Development and field experiment of routing-free multi-hop wireless sensor networks for structural monitoring

To make wireless sensor networks practical tools for structural monitoring, there are two issues. The first is ensuring robustness of wireless communication. Multi-hop network technology is necessary to deploy sensors on a bridge because there are many obstacles on bridges, and the lengths of bridges are often longer than radio communication range. The second is reducing power consumption. Radio module and acceleration sensor are power hungry, so how to ensure battery life must be considered. The purpose of this paper is to solve these two issues while satisfying requirements of structural monitoring including time synchronization, 100% reliable transport, and high throughput. To this end, we are developing wireless structural monitoring system using Choco, which is a communication protocol which exploits concurrent transmission flooding (CTF). Our system can provide synchronization and robustness thanks to CTF. Furthermore, the system achieves low-power, 100% reliable, and high-throughput transport thanks to Choco's fine-grained scheduling. Through field deployment in an urban expressway, we show that applying CTF to structural monitoring is an effective approach.