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

We analyze limited-wavelength translation in regular all-optical, wavelengt h division multiplexed (WDM) networks, where up to W wavelengths, each of w hich can carry one circuit, are multiplexed onto a network link. All-optica l wavelength translators with a limited translation range permit an incomin g wavelength to be switched only to a small subset of the outgoing waveleng ths, We focus on the wraparound mesh and hypercube WDM networks, and analyz e the case where an incoming wavelength can be 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 a llows us to obtain the probability that a session arriving at a node at a r andom time successfully establishes a connection from its source node to it s destination node in each of these topologies. Based on this probability, we quantify the throughput and blocking performance of limited wavelength t ranslation, and compare it to that of no wavelength translation and full wa velength translation. We demonstrate that in regular networks it can obtain most of the performance advantages of full translation at a fraction of th e cost, and we present a simple, economical switch architecture to effect l imited wavelength translation at a cost that is effectively independent of the number of wavelengths W in the system.