Multicast traffic grooming in WDM optical mesh networks

We consider the grooming of multicast traffic in WDM optical mesh networks with sparse nodal light splitting capability. Given multicast routing trees for individual multicast sessions, the multicast traffic grooming problem is NP-hard. Moreover, constructing an optimal multicast routing tree in WDM optical mesh networks is also an NP-hard problem. We formulate the problem of multicast traffic grooming in WDM optical mesh networks as an integer linear program. We propose a heuristic algorithm for constructing multicast routing trees and a first-fit algorithm for traffic grooming, assuming wavelength conversion capability in the network nodes. By intelligently grooming several multicast sessions with fractional wavelength bandwidth requirements onto a single wavelength, we demonstrate that our algorithms achieve a significant reduction in the maximum number of wavelengths required in a link as well as in the total number of wavelength links needed.