Wearable cameras such as Snap Spectacles promise to share videos instantaneously with the world.  But, because these cameras must use smaller batteries to stay lightweight and functional, these devices can't perform high-definition video streaming.

Now, engineers at the University of Washington have developed a new HD video streaming method that doesn't need to be plugged in. Their prototype skips the power-hungry parts and a smartphone processes the video instead. They do this using a technique called backscatter, through which a device can share information by reflecting signals that have been transmitted to it.

The fundamental assumption people have made so far is that backscatter can be used only for "low data-rate" sensors such as temperature sensors.  This work breaks that assumption and shows that backscatter can indeed support even full HD video.

The team presented these findings recently at the Advanced Computing Systems Association's Symposium on Networked Systems Design and Implementation. The UW team developed a new system in which the pixels in the camera are directly connected to the antenna, and it sends intensity values via backscatter to a nearby smartphone. The phone, which doesn't have the same size and weight restrictions as a small streaming camera, processes the video.

It's sort of similar to how the cells in the brain communicate with each other. Neurons are either signaling or they're not, so the information is encoded in the timing of their action potentials. The team tested their idea using a prototype that converted HD YouTube videos into raw pixel data. Then they fed the pixels into their backscatter system. Their design could stream 720p HD videos at 10 frames per second to a device up to 14 feet away. 

That's like a camera recording a scene and sending the video to a device in the next room.

The group's system uses 1,000 to 10,000 times less power than current streaming technology. But it still has a small battery that supports continuous operation. The next step is to make wireless video cameras that are completely battery-free.

There are many applications.  Right now, home security cameras have to be plugged in all the time. But with this technology, people can effectively cut the cord for wireless streaming cameras. The group also envisions a world where these cameras are smart enough to only turn on when they are needed for their specific purpose, which could save even more energy.

Cameras are critical for a number of internet-connected applications, but so far, they have been constrained by their power consumption.  This video technology has the potential to transform the industry as we know it.

Just imagine you go to a football game, five years from now.  There could be tiny HD cameras everywhere recording the action: stuck on players' helmets and everywhere across the stadium. And you don't have to ever worry about changing their batteries.

This technology has been licensed to Jeeva Wireless, a Seattle-based startup founded by a team of UW researchers.