p-Cycle-based protection of multicast connections in metropolitan area optical networks with physical layer impairments constraints

This paper investigates the problem of protecting multicast sessions in optical networks utilizing a novel cycle-based heuristic algorithm called Q-based p-Cycles Heuristic (QBPCH), that is used for the decomposition of the graph network into a set of p-cycles, while taking into account the physical layer impairments (PLIs) via a Q-budgeting approach. In this technique the length of these cycles is constrained in order to limit the effect of the impairments on the protection paths. The proposed scheme exhibits improved performance in terms of blocking probability, when compared to another proposed heuristic, namely p-Cycles Heuristic (PCH), that aims at decomposing the graph network into a set of p-cycles that maximizes the number of straddling links in the network. Both proposed schemes are also compared to a traditional ring cover heuristic (RC) and to a Hamiltonian cycle (HC) approach and it is shown that QBPCH performs the best in terms of blocking probability when the PLIs are considered.