Submerged WDM network implementation using all optical wavelength routers

Wavelength division multiplexing demonstrates a great potential for the next generation of undersea fibre optic cable networks. WDM techniques will allow greater transmission capacity and network flexibility compared to the present single channel optical amplifier systems. Complex network connectivity can be implemented for the first time with the use of an all optical wavelength add/drop multiplexer (WADM) incorporated into the submerged branching unit. One or more channels can be added and dropped at each branching unit and multiple wavelength re-use is allowed to establish the required connectivity between the nodes. Traffic protection and channel independence can also be managed. This ensures international operators that their traffic is protected against failures or interference in parts of the system not involved in their transmission path. This paper describes the general features of the submerged branching unit as well as specific implementations for different network architectures. The means for providing network connectivity and wavelength routing is explained. The requirements for add/drop channel management and traffic independence are described. Future solutions for achieving enhanced routing flexibility and reconfigurable capacity allocation also discussed