Reliable Detection of Signal Tones in Presence of Collisions

Abstract

A reliable and energy-efficient contention resolution mechanism (CRM) is a crucial component of MAC protocols for wireless sensor networks (WSNs). Among a number of CRM proposals, CRMs based on exchanging short signal tones between competing nodes have recently drawn attention due to their promise of collisionfreedom and energy-efficiency. However, the basic assumption of these protocols, i.e. the possibility to reliably detect the presence/absence of a signal tone in case of simultaneous transmissions from multiple nodes, has not yet been confirmed. In this paper a technique for signal tone generation/detection is presented, which uses only standard features of off-the-shelf RF transmitters. Furthermore, the results of an experimental validation carried out in a real testbed are presented which demonstrates a high accuracy of signal tone detection in the presence of multiple simultaneous transmissions.