Towards feasible topology formation algorithms for Bluetooth-based WPAN's

In this paper, we tackle the problem of topology formation in Bluetooth wireless personal area networks (BT-WPANs). We first overview and extend a previously proposed centralized optimization approach, and discuss its results. Then we outline the main steps of two procedures that can lead to feasible distributed algorithms for the incremental construction of the topology of a BT-WPAN. The centralized optimization approach has the advantage of producing topologies that minimize the traffic load, of the most congested, node in the network (thus also minimizing energy consumption) while meeting the constraints on the BT-WPAN structure and capacity. However, the centralized nature and the high complexity of the optimization are a strong limitation of the proposed approach. Distributed algorithms for the topology formation of BT-WPANs are much more attractive, provided their algorithmic complexity and energy cost are sufficiently low to allow implementation in large BT-WPANs. We discuss distributed procedures for the insertion and the removal of a node in/from a BT-WPAN, which are easily implementable and able to compromise between the system efficiency and its ability to promptly recover from topology changes. These procedures are the key building blocks for a distributed solution approach to the BT-WPAN topology formation problem.