Analytical Modeling of WDMMedia Access Protocols

Abstract – This paper introduces a mathematical model for the analysis of media access protocols for star-coupled wavelength division multiplexed (WDM) photonic networks. The proposed technique provides accurate performance prediction while also preserving model flexibility. General traffic generation and resource holding time distributions are supported with this semi-markov based approach. The model is independent of the system size and is linearly scalable to any arbitrary queue capacity. The analytic technique is introduced through the study of two pre-allocation protocols designed for WDM star-coupled photonic networks. The protocols consideredin this paper have been proposedfor networks with WDM channels pre-allocated to the nodes in the network. The pre-allocation approach reduces the resulting system complexity since both tunable transmitters and receivers are not required, and also has the advantage of being applicable to systems where there are many more nodes than wavelength channels. Both protocols are designed to operate in a multiple-channel multiple-access environment and require each node to possess a tunable transmitter and a fixed (or slow tunable) receiver. The developed models are validated through discrete-event simulation. The performance of the two protocols is studied in terms of average packet delay and network throughput for variations in the system parameters.