Energy-Efficient Operation of Bluetooth Networks using Park Mode

The Bluetooth technology is mainly implemented in battery-powered devices, such that the low power design has been considered into several aspects of the Bluetooth protocol stack. In particular, the Bluetooth Specification has introduced several latency modes: Park, Sniff and Hold. In each latency mode, a Bluetooth device can go to a low-power (sleeping) mode and thereby save the battery energy. The parameters of these latency modes have been listed in the Bluetooth specification, but the actual algorithms to employ the latency modes within an operating Bluetooth network have been left open for the implementation. The Park mode is flexible enough to support building of scalable Bluetooth networks. Our initial application of the Park mode considers the case of single-hop network with up to 8 devices, such that the devices can be interconnected in a single piconet. However, the conventional piconet exhibits unfairness? a master device consumes much more energy than a slave device. We use the Park mode to remove this unfairness and to ensure longer lifetime of the Bluetooth network when all devices have equal capabilities related to energy. In the next phase, this project will address the proposal of flexible scatternet structures based on Park mode, which are expected to yield better communication performance and energy efficiency for a bursty traffic scenarios. (Petar Popovski, Gerben Kuijpers, Hiroyuki Yomo, Tatiana K. Madsen)