4 research outputs found

    A Novel Solution to the Dynamic Routing and Wavelength Assignment Problem in Transparent Optical Networks

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    We present an evolutionary programming algorithm for solving the dynamic routing and wavelength assignment (DRWA) problem in optical wavelength-division multiplexing (WDM) networks under wavelength continuity constraint. We assume an ideal physical channel and therefore neglect the blocking of connection requests due to the physical impairments. The problem formulation includes suitable constraints that enable the algorithm to balance the load among the individuals and thus results in a lower blocking probability and lower mean execution time than the existing bio-inspired algorithms available in the literature for the DRWA problems. Three types of wavelength assignment techniques, such as First fit, Random, and Round Robin wavelength assignment techniques have been investigated here. The ability to guarantee both low blocking probability without any wavelength converters and small delay makes the improved algorithm very attractive for current optical switching networks.Comment: 12 Pages, IJCNC Journal 201

    Heuristic for the design of fault tolerant logical topology.

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    Wavelength division multiplexing (WDM) in optical fiber networks is widely viewed as the savior for its potential to satisfy the huge bandwidth requirement of network users. Optical cross connect (OCX) in WDM network facilitates the switching of signal on any wavelength from any input port to any output port. As a result, it is possible to establish ligthpaths between any pair of nodes. The set of lightpaths established over fiber links defines logical topology. In our thesis, we proposed a heuristic approach for the design of fault tolerant logical topology. Our design approach generalizes the design protection concept and enforces wavelength continuity constraint in a multi-hop optical network. In our work, we first designed logical topology for fault free state of the network. We, then, added additional lightpaths for each single link failure scenario. Numerical results clearly show that our approach outperforms Shared path protection and Dedicated path protection. Our simulation result shows that our approach is feasible for large networks. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .S24. Source: Masters Abstracts International, Volume: 44-03, page: 1413. Thesis (M.Sc.)--University of Windsor (Canada), 2005

    Interactive proof system variants and approximation algorithms for optical networks

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 111-121).by Ravi Sundaram.Ph.D
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