I. Introduction
Wavelength division multiplexing (WDM) is emerging as a promising technology for the next generation of high-speed communication networks. It eases the speed mismatch between optics and electronics by partitioning the enormous optical bandwidth into multiple channels at the data rate of the electronics interface. The nodes in such a network can transmit and receive the packets on any of the available channels using one or more tunable transmitters and/or tunable receivers. Several system structures have been proposed as in [1] and [2]. A typical and simple topology is the one with a single-hop topology, which directly connects the network nodes to a passive star coupler [1].