The field of protection systems used in power systems is more and more dominated by computer based relays. In the power systems of Europe, but not only, the deregulation is appeared and works. Due to the operational demands imposed on transmission networks by this, it is clearly that wide-area measurements and their integration in protection and control systems becomes more then a necessity.Wide Area Protection (WAP) using fiber optic is one exemple of integration of communication in protection systems. Transelectrica SA ( Romanian Transmission Power Grid and System Operator), trough the Teletrans Sa (which ensure the operation and maintenance for telecomunication networks and systems owned by Transelectrica SA), has a strongly and robust communication architecture witch can be used for WAPaC (Wide Area Protection and Control) of Transmission Power Grig, in order to extend the system operational limits
