APPARATUS FOR RECEIVING AND TRANSMITTING DATA IN REAL TIME IN ASYNCHRONOUS TRANSMISSION MODE

摘要

PURPOSE: An apparatus for receiving and transmitting data in real time is provided to reduce data transmission delay variations and clock jitters by reducing a data delay occurring in a process of each of layers. CONSTITUTION: A data flow controller(12) determines output time of various information constructing common part convergence sub-layer-protocol data unit(CPCS-PDU) by receiving transport stream(TS) border identification signal from a TS multiplexer(11). A CPCS trailer 4 byte storage memory(13) stores a CPCS-UU and a call processing indicator(CPI), length field of a CPCS trailer to be transmitted. A cyclic redundancy checks-32(CRC-32) checksum producer(14) receives a first-half 4 byte value of CPCS trailer and TS inputted from the TS multiplexer(11), calculates a CRC-32 checksum value, and transmits data to an asynchronous transfer mode(ATM) layer processor(16) at a designated time set by the data flow controller(12). A selector(15) receives a control signal from the data flow controller(12) and an output of the selector(15) is forward to an ATM layer processor(16) through one of the TS multiplexer(11), the CRC-32 checksum producer(14), C PCS trailer 4 byte storage memory(13).