The relay communication system is the heart of the protective scheme. The independent operation of the relays scheme for the protection of transmission line is not adequate in some cases where the time delay to clear faults beyond the zone1 reach for distance relays may be considered unacceptable. The need for additional intelligence in the protection of some transmission lines arises due to the failing of Distance protection. As the future may see more global the protection designs also require highbandwidth communications in order to achieve the required speed. In this paper there is the study and comparison of various communication based protective relaying schemes which utilize a communications path to send signals from the relaying system at one end of the line to that at the other end.