Limited Wavelength Translation in All-Optical WDM Mesh Networks

We analyze limited wavelength translation in all-optical, wavelength division multiplexed (WDM) wraparound mesh networks, where upto W wavelengths, each of which can carry one circuit, are multiplexed onto a network link. All-optical wavelength translators with a limited translation range permit an incoming wavelength to be switched only to a small subset of the outgoing wavelengths. Although more restrictive than full wavelength translation (which permits an incoming wavelength to be switched to any outgoing wavelength), limited wavelength translation is a topic of recent study, since current practical wavelength translators are capable only of limited translation. We consider the case where an incoming wavelength can be switched to one of k (k = 2,3) outgoing wavelengths (called the feasible wavelength set), and we obtain the probability that a session arriving at a node at a random time successfully establishes a connection from its source node to its destination node. Our analysis captures the state of a feasible wavelength set at a network node, which allows us to obtain the probability of successfully establishing the circuit. Based on this probability y, we quantify the benefits of limited wavelength translation by demonstrating that in mesh networks, it can obtain most of the performance advantages of full translation at a fraction of the cost. Our work is the first to analyze limited wavelength translation for mesh networks under a probabilistic model, and accurately predicts the network performance over a wider range of network loads than previous works.