what's a beacon? bluetooth low energy explained simply

BLE is based upon the common Bluetooth wireless standard, but it has been completely retooled to minimize energy usage, thus allowing wireless devices to operate for years on a watch battery. It is this extraordinary battery life, combined with a ~100 meter range and a very low cost, which will make possible hundreds of applications not previously viable. Central to the BLE technology is the “beacon”. A beacon is a self-contained wireless device that can transmit its information to as far away as 100 meters, can host a range of sensors including temperature, humidity, direction, motion, and light, all in a package no bigger than a coin, at a cost of under $20, and with a battery lasting up to 2 years. Today, Smartphone Apps will “see” and respond to beacons, even if the Apps are not currently open on the phone, which is what makes this technology so transformative. What is most important about beacons is that they add context to applications. For example, by sensing a beacon in a coffee shop, a loyalty card App will know which coffee shop the patron is in and will be able to automatically determine if a free coffee award has been earned. Similarly, a Gallery App will know from a beacon which piece of Art a viewer is standing in front of and will thus be able to deliver the correct descriptive content. Robin Heydon says in his 2013 book about BLE: “Sometimes, once in a lifetime, a new technology comes along that changes the world; for example, AM radio, television, and wireless Internet. Bluetooth low energy is at the cusp of the next revolution…”