# US 12,193,106 B2 · Adaptive service areas for multicast session continuity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,193,106 B2 - Document ID: US12193106B2 - Status: Granted - Kind: B2 - Application number: 17/785,535 - Filed: 2020-12-11 - Published: 2023-01-12 - Granted: 2025-01-07 - Earliest claimed: 2019-12-17 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Joakim Åkesson; Erik Stare; Jie Ling - Web page: https://patentgrep.com/patent/US12193106B2 ## CPC - 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 4/10: Push-to-Talk [PTT] or Push-On-Call services - H04W 72/30: Resource management for broadcast services - H04W 76/11: Allocation or use of connection identifiers - H04W 92/20: between access points - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Systems and methods are disclosed herein for providing adaptive service areas for multicast session continuity. Embodiments of a method performed by a radio access node in a Radio Access Network (RAN) are disclosed. Such embodiments introduce mobility of User Equipments (UEs) participating in a multicast/broadcast service, which is managed by the RAN. This means that the broadcast area will dynamically adapt as participating UEs move and/or radio conditions change. ## Claims ### Claim 1 A method performed by a first radio access node in a Radio Access Network, RAN, for providing adaptive service areas in a multicast transmission session, the method comprising: participating in a multicast transmission session for a service, comprising a multicast stream currently transmitted at least by the first radio access node to one or more User Equipment, UE, in a first cell; providing, when a RAN decision is made to include cells of the first radio access node in the transmission of the service, a preparation notification to a second radio access node neighboring the first radio access node to prepare for mobility of the one or more UE to the neighbor second radio access node, the preparation notification comprising session information to prepare for the multicast transmission session for the service; and deciding to include the second radio access node in the multicast transmission session, deciding to include the second radio access node in the multicast transmission session being based on a radio condition in the RAN comprising the first radio access node and the second radio access node, the radio condition including a signal strength for a UE having a Temporary Mobile Group Identity, TMGI, associated with the multicast transmission session. ### Claim 2 (depends on 1) The method of claim 1, further comprising joining the multicast transmission session; wherein the preparation notification is provided to the second radio access node in response to joining the multicast transmission session. ### Claim 3 (depends on 1) The method of claim 1, wherein the session information comprises at least one of a Temporary Mobile Group Identity, TMGI, or an address for the multicast stream. ### Claim 4 (depends on 1) The method of claim 1, wherein deciding to include the second radio access node in the multicast transmission session comprises determining that a UE receiving the multicast stream has entered or is about to enter a second cell of the second radio access node. ### Claim 5 (depends on 1) The method of claim 1, further comprising: deciding to remove the first cell from the multicast stream; and ceasing transmission of the multicast stream in the first cell. ### Claim 6 (depends on 5) The method of claim 5, wherein deciding to remove the first cell from the multicast stream comprises determining that no UE to receive the multicast stream remains in the first cell. ### Claim 7 (depends on 1) The method of claim 1, wherein the multicast stream is provided by a User Plane Function, UPF. ### Claim 8 (depends on 1) The method of claim 1, wherein the multicast stream is provided by an Internet Protocol, IP, multicast. ### Claim 9 (depends on 1) The method of claim 1, wherein the preparation notification is further provided to all neighboring radio access nodes of the first radio access node in response to joining the multicast transmission session. ### Claim 10 (depends on 1) The method of claim 1, wherein the preparation notification is further provided to a subset of all neighboring radio access nodes of the first radio access node in response to joining the multicast transmission session. ### Claim 11 (depends on 1) The method of claim 1, further comprising identifying the second radio access node as a neighboring radio access node. ### Claim 12 (depends on 11) The method of claim 11, wherein the second radio access node is identified as a neighboring radio access node by Automatic Neighbor Relation, ANR, manual configuration, or both ANR and manual configuration. ### Claim 13 (depends on 11) The method of claim 11, wherein neighboring radio access nodes are identified based on at least one of cell location, UE location, or a determined handover probability during the multicast transmission session. ### Claim 14 (depends on 1) The method of claim 1, further comprising, in response to a determination for the second radio access node to begin transmitting the multicast stream, providing scheduling information, synchronization information, or both scheduling information and synchronization information to the second radio access node. ### Claim 15 (depends on 14) The method of claim 14, further comprising making the determination for the second