“HitchHike is the first self-sufficient WiFi system that enables data transmission using just micro-watts of energy – almost zero,” researcher Pengyu Zhang said. “It can be used as it is with existing WiFi without modification or additional equipment. You can use it right now with a cell phone and your off-the-shelf WiFi router.”
According to the team, HitchHike is so low power that a small battery could drive it for a decade or more. It even has the potential to harvest energy from existing radio waves and use that electromagnetic energy, plucked from its surroundings, to power itself – perhaps indefinitely.
“HitchHike could lead to widespread adoption in the Internet of Things,” explained associate professor Sachin Katti. “Sensors could be deployed anywhere we can put a coin battery that has existing WiFi. The technology could potentially even operate without batteries. That would be a big development in this field.”
The Hitchhike prototype is a processor and a radio. With a range of up to 50m and able to transmit up to 300kbits/s, it supposedly measures the size of a postage stamp, but the engineers believe that they can make it smaller for use in implanted bio-devices like a wireless heart rate sensor.
HitchHike translates incoming radio waves from a smartphone or a laptop to its own message and retransmits its own data on a different WiFi channel to avoid radio interference between the original signal and its new data stream.
On the processor front, HitchHike is a simple translation device. HitchHike translates the incoming code words into its own data. If the incoming code word indicates a zero and HitchHike wants it to remain a zero, it passes that code word unaltered. If, however, HitchHike wants to change that zero to a one, or vice versa, it translates it to the alternate code word.
The researchers say HitchHike could be available to be incorporated into wireless devices in the next three to five years.