iBeacon, Eddystone and AltBeacon are the three main beacon technologies. All of them use the standard Bluetooth Low Energy (LE) advertising format. Bluetooth LE is designed for short bursts of radio that uses little power and is therefore suitable for battery operation. Each of the advertising variants uses a unique advertising packet format that defines what kind of data the beacon transmits.
iBeacon, launched by Apple in 2013, was the first to adopt this technology and created a new wave in proximity services. It uses a simple advertising format, which consists of a UUID (universally unique identifier), Major, and Minor identifiers.
Eddystone, introduced by Google in 2015, offers a more complex advertising packet format with four different frame types: Eddystone-UID (similar to iBeacon’s UUID), Eddystone-URL (broadcasting web address), Eddystone-TLM (telemetry information about the beacon itself), and Eddystone-EID (an encrypted version of Eddystone-UID for secure applications).
Altbeacon, an open-source specification introduced by Radius Networks, provides a simpler format similar to iBeacon.
The functionality of beacon technologies are different on iOS and Android due to differences in the operating systems themselves. Apple’s strict app guidelines and strong emphasis on user privacy limit the ability of apps to perform tasks in the background. For instance, iOS only allows apps to scan for iBeacon formatted advertisements in the background using the CoreLocation library, not CoreLocation. Eddystone or AltBeacon can only be read in background using CoreLocation. Android offers more flexibility for background tasks and can work with iBeacon, Eddystone and Altbeacon.
Although Eddystone and Altbeacon have their merits, iBeacon is the advertising of choice for most scenarios involving smartphone apps due to the integration with iOS.