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EP-4117338-B1 - DATA TRANSMISSION WITH QFI MAPPING FOR MULTICAST/BROADCAST SERVICE HANDOVER

EP4117338B1EP 4117338 B1EP4117338 B1EP 4117338B1EP-4117338-B1

Inventors

  • JIA, Jianxin
  • WU, WENFU
  • ZONG, ZAIFENG

Dates

Publication Date
20260506
Application Date
20210322

Claims (3)

  1. A data transmission method performed by a source access network device, comprising: receiving, by the source access network device, data of a first multicast/broadcast service from a first core network device through a first tunnel, wherein the first tunnel is a transmission tunnel of the first multicast/broadcast service and comprises a first forwarding tunnel which is a forwarding tunnel that corresponds to the first multicast/broadcast service and that is of a first terminal device, or a second forwarding tunnel which is a forwarding tunnel corresponding to a protocol data unit of a PDU session of the first terminal device; replicating, by the source access network device, first data, and forwarding the first data to a target access network device through the first forwarding tunnel or the second forwarding tunnel, wherein the first data is a part or all of the data that is of the first multicast/broadcast service and that is received by the source access network device through the first tunnel, comprising: receiving, by the source access network device from the first core network device through the first tunnel, a first quality of service flow identifier QFI corresponding to the first data; determining, by the source access network device based on a first mapping relationship, a second QFI corresponding to the first QFI, wherein the first mapping relationship comprises a correspondence between a QFI used when the data of the first multicast/broadcast service is transmitted through the first tunnel and a QFI used when the data of the first multicast/broadcast service is transmitted through a tunnel of the PDU session; replicating, by the source access network device, the first data; and sending, by the source access network device, the replicated first data and the second QFI to the target access network device through the second forwarding tunnel; receiving (S501), by a source access network device, a first end marker from the first core network device through the first tunnel, wherein the end marker comprises first information used to determine the first terminal device; determining (S502), by the source access network device based on the first information, that the first end marker acts on the first terminal device; and in response to receiving the first end marker, stopping (S503), by the source access network device, forwarding data of the first multicast/broadcast service to a target access network device through a forwarding tunnel of the first terminal device comprising stopping, by the source access network device, forwarding the first data to the target access network device through the forwarding tunnel.
  2. The method according to claim 1, further comprising: receiving, by the source access network device, the first mapping relationship from a session management function network element SMF.
  3. A network device, wherein the network device comprises a processor (1502) and a memory (1501); the processor (1502) is configured to execute instructions stored in the memory (1501); and when the instructions are run, the network device (1400, 1500) is enabled to perform the method according to any one of claim 1 or 2

Description

TECHNICAL FIELD This disclosure relates to the field of communication technologies, and in particular, to a data transmission method and apparatus. BACKGROUND With development of the mobile Internet, mobile high-definition video services are experiencing a surge. Users gradually change from watching hot programs in a conventional manner, such as on fixed televisions, to watching hot programs on mobile phones and the mobile Internet. Therefore, video services have an increasingly strong impact on mobile networks. If transmission of video services can be optimized through air interface multicast, the impact of video traffic on mobile networks will be greatly reduced. In previous generations of mobile communication technologies, for example, a 3rd generation (the 3rd generation, 3G) mobile communication technology and a 4th generation (the 4th generation, 4G) mobile communication technology, it is difficult to promote a multicast solution. Specifically, in an existing multicast solution, a dedicated network element and interface that support multicast need to be added based on an existing communication architecture, and a dedicated multicast channel is further required for support. This not only increases overheads of operators, but also increases complexity of terminals. To overcome the foregoing difficulties, supporting a 5th generation (5th generation, 5G) multicast/broadcast function (5G Multicast Broadcast Service, 5MBS) becomes a key research topic. A key research issue (Key Issue) of the 5MBS research topic is service continuity (Service Continuity). For the research issue, in a scenario in which both an access network device supporting a multicast/broadcast function and an access network device not supporting the multicast/broadcast function exist, how to ensure continuity of a multicast/broadcast service of a terminal device when the terminal device is handed over from a source access network device to a target access network device is an urgent problem to be resolved. SAMSUNG, "Group communications with early E-RAB establishment", vol. SA WG2, no. San Francisco, USA; 20131111 - 20131115, (20131112), 3GPP DRAFT; S2-134055, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE relates to a working document of the 3GPP. It discloses a proposed solution aiming at removing and/or reducing interruption in the service continuity for group communication. WO 2018/130968 A1 relates to 5G QOS flow to radio bearer remapping. SUMMARY The object of the present invention is to provide a data transmission method and apparatus. In a scenario in which both an access network device supporting a multicast/broadcast function and an access network device not supporting the multicast/broadcast function exist, continuity of a multicast/broadcast service is ensured when a terminal device is handed over from a source access network device to a target access network device. The invention is disclosed in the appended claims. These or other aspects of this application are more concise and easier to understand in the description of the following embodiments. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram of a system architecture to which an embodiment of this application is applicable;FIG. 2 is a schematic flowchart of data transmission according to an embodiment of this application;FIG. 3 is another schematic flowchart of data transmission according to an embodiment of this application;FIG. 4 is a schematic diagram of an application scenario according to this application;FIG. 5 is a schematic flowchart corresponding to a data transmission method according to an embodiment of this application;FIG. 6 is a schematic flowchart corresponding to another data transmission method according to an embodiment of this application;FIG. 7A and FIG. 7B are a schematic flowchart corresponding to another data transmission method according to an embodiment of this application;FIG. 8 is a schematic flowchart corresponding to a complete data transmission method according to an embodiment of this application;FIG. 9 to FIG. 13 each are a schematic flowchart corresponding to an end marker construction method according to an embodiment of this application;FIG. 14 is a schematic diagram of a structure of an apparatus according to this application; andFIG. 15 is a schematic diagram of a structure of another apparatus according to this application. In the following description, features which in the above summary of the invention have been marked as "not claimed" are also hereinafter, when they are described and explained with reference to the drawings, to be understood as "not claimed" or "not part of the invention". DESCRIPTION OF EMBODIMENTS To make the objectives, technical solutions, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings. A specific operation method in method embodiments may also be applied to a device embodiment or