Slotted Advance Reservation for Multicast-Incapable Optical Wavelength Division Multiplexing Networks

Abstract

In this paper we investigate techniques for provisioning advance reservation (AR) multicast requests in multicast-incapable (MI) networks, which lack the ability to split an incoming signal to multiple output ports, without performing an O-E-O conversion. AR traffic consists of connection requests that arrive and reserve network resources at some time before they need them to ensure better qualityof service than on-demand requests would receive. The traditional approach of providing multicast support in MI networks is to use an overlay approach in which a set of lightpaths is established from the source to each multicast destination member independently. This approach is wasteful of wavelength resources, particularly as the multicast destination set grows. We propose two alternative overlay approaches that take advantage of multiple-hop overlay-tree structures to limit the consumption of wavelengths in the network. We investigate static traffic scenarios on various network topologies and develop integer linear programs (ILPs) to optimally solve all three of the overlay-tree problems presented in this work with the goal of minimizing the total number of wavelengths required to service a multicast request set. We also present efficient heuristics that build and select overlay-trees that lower dynamic connection blocking and wavelength consumption. We compare the heuristics to the optimal ILPs on a small-scale network, and then further evaluate the heuristics on several large-scale topologies. In all scenarios, we are able to conclude that by sacrificing a minimization of O-E-O conversions, our more flexible overlay approaches, called drop at member node (MI-DMN) and dropatany node (MI-DAN), are superiorinterms of resource usage when compared with the traditional na��ve approach. Further dynamic traffic evaluations reveal that blocking may be lowered over the na��ve approach by more thantwoordersofmagnitudeatlowtomedium traffic loads.