ON THE FAULT-TOLERANCE AND SIZE OF WDM OPTICAL NETWORKS

In optical networks the approach called wavelength division multiplexing allows multiple data streams to be transmitted concurrently along a single optical link, with different streams assigned separate wavelengths. In this paper we refer to all-optical networks, in which each connection is totally optical except at the terminal nodes. For these networks we determine the minimum possible number of links required to perform a fault tolerant broadcast from any node, in terms of the number of nodes, the number of link failures to tolerate and the number of wavelengths to use. We also give lower and upper bounds on the number of wavelengths required for any broadcast which tolerates a given number of link failures on networks with arbitrary topologies.