CONTENTION MULTIPLEXER

PROBLEM TO BE SOLVED: To reduce the wait time from occurrence of a transmission request till actual transmission. SOLUTION: Each buffer section 10 (N) stores fixed length data 17 (N) sent from a corresponding terminal T (N) and sends the data according to a scheduled transmission time by a scheduler 12. Furthermore, each buffer section 10 (N) stores one set of fixed length data 17 (N) or over, then sets a transmission request signal 14 (N) to be active. When the plural signals 14 (N) are simultaneously active, an encoder 11 selects any of them according to prescribed priority and selects it when the signal 14 (N) of any of them is set active. The shceduler reserves a transmission time of the buffer section 10(N) every time the signal 14 (N) is selected. The reservation is made in such a way that the transmission interval of the fixed length data 17 (N) is not less than the allowable minimum data transmission interval.