1. ITU-T, Synchronous Digital Hierarchy, Recommendations G.707, G.708, Geneva, Switzerland, 1988
2. IEEE Globecom '85, New Orleans;Boem,1985
3. ITU-T Recommendation G.784, Synchronous Digital Hierarchy (SDH) management, June 1999
4. ITU-T Recommendation G.841, Types and characteristics of SDH network protection architectures, Draft revised, March 2000
5. ITU-T Recommendation G.709/Y.1331, Network Node Interface for the Optical Transport Networks (OTN), February 9, 2001