Abstract: A system which improves coverage in overlapping coverage areas between two type-A or type-B cellular radio telephone systems is able to direct a subscriber unit in the overlapping coverage area to the home or primary system, thereby minimizing the subscriber unit's roaming-type expenses. The system includes a control channel receiver, a control unit, and a control channel transmitter/receiver pair, in combination with a transmit/receive antenna. The system transmits a control channel, which is associated with the home system, into the overlapping region. The control channel is intended to be the strongest channel in that region. Any subscriber units in the region associated with the home system which respond to that control channel will be directed to other control channels associated with the home system. Those subscriber units will receive service from the home system, as opposed to the foreign system which may provide other strong control channels in the overlapping coverage area.

Abstract: An arrangement for establishing communication between a first mobile radio transceiver and a second mobile radio transceiver through a repeater over a radio frequency channel selected from a plurality of such channels. A repeater distinguishes between two-tone signalling sequences and four-tone signalling sequences by determining the arrival rate over some predefined interval of a received signalling sequence. The repeater transmits a busy signal to alert mobile stations seeking to acquire a channel that the repeater is busy. The repeater interrupts the transmitted busy signal during a portion of the four-tone signalling sequence but not the two-tone signalling sequence to help prevent two-tone mobile stations from falsing on four-tone signalling sequences. The arrangement is thus made compatible with both two-tone signalling and four-tone signalling formats.