Optical multicast with differentiated leaf availability guaranteed in WDM networks

As multicast applications become more and more popular, implementing multicast in optical domain has attracted more and more attention due to its more efficient bandwidth usage. And also these services have Quality-of-Service (QoS) requirement. In this paper, the problem of cost-effective optical multicast provisioning to satisfy the differentiated leaf availability requirements is formally stated. A Mixed Integer Linear Program (MILP) formulation is proposed for provisioning dedicated light-tree protection with differentiated leaf availability guaranteed. The algorithm is so complex and infeasible that we also propose a feasible two-step approximate approach to solve the problem. Different from the previous schemes, our scheme finds out the primary light-trees and backup paths for multicast sessions destination nodes whose availability is not satisfied with the availability requirement. Because of taking the different leaf availability requirements into account, the proposed algorithm finds out more efficient feasible solution requiring less network resources.