so that the AMF network element forwards the session configuration modification indication in the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy.

[0166] In one of the embodiments, the call request is a request initiated by the P-CSCF network element when it determines that the PCF network element has a fault based on the communication request initiated by the calling terminal, the communication response message fed back by the called terminal for the communication request, and the answer failure message fed back by the PCF network element for the communication request.

[0167] In one of the embodiments, the request acquisition module 11 is further used to: acquire a call request initiated by the P-CSCF network element based on the target communication port;

[0168] Among them, the target communication port corresponds to the communication address of the SMF network element, and the communication address of the SMF network element is obtained by parsing the communication response message fed back by the called terminal in response to the communication request.

[0169] In one of the embodiments, the device also includes a notification module, which is used to: obtain a communication indication sent by the AMF network element; the communication indication is generated by the AMF network element when receiving a channel construction success message sent by the user terminal; the channel construction success message is generated when the user terminal successfully builds a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy;

[0170] The communication instruction is sent to the P-CSCF network element.

[0171] Each module in the above-mentioned channel establishment device can be implemented in whole or in part by software, hardware or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the session management function network element in the form of hardware, or can be stored in the memory in the session management function network element in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0172] In an exemplary embodiment, a session management function network element is provided. The session management function network element may be a server, and its internal structure diagram may be as follows: Figure 8 As shown. The session management function network element includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a channel establishment interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the channel establishment interface is connected to the system bus through the input / output interface. Among them, the processor of the session management function network element is used to provide computing and control capabilities. The memory of the session management function network element includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the session management function network element is used to store data of the channel establishment method. The input / output interface of the session management function network element is used to exchange information between the processor and the external device. The channel establishment interface of the session management function network element is used to establish a channel with an external terminal through a network connection. When the computer program is executed by the processor, a channel establishment method is implemented.

[0173] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the session management function network element to which the solution of the present application is applied. The specific session management function network element may include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0174] In an exemplary embodiment, a session management function network element is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0175] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0176] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0177] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0178] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0179] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0180] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0181] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0182] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0183] Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails;

[0184] Determine the policy and charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request;

[0185] The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

[0186] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0187] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0188] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0189] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A channel establishment method, characterized in that: Applied to a session management function (SMF) network element, the method comprises: Obtaining a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails; Determine, according to the user identification information of the user terminal carried in the call request, a policy and a charging control PCC policy corresponding to the user terminal; The PCC policy is sent to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

2. The method according to claim 1, characterized in that The sending the PCC policy to the user terminal includes: Send a session update request to the user plane control UPF network element; wherein the session update request includes the service quality requirements and service description information in the PCC policy; the session update request is used to instruct the UPF network element to update the data packet identification mechanism corresponding to the user terminal according to the service description information, and update the data packet processing mechanism corresponding to the user terminal according to the service quality requirements, and feedback an update response message after the update is successful; When the update response message fed back by the UPF network element is obtained, the session configuration modification indication in the PCC policy is sent to the user terminal.

3. The method according to claim 2, characterized in that The sending the session configuration modification indication in the PCC policy to the user terminal includes: The session configuration modification indication in the PCC policy is sent to the access and mobility management function AMF network element, so that the AMF network element forwards the session configuration modification indication in the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the session configuration modification indication in the PCC policy.

4. The method according to claim 1, characterized in that The call request is a request initiated by the P-CSCF network element when it determines that a PCF network element fails based on a communication request initiated by a calling terminal, a communication response message fed back by the called terminal for the communication request, and an answer failure message fed back by the PCF network element for the communication request.

5. The method according to claim 4, characterized in that The obtaining of the call request initiated by the proxy call session control function P-CSCF network element includes: Obtaining a call request initiated by the P-CSCF network element based on the target communication port; Among them, the target communication port corresponds to the communication address of the SMF network element, and the communication address of the SMF network element is obtained by parsing the communication response message fed back by the called terminal in response to the communication request.

6. The method according to claim 3, characterized in that The method further comprises: Obtaining a communication indication sent by the AMF network element; the communication indication is generated by the AMF network element when receiving a channel establishment success message sent by the user terminal; the channel establishment success message is generated by the user terminal when a communication channel between the user terminal and other user terminals is successfully established according to the session configuration modification indication in the PCC policy; The communication instruction is sent to the P-CSCF network element.

7. A channel establishment device, characterized in that: Configured in a session management function SMF network element, the device includes: A request acquisition module, used to acquire a call request initiated by a proxy call session control function P-CSCF network element; wherein the call request is initiated by the P-CSCF network element when it is determined that a policy control function PCF network element fails; A policy acquisition module, configured to determine a policy and a charging control PCC policy corresponding to the user terminal according to the user identification information of the user terminal carried in the call request; The channel establishing module is used to send the PCC policy to the user terminal, so that the user terminal builds a communication channel between the user terminal and other user terminals according to the PCC policy.

8. A session management function network element, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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