As it is for everything Google or Android, Eddystone is an open source protocol specification by Google released in July 2015, which defines Bluetooth Low Energy message format specifically for Beacons. Unlike iBeacon, which is officially supported by iOS devices only, Eddystone has official support for both iOS and Android.
To read and explore the Eddystone specification, visit https://github.com/google/eddystone.
The Eddystone protocol format has been named after the famous Eddystone lighthouse in the UK and defines four different message formats as shown as follows:
Figure 4: Eddystone Beacon Format (Source: developer.mbed.org ...
