Two-layer hierarchical wavelength routing for islands of transparency optical networks

Although significant advances have been achieved towards the deployment of all-optical networks, optical–electrical–optical (OEO) regeneration is still required due to the lack of proper all-optical processing and all-optical buffering. In order to have a practical, reliable, and cost effective optical transport network, the combination of both all-optical and OEO technologies is necessary. The “islands of transparency” network architecture has been proposed as a solution. This paper presents a two-layer hierarchical wavelength routing (THWR) protocol for the island of transparency optical network. The proposed THWR is a link state protocol that uses a two-layer hierarchy that partitions the network into routing areas, each of which represents an island of transparency. The proposed THWR implements a dynamic wavelength routing capability to balance the network load and avoid the congested area automatically. The complexity analysis and the simulation results of THWR are shown in the paper. The results show THWR is an effective protocol that meets the requirements for optical networks.