Abstract-The Bluetooth discovery process requires use of the inquiry substate which not only consumes significant power, but prevents normal data traffic flow and simultaneously acts as a potential noise source for neighboring networks. Therefore, the inquiry substate dwell time should be limited to discovering an acceptable number of neighboring devices. Although an estimate of the probability density function of the time to discover scanning devices is straightforward, the complex temporal and spectral interactions between two devices make precise inquiry time characterization difficult. We characterize these interactions and derive detailed analytical expressions for the probability distribution of the inquiry time for a Bluetooth-enabled device that follows v1.1 of the Bluetooth specification and uses the default 11.25 ms inquiry scan window that opens every 1.28 s. Subsequently, we show a single inquirer will locate 99 percent of all scanning devices within transmission range in 5.12 seconds rather than the 10.24 s recommended in the specification. Using specification v1.2, we show that the inquiry time can be reduced to 3.84 seconds and 1.28 seconds using the standard and interlaced inquiry scan modes, respectively. Substantial inquiry time reduction results in reduced power requirements and increased throughput by increasing data traffic and reducing interference with neighboring piconets. Our results are validated via comparison with existing simulation models and measurement studies. The models used to derive the distribution also lend themselves to characterizing the discovery time with variations in the discovery process.Index Terms-Mobile computing, algorithm/protocol design and analysis, mobile communication systems (Bluetooth inquiry probability distribution).

No abstract

No abstract

The key to successfully establishing and maintaining a Bluetooth scatternet is the inquiry procedure which discovers Bluetooth devices within range. The inquiry procedure uses a subset of the hop frequencies used by a piconet. While nodes in a scatternet are in the inquiry substate, they can cause significant interference to the neighboring piconets. Nodes seeking to join a piconet cause significant interference to those neighboring piconets attempting normal communication in the connection mode as well. We develop an analytical model of this interference and extend the model to predict interference from any number of interfering nodes. We show that a single inquiring node is expected to disrupt 1.3% of the packets in a neighboring piconet with interference approaching 73% as the number of inquiring nodes increases.