A dynamic slot assignment scheme for slave-to-slave and multicast-like communication in Bluetooth personal area networks

Bluetooth is a radio technology for wireless personal area networking (WPAN) operating in the 2.4 GHz ISM frequency band. The Bluetooth MAC protocol is based on the master/slave concept wherein any communication between slave devices has to go through the master. While this model provides for simplicity, it incurs longer delay between any two slave devices due to far from optimal packet forwarding, the use of double the bandwidth, and also it wastes additional energy 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, clearly resulting in inefficiency. We propose a novel dynamic slot assignment (DSA) scheme whereby the master device dynamically assigns slots to slaves so as to allow them to communicate directly with each other without master intervention. This proposed mechanism also provides for quality of service (QoS) requests, and multi-device conversation by which a multicast-like communication is implemented within a piconet. Through extensive simulation, we observe that this mechanism greatly enhances Bluetooth performance in terms of delay and throughput while incurring extremely low overhead.