Hop Count Based Optimization of Bluetooth Scatternets

In the past five years Bluetooth scatternets were one of the most promising wireless networking technologies for ad hoc networking. In such networks, mobility together with the fact that wireless network nodes may change their communication peers in time, generate permanently changing traffic flows. Thus, forming an optimal scatternet for a given traffic pattern may be not enough, rather a scatternet that best supports traffic flows as they vary in time is required. In this paper we study the optimization of scatternets through the reduction of communication path lengths. After demonstrating analytically that there is a strong relationship between the communication path length on one hand and throughput and power consumption on the other hand, we propose a novel heuristic algorithm suite capable of dynamically adapting the network topology to the existing traffic connections between the scatternet nodes. The periodic adaptation of the scatternet topology to the traffic connections enables the routing algorithms to identify shorter paths between communicating network nodes, thus allowing for more efficient communications. We evaluate our approach through simulations, in the presence of dynamic traffic flows and mobility.