14:02 BST
University of Washington (UW) researchers have developed a low-cost, long-range data-communication system that could make it possible for medical sensors or billions of low-cost “internet of things” objects to connect via radio signals at long distances (up to 2.8 kilometers) and with 1000 times lower required power (9.25 microwatts in an experiment) compared to existing technologies. The new system uses “backscatter,” which uses energy from ambient transmissions (from WiFi, for example) to power a passive sensor that encodes and scatter-reflects the signal.