Maintenance method and apparatus for providing a high-integrity, unidirectional, standardized ATM/SONET/DS3 transport signal link for a video distribution network

摘要

A high-integrity video distribution signal is provided unidirectionally from one network node to another network node according to a standard digital communications format (ATM; SONET; DS3) that defines digital signal communications in a bidirectional manner with equal bandwidth in each direction. The one network node providing the video distribution signal simultaneously monitors the video distribution signal, e.g. by a modified loopback (in conjunction with optical power monitoring) for providing a performance monitoring function indicative only of performance of the one network node that provides the video distribution signal, wherein the another network node receiving the video distribution signal performs its own performance monitoring and communicates its performance in the network in a manner other than in the bidirectional manner defined in the standard, wherein the end result is providing the same level of performance monitoring and fault isolation that presently exists in a bidirectional system. <IMAGE> <IMAGE>