A prototype developed by engineers at the University of Washington is able to stream HD video at 10K lower than current methods and without batteries. The new HD streaming method doesn’t need to be plugged in, which is useful as the low-power HD streaming architecture targets wearable cameras. Like a smartphone, it skips the parts that require most power and processes the video instead. The prototype uses a technique called backscatter, via which a device is able to 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,” co-author Shyam Gollakota, associate professor in the UW’s Paul G. Allen School of Computer Science & Engineering told UW News. “This work breaks that assumption and shows that backscatter can indeed support even full HD video.”
The UW team presented their findings earlier this month at the Advanced Computing Systems Association’s Symposium on Networked Systems Design and Implementation and released an academic paper, “Towards Battery-Free HD Video Streaming”. In the paper, they describe their driving question as, “Can we design a low-power camera that can perform HD video streaming to a nearby mobile device such as a smartphone?”
In today’s streaming cameras, the camera initially processes and compresses the video before it can be transmitted over WiFi. This process takes a lot of power, especially for HD videos, making a lightweight streaming camera, which doesn’t require large batteries or a power source out of reach.
The UW’s prototype eliminates these components and instead connects the pixels in the camera directly to the antenna, which sends intensity values via backscatter to a nearby smartphone. The phone (that doesn’t have the same size and weight restrictions as a small streaming camera) processes the video instead.
When the video is transmitted, the system translates each frame’s pixel information into a series of pulses, in which the width of every pulse represents a pixel value. The brightness of the pixel and the time duration of the pulse are proportional to one another.
During testing, the team used a prototype that involved converting HD YouTube videos into raw pixel data, which they then fed into their backscatter system. They found that they were able to stream 720p HD videos at 10 frames per second to a device that could be as far away as 14 feet.
The system uses 1,000 to 10,000 times less power than current streaming technology. However, it still has a small battery that supports continuous operation. The next goal is to make wireless video cameras that are entirely battery-free.
Potential use case scenarios include home security cameras and ultimately an energy-saving world in which the cameras are smart enough to only turn on when they are needed for a specific purpose.
Co-author of the report, Shyam Gollakota, said “This video technology has the potential to transform the industry as we know it. Cameras are critical for a number of internet-connected applications, but so far they have been constrained by their power consumption,” he said.
The technology has been licensed to Jeeva Wireless, a Seattle-based startup “revolutionizing the way devices communicate”. It was founded by UW researchers, including several of the team behind the prototype.
This research was funded by the National Science Foundation, the Alfred P. Sloan Foundation and Google Faculty Research Awards.