Performance Analysis of Optical Burst Switched Networks

Abstract

In this dissertation, we studied the performance of Optical Burst Switching (OBS). OBS is a promising new solution for the next-generation optical Internet.

In the first part of the dissertation, we studied a novel WDM ring network with OBS. The ring consists of N nodes, and each node owns a home wavelength on which it transmits its bursts. The ring operates under the fixed transmitter tunable receiver (FTTR) scheme. Control information is transmitted on a separate control channel. We proposed five different burst switching access protocols. We also studied the performance of these access protocols in terms of throughput, packet delay, throughput fairness, and delay fairness under different network parameters: average packet arrival rate, maximum burst size, and minimum burst size. Finally, we proposed a new offset calculation method, which can significantly simplify the access protocol design, and reduce the packet delay for all access protocols.

In the second part of the dissertation, we analyzed an edge node of a WDM OBS mesh network using a new burst arrival process, which is more realistic than the well-known Poisson process. The edge node is modeled as a closed non-product-form queueing network, consisting of special nodes with orbiting customers. Despite the rich literature in queueing network analysis, this particular queueing network with orbiting customers has not been analyzed before. We developed algorithms for both the single-class and multi-class queueing networks. The single-class queueing network is solved using Marie's method. In the case of no converters, we obtained a closed-form expression of the conditional throughput of the special node with orbiting customers. The multi-class queueing network is analyzed by decomposition. Specifically, a multiple-class queueing network is decomposed into a set of two-class queueing networks, and each of them is then solved by Neuse and Chandy's Heuristic Aggregation Method. We also developed a much faster approximation algorithm for the analysis of an edge OBS node with a large number of wavelengths. Comparisons against simulation data suggest that our algorithms have a good accuracy.