Reflected WiFi could be low-power communication tool for wearables

One of the biggest issues with wearables, as small and lightweight as they are, is power consumption. The most efficient and least feature filled of the lot can last for perhaps a week without charge, but the most power hungry need to be recharged in just a matter of hours. How then, can we mitigate this? By looking at some of the biggest power drains on wearable devices and improving them.

Perhaps the biggest power draw (especially on devices without displays) is wireless access. While most often handled by low powered bluetooth, sometimes WiFi is necessary and searching for networks and remaining connected can draw a considerable amount of power from a wearable device’s battery. That’s why a team of researchers at UCLA has been working on a system of reflecting ambient WiFi signals back to a router, allowing for them to be customised and therefore sending new information, without the need for a transmitter and in some cases, even a battery at all.

Of course the downside to modifying these passive signals is that the data transfer speed isn’t quite as strong as contemporary WiFi. The team managed to generate a bandwidth of around 3Mbps second, which while a lot faster than anything we had a few years ago, isn’t going to blow the socks off of your average router’s abilities.


However, we’re not talking about streaming HD video here, but wearable data and information, which is usually in the low kilobytes in terms of size, so transmission need not be complicated, which is why this technology could be perfect for wearables. The developers are currently limited in range to under 10 feet at that transmission rate, but believe that over time they can tweak it so that it’s around 65 feet at the same bandwidth.

What will be interesting to see is if any wearable manufacturers buy this technology from the researchers, or if they try and develop their own WiFi ambient back-scatter devices in order to take advantage of the technology. It would need to work with a mobile handset that can act as a WiFi hotspot, but that’s pretty easy to achieve. Chances are WiFi could offer much tighter security than bluetooth streams of data as well, so there’s certainly a lot of advantages to this system over what most devices use at the moment.

Google might be the first to take advantages, as it’s been talking up the back-scatter approach on its research blog.