A.7 Late entry to group communication

33.1793GPPRelease 13Security of Mission Critical Push To Talk (MCPTT) over LTETS

[33.179 MCPTT-A.7-001] An authorized MCPTT User shall be able to obtain the information necessary to derive the group security context for the MCPTT Group while an MCPTT Group communication is on-going. As a result, the MCPTT User shall be able to listen to the group communication within 350ms. This requirement applies for both on-network and off-network MCPTT operation.