Traffic Prioritization in Sensor Networks using Bandwidth Scavenging

Abstract

This chapter presents a history-based statistical channel access mechanism for enabling traffic prioritization in wireless sensor networks. Prioritized access is realized such that low priority non-real-time sensors can access channel bandwidth that is unused by high priority real-time traffic. The key idea is for the low priority sensor nodes to first observe and statistically model the channel usage pattern by the high priority traffic, then make advantageous probabilistic transmissions so that the non-priority traffic throughput is maximized while protecting the high-priority traffic from disruptions. The chapter details a practical whitespace measurement scheme and presents a channel history based prioritization protocol. The access mechanism is implemented in a TelosB mote-based sensor testbed in which the non-priority motes continually measure the RSSI to infer the channel usage pattern and probabilistically access the channel while different types of traffic are sent by high-priority TelosB motes.