An approximation algorithm for provisioning of survivable multicast sessions in WDM networks

It has been widely recognized in the literature that it is imperative to protect light-tree based multicast sessions against single link failures since a single fiber failure can disrupt the information dissemination to several destination nodes. In this paper, we address the problem of routing survivable multicast sessions (RSMS) in wavelength-division multiplexing (WDM) mesh networks. We consider the dynamic network environment, where multicast sessions arrive dynamically one after another. Our objective is to be able to consume as least cost (e.g., wavelengths) as possible for one-at-a-time arrivals and no priori knowledge of future arrivals. We present an approximation algorithm that outperforms previously proposed algorithms for the RSMS problem such as optimal path-pair-based shared disjoint paths (OPP-SDP). To the best of our knowledge, this is the first approximation algorithm proposed for the RSMS problem. We prove that the cost of the solution obtained by the HCBA algorithm is at most 4 times that of the optimal solution. We show by simulation that our algorithm performs very close to the optimal solution obtained by solving a mathematical formulation for the RSMS problem. We also show that, compared with the OPP-SDP algorithm, our algorithm can significantly reduce the average cost and the blocking probability.