Traffic grooming methods for undersea trunk and branch architectures

Undersea cable systems generally span many sovereign countries with variety of bandwidth needs. Trunk and branch arrangement provides a secure and cost-effective way of connecting these countries with a single cable system. However the cost per bandwidth mile of undersea cable systems is very high which makes efficient traffic grooming necessary. In this paper, we propose three grooming schemes in context of a trunk and branch network that deploys SDH ring transport to provide SDH pipes to carry PDH signals. The proposed methods are general and extend to other arrangements such as mesh-type transport and other signal levels.