Cost-Efficient Fiber Connection Topology Design for Metropolitan Area WDM Networks

In this paper, we provide some analytical insights into physical architectures that can serve as benchmarks for designing a cost-efficient WDM metropolitan area network (MAN). For uniform all-to-all traffic and regular topologies with nodal symmetry, we identify a class of regular graphs-Generalized Moore Graphs-that have several attractive properties by formulating a first-order cost model and characterizing the tradeoff between fiber and switching resources. Our results show that, in conjunction with minimum hop routing, Moore Graphs achieve the minimum cost and simultaneously use the least number of wavelengths. We also take steps to broaden the scope of our work by addressing irregular network topologies, which represent most existing networks. Our results show that Generalized Moore Graphs can be used to provide useful estimates of the cost of irregular networks and can serve as good reference architectures for the designs of practical networks.