A wireless communication system is disclosed comprising a call controller to establish a communication session in a first communication mode between two or more users; receive a request from at least one of the users to switch the first communication mode of the communication session to a second communication mode; and switch the first communication mode of the communication session to the second communication mode. The first and second communication mode may respectively comprise half-duplex and full-duplex modes, or vice-versa. Other disclosed embodiments relate to a call controller for to setup multiple communication mode sessions in a wireless communication system, and a subscriber unit able to request and accept a switch to a different communication mode in an ongoing communication session.