Time/phase synchronization distribution over Optical Transport Network(OTN)

This paper studies the issues that are relevant to distributing accurate time/phase over Optical Transport Network (OTN). Each node and link can introduce asymmetry, which affects the adequate time/phase accuracy over the networks. In order to achieve better accuracy, it is necessary to correct time through the various network nodes. Both boundary clock mode and novel hybrid clock mode are proposed for supporting IEEE1588v2. In the case of OTN, the asymmetry due to the use of different wavelengths in the two directions is taken into account. The theoretical framework for the analysis of link delay asymmetry and also its compensation are provided.