Wireless sensor networks (WSNs) are being used in various applications, such as structural health monitoring and industrial control. Since energy efficiency is one of the major design factors, the existing WSNs primarily rely on low-power, low-rate wireless technologies, such as 802.15.4 and Bluetooth. In this article, by proposing Sensifi, we strive to tackle the challenges of developing ultrahigh-rate WSNs based on the 802.11 (WiFi) standard. As an illustrative structural health monitoring application, we consider the spacecraft vibration test and identify system design requirements and challenges. Our main contributions are as follows. First, we propose packet encoding methods to reduce the overhead of assigning accurate timestamps to samples. Second, we propose energy-efficiency methods to enhance the system's lifetime. Third, to enhance sampling rate and mitigate sampling rate instability, we reduce the overhead of processing outgoing packets through the network stack. Fourth, we study and reduce the delay of processing time synchronization packets through the network stack. Fifth, we propose a low-power node design, particularly targeting vibration monitoring. Sixth, we use our node design to empirically evaluate energy efficiency, sampling rate, and data rate. We leave large-scale evaluations as future work.

WASP’s goal is to augment and eventually replace the bulky, costly, and complex data acquisition systems used for vibrational reliability tests on satellites. As a mechanism to guarantee that a spacecraft is mechanically durable and strong enough to withstand the acceleration forces experienced on the vessel during launch, companies conduct vibrational experiments on their spacecrafts by subjecting them to high G-force events. Using wired accelerometers connected to obstructive cables, the mounting process and test setups required to perform such experiments are expensive, laborious, and have the potential to generate measurement inaccuracies. We developed a low-cost, battery-powered module, designed for engineers, to replace the current sensors and data acquisition systems with a wireless solution. This will enable precise testing of conditions on a smaller time frame and at a lower cost and help eliminate the disadvantages of a wired system. A custom circuit board has been fabricated containing the critical measurement and processing components required to realize this objective, as well as a complete software solution to facilitate data transmission to a wireless router over WiFi.