Experimental study of concurrent transmission in wireless sensor networks

Abstract

We undertake a systematic experimental study of the effects of concurrent packet transmissions in low-power wireless networks. Our measurements, conducted with Mica2 motes equipped with CC1000 radios, confirm that guaranteeing successful packet reception with high probability in the presence of concurrent transmissions requires that the signal-to-interference-plus-noise-ratio (SINR) exceed a critical threshold. However, we find a significant variation of about 6 dB in the threshold for groups of radios operating at different transmission powers. We find that it is harder to estimate the level of interference in the presence of multiple interferers. We also find that the measured SINR threshold generally increases with the number of interferers. Our study offers a better understanding of concurrent transmissions and suggests richer interference models and useful guidelines to improve the design and analysis of higher layer protocols.