Handling of MBS session related back-off timer

A method, comprising:

• maintaining a protocol data unit (PDU) session by a user equipment (UE) in a 5G network;
• receiving a PDU session modification command message from the network, wherein the PDU session modification command message comprises a received multicast broadcast services (MBS) container IE associated with an MBS session;
• determining that the received MBS container IE indicates the network either rejects the UE to join the MBS session or removes the UE from the MBS session, wherein the received MBS container IE comprises a reject cause and a non-zero backoff timer value;
• and
• starting a backoff timer having the backoff timer value in response to the received MBS container IE, wherein the backoff timer is not deactivated and the UE refrains from requesting to join the same MBS session before the backoff timer expiry.

A User Equipment (UE), comprising:

• a protocol data unit (PDU) session handling circuit that maintains a PDU session in a 5G network;
• a receiver that receives a PDU session modification command message from the network, wherein the PDU session modification command message comprises a received multicast broadcast services (MBS) container IE associated with an MBS session;
• a control circuit that determines the received MBS container IE indicates the network either rejects the UE to join the MBS session or removes the UE from the MBS session, wherein the received MBS container IE comprises a reject cause and a backoff timer value;
• and
• a backoff timer having the backoff timer value, wherein the UE starts the backoff timer in response to the received MBS container IE and refrains from requesting to join the same MBS session before the timer expiry.