Reliable light-tree construction with weighted SRLGs in optical networks

The construction of light-trees is one of the fundamental problems for all-optical multicast routing due to large emerging applications such as grid computing, IPTV, and distributed games. In this paper, we study the reliable light-tree construction (RLC) problem with the objective of maximizing the reliability of the multicast communication in optical networks. We first describe the network model, reliable function, and multicast request. We then formulate the reliable light-tree construction problem and prove that RLC is NP-complete. We provide an algorithm, named Minimum SRLG Cover (MSC), to achieve optimal solution in exponential time. Since RLC is NP-complete, we provide two greedy algorithms, named Reliable Shortest Path Tree (RSPT) and Quickest SRLG Cover (QSC). Numerical results show that RSPT and QSC obtain good results in both large and small problems. Numerical results also demonstrate that RSPT achieves better performance than QSC when the number of destinations is small while QSC is better when the number of destinations is large.