An analysis of limited wavelength translation in regular all-optical WDM networks

We analyze limited-wavelength translation in regular all-optical, wavelength division multiplexed (WDM) networks, where up to W wavelengths, each of which ran 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. We focus on the wraparound mesh and hypercube WDM networks, and analyze the case where an incoming wavelength can he switched to one of k (k=2, 3) outgoing wavelengths (called the feasible wavelength set). Our analysis captures the state of a feasible wavelength set at a network node, which allows us to 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 in each of these topologies. Based on this probability, we quantify the throughput and blocking performance of limited wavelength translation, and compare it to that of no wavelength translation and full wavelength translation. We demonstrate that in regular networks it can obtain most of the performance advantages of full translation at a fraction of the cost, and we present a simple, economical switch architecture to effect limited wavelength translation at a cost that is effectively independent of the number of wavelengths W in the system.