Communication Channel Requirements for Pilot Protection

Pilot relaying has been applied for transmission line protection since the 30's. The well known communication channels (pilot wire or Power Line Carrier) are increasingly being replaced by digital channels.  Dark fiber (dedicated fiber optic cable), multiplexed fiber optic systems (T1 and SONET) and 56 kbps phone lines are now made available for pilot protection purposes. The new channels provide much higher data transfer rate but reliability and security performance criteria developed for the telecommunications industry are not easily translated to teleprotection applications. More