Abstract: A data transmission method, including receiving, by a terminal device, first information from a session management function (SMF) network element, where the first information indicates to bind a first packet data unit (PDU) session and a second PDU session, and transmitting, by the terminal device, data based on the bound first PDU session and the bound second PDU session.

Abstract: A method for determining a network quality of service (QoS) flow, a network element, and a system include receiving, by a session management function network element, a policy and charging control (PCC) rule from a policy control function network element, where the PCC rule includes QoS parameters, the QoS parameters include standardized QoS parameter indication information and a non-standardized QoS parameter, and the non-standardized QoS parameter includes at least one attribute comprised in a standardized QoS parameter corresponding to the standardized QoS parameter indication information and a corresponding value of the at least one attribute, and determining, by the session management function network element based on the standardized QoS parameter indication information and the non-standardized QoS parameter, a QoS flow corresponding to the PCC rule.

Abstract: An event report sending method in which a session management network element receives an event notification request from a policy control network element, where the event notification request includes an event identifier and a notification address for receiving an event report of an event report receiving network element, and where the event report receiving network element is an application function network element or a network exposure function network element. The session management network element sends, a first message comprising the event identifier and the notification address to a user plane network element, where the first message indicates to the user plane network element to send, to the notification address, a first event report corresponding to the event identifier. Thus, the network exposure function network element sends the received first event report to the application function network element, such that the application function network element obtains the event report.

Abstract: A policy control method, a device, and a system, the method including receiving, by a session management network element, from a policy control network element, LAN traffic steering information corresponding to a first application, selecting one or more user plane network elements based on the LAN traffic steering information, determining policy rules corresponding to each user play network element of the user plane network elements, the policy rules being associated with steering data of the first application sent by an upstream network element, where the policy rules are further associated with sending data processed by the local application server for the first application in the target LAN to a downstream network element, and sending, by the session management network element, the corresponding policy rules to each user plane network element of the one or more user plane network elements.

Abstract: A method for determining a network quality of service (QoS) flow, a network element, and a system include receiving, by a session management function network element, a policy and charging control (PCC) rule from a policy control function network element, where the PCC rule includes QoS parameters, the QoS parameters include standardized QoS parameter indication information and a non-standardized QoS parameter, and the non-standardized QoS parameter includes at least one attribute comprised in a standardized QoS parameter corresponding to the standardized QoS parameter indication information and a corresponding value of the at least one attribute, and determining, by the session management function network element based on the standardized QoS parameter indication information and the non-standardized QoS parameter, a QoS flow corresponding to the PCC rule.

Abstract: A network element selection method and apparatus, where the method includes: receiving, by a first network element in a first communications system, a first message from a terminal device, wherein the first message is used to request to establish a session; and in response to the first message, determining, by the first network element in the first communications system, a target session management function network element based on a capability of the terminal device and third subscription information of the terminal device. According to the method, a terminal device that supports a 4G system and a 5G system and that has no interworking requirement can properly select a network element.

Abstract: Embodiments of the present invention disclose a method, a network element, and a system for determining a target RAT. The method includes: receiving, by an access network element, access control information of a UE that is sent by a mobility management network element, where the access control information includes an identity of a PLMN and a radio access technology RAT allowed and/or a RAT not allowed by the PLMN; and determining, by the access network element, a target RAT for the UE according to the access control information.

Abstract: A method, a related apparatus, and a system for recovering a called service of a terminal are provided. The method includes: when a called request of a user terminal is received, querying an initial proxy-call session control function (P-CSCF) entity with which the user terminal currently registers; if it is detected that the initial P-CSCF is faulty, selecting an available P-CSCF and sending, to the available P-CSCF, a notification message that carries a redundancy identifier, where the redundancy identifier is used to instruct the available P-CSCF to trigger the user terminal to re-register with the P-CSCF; and when a registration complete message sent by the P-CSCF with which the user terminal re-registers is received, delivering the called request to the re-registered P-CSCF to bear a called service of the user terminal.

Abstract: A method, a related apparatus, and a system for recovering a called service of a terminal are provided. The method includes: when a called request of a user terminal is received, querying an initial proxy-call session control function (P-CSCF) entity with which the user terminal currently registers; if it is detected that the initial P-CSCF is faulty, selecting an available P-CSCF and sending, to the available P-CSCF, a notification message that carries a redundancy identifier, where the redundancy identifier is used to instruct the available P-CSCF to trigger the user terminal to re-register with the P-CSCF; and when a registration complete message sent by the P-CSCF with which the user terminal re-registers is received, delivering the called request to the re-registered P-CSCF to bear a called service of the user terminal.

Abstract: In a location change reporting method, a session management function entity receives from a mobility management entity information including location change information of user equipment (UE) in a first presence reporting area (PRA), an identity of the first PRA, and an identity of a PRA set that includes the first PRA. The session management function entity identifies, based on the identity of the PRA set and locally stored PRA subscription information, a subscription entity that subscribes to location change events of the UE in the PRA set, and sends the identity of the first PRA and the location change information of the UE in the first PRA to the subscription entity.

