tailieunhanh - Báo cáo " GA-based dynamic survivable routing in WDM optical networks with shared backup paths "

This paper considers the problem of dynamic survivable routing in WDM networks with single link failure model. This work mainly concerns in how to dynamically determine a protection cycle (., two link-disjoint paths between a node pair) to establish a dependable lightpath with backup paths sharing. The problem is identified as NP-complete, thus a heuristic for finding near optimal solution with reasonable computation time is usually preferred. | VNU Journal of Science Mathematics - Physics 23 2007 122-130 GA-based dynamic survivable routing in WDM optical networks with shared backup paths Vinh Trong Le Department of Mathematics Mechanics and Informatics College of Science VNU 334 Nguyen Trai Thanh Xuan Hanoi Vietnam Received 15 November 2006 received in revised form 2 August 2007 Abstract. This paper considers the problem of dynamic survivable routing in WDM networks with single link failure model. This work mainly concerns in how to dynamically determine a protection cycle . two link-disjoint paths between a node pair to establish a dependable lightpath with backup paths sharing. The problem is identified as NP-complete thus a heuristic for finding near optimal solution with reasonable computation time is usually preferred. Inspired from the principle of genetic algorithms GA a GA-based survivable routing algorithm for the problem with a new fitness function which allows us to improve blocking performance will be proposed. Extensive simulation results upon the ns-2 network simulator and two typical network topologies show that our algorithm can achieve a significantly lower blocking probability than conventional algorithms. 1. Introduction The optical networks using wavelength division multiplexing WDM could provide huge bandwidth capacity for next-generation Internet. These networks are promising candidate to meet the bandwidth demands from various emerging multimedia applications such that web applications video on demand multimedia conference image access and distribution home broadband services etc. 1 B C A OCX OCX X Ă2 A d E Fig. 1. Architecture of a wavelength-routed network. An all-optical WDM network consists of optical cross-connects OXCs interconnected by fiber links in which an OXC can switch an optical signal from an input to an output link without Tel. 84-4-8581135 E-mail vinhlt@ 122 Vinh Trong Le VNU Journal of Science Mathematics - Physics 23 2007 122-130 123 performing .