Abstract: A communication device (200) operates in a wide area communication system having a number of sites. The communication device (200) includes a first receiver for receiving communication signals from an active site (120). The information received from the active site (120) includes the location information and the quality of the adjacent sites (102, 104, 106, and 108). The communication device (200) includes a GPS receiver (210) for establishing its own location. The location of adjacent sites along with their quality is ranked to produce a ranking table. A controller (208) is utilized to sense when the signal strength of the communication signals received from the active site (120) falls below a desired level. The communication device (200) switches to a new site on top of the ranking list when this condition of low signal strength is present.

Abstract: Each subscriber unit (108) operating on a communication system (100) selects either encrypted or unencrypted transmission mode as a current transmission mode. Before participating in a communication, each subscriber unit (108) receives a message identifying an authorized transmission mode. Only when the current transmission mode corresponds to the authorized transition mode may each subscriber unit (108) transmit so as to participate in the communication.