# US 12,192,589 B2 · Multicast service transmission method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,589 B2 - Document ID: US12192589B2 - Status: Granted - Kind: B2 - Application number: 17/892,119 - Filed: 2022-08-22 - Published: 2022-12-22 - Granted: 2025-01-07 - Earliest claimed: 2020-02-21 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Jianxin Jia; Wenfu Wu; Zaifeng Zong - Web page: https://patentgrep.com/patent/US12192589B2 ## CPC - H04N 21/6131: {involving transmission via a mobile phone network (wireless downlink channel access H04W74/006)} - H04N 21/6405: Multicasting {(data broadcast and multicast in packet switching networks H04L12/18)} - H04N 21/266: Channel or content management, e.g. generation and management of keys and entitlement messages in a conditional access system, merging a VOD unicast channel into a multicast channel - H04N 21/6408: Unicasting - H04W 4/06: Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services - H04W 76/40: for selective distribution or broadcast - H04W 76/11: Allocation or use of connection identifiers - H04W 76/12: Setup of transport tunnels - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract This application provides a multicast service transmission method and apparatus, to deliver a multicast service regardless of whether there is a device supporting multicast in a system, so as to improve flexibility and reliability of the multicast service transmission. The method performed by a session management network element includes: receiving a first message or a second message, where the first message requests to add a terminal device to a multicast service, the second message is used to update a PDU session of the terminal device, and the PDU session is associated with the multicast service; and determining, based on multicast capability information of the terminal device and/or multicast capability information of an access network device, a delivery mode of the multicast service, where the access network device is an access network device currently accessed by the terminal device or a target access network device of the terminal device. ## Claims ### Claim 1 A multicast/broadcast service transmission method, comprising: receiving, by a session management network element, a second message, the second message updating a protocol data unit (PDU) session of a terminal device, and the PDU session is associated with a multicast/broadcast service; determining, by the session management network element based on multicast/broadcast capability information of an access network device, a delivery mode of the multicast/broadcast service, the multicast/broadcast capability information of the access network device indicating whether the access network device supports multicast/broadcast, and the access network device is currently accessed by the terminal device or by a target access network device of the terminal device; and mapping, by the session management network element, a multicast/broadcast quality of service (QoS) flow of the multicast/broadcast service to a unicast QoS flow of the PDU session, the unicast QoS flow being used to transmit the multicast/broadcast data, the unicast QoS Flow Identifier (QFI) of the unicast QoS flow comprising an unused QFI of the PDU session. ### Claim 2 (depends on 1) The method according to claim 1, wherein the second message is a Nsmf_PDUSession_UpdateSMContext Request. ### Claim 3 (depends on 1) The method according to claim 1, wherein the delivery mode comprises a multicast/broadcast mode and/or a unicast mode. ### Claim 4 (depends on 3) The method according to claim 3, wherein the multicast/broadcast mode comprises a 5GC shared multicast broadcast service (MBS) traffic delivery method, and the unicast mode comprises a 5GC individual MBS traffic delivery method. ### Claim 5 (depends on 3) The method according to claim 3, wherein in the multicast/broadcast mode, a user plane function (UPF) delivers multicast/broadcast data of the multicast/broadcast service to the access network device using a multicast session tunnel, and the access network device delivers the multicast/broadcast data to the terminal device in a point to multi-point (PTM) manner; and the unicast mode delivers the multicast/broadcast data to the terminal device using a PDU session, the PDU session relating to the multicast/broadcast service. ### Claim 6 (depends on 1) The method according to claim 1, further comprising: determining, by the session management network element based on multicast/broadcast QoS information of the multicast/broadcast service, the unicast QoS flow corresponding to the multicast/broadcast service; and adding, by the session management network element, the unicast QoS flow to the PDU session of the terminal device, wherein the unicast QoS flow is used to deliver the multicast/broadcast data. ### Claim 7 (depends on 1) The method according to claim 1, further comprising: sending, by the session management network element, a correspondence between a multicast/broadcast QoS flow identifier (QFI) of the multicast/broadcast QoS flow and a unicast QFI of the unicast QoS flow to the access network device. ### Claim 8 (depends on 1) The method according to claim 1, further comprising: receiving, by the session management network element, the multicast/broadcast capability