A cellular communication system, a mobile station and a mthod of operation therefor

A cellular communication system (100) comprises at least one central (base) station (101) and a plurality of remote units (mobile stations)(105-111) which may communicate in direct mode with each other without involving the central station. The remote units (105-111) may also communicate in trunked mode via the central station. The communication system (100) comprises a control remote unit (mobile station) (113) which comprises a direct mode controller (209) for entering a direct mode controller mode. In this mode, the direct mode controller (209) controls a transmitter (205) to transmit direct mode control messages to the other remote units (105-111). The direct mode control messages comprise information associated with radio channels for direct mode communication including for example synchronisation information, radio channel allocation information, radio channel availability information etc. The information may facilitate the operation of the remote units (105-111) and improve direct mode performance. The invention is suitable e.g. for a TETRA communication system.