TOPOLOGICAL DESIGN OF RING NETWORKS

In this paper the shortcomings of conventional ring networks are discussed and how these shortcominings are solved by the enhanced ring architecture is explained. Enhanced ring architecture is a two level ring network connecting the local rings by a backbone ring. Studied is the ring network design problem-the formation of local loops with a size restriction connected to a backbone ring. The Parallel Savings Algorithm which generates good feasible solutions is presented. The K Iterated Travelling Salesman Tours Partitioning is studied and analyzed for its worst case error. This algorithm is based on partitioning a multi-center travelling salesman tour in order to generate a feasible solution to the ring network design problem. It has a worst case error bound of 4 - 3/2K where K is the size of the local rings when K greater-than-or-equal-to 3. The heuristic solution cost is at most 4 - 3/2K times the optimum value. It is based on the Christofides' extended heuristic for the multi-center travelling salesman problem which makes the procedure a polynomial one.