The protection of optical mesh networks to survive the tremendous amount of network traffic is one of the most critical parts of such networks. The important aspects of the protection schemes are minimum redundancy as well as low response time. The existing shared backs up path protection schemes impose more that 30% redundancy. However such methods suffer from long response times. Moreover, there are protection schemes for mesh topologies which are based on the division of the networks into rings. Such schemes require 50ms switching time; however they had the disadvantage of high redundancy requirement. The so called p- cycle method resolved the high redundancy requirement of ring-based protection methods. it requires optimum cycles with appropriate capacities assignment. Consequently, a linear programming procedure has to be used to find the optimum cycles which leads to a Nondeterministic Polynomial time (NP) problem for a dense network. A heuristic algorithm has been suggested that attempts to find the near optimum cycles. The computational time of such a method increases as the number of the wavelengths increases. In this thesis a heuristic algorithm is proposed in which the computation time is independent of the number of the wavelengths. Furthermore, the proposed algorithm has less computational time than the proceeding heuristic algorithm. Simulation results for two different network topologies, confirm the advantage of the proposed algorithm.
