Design and implementation of QoS-driven dynamic slot assignment and piconet partitioning algorithms over Bluetooth WPANs

Bluetooth is a promising wireless technology aiming at supporting electronic devices to be instantly interconnected into short-range ad hoc networks. The Bluetooth medium access control protocol is based on the master/slave concept wherein any communication between slave devices has to go through the master. While this model is simple, it incurs longer delay between any two slave devices due to the use of non-optimal packet forwarding scheme and the use of double the bandwidth at the master. Moreover, if more than two devices want to communicate as a group, this can only be achieved by either multiple unicast transmissions or a piconet-wide broadcast from the master. To handle these issues efficiently, we propose a novel combination of dynamic slot assignment (DSA) and piconet partitioning. With DSA, the piconet master dynamically assigns slots to slaves so as to allow them to communicate directly with each other without any intervention from the master. Such proposed communication architecture provides for quality of service (QoS) requests, admission control, and multi-device conversation by which a multicast-like communication is feasible within a piconet. To widen the scope of DSA, we propose QoS-driven enhanced DSA (EDSA) where dynamic piconet partitioning and scatternet support comes into picture. Devices are grouped in piconets according to their connection endpoints in EDSA, enabling it to be employed over a scatternet. We have performed extensive simulations and observe that these schemes drastically enhance Bluetooth performance in terms of delay and throughput, while significantly reducing network power consumption.