Low Power Wireless Protocols and Platforms for Internet of Things

Thesis (Ph.D.)--University of Washington, 2020Internet of Things (IoT) is an exciting area of research where our goal is to embed connectivity into billions of everyday objects. There are two key problems to reach this goal. First, existing wireless communication technologies fail to fulfill the IoT connectivity requirements -- low power, long range, low cost and supporting large number of end points. Backscatter communication is low power and low cost however it is known to have a limited range. Active radio systems are able to support long ranges but are power consuming and cost several dollars. Second, the research community is severely constrained by the lack of a flexible, easily deployable platform for prototyping IoT endpoints that would allow for ground up protocol development and investigation of how such protocols perform at scale. In this dissertation, we present wireless communication protocols and platforms that address these challenges. We design and build three wireless solutions. We first build LoRa Backscatter, the first wireless system that provides reliable and long-range communication at tens of microwatts of power as well as cost less than a dime. Next, we build NetScatter, the first wireless protocol that scales to hundreds of concurrent transmissions from backscatter devices while being ultra-low power, low cost and supporting long range. Finally, we build TinySDR, the first SDR platform tailored for IoT applications which is fully programmable and standalone, consumes ultra-low power during sleep and supports over the air programming for both physical and MAC layer