Abstract: Embodiments of this application provide a multicast/broadcast service communication method, an apparatus, and a system. The method includes: a first terminal device receives first information, where the first information indicates activation or release of a first multicast/broadcast session, the first terminal device joins the first multicast/broadcast session, the first terminal device is in a radio resource control inactive state, and the first multicast/broadcast session is used for transmitting a first multicast/broadcast service; and the first terminal device enters a connected state or keeps in the radio resource control inactive state based on the first information. According to the method, a terminal device that is in a radio resource control inactive state and that is allowed to receive a multicast/broadcast service in this state does not enter a connected state, thereby helping reduce network overheads.

Abstract: Embodiments of this application provide a multicast communication method that includes: receiving, by a user plane function network element, a multicast packet, where the multicast packet includes a multicast address; matching, by the user plane function network element, the multicast packet with a packet detection rule PDR on the user plane function network element; and if the multicast packet successfully matches a first PDR, and the first PDR indicates to carry on matching another PDR, carrying on, by the user plane function network element, matching the multicast packet with another PDR. Optionally, the another PDR is a PDR whose priority is not higher than that of the first PDR.

Abstract: The present disclosure relates to media unit transmission methods and apparatuses. In one example method, a user plane network element receives a media unit, where the media unit includes a plurality of data packets. The user plane network element sets marking information for the media unit, where the marking information is for determining that the media unit is a media unit allowed to be discarded. The user plane network element sends the media unit that carries the marking information.

Abstract: When a UE that has joined a first multicast/broadcast service and is in a radio resource control inactive state determines that an access network device changes to a first access network device, or when a terminal device determines that a cell changes to a cell of the first access network device, the terminal device may send at least one of a first message, a second message, a third message, a ninth message, or a tenth message to the first access network device. Correspondingly, the first access network device may learn, based on at least one of the first message, the second message, the third message, the ninth message, or the tenth message, that the terminal device moves to a coverage area of the first access network device to receive the first multicast/broadcast service.

Abstract: A method includes: receiving first information, where the first information indicates a data network to which a first anchor user plane function (UPF) network element managed by a second session management function (SMF) network element is connected; determining based on the first information, first rule information to be executed by a first network element managed by the second SMF network element, where the first network element includes at least one of the first anchor UPF network element or a branching point connected to the first anchor UPF network element, where the branching point is a UPF network element having a traffic offload function, where the first rule information indicates a processing method to be performed on a data packet of a first application, and where the data packet of the first application is transmitted through the first anchor UPF network element; and sending second information including the first rule information.

Abstract: This application provides a method and an apparatus for discovering an edge service. The method includes: A first network element receives first information, where the first information includes first service information. The first network element receives second information, where the second information includes first domain name information. When the first domain name information corresponds to the first service information, the first network element determines, for a first terminal device, an application server that is the same as that of a second terminal device or an application server in an edge network that is the same as that of a second terminal device. The first network element sends a third rule, where the third rule includes second option information, and the second option information is used by a DNS server to determine application server address information.

Abstract: Embodiments of this application provide a method and an apparatus for determining a user equipment route selection policy. The method may include: A first policy control network element obtains first information, where the first information is used to determine a first user equipment route selection policy. The first policy control network element sends the first user equipment route selection policy to first user equipment, where the first policy control network element belongs to a visited network of the first user equipment. According to this application, user equipment roams to a visited network, and a user equipment route selection policy may be determined by the first policy control network element based on the first information, so that the visited network may provide the user equipment route selection policy for the user equipment, to implement a route selection service of the user equipment in a roaming scenario.

Abstract: This application provides an indication information transmission method and a related apparatus. The method includes: An intermediate session management network element sends third indication information to a target user plane network element based on second indication information from a session management network element, so that the target user plane network element buffers an uplink packet based on the third indication information. When learning that handover to a target application network element has been completed, the session management network element may send fourth indication information to the intermediate session management network element, so that the intermediate session management network element sends fifth indication information to the target user plane network element based on the fourth indication information, and the target user plane network element forwards the uplink packet based on the fifth indication information.

Abstract: This application provides a method and an apparatus for determining an application server. The method is performed by a first network element and includes: receiving first request information, where the first request information includes first service description information, the first service description information identifies a service accessed by a terminal device, and the first request information is for requesting to determine first information for the terminal device; and in a case that the terminal device belongs to a first terminal group, determining the first information, where the first information is for determining a first application server for a terminal device in the first terminal group. Based on the foregoing technical solution, a same edge application server can be determined for terminal devices that access a same (specific) service and that are located in a specific area location.