information of the access network device from an access and mobility management network element. ### Claim 9 A multicast/broadcast service transmission system, comprising: an access network device; and a session management network element in communication with the access network device, the session management network element is configured to: receive a second message, the second message updating a protocol data unit (PDU) session of a terminal device, and the PDU session is associated with a multicast/broadcast service; determine, based on a multicast/broadcast capability information of the access network device, a delivery mode of the multicast/broadcast service, the multicast/broadcast capability information of the access network device indicating whether the access network device supports multicast/broadcast, and the access network device is currently accessed by the terminal device or by a target access network device of the terminal device; and map a multicast/broadcast quality of service (QOS) flow of the multicast/broadcast service to a unicast QoS flow of the PDU session, the unicast QoS flow being used to transmit the multicast/broadcast data, the unicast QoS Flow Identifier (QFI) of the unicast QoS flow comprising an unused QFI of the PDU session. ### Claim 10 (depends on 9) The system according to claim 9, further comprising an access and mobility management network element, wherein: the access network device is configured to send the multicast/broadcast capability information of the access network device to the access and mobility management network element; and the access and mobility management network element is configured to send the multicast/broadcast capability information of the access network device to the session management network element. ### Claim 11 (depends on 9) The system according to claim 9, wherein the second message is a Nsmf_PDUSession_UpdateSMContext Request. ### Claim 12 (depends on 9) The system according to claim 9, wherein the delivery mode comprises a multicast/broadcast mode and/or a unicast mode. ### Claim 13 (depends on 12) The system according to claim 12, wherein the multicast/broadcast mode comprises a 5GC shared multicast broadcast service (MBS) traffic delivery method, and the unicast mode comprises a 5GC individual MBS traffic delivery method. ### Claim 14 (depends on 12) The system according to claim 12, wherein in the multicast/broadcast mode, a user plane function (UPF) delivers multicast/broadcast data of the multicast/broadcast service to the access network device using a multicast session tunnel, and the access network device delivers the multicast/broadcast data to the terminal device in a point to multi-point (PTM) manner; and the unicast mode delivers the multicast/broadcast data to the terminal device using a PDU session, the PDU session relating to the multicast/broadcast service. ### Claim 15 (depends on 9) The system according to claim 9, wherein the session management network element is further configured to: send a correspondence between a multicast/broadcast QoS flow identifier (QFI) of the multicast/broadcast QoS flow and a unicast QFI of the unicast QoS flow to the access network device. ### Claim 16 A multicast service transmission apparatus comprising: a memory, configured to store instructions; and at least one processor, configured to execute the instructions stored in the memory to perform the following steps: receive a second message, the second message updating a protocol data unit (PDU) session of a terminal device, and the PDU session is associated with a multicast/broadcast service; determine, based on multicast/broadcast capability information of an access network device, a delivery mode of the multicast/broadcast service, the multicast/broadcast capability information of the access network device indicating whether the access network device supports multicast/broadcast, and the access network device is currently accessed by the terminal device or by a target access network device of the terminal device; and mapping a multicast/broadcast quality of service (QOS) flow of the multicast/broadcast service to a unicast QoS flow of the PDU session, the unicast QoS flow being used to transmit the multicast/broadcast data, the unicast QoS Flow Identifier (QFI) of the unicast QoS flow comprising an unused QFI of the PDU session. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein the second message is a Nsmf_PDUSession_UpdateSMContext Request. ### Claim 18 (depends on 16) The apparatus according to claim 16, wherein the delivery mode comprises a multicast/broadcast mode and/or a unicast mode. ### Claim 19 (depends on 18) The apparatus according to claim 18, wherein the multicast/broadcast mode comprises a 5GC shared multicast broadcast service (MBS) traffic delivery method, and the unicast mode comprises a 5GC individual MBS traffic delivery method. ### Claim 20 (depends on 16) The apparatus according to claim 16, wherein the at least one processor is further configured to: determine, based on multicast/broadcast QoS information of the multicast/broadcast service, the unicast QoS flow corresponding to the multicast/broadcast service; and add the unicast QoS flow to the PDU session of the terminal device, wherein the unicast QoS flow is used to deliver the multicast/broadcast data.