Method and apparatus for multicast and broadcast services
Embodiments of the present application relate to a method and apparatus for multicast and broadcast services (MBS). An exemplary method includes: transmitting a bearer context identity (ID) to identify a tunnel for a radio bearer (RB) and associate the tunnel with at least one of: a multicast data radio bearer (M-DRB); and at least one unicast data radio bearers (U-DRB). Embodiments of the present application can support multiple transmission modes, for example, the SC-PTM mode, the MC-PTM mode, and the unicast mode.
1 . A method, comprising:
receiving, at a base station, a multicast and broadcast service (MBS) session associated with a quality of service (QoS) flow;
identifying, between a central unit (CU) and a distributed unit (DU) of the base station, a shared tunnel for a radio bearer (RB), the shared tunnel identified by transmitting a bearer context identify (ID) between the CU and the DU;
associating the shared tunnel with: (i) a multicast data radio bearer (M-DRB); and (ii) at least one unicast data radio bearers (U-DRB); and
mapping the QoS flow to the M-DRB and the at least one U-DRB to enable the shared tunnel to support multiple transmission modes simultaneously.
2 . The method of claim 1 , further comprising: receiving, by the CU from the DU, a transport network layer (TNL) information of the shared tunnel.
3 . The method of claim 2 , wherein:
the bearer context ID that identifies the shared tunnel is included in a bearer context setup request message and the TNL information of the tunnel is included in a bearer context setup response message;
the TNL information indicates an internet protocol (IP) address and a general packet radio service (GPRS) tunneling protocol (GTP) user plane (GTP-U) tunnel endpoint identifier (TEID); and
the base station comprises the central unit (CU) separated into a CU control plane (CU-CP) unit communicatively coupled via an E1 interface to a CU user plane (CU-UP) unit, and the base station comprises the DU communicatively coupled to the CU-CP unit via an F1-control (F1-C) interface and coupled to the CU-UP via an F1-user (F1-U) interface.
4 . The method of claim 1 , wherein the bearer context ID that identifies the shared tunnel is generated in a tunnel establishment procedure.
5 . The method of claim 4 , wherein the bearer context ID is indicated in TNL information of the tunnel, the TNL information of the tunnel identifying a shared tunnel for data transmission of both the M-DRB and the at least one U-DRB.
6 . A base station comprising:
a central unit (CU); and
a distributed unit (DU) communicatively coupled to the CU;
at least one non-transitory computer-readable medium having computer executable instructions stored therein;
at least one receiving circuitry;
at least one transmitting circuitry; and
at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry;
wherein the at least one processor is configured to cause the base station to:
receive, at the base station, a multicast and broadcast service (MBS) session associated with a quality of service (QoS) flow;
identify a shared tunnel, between the CU and the DU, for a radio bearer (RB), the shared tunnel identified by transmitting a bearer context identify (ID) between the CU and the DU;
associate the shared tunnel with: (i) a multicast data radio bearer (M-DRB); and (ii) at least one unicast data radio bearers (U-DRB); and
map the QoS flow to the M-DRB and the at least one U-DRB to enable the shared tunnel to support multiple transmission modes simultaneously.
7 . The base station of claim 6 , wherein the at least one processor is configured to:
receive, at the CU from the DU, transport network layer (TNL) information of the shared tunnel.
8 . The base station of claim 7 , wherein:
the bearer context ID that identifies the shared tunnel is included in a bearer context setup request message and the TNL information of the tunnel is included in a bearer context setup response message; and
the TNL information indicates an internet protocol (IP) address and a general packet radio service (GPRS) tunneling protocol (GTP) user plane (GTP-U) tunnel endpoint identifier (TEID).
9 . The base station of claim 6 , wherein the bearer context ID that identifies the shared tunnel is generated in a tunnel establishment procedure.
10 . The base station of claim 9 , wherein the bearer context ID is indicated in TNL information of the tunnel, the TNL information of the tunnel identifying a shared tunnel for data transmission of both the M-DRB and the at least one U-DRB.
