Routing fault-tolerant sliding scheduled traffic in WDM optical mesh networks

This paper deals with the problem of routing and wavelength assignment (RWA) of fault-tolerant sliding scheduled lightpath demands (FSSLDs) in WDM optical mesh networks. Sliding scheduled traffic model allows the service provider and end-users to negotiate the starting time and ending time of the demands. We have developed a time conflict resolving algorithm that exploits the time disjointness that could exist among FSSLDs by rearranging the demands and then dividing them into time-independent windows. We then present, two RWA algorithms to efficiently route scheduled lightpath demands from time-independent windows. The proposed algorithms schedule both primary and end-to-end protection routes and also assign wavelengths for the duration of the demands. Extensive simulations are conducted on ARPANET, NSFNET, USANET, and Mesh 8×8, 10×10, 12×12 networks. By rearranging the demands and exploiting time-disjointness across demands, the proposed algorithms can reuse the wavelengths and hence reduces the amount of global resources required and blocking probability.