Abstract : We provide models for evaluating the performance, cost and power consumption of different architectures suitable for a metropolitan area network (MAN). We then apply these models to compare today's SONET/SDH metro rings with different alternatives envisaged for next-generation MAN: an Ethernet-carrier grade ring, an optical hub-based architecture and an optical time-slotted WDM ring. Our results indicate that the optical architectures are likely to decrease power consumption by up to 75 %, when compared to present day MANs. Moreover, by allowing the capacity of each wavelength to be dynamically shared among all nodes, a transparent slotted WDM yields throughput performance which is practically equivalent to that of today's electronic architectures, for equal capacity.
