LAUSR

This paper presents a joint topology control and routing design of reconfigurable ring-tree (RRT) topology for Bluetooth non-uniform networks. The non-uniform network consists of one dense and many other sparse regions. In the dense area, the RRT builds a ringshaped topology as a backbone subnet in a distributive manner, which is expanded by a treeshaped topology to other more sparse areas. For various sizes of networks, the size of the ring subnet is controlled by the trade-off between the network performance and the construction cost. Because corresponding nodes in the ring subnet do not procure the global computation situations, obtaining the optimal ring size is an NP-complete problem. In seeking to finalise the optimum ring size, an empirical max-search strategy is provided to attain the preferred cost-performance ratio. The max-search strategy is a methodical decision policy, carried out by three working elements: the topology construction, the packet routing and the maximum decision elements. The topology construction element engenders the ring-tree topology, the packet routing element processes the routing performance with a uniform traffic model, and the maximum decision element utilises a decision-making criterion to discover the optimum ring size. Experimental values demonstrate that the optimum ring size can be resolved by the max-search scheme for various sizes of networks, and the RRT delivers a better throughput performance than that of the conventional BlueHRT and Bluetree networks.