Mission critical push to talk multimedia broadcast multicast service subchannel control message protection

摘要

Mission critical push-to-talk (MCPTT) nodes (410, 510, 600, 800) are connected to a group of user equipments (UEs) (405, 505, 700, 900) served by the MCPTT nodes. The MCPTT node generates a multimedia broadcast multicast service (MBMS) sub-channel control key (MSCCK) (S305), transmits a first message to the UE by unicast, and the first message transmits the generated MSCCK. Including (S310), generating at least one MBMS subchannel control message (S315), applying integrity protection and / or confidentiality protection to the at least one MBMS subchannel control message using MSCCK (S320); At least one MBMS subchannel control message is transmitted by multicast (S325). [Selection] Figure 3A