An Adaptive Interpiconet Scheduling Algorithm Based on HOLD Mode in Bluetooth Scatternets

To efficiently relay packets between associated piconets in an arbitrary-sized scatternet, an adaptive interpiconet scheduling algorithm is a requisite in a bridge. In this paper, we proposed a new interpiconet scheduling algorithm based on the HOLD mode - a power-saving mode of Bluetooth - to reduce the average interpiconet packet delay while increasing the utilization of a bridge. Generally speaking, interpiconet packet delay mainly results from the phenomenon that a bridge stays in one piconet without any interpiconet transmission activity in progress while other associated piconets are waiting for the bridge to deal with interpiconet packets. Thus, our proposed scheme estimates the time duration for which the bridge should stay in each piconet according to the traffic pattern so that the bridge can avoid being idle as possible. In particular, neither Bluetooth specification modifications nor any extra devices are needed to integrate our proposed interpiconet scheduling algorithm. Finally, the simulation results show the superiority of our proposed scheme, including low average delay, high throughput, and remarkable scalability.