COMMUNICATION SYSTEM

摘要

This system includes a main station (MS) and a plurality of substations (SX/SZ) which include each a transceiver and are all connected in parallel to first (UL) and second (DL) unidirectional links on which recurrent first and second cells of fixed length are transmitted in opposite direction. Each of these cells contains a plurality of signalling channels smaller than the number of substations. When a substation has to transmit data it starts an allocation procedure wherein the substation cooperates with the main station and by which a channel is allocated to it. Afterwards prior to transmitting the data the substation transmits a request signal in the allocated channel and starts transmission after having received from the main station a grant signal in the homologous signalling channel of a second cell. De-allocation of a channel occurs as soon as the latter is no longer needed.