Line current differential: Communication channel considerations

This paper briefly describes line current differential schemes, and focuses on their dependencies on communication channels. Dependencies on bit error rate and transmission latency are discussed. Effect of time synchronization accuracy on sensitivity of line current differential scheme is explained in details. Types of communication channels are discussed including dedicated, multiplexed and packet-based. Special attention is given to dedicated channel whose meaning has evolved with development of communication technologies from dedicated physical connection to dedicated bandwidth, etc. Examples of common and evolving communication technologies used for line current differential schemes are given, including the IEEE C37.94 N x 64Kbit/s and Multi-protocol Label Switching (MPLS). Known challenges with adoption of these technologies are also provided.