Abstract: A method, a related apparatus, and a system for recovering a called service of a terminal are provided. The method includes: when a called request of a user terminal is received, querying an initial proxy-call session control function (P-CSCF) entity with which the user terminal currently registers; if it is detected that the initial P-CSCF is faulty, selecting an available P-CSCF and sending, to the available P-CSCF, a notification message that carries a redundancy identifier, where the redundancy identifier is used to instruct the available P-CSCF to trigger the user terminal to re-register with the P-CSCF; and when a registration complete message sent by the P-CSCF with which the user terminal re-registers is received, delivering the called request to the re-registered P-CSCF to bear a called service of the user terminal.

Abstract: In a location change reporting method, a session management function entity receives from a mobility management entity information including location change information of UE in a first presence reporting area (PRA), an identity of the first PRA, and an identity of a PRA set that includes the first PRA. The session management function entity identifies, based on the identity of the PRA set and locally stored PRA subscription information, a subscription entity that subscribes to location change events of the UE in the PRA set, and sends the identity of the first PRA and the location change information of the UE in the first PRA to the subscription entity.

Abstract: A network element selection method and apparatus, where the method includes: receiving, by a first network element in a first communications system, a first message from a terminal device, wherein the first message is used to request to establish a session; and in response to the first message, determining, by the first network element in the first communications system, a target session management function network element based on a capability of the terminal device and third subscription information of the terminal device. According to the method, a terminal device that supports a 4G system and a 5G system and that has no interworking requirement can properly select a network element.

Abstract: A policy control method includes receiving, by a policy control network element, an update request message carrying information about a first mobility management network element from the first mobility management network element, updating, by the policy control network element according to the update request message, information about a second mobility management network element in information of a policy association corresponding to a terminal that is stored in the policy control network element to information about the first mobility management network element. The policy control network updates the information about the second mobility management network element in the information of the policy association to the information about the first mobility management network element instead of deleting the policy association and re-establishing a policy association with the first mobility management network element.

Abstract: A method, an apparatus, and a system for processing registration backup data are disclosed. A Serving Call Session Control Function (S-CSCF) receives a request from a User Equipment (UE) and judges whether the request carries multi-registration information so as to decide whether to add multi-registration indication information into a Server Assignment Request (SAR) message sent to a Home Subscriber Server (HSS). The HSS performs operations according to whether the SAR message carries the multi-registration indication information, therefore avoiding unnecessary signaling interactions, reducing the signaling load, avoiding unnecessary data processing between the HSS and the S-CSCF, and saving system resources.

Abstract: A network element selection method and apparatus, where the method includes: receiving, by a first network element in a first communications system, a first message from a terminal device, wherein the first message is used to request to establish a session; and in response to the first message, determining, by the first network element in the first communications system, a target session management function network element based on a capability of the terminal device and third subscription information of the terminal device. According to the method, a terminal device that supports a 4G system and a 5G system and that has no interworking requirement can properly select a network element.

Abstract: A method, apparatus, and system for disaster recovery of an Internet Protocol (IP) Multimedia Subsystem (IMS), where the method includes: triggering a redundant Call Session Control Function (CSCF); obtaining, by the redundant CSCF, user backup data of registered IMS Private User Identities (IMPIs) that are associated with IMPUs and user service configuration data of IMS Public User Identities (IMPUs) in an IMS subscription from a network storage entity of a user; and recovering, by the redundant CSCF, a corresponding service according to the obtained user backup data of the registered IMPIs and user service configuration data of the IMPUs in the IMS subscription. Hence, the one-IMPU multi-IMPI, one-IMPI multi-IMPU, or multi-IMPI multi-IMPU service can be recovered, and this enables the user to have better service continuity experiences.

Abstract: This application provides a method for determining a network quality of service flow, a network element, and a system. The method includes: receiving, by a session management function network element, a policy and charging control PCC rule from a policy control function network element, where the PCC rule includes quality of service QoS parameters, the QoS parameters include standardized QoS parameter indication information and a non-standardized QoS parameter, and the non-standardized QoS parameter includes at least one attribute comprised in a standardized QoS parameter corresponding to the standardized QoS parameter indication information and a corresponding value of the at least one attribute; and determining, by the session management function network element based on the standardized QoS parameter indication information and the non-standardized QoS parameter, a quality of service QoS flow corresponding to the PCC rule.

Abstract: The present disclosure provides a method which includes: receiving a message, where the message carries a parameter indicating a validity period of a short message sent to a user or indication information indicating whether a record needs to be added to MWD of a user when a short message cannot be transmitted or fails to be transmitted; determining that the short message cannot be transmitted or the short message fails to be transmitted, and a value of the parameter is 0 or the indication information indicates that the record does not need to be added to the MWD of the user when the short message cannot be transmitted or fails to be transmitted; and skipping adding the record to the MWD of the user, where the record includes an identifier of a service center for short message service serving the user. According to the method, additional signaling interaction is reduced.

Abstract: A method, an apparatus, and a system for processing registration backup data are disclosed. A Serving Call Session Control Function (S-CSCF) receives a request from a User Equipment (UE) and judges whether the request carries multi-registration information so as to decide whether to add multi-registration indication information into a Server Assignment Request (SAR) message sent to a Home Subscriber Server (HSS). The HSS performs operations according to whether the SAR message carries the multi-registration indication information, therefore avoiding unnecessary signaling interactions, reducing the signaling load, avoiding unnecessary data processing between the HSS and the S-CSCF, and saving system resources.