Patent ID: 6940812

Claim:
A transmission apparatus for constant bit rate data cells, which is adapted to transmit data cells of data packets in sequence to an asynchronous transfer mode network, in matching with a transmission cycle, comprising: a data buffer which holds a plurality of data packets, into which a stream of data to be transmitted is divided; a control memory which stores control information regarding the stream of data to be transmitted; and a controller which transmits said plurality of data packets for respective data cells of constant bit rates to said network based on said control information stored in said control memory, wherein said controller determines when new control information is processed and whether or not a data cell sent out through a slot immediately before to said network has been a head data cell of the data packet, prevents the data cell, which is carried out at the current transmission cycle, from starting of the transmission based on said new control information, if the data cell sent out through a slot immediately before has been the head data cell, and starts the transmission of the data cell of a constant bit rate at the current transmission cycle based on said new control information, if the data cell sent out through a slot immediately before has not been the head data cell.