Constrained wavelength assignment for multicast in WDM networks

The next generation multimedia applications such as video conferencing and HDTV have raised tremendous challenges on the network design, both in bandwidth and service. As wavelength division multiplexing (WDM) networks have emerged as a promising candidate for future networks with large bandwidth, supporting efficient multicast in WDM networks becomes eminent. Different from the IP layer, the cost of multicast at the WDM layer involves not only bandwidth (wavelength) cost but also wavelength conversion cost. In this paper, we study the multicast problem in WDM networks supporting wavelength conversion. In particular, we address the problem of minimizing cost of wavelength conversion in a multicast tree with upper bound on the number of conversions from source to destinations. An efficient optimal wavelength assignment algorithm is presented.