Characterization of asymmetry in low-power wireless links: An empirical study

Abstract

Experimental studies in wireless sensor network (WSN) have shown that asymmetry in low-power wireless links have a significant effect on the performance of WSN protocols. Protocols, which work in simulation studies often fail when link asymmetry is encountered in real deployments. Therefore, characterization of link asymmetry is of importance for the design and operation of resilient WSN protocols in real scenarios. This paper details an empirical study to characterize link asymmetry in WSNs. It presents a systematic approach to measure the effects of hardware performance and environmental factors on link asymmetry using off-the-shelf WSN devices. It shows that, for the given hardware platform, transmitter power and receiver sensitivity are the major factors responsible for asymmetry in low-power wireless links, while frequency misalignment in the transmitter and power variations in the antenna are unlikely causes for it. © 2011 Springer-Verlag Berlin Heidelberg.