Methods and systems are disclosed for forcing at least some members of a communication group to join a new group call when they are participating in an another group call to a different communication group. A wireless communication device that seeks to initiate the new group call transmits a request-to-transmit (RTT) on a reverse channel to initiate the new group call. This way, at least some of group members participating in the other group call can be allowed to join the new group call. The recipients of the RTT can then switch from a primary channel on which the other group call is taking place to an alternative channel to join the new group call. In one implemenation, the disclosed embodiments can be applied to a two-way wireless communication system that employs a TDMA channel access scheme.