iBeacons are Bluetooth Low Energy (BLE, also known as Bluetooth Smart) transmitters that notify nearby receivers, such as a smart phone, of their presence for the purposes of proximity sensing. A unique identifier allows the the receiver to take specific action such as displaying a notification message or configuring itself to use a smart device such as a lamp, smart-switch or other sensor.
Apple introduced iBeacons with iOS 7 and trademarked the term for a "a new class of low-powered, low-cost transmitters that can notify nearby iOS 7 devices of their presence." Since it's release, iBeacon SDKs have also been introduced for Android. Support for sensing iBeacons requires a Bluetooth 4.0 device that supports Bluetooth Low Energy (BLE) mode.
Proximity sensing can typically categorize an iBeacon into three ranges: immediate (centimeters), near (several meters) and far (many meters). As with typical RF ranging techniques, interference and occlusion can affect the accuracy.
iBeacons can be identified by three values they are broadcasting
- UUID(16 Byte)
- Major value(2 Byte)
- Minor value(2 Byte)
iBeacons can be used for indoor location system.
The iBeacon advertising packet contains the UUID, Major, Minor, and Tx Power. Tx Power is 1 Byte, and tells you what the signal strength is at 1 meter away. A device can estimate its distance from a beacon by comparing the rssi and tx power values.
