Energy efficiency of hybrid optical switching

Hybrid optical switching (HOS) has the potential to provide highly efficient operation through combining various switching paradigms and different implementation options within the same network. The flexibility of choosing between circuit, packet or burst switching and electronic or optical implementation results in an improvement in both energy and data transport efficiency because the most appropriate method and less power consuming elements can be selected and used for transmission of data through the network while inactive elements are switched off or put in a low-power mode. In this paper, we propose a novel network concept that we refer to as adaptive hybrid optical switching (AHOS) and present and investigate several architectures and realization options for AHOS nodes. The corresponding control plane comprises two layers, of which one implements routing, signalling and link management functions as defined in the GMPLS standard while the other one is responsible for managing already established circuits and scheduling the transmission of packets and bursts. We present results on both performance and energy consumption for different AHOS node realizations, network configurations and traffic patterns, which prove the potential for a high improvement in energy efficiency from 100% to approximately 1,000% with respect to the conventional electronic packet routers.