SYNCHRONISING CONSTANT BIT RATE TRANSMISSIONS IN ATM NETWORK

摘要

The synchronisation method involves converting a data stream with constant bit rate on the transmission side from an interworking unit (2) into an asynchronous transfer mode (ATM) cell stream. After transmission to the receiver side, the ATM cells are stored in the input buffer (6). A time stamp is associated with each ATM cell in the buffer which correlates with the time of reception of that cell. The data stored in the ATM cells are output through the interworking unit (9) as a data stream with a constant bit rate. The output starts delayed from the reception time by a time TA. For the delay time, a target value tv is provided, which is greater than the variation of the transmission time of the ATM cells from the transmitter to the receiver. The current delay time is determined by taking the difference between the delay time Ta and the transmission time. An error signal is determined and transmitted to the regulator (13). A control signal is transmitted to the time base (14) and is used to adjust the clock frequency.