| Summary: | 碩士 === 國立中正大學 === 資訊工程研究所 === 92 === In WDM-based network, a single ‾ber failure may lead to multiple logical lightpaths failures.For this reason, even biconnected logical topologies routed on a WDM physical topology
may become disconnected after a single physical link failure. In this thesis, we proposea survivable and efficient routing approach, which is ear-decomposition based, to design protected routing of the logical topology that will withstand a physical link failure. Our approach bases on the technique of ear decomposition to divide the logical topology into several ears, and restricts the lightpaths of the same ear are routed by using disjoint physical links. This work is NP-complete and so we formulate it as an ILP problem based on the results of ear decomposition. Moreover, we also prove this strategy is not only feasible but also correct.Finally, we use the ILP formulation, shortest path routing algorithm and least weight routing algorithm to route various logical topologies over the physical network and compare our results with the corresponding solutions of disjoint-cycle based approach, a developed policy before. Simulations show that our approach achieves a high-performance in terms of the survivable routing and still possesses a satis‾ed performance for the balance of traffic loads.
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