Heuristic algorithms for multicast traffic grooming in WDM mesh networks

Multicast traffic grooming is used to multiplex or groom multiple low bandwidth multicast connections into a high bandwidth wavelength channel or light-tree to increase the utilization of wavelength. However, multicast traffic grooming is NP-hard problem. Thus, we propose two heuristic algorithms with polynomial complexities, called Adjacent Node Component based Grooming for Throughput (ANCG-T) and Dividable Light-Tree Grooming (DLTG) algorithm, to achieve scalable design for realistic networks in realistic networks. ANCG-T algorithm is to divide light-tree into sub-light-trees which are within two optical hops, to increase sharing of resources. DLTG algorithm is based on grooming traffic to light-trees and also on dividing a light-tree to sub-light-trees and then grooming traffic to these sub-light-trees to improve resource utilization. Simulations show that both the algorithms have throughput performances which are very close to optimal results, and that the DLTG algorithm can achieve better network throughput than the ANCG-T algorithm.