RELIABLE DETECTION OF SIGNAL TONES IN PRESENCE OF COLLISIONS

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 collision-freedom and energy-efficiency. However, the basic assumption of these protocols, i.e. the possibility to reliably detect the presence/absence of signal tone in case of simultaneous transmissions from multiple nodes, has not yet been confirmed. In this paper we present a technique for signal tone generation/detection, which uses only standard features of off-the-shelf RF transmitters. Furthermore, we present results of an experimental validation carried out in a real testbed which demonstrate a high accuracy of signal tone detection in presence of multiple simultaneous transmissions