A Forward-Backward Optical Wavelength Path Establishment Scheme with Low Blocking Probability in WDM Networks

We study dynamic routing and wavelength assignment scheme when there are any available wavelengths on a route in the wavelength-routed networks. An optical wavelength path request is blocked when there are no available wavelengths over the selected route. In this paper, we present a new optical path establishment scheme for achieving low-blocking probability and shortening mean setup delay. It consists of two schemes. One is to start optical wavelength path establishment process from a source node on least hops route (LHR) when used wavelength is released. The other is to start it from a destination node on least load route (LLR) after reservation failure on LHR. We simulated two different topologies. It is shown the proposed scheme is better than existing schemes in both the topologies.