President Obama got a glimpse of the latter technology during last year’s White House Demo Day in the form of Emerald, a device geared towards elderly people that can detect physical activity and falls throughout an entire home. (Using more precise sensors, the same MIT researchers went on to develop systems that can distinguish between different people standing behind walls, and remotely monitor breathing and heart rates with 99 percent accuracy. They could tell how many people were in a room from behind a solid wooden door, a 6-inch hollow wall supported by steel beams, or an 8-inch concrete wall-and detect messages drawn in the air from a distance of five meters (but still in another room) with 100 percent accuracy. A pair of MIT researchers wrote in 2013 that they could use a router to detect the number of humans in a room and identify some basic arm gestures, even through a wall. Eventually, the researchers wrote, the system could become accurate enough that it could sound an alarm if an unrecognized intruder entered. It achieved 93 percent accuracy when choosing among two people, and 77 percent when choosing from among six. Their system, Wi-Fi ID, focused on gait as a way to identify people from among a small group. The researchers proposed using their technology in a smart-home setting: If the router senses one person’s entry into a room, it could communicate with other connected devices-lights, appliances, window shades-to customize the room to that person’s preferences.įreeSense mirrored another Wi-Fi-based identification system that a group of researchers from Australia and the UK presented at a conference earlier this year. If it’s choosing between six people, it identifies the right one 89 percent of the time. If it’s told that the next passerby will be one of two people, the system can correctly identify which it is 95 percent of the time. After memorizing body shapes, the system, which the researchers named FreeSense, watches for people walking across its line of sight. The system must first be trained: It has to learn individuals’ body shapes so that it can identify them later.
#Who is my wifi archive#
Earlier this month, a group of computer-science researchers at Northwestern Polytechnical University in China posted a paper to an online archive of scientific research, detailing a system that can accurately identify humans as they walk through a door nine times out of ten. Several recent experiments have focused on using Wi-Fi signals to identify people, either based on their body shape or the specific way they tend to move. By analyzing the exact ways that a Wi-Fi signal is altered when a human moves through it, researchers can “see” what someone writes with their finger in the air, identify a particular person by the way that they walk, and even read a person’s lips with startling accuracy-in some cases even if a router isn’t in the same room as the person performing the actions. With that data, the router can make small adjustments to communicate more reliably with the devices it’s connected to.īut it can also be used to monitor humans-and in surprisingly detailed ways.Īs people move through a space with a Wi-Fi signal, their bodies affect it, absorbing some waves and reflecting others in various directions. As it communicates with the devices, the router is also gathering information about how its signals are traveling through the air, and whether they’re being disrupted by obstacles or interference. When those devices connect to a router, they send requests for information-a weather forecast, the latest sports scores, a news article-and, in turn, receive that data, all over the air. Homes, streets, businesses, and office buildings are constantly blasting wireless signals every which way for the benefit of nearby phones, tablets, laptops, wearables, and other connected paraphernalia. City dwellers spend nearly every moment of every day awash in Wi-Fi signals.