PURPOSE: To reduce the amount of data required for controlling connecting state of an on-satellite switch in demand assign SS-TDMA communication.

CONSTITUTION: This system is provided with a first step (12, 14) where a burst that can be secured in the present switch connection state as it is assigned, second step (16, 18) where bidirectional bursts that can be secured by the same switch data by changing the connecting state of the switch are assigned when the bursts are deficient in first step, and third step (20, 22) where the bidirectional burst is assigned by different switch data when the burst is further deficient in the setting of plural bidirectional calls.