Routing, Wavelength Assignment, Dimensioning and Performance of Optical Networks with Multicast Service

Iowa State University, Ames IA

Investigators

Abstract

Optical communication networks employing wavelength division multiplexing can support several communication sessions using a limited number of wavelength channels. The employment ofwave- length reuse in different parts of the network contributes to the increase in the number of sessions that can be supported. As such, these networks can provide a means to serve those applica- tions which individually or collectively require large amounts of bandwidth. An important class of services with such property is the class of multicast, or multipoint traffic, which requires the delivery of data from the source to a group of destinations. Although a few studies have addressed packet-switched multicast services in broadcast-and-select optical networks, the topics of routing, wavelength assignment, dimensioning, and performance of circuit-switched multicast services in wavelength routing optical networks have received little attention. This project deals with multicast services in optical networks, with and without wavelength converters. Such applications can be served using wavelength routing networks. The project has several objectives. First, we would like to develop multicast tree construction algorithms for optical networks which take into account the optical network constraints into account, such as thepower budget, wavelength collisions and wavelength continuity, aswell as the cost and type of splitters and wavelength converters. Optimal network provisioning and dimensioning under multicast service, given the traffic demands and cost constraints, is another objective. We also plan to investigate the possibility of formulating a joint problem for the optimal provisioning, and the optimal wavelength converter and splitter placement. It is also planned that routing, and wavelength selection algo- rithms will be developed for multicast services in optical networks. It is also planned to study the effect of these algorithms on the dimensioning and performance of the network. All this requires construction of accurate analytical models for the evaluation of call blocking probabilities under different routing and wavelength selection algorithms. As the efficient support of multicast traffic requires the branching of the traffic at several points in the network, these models are expected to be very involved, especially that several standard independence assumptions cannot be used in this case. In addition to general performance models, bounds on performance will be established, which will provide a guide to the provisioning and dimensioning of networks for multicast service. Such bounds will be established through the identification of extreme network topologies which serve to provide these bounds. The results of this work are expected to advance the understanding of the behavior of optical networks under futuristic, yet more involved, traffic conditions. At the same time, these results will contribute to the design and dimensioning of such networks.