  We introduce inter-technology backscatter, a novel approach that transforms
wireless transmissions from one technology to another, on the air.
Specifically, we show for the first time that Bluetooth transmissions can be
used to create Wi-Fi and ZigBee-compatible signals using backscatter
communication. Since Bluetooth, Wi-Fi and ZigBee radios are widely available,
this approach enables a backscatter design that works using only commodity
devices.
  We build prototype backscatter hardware using an FPGA and experiment with
various Wi-Fi, Bluetooth and ZigBee devices. Our experiments show we can create
2-11 Mbps Wi-Fi standards-compliant signals by backscattering Bluetooth
transmissions. To show the generality of our approach, we also demonstrate
generation of standards-complaint ZigBee signals by backscattering Bluetooth
transmissions. Finally, we build proof-of-concepts for previously infeasible
applications including the first contact lens form-factor antenna prototype and
an implantable neural recording interface that communicate directly with
commodity devices such as smartphones and watches, thus enabling the vision of
Internet connected implanted devices.
