Shared-segment protection is a promising protection scheme in wavelength-division multiplexing optical networks. In segment protection, there exist multiple strategies to partition a given working path, and different strategies lead to different network performance. According to the strategy used to partition a working path, we classify segment protection into predetermined partitioning, postdetermined partitioning, and integrated partitioning. We show that integrated partitioning combines the advantages of the other two strategies. In addition, we propose a new heuristic using an integrated partitioning strategy, called an auxiliary-graph-based segment protection (AGBSP) algorithm. Based on an auxiliary graph, AGBSP dynamically selects an optimal set of backup segments from all predetermined possible backup segments for a given working path. We compare AGBSP with shared-path protection and other efficient segment protection algorithms proposed in the literature. The results show that AGBSP achieves the best performance in terms of blocking probability and resource overbuild ratio, and it has a short recovery time.
© 2005 Optical Society of AmericaPDF Article