A Traffic Grooming, Routing and Wavelength Assignment Algorithm for Optical WDM Mesh Networks

Recently, there has been a growing excitement in the area of optical wavelength division multiplexing (WDM) networks. While a single fiber has a huge bandwidth capacity and a wavelength has over a gigabit per second transmission speed, the traffic demands at speed that are lower than the full wavelength capacity are frequent in the current WDM network. Researchers and optical networking industries are now trying to find a way to support multiple low-speed traffic streams onto a single high-speed wavelength to improve the wavelength channel utilization and to minimize the amount of electronic multiplexing equipment.
The issue of traffic grooming, routing and wavelength assignment in optical WDM networks in this thesis is formulated as a combinatorial optimization problem, of which the objective function is to minimize the total leasing cost for network service provider (NSP) upon the underlying WDM network subject to physical link capacity constraints, wavelength continuity constraints, and wavelength add/drop port constraints. The decision variables in these formulations include traffic demand routing, lightpath in WDM layer routing and wavelength assignment, the number of leasing wavelengths in each fiber link, and the number of leasing add/drop ports in each optical cross-connects switch (OXC) .
The basic approach to the algorithm development for this thesis is Lagrangian relaxation in conjunction with a number of optimization techniques. In computational experiments, the proposed algorithms are evaluated on different network topologies..