Implementation and performance study of ATM terminal adapter for teleprotection signals transmission in power telecommunication network

This paper reports the implementation and performance of ATM TA (asynchronous transfer mode terminal adapter) for transmission of CR (carrier relay) signals in power telecommunication network. The characteristics of the teleprotection signals concerning PCM current differential relaying system are considered for the development because the teleprotection system signal has the most strict transmission delay constraints on the power telecommunication networks. Thus it is confirmed that transmission of CR signals is possible using this ATM TA. An ATM broadband terminal adapter is developed to meet the requirements of transmission delay time and delay time difference constraints of the PCM current differential relaying system, applying partial-fill algorithm and adaptive clocking method in a different way with the general ATM terminal adapter which supports CBR (constant bit rate) service. In the performance test, we found that the teleprotection signals transmission concerning PCM current differential relaying system is possible in the unstructured mode service