radio access node to begin transmitting the multicast stream. ### Claim 16 (depends on 14) The method of claim 14, further comprising receiving the determination for the second radio access node to begin transmitting the multicast stream from the second radio access node or another node in the RAN. ### Claim 17 A method performed by a second radio access node in a Radio Access Network, RAN, for adaptively joining a multicast stream, the method comprising: receiving, when a RAN decision is made to include cells of the first radio access node in the transmission of the service, a preparation notification from a neighboring first radio access node in the RAN to prepare for mobility of one or more UE from the neighbor first radio access node, the preparation notification comprising session information to prepare for a multicast transmission session for a service having a multicast stream transmitted at least by the first radio access node to said one or more UE in a first cell; joining the multicast transmission session using the session information; transmitting the multicast stream for the service to one or more User Equipment, UE, in a second cell of the second radio access node; and deciding to include the second radio access node in the multicast transmission session, deciding to include the second radio access node in the multicast transmission session being based on a radio condition in the RAN comprising the first radio access node and the second radio access node, the radio condition including a signal strength for a UE having a Temporary Mobile Group Identity, TMGI, associated with the multicast transmission session. ### Claim 18 (depends on 17) The method of claim 17, wherein the session information comprises at least one of a Temporary Mobile Group Identity, TMGI, or an address for the multicast stream. ### Claim 19 (depends on 18) The method of claim 18, wherein joining the multicast transmission session comprises joining a multicast group associated with the TMGI. ### Claim 20 (depends on 17) The method of claim 17, further comprising receiving the multicast stream from a User Plane Function, UPF, after joining the multicast transmission session. ### Claim 21 (depends on 20) The method of claim 20, wherein joining the multicast transmission session further comprises requesting the multicast stream from the UPF in response to the preparation notification. ### Claim 22 (depends on 17) The method of claim 17, further comprising receiving the multicast stream from an Internet Protocol, IP, multicast after joining the multicast transmission session. ### Claim 23 (depends on 17) The method of claim 17, wherein deciding to include the second radio access node in the multicast transmission session comprises determining that a UE receiving the multicast stream has entered or is about to enter the second cell. ### Claim 24 (depends on 17) The method of claim 17, further comprising receiving scheduling information, synchronization information, or both scheduling information and synchronization information from the RAN after joining the multicast transmission session. ### Claim 25 (depends on 24) The method of claim 24, wherein the multicast stream is unpacked and transmitted in the second cell in response to receiving the scheduling information, synchronization information, or both scheduling information and synchronization information. ### Claim 26 (depends on 24) The method of claim 24, further comprising receiving the multicast stream without processing or transmitting the multicast stream until the scheduling information, synchronization information, or both scheduling information and synchronization information is received. ### Claim 27 (depends on 24) The method of claim 24, wherein the scheduling information, synchronization information, or both scheduling information and synchronization information is received from the first radio access node. ### Claim 28 (depends on 24) The method of claim 24, wherein the scheduling information, synchronization information, or both scheduling information and synchronization information is received from another node in the RAN. ### Claim 29 A radio access node in a cellular Radio Access Network, RAN, for adaptively changing multicast areas in a multicast transmission session, the radio access node comprising: a radio interface; and processing circuitry configured cause the radio access node to: participate in a multicast transmission session for a service, comprising a multicast stream currently transmitted at least by the first radio access node to one or more User Equipment, UE, in a first cell; provide, when a RAN decision is made to include cells of the first radio access node in the transmission of the service, a preparation notification to a second radio access node neighboring the first radio access node to prepare for mobility of the one or more UE to the neighbor second radio access node, the preparation notification comprising session information to prepare for the multicast transmission session for the service; and decide to include the second radio access node in the multicast transmission session, deciding to include the second radio access node in the multicast transmission session being based on a radio condition in the RAN comprising the first radio access node and the second radio access node, the radio condition including a signal strength for a UE having a Temporary Mobile Group Identity, TMGI, associated with the multicast transmission session.