Abstract-The construction of light-trees is one of the principal subproblems for all-optical multicast routing in sparse splitting wavelength division multiplexing (WDM) networks. Due to the light splitting constraint and the absence of wavelength converters, several light-trees may be required to establish a multicast session. However, the computation of the cost-optimal multicast light-trees is NP-hard. In this paper, first we study the cost bounds of the light-trees built for a multicast session in unweighted WDM networks. Then, partially based on this result, the approximation ratios of some classical multicast light-tree computation algorithms, i.e., the reroute-to-source (R2S) and member-only (MO) algorithms, are derived in both unweighted and non-equally-weighted WDM networks. Moreover, integer linear programming formulations are introduced and carried out to search the optimal light-trees for multicast routing. The cost bounds and approximation ratios of the R2S and MO algorithms in some candidate WDM backbone networks are examined through simulations.
Zhou et al. REF derived two approximate optimal multicast light-tree computation algorithms (the rerouteto-source algorithm and the member-only algorithm) for both unweighted and non-equally weighted WDM networks.
Cost Bounds and Approximation Ratios of Multicast Light-Trees in WDM Networks
IEEE/OSA Journal of Optical Communications and Networking
IEEE/OSA Journal of Optical Communications and Networking
Computer Science