SONET self-healing networks for STS-1/Nc path restoration

The initiation of the self-healing algorithm is discussed in a practical synchronous optical network (SONET) environment, where a variety of network elements, such as digital cross-connect systems (DCSs) and add-drop multiplex (ADM), are accommodated. From a local algorithm initiation point of view, the STS-1/Nc path level restoration is preferable to the OC-N level line restoration. In this case, the algorithm is basically initiated in the path terminating DCSs upon detection of each STS-1/Nc path AIS. The authors propose an integrated design and control of the ring architecture and the DCS-based self-healing algorithm for restoration against various failure scenarios in an efficient fashion. Under the proposed control, either the ring architecture or the DCS-based self-healing algorithm is selected as the restoration scheme according to the failure position in each STS-1/Nc path