WDM metropolitan area network based on CSMA/CA packet switching

The bursty nature of traffic in metropolitan area networks results in under utilized and inefficient SONET networks. The hybrid optoelectronic ring net work (HORNET) is a network being developed at the Optical Communications Re search Laboratory at Stanford University to address the problems of SONET t ransport in metropolitan area networks (MAN's). HORNET performs packet swit ching using a fast-tunable wavelength transmitter, which hops to different wavelengths on a packet-by-packet basis. In this letter, we present simulat ion results which quantify the benefits of a wavelength tunable transmitter in a packet switched wavelength-division-multiplexed MAN. We show that a t unable transmitter is able to take advantage of imbalances in wavelength ut ilization, and provides a 45% improvement in packet latency characteristics . We also show that in order to maintain these benefits the tuning time of the transmitter cannot exceed 10% of the packet transmit time.