Q-based provisioning for multicast connections in translucent metropolitan area networks

This paper investigates the problem of identifying the most efficient nodes in translucent metropolitan optical networks to be equipped with 3R regeneration for provisioning multicast calls while taking into account the physical layer impairments via the Q-factor metric and the tree topology of the multicast connections during the regeneration placement procedure. Two regeneration placement heuristics are proposed, namely the Q-based regenerator placement (QbRP) heuristic and the Q-based regenerator placement with path correlation (QbRPC) heuristic. Simulations are performed on a number of metropolitan area networks considering a static traffic model for both the proposed heuristics and for a known regeneration placement heuristic, namely the nodal degree first (NDF) algorithm. Results showed that both QbRP and QbRPC outperform NDF while QbRPC performs the best among the three. Furthermore, results showed that the same performance is achieved in a network where only a small percentage of nodes is equipped with regenerators compared to a network with regenerators at all network nodes.