Abstract: A carrier frequency is apportioned to timeslots, and logical channels are formed between the base station and mobile terminals to support services in connection with these mobile terminals. Each of the logical channels consists of recurring timeslots allocated to at least one mobile terminal on the carrier frequency. To implement one of the services which involves transmission of periodically updated information, a recurrence frequency is selected from a plurality of possible values, as being substantially the inverse of the updating period for said information, and a logical channel is formed between the base station and a mobile terminal by allocating timeslots having the selected recurrence frequency on the carrier frequency.

Abstract: A base station forms a time-division multiplexing physical control channel comprising a set of presynchronization timeslots each carrying the same synchronization signal, and a set of synchronization supplement timeslots respectively associated with the presynchronization slots. Each synchronization supplement slot carries the same synchronization signal representing system information and furthermore a signal identifying said synchronization supplement slot, thereby enabling to complete the synchronization achieved on the basis of the presynchronization slots.