Time based resource-consumption-aware spectrum assignment for multicast traffic in elastic optical networks

Given the importance of multicast traffic in current optical networks, many effective multicast routing and spectrum assignment (MRSA) algorithms have been proposed to achieve efficient multicast transmission in elastic optical networks (EONs). However, most of these MRSA algorithms were focus on optimizing only the spectrum resources allocated to multicast service requests, but ignored some fragmented spectrum resources remained after spectrum allocation. Although some fragment-aware MRSA algorithms were proposed for EONs to restrain the fragmented spectrum generated in provisioning multicast transmission, they could hardly precisely compute the amount of the fragmented resources while optimizing the allocated resources for the multicast transmission in EONs. This is because that the fragmented and the allocated spectrum resources always have different duration characteristics. In this paper, we propose a time-based composite-consumption-aware (TCCA) MRSA algorithm to optimize both the fragmented and the allocated resources consumed by the multicast transmission in EONs. By additionally taking the holding time of each multicast service request into account, the proposed algorithm can comprehensively optimize both the fragmented and the allocated resource consumption for the multicast transmission in EONs. Since the comprehensive resource consumption, including both the fragmented and the allocated resource consumption, is optimized by the proposed TCCA algorithm, more available resources can be remained for the subsequent multicast requests, which can increase the request blocking performance in EONs. Simulation results verify that the proposed algorithm can reduce the comprehensive resource consumption for the multicast transmission in EONs with low request blocking probability.