Date Added: Nov 2009
Wireless sensor networks are an emerging technology suitable for Cyber-Physical Systems. However, the wireless links are vulnerable to other interference from various sources. In this paper, the authors present an empirical study on wireless links of WSN in ten apartments. Their empirical study leads to several important insights for developing robust sensor networks in real-life environments: first, automatic repeat request is not sufficient due to the consecutive packet loss. Second, static channel configuration is not sufficient since there is no common persistently good channel. Third, Dynamic channel hopping on a per-link basis can achieve a high reliability. Based on these insights, they propose a simple and yet effective channel hopping protocol that can handle the dynamics of channel conditions in real-life environment.