Burst Loss Probabilities in an OBS Network with Dynamic Simultaneous Link Possession

In an Optical Burst Switched (OBS) network, depending on the maximum burst size, the minimum link lengths and the data rate, bursts may span two, three and even more links simultaneously as they travel from their source to their destination. Bursts dynamically move from occupying one set of links to the next by releasing a wavelength on one link and occupying a wavelength on the next link along their route. This behavior greatly differs from the widely studied packet-switched and circuit-switched networks and thus it requires the development of new performance models. In this chapter, we consider bursts, which are assumed to be long enough to occupy wavelengths on two successive links simultaneously but our analysis can be extended for bursts that hold any number of links. The burst arrival process is modeled by a two-state Markov process, called IDLE/ON, which accurately captures the burst transmission at the edge of the OBS network. We present a new queueing model which captures the dynamic simultaneous link possession and allows us to evaluate the burst loss probabilities of a path in an OBS network. Decomposition and state-dependent arrivals are used in order to analyze the queueing network. The approximate results were verified by simulation for a variety of input parameters and the approximation algorithm was found to have a good accuracy.