Perfect difference sets for neighbor discovery: energy efficient and fair

Abstract

We present an energy efficient neighbor discovery framework that enables Linux and TinyOS based systems to discover and connect to neighbors via IEEE 802.11 and IEEE 802.15.4, which are only available sporadically. Using quorum schemes, we schedule on and off times of the wireless transmitters, to guarantee mutual discovery with minimum power given a specific latency requirement. Neighbor discovery is fundamental to intermittently connected networks, such as disruption and delay tolerant networks and optimizing it, can lead to significant overall energy savings. Using perfect difference sets, our results indicate that we reduce the latency by up to 10 times at a duty cycle of 2% compared to the state of the art. We further define and characterize our neighbor discovery scheme with respect to fairness for asymmetric energy scenarios. Using these results, we allow energy-harvesting applications to adjust neighbor discovery based on their current energy requirements as a well defined trade-off.