Online Multicasting in WDM Networks with Shared Light Splitter Bank

Abstract

We study online multicasting in WDM networks with shared light splitter bank. Our objective is to maximize the network throughput. It is desirable that the cost of realizing each multicast request be minimized, and the network throughput will be maximized ultimately through the cost saving on each individual request. We first propose a cost model for realizing an online multicast request under such network environments with limited light splitters and wavelength converters, which models the cost of utilization of network resources, particularly in modelling the light splitting and wavelength conversion ability at nodes. We then show that finding a cost-optimal multicast tree for a multicast request under the proposed cost model is NP-complete, and instead devise approximation and heuristic algorithms for it. We finally conduct experiments to evaluate the performance of the proposed algorithms. The results show that the proposed algorithms are efficient and effective in terms of network throughput.