A heuristic algorithm for shared segment protection in mesh WDM networks with limited backup path/segments length

This paper investigates the problem of dynamic survivable lightpath provisioning against single-link failure in optical mesh networks employingwavelength-divisionmultiplexing (WDM).We focus on the special problem of provisioning lightpath requests according to their differentiated protection-switching time, since lightpath may have different protection-switching time requirements. We assume that the protection-switching time requirements of connections can be transformed to the hop limits of backup path/segments by using techniques proposed in the literature such as [Y. Luo, N. Ansari, Survivable GMPLS networks withQoS guarantees, IEE Proc. Commun., vol. 152, (4) (2005) 427–431]. We propose a heuristic algorithm, namely Suurballe-based Heuristic Algorithm using Least number of segments for SSP with hop Limit (SHALL), to efficiently solve this problem.We inspect the effects of hop limit on various performancematrices and compare the SHALL approach with three other well-known protection approaches, namely shared path protection (SPP), shared link based protection (LBP) and cascaded diverse routing (CDR). Numerical results demonstrate that the SHALL approach outperforms its counterparts in blocking probability and protection-switching time with mirror decrease of spare capacity efficiency. 2006 Elsevier B.V. All rights reserved.