Abstract: In accordance with an embodiment, a method may include: receiving a domain name system DNS query message from a terminal device, where the DNS query message is used to obtain an edge server address; and sending the DNS query message to an edge application server discovery network element in a visited network based on first information, where the first information is used to forward one or more DNS messages to the edge application server discovery network element.

Abstract: Embodiments of this application provide a multicast communication method that includes: receiving, by a user plane function network element, a multicast packet, where the multicast packet includes a multicast address; matching, by the user plane function network element, the multicast packet with a packet detection rule PDR on the user plane function network element; and if the multicast packet successfully matches a first PDR, and the first PDR indicates to carry on matching another PDR, carrying on, by the user plane function network element, matching the multicast packet with another PDR. Optionally, the another PDR is a PDR whose priority is not higher than that of the first PDR.

Abstract: Embodiments of this application provide a communication method and apparatus, and a device. An example method includes: A base station receives a first message from a first network device, the first message includes first indication information, and the first indication information indicates a multicast session. The base station sends radio bearer information corresponding to the multicast session to a terminal device based on the first message, where the first message includes information indicating the terminal device, and where the radio bearer information indicates to the terminal device to join the multicast session.

Abstract: A method and an apparatus for selecting a session management network element, where a mobility management network element may obtain information about one or more first session management network elements, and support selecting a session management network element in a home routed mode or an enhanced topology mode.

Abstract: A communication method, apparatus, and system. The method may include: a user plane network element receives characteristic information of an application and seventh indication information from a session management network element, and the user plane network element determines, based on the seventh indication information, a frame type corresponding to a data packet of the application, where the frame type is determined based on the characteristic information of the application. In this way, distinguishing processing can be performed on the data packet based on the frame type of the data packet, thus meeting transmission requirements of data packets of different frame types.

Abstract: A session management method, device, and system, such that a terminal can access a local data network using a local user plane function (UPF) network element even when the terminal is out of a management area of a remote anchor session management function (SMF) network element. The method includes: receiving, by an intermediate session management network element, one or more local data network access identifiers (DNAIs); and determining, by the intermediate session management network element, a target DNAI based on current location information of a terminal and the one or more local DNAIs, where the target DNAI is used to select a local session management network element for the terminal.

Abstract: An edge service obtaining method includes that a server discovery function network element receives a plurality of DNS response messages sent by a DNS server, where the plurality of DNS response messages includes address information of EASs to be queried by a terminal device; and determines, based on first indication information, to send a DNS information report to a first core network element once for the plurality of DNS response messages.

Abstract: A mobility management network element in a visited network performs a method in a home-routed roaming operation to facilitate a switching of a terminal in a session to the visited network. The mobility management network element obtains single network slice selection assistance information (S-NSSAI) for a home network of the terminal corresponding to the session of the terminal. The mobility management network element also obtains S-NSSAI for the visited network corresponding to the session of the terminal, according to a mapping relationship between the S-NSSAI for the home network and the S-NSSAI for the visited network. The mobility management network element then sends the S-NSSAI for the visited network to an access device of the terminal in the visited network, for the access device to process the session.

Abstract: Embodiments of this application provide a communication method and apparatus, and a device. An example method includes: A base station receives a first message from a first network device, where the first message is used to indicate to add a terminal device to a multicast session corresponding to a multicast service, the first message includes first indication information, and the first indication information is used to indicate the multicast session. The base station sends radio bearer information corresponding to the multicast session to the terminal device based on the first message, where the radio bearer information is used by the terminal device to join the multicast session.

Abstract: A communication method, a communications device, and a communications system to avoid, when an access and mobility management function (AMF) entity fails, a case in which a re-registration process of a terminal that is being served is triggered because a context of the terminal is lost. The method includes: obtaining, by a communications device, a first group identifier of a terminal group to which a first terminal served by a first mobility management entity belongs; and sending, by the communications device, a message related to the first terminal to a second mobility management entity based on the first group identifier when an exception occurs in the first mobility management entity, where the second mobility management entity is a mobility management entity in which a context of the first terminal exists.

Abstract: This application discloses a load relocation method, apparatus, and a system. The method includes determining, by a communications network entity, a target access management entity for load relocation; and sending, to an access network entity, an identifier of an original access management entity and an identifier of the target access management entity or an address of the target access management entity with respect to the access network entity. The access network entity sends a message from a user equipment (UE) to the target access management entity based on the identifier of the original access management entity carried in the message from the UE. In the foregoing solution, signaling overheads in a load relocation process are reduced and load relocation efficiency is improved.