Abstract: In a communication system having a plurality of base stations for communication with mobile terminals, each station is allocated one of nine communication channels. The allocation is arranged such that adjacent channels are spaced further apart than non-adjacent channels so as to eliminate interference.

Abstract: A communication system using a control bus and an audio bus to interconnect operator positions and radio positions. Each position is allocated, by a timing circuit, time slots on the control bus during which it applies digital words to the control bus indicating its own identity and information to be transmitted to other positions. Because data applied to the control bus by the operator positions is time multiplexed, requests from operator positions for a particular radio facility are dealt with in turn by the radio positions so that operators at the operator positions cannot compete for the same ratio facility. The need for a general purpose computer and its associated software is avoided. Each radio at the radio positions is able to communicate to the operators at the operator positions its current mode of operation so that the operators can always be sure that the system is operating correctly.