Stanford University Networking Seminar
Can we use WiFi to connect IoT devices without batteries? We present HitchHike, a low power backscatter system that can be deployed entirely using commodity WiFi infrastructure while consuming 30 uW of power. With HitchHike, a low power tag reflects existing WiFi signals from a commodity WiFi access point, and the backscattered signals can then be decoded as a standard WiFi packet by a commodity WiFi receiver. HitchHike's key capability is to enable such WiFi connectivity with a power consumption that is three orders of magnitude lower than current WiFi radios. Such low power consumption means that these new radios can be powered entirely by energy harvesting and would require no batteries or charging! This will enable a whole class of applications for IoT devices and enable us to embed sensors anywhere where there is WiFi and without having to worry about sensors running out of power. Along with the talk, we will show a video demo where HitchHike was used to transmit ECG sensor data with close-to-zero power consumption. Our experiments show that HitchHike can achieve an uplink throughput of up to 300Kbps at ranges of up to 34m.
Pengyu Zhang is a postdoc researcher at Stanford working with Prof Sachin Katti. His research focuses on mobile computing and low-power wireless sensing. He obtained his Ph.D. from UMass Amherst and his bachelor from Tsinghua University. He received the best paper award runner-up award at MobiCom 2014, the honor mention award at UbiComp 2016, and the 2016 outstanding doctoral dissertation award at UMass Amherst.