A scalable logical topology for optical networks

Abstract

One of the approaches investigated for multihop lightwave networks is to consider regular graphs as the logical topology for a multihop network. Standard regular topologies are defined only for networks with the number of nodes satisfying some rigid criteria and are not directly usable for multihop networks. Only a few recent proposals (e.g., GEMNET) are regular and yet allow the number of nodes to have any arbitrary value. These networks have one major problem – node addition requires a major redefinition of the network. For example, in a multistar implementation, a large number of retuning of transmitters and receivers and/or renumbering nodes are needed for GEMNET. In this paper we present a new logical topology which has a low diameter but is not strictly regular. The interesting aspect of this topology is that it allows the network to be expanded incrementally involving a relatively small number of edge definitions/redefinitions. In this paper we have described our new topology and its properties. We have also implemented a routing scheme that ensures a low diameter and an algorithm for adding nodes to the network.