Optical network design to minimize switching and transceiver equipment costs

We consider a network consisting of NN nodes and a certain number of links MM that could be used to interconnect these nodes. The problem we address is to determine the smallest subset of switching nodes (in which to provide optical or electronic switching capability) necessary and sufficient to provide full end-to-end connectivity among all nodes. It is shown that this selection leads to the minimum number of transceivers needed to achieve full connectivity. We then address the same problem with the additional requirement of survivability, whereby the failure of any one link does not lead to any disconnection in the network. To solve the above stated problems, we employ heuristic and optimal algorithms; we find that the minimum number of switching sites is well estimated as a function of a single parameter, the network connectivity α=2MN(N−1). (This is an extended version of the paper presented at Broadnets 2006.)