Blocking analysis for green WDM networks with transponder power management

We use an analytical formulation based on Markov chains to evaluate blocking and energy-saving performance of a Wavelength Division Multiplexing (WDM) network with transponder power management. We consider three power modes for transponders, i.e., powered-on (ON), idle (sleep) or powered-off (OFF). To guarantee fast provisioning to high priority (e.g., real time) connections, we assume that some idle transponders (that can be re-activated much faster than powered-off transponders) are reserved for such connections. Some other connections may not have strict set-up time constraint, and can wait until a powered-off transponder is activated and available. We find that at least 32% of power savings can be obtained with such management strategy, for an acceptable degradation in the overall network blocking performance.