Passive wi-fi and interscatter

The ubiquity of Wi-Fi has been a boon to pervasive connectivity of devices; We have Wi-Fi in our homes, schools, offices, and even factories. However, Wi-Fi has long been underutilized in the IoT space in favor of other wireless protocols such as Zigbee or BLE. This results in less than optimal deployment solutions that do not fully take advantage of the enormous existing installation base of Wi-Fi. One of the main reasons for the lack of use of Wi-Fi in IoT is the incredible power consumtion of Wi-Fi radios. While transmitting, a Wi-Fi radio can consume 100s of mW of power, much too much for a simple batter limited IoT device. With Passive Wi-Fi we show how Wi-Fi connectivity can be achieved for 10,000x lower power than traditional Wi-Fi and 1,000x lower power than BLE or Zigbee by synthesizing Wi-Fi packets using only reflections. This opens up the possibility of using Wi-Fi everywhere, even on the most power constrained of IoT devices. Additionally, with Interscatter we demonstrate how to use reflections to transform BLE transmissions into Wi-Fi packets. This can allow phones, smartwatches, or other BLE devices to interrogate low power backscatter devices with no hardware modifications, and brings backscatter into the personal area network space. These technologies have the potential to make backscatter a first class citizen in IoT wireless communication by allowing them to communicate with existing ecosystems and current consumer devices.