11 . The base station of claim 7 , wherein the bearer context ID that identifies the shared tunnel is transmitted in a bearer setup request message for establishing an M-DRB and/or a U-DRB, and the at least one processor is configured to:
receive a bearer setup response message, wherein the bearer setup response message indicates the bearer context ID and a multicast area including at least one cell.
12 . The base station of claim 7 , wherein the bearer context ID that identifies the shared tunnel is transmitted in a bearer setup request message for establishing an M-DRB and/or a U-DRB, and the at least one processor is configured to:
receive a bearer setup response message, which indicates whether a point to point (PTP) mode, and/or a single cell point to multipoint (SC-PTM) mode or a multi-cell point to multipoint (MC-PTM) mode is used.
13 . The base station of claim 12 , wherein:
the bearer setup response message also indicates at least one of: the bearer context ID, the M-DRB ID, and a group radio network temporary identifier (G-RNTI) and scheduling information associated with each cell of at least one cell in an area; and
in response to the bearer setup response message indicating the SC-PTM mode is being used, the at least one processor is configured to:
generate a radio resource control (RRC) M-DRB configuration for each cell of the at least one cell, wherein the RRC M-DRB configuration indicates the G-RNTI and the scheduling information associated with the cell; and
transmit the RRC M-DRB configuration for each cell of the at least one cell via a non-user equipment (UE) associated signaling.
14 . The base station of claim 10 , wherein:
the bearer setup response message also indicates at least one of: the bearer context ID, the M-DRB ID, and a group radio network temporary identifier (G-RNTI) and scheduling information associated with an area that includes at least one cell; and
in response to the bearer setup response message indicating the SC-PTM mode is being used, the at least one processor:
generates a radio resource control (RRC) M-DRB configuration for the area, wherein the RRC M-DRB configuration indicates the G-RNTI and the scheduling information associated with the area; and
transmits the RRC M-DRB configuration for the area via a non-user equipment (UE) associated signaling.
15 . A base station comprising:
a central unit (CU) comprising at least one of service data adaptation protocol (SDAP) functionality and packet data convergence protocol (PDCP) layer functionality;
a distributed unit (DU) communicatively coupled to the CU;
at least one non-transitory computer-readable medium having computer executable instructions stored therein;
at least one receiving circuitry;
at least one transmitting circuitry; and
at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry, wherein the at least one processor is configured to cause the base station to:
receive, at the CU, a multicast and broadcast service (MBS) session;
identify a first tunnel, between the CU and the DU, for a radio bearer (RB), the first tunnel identified by identified by transmitting a bearer context identify (ID) between the CU and the DU;
associate the first tunnel with: a multicast data radio bearer (M-DRB);
identify a second tunnel, between the CU and the DU, for an RB;
associate the second tunnel with at least one unicast data radio bearers (U-DRB); and
associate the at least one of the SDAP functionality and the PDCP layer functionality to the first tunnel and the second tunnel to keep service continuity, enabling support of multiple transmission modes simultaneously.
16 . The base station of claim 15 , wherein the computer executable instructions cause the at least one processor to:
transmit, to the CU from the DU, transport network layer (TNL) information of the tunnel;
wherein the bearer context ID to identify the first tunnel is included in a bearer context setup request message and the TNL information of the tunnel is included in a bearer context setup response message.
17 . The base station of claim 15 , wherein the bearer context ID to identify the first tunnel is generated in a tunnel establishment procedure.
18 . The base station of claim 17 , wherein the bearer context ID is indicated in TNL information of the tunnel, the TNL information of the tunnel identifying a shared tunnel for data transmission of both the M-DRB and the at least one U-DRB.
19 . The base station of claim 15 , wherein the bearer context ID to identify the first tunnel is included in a bearer setup request message for establishing an M-DRB and/or a U-DRB, and the bearer setup request message includes an indication indicating whether a point to point (PTP) mode, and/or a single cell point to multipoint (SC-PTM) mode or a multi-cell point to multipoint (MC-PTM) mode is used.
20 . The base station of claim 15 , wherein the at least one processor is configured to:
transmit a bearer setup response message, wherein the bearer setup response message indicates whether the point to point (PTP) mode, and/or the single cell point to multipoint (SC-PTM) mode or the multi-cell point to multipoint (MC-PTM) mode is used.