Design Based Routing with Waveband and Wavelength Assignment in Wavelength Division Multiplexing Networks using Multi-Granular Optical Cross-Connects

In this paper, we extend design based routing (DBR), which is originally proposed for opaque wavelength division multiplexing (WDM) networks without waveband switching (WBS), to transparent WDM networks with WBS. We formulate and solve the corresponding integer linear programming (ILP) problems to facilitate the use of DBR for transparent WDM networks with WBS, referred to as DBR with Waveband and Wavelength Assignment (DBRWWA). The goal of DBRWWA is to minimize the total link cost subject to the constraints on traffic demands and on network resources. DBRWWA guides online routing of dynamic lightpath requests in WDM networks with WBS, where traffic engineered routes are computed offline based on the prior information on traffic demand statistics. We investigate two novel heuristics, called the maximum waveband-wavelength first (MaxWWF) algorithm and the minimum waveband-wavelength first (MinWWF) algorithm, as well as existing first-fit and random-fit algorithms. The proposed heuristics consider all properties of WBS, including waveband and wavelength continuity constraints. We consider end-to-end WBS (ETE-WBS) for lightpath grouping. The online heuristics are combined with shortest path first (SPF) routing, DBR, and DBRWWA to support dynamic traffic. Simulation results show that DBRWWA has on average lower blocking probability compared to DBR, while both DBRWWA and DBR greatly outperform SPF routing in terms of the blocking probability.