User equipment, network node and methods therein
A method performed by a User Equipment, UE, is provided. The UE receives (s 302 ) a first message comprising a group identifier, ID, allocated for a particular multicast-broadcast services, MBS, session. While camping on radio access network, RAN, node that does not support MBS services and while being in a radio resource control, RRC, state other than RRC_CONNECTED, the UE receives (s 304 ) from the RAN node a paging message. The UE determines (s 306 ) whether the paging message comprises the group ID.
1. A method performed by a user equipment (UE), the method comprising:
transmitting a request to join a particular multicast-broadcast services (MBS) session, the request comprising an MBS session identifier (ID) identifying the particular MBS session,
in response to the request, receiving a first message comprising a group ID allocated for the particular MBS session, the group ID being different than the MBS session ID and comprising a group 5G-S-Temporary Mobile Subscriber Identity (5G-S-TMSI) assignable to a plurality of UEs that join the particular MBS session via unicast; and
while the UE is camping on a radio access network (RAN) node that does not support MBS and is in a radio resource control (RRC) state other than RRC_CONNECTED, receiving from the RAN node a paging message; and
determining whether the paging message comprises the group ID.
2. The method of claim 1 , further comprising in response to determining that the paging message comprises the group ID, establishing a connection with the RAN node.
3. The method of claim 2 , further comprising after establishing the connection with the RAN node, receiving data for the MBS session via a unicast transmission from the RAN node.
4. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE), cause the UE to perform operations corresponding to the method of claim 1 .
5. A user equipment (UE) comprising:
communication interface circuitry configured to communicate with a radio access network (RAN); and
processing circuitry operably coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to:
transmit a request to join a particular multicast-broadcast services (MBS) session, wherein the request includes an MBS session identifier (ID) identifying the particular MBS session;
in response to the request, receive a first message comprising a group ID allocated for the particular MBS session, wherein the group ID is different than the MBS session ID and comprises a group 5G-S-Temporary Mobile Subscriber Identity (5G-S-TMSI) assignable to a plurality of UEs that join the particular MBS session via unicast; and
while the UE is camping on a radio access network (RAN) node that does not support MBS and is in a radio resource control (RRC) state other than RRC_CONNECTED, receive from the RAN node a paging message; and
determine whether the paging message comprises the group ID.
6. The UE of claim 5 , wherein the processing circuitry and the communication interface circuitry are further configured to establish a connection with the RAN node in response to determining that the paging message comprises the group ID.
7. The UE of claim 6 , wherein the processing circuitry and the communication interface circuitry are further configured to, after establishing the connection with the RAN node, receive data for the MBS session via a unicast transmission from the RAN node.
8. A method performed by a network node configured to implement a core network function, the method comprising:
receiving a request for a user equipment (UE) to join a particular multicast-broadcast services (MBS) session, wherein the request includes an MBS session identifier (ID) identifying the particular MBS session;
allocating a group ID for the particular MBS session, the group ID being different than the MBS session ID and comprising a group 5G-S-Temporary Mobile Subscriber Identity (5G-S-TMSI) assignable to a plurality of UEs that join the particular MBS session via unicast; and
transmitting, towards the UE, a message that includes the group ID.
9. The method of claim 8 , wherein the message is transmitted to a session management function (SMF) of the core network.
10. The method of claim 8 , further comprising transmitting, to an access and mobility management function (AMF) of the core network, a session start request message indicating the group ID.
11. The method of claim 10 , wherein the session start request message triggers the AMF to initiate a paging procedure for the UE when the following conditions are present: the AMF is serving the UE, the UE has joined the MBS session, and the UE is in a radio resource control (RRC) state other than RRC_CONNECTED.
12. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a network node configured to implement a core network function, cause the network node to perform operations corresponding to the method of claim 8 .
13. A network node configured to implement a core network function, wherein the network node comprises:
communication interface circuitry configured to communicate with other core network functions; and
processing circuitry operably coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to:
receive a request for a user equipment (UE) to join a particular multicast-broadcast services (MBS) session, wherein the request includes an MBS session identifier (ID) identifying the particular MBS session;
allocate a group ID for the particular MBS session, the group ID being different than the MBS session ID and comprising a group 5G-S-Temporary Mobile Subscriber Identity (5G-S-TMSI) assignable to a plurality of UEs that join the particular MBS session via unicast; and
transmit, towards the UE, a message that includes the group ID.
14. The network node of claim 13 , wherein the message is transmitted to a session management function (SMF) of the core network.
15. The network node of claim 13 , wherein the processing circuitry and the communication interface circuitry are further configured to transmit, to an access and mobility management function (AMF) of the core network, a session start request message indicating the group ID.
16. The network node of claim 15 , wherein the session start request message triggers the AMF to initiate a paging procedure for the UE when the following conditions are present: the AMF is serving the UE, the UE has joined the MBS session, and the UE is in a radio resource control (RRC) state other than RRC_CONNECTED.