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

Abstract

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 timeindependent windows. We then present, two RWA algorithms to efficiently route scheduled lightpath demands from timeindependent 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.