Chapter 2. The iBeacon Protocol
iBeacons are transmit-only devices. They work by periodically transmitting numerical identifiers that are mapped into actions by an application on a mobile device. As a result, the “protocol” that they use is simple and is basically a vehicle to deliver numerical identifiers to nearby clients.
Translating those numbers into concrete action requires building an app for mobile devices. The simplicity of the protocol hides the big challenge, which is that application developers and user experience designers need to figure out how to make applications interact more tightly with the physical world.
Bluetooth Basics of an iBeacon
The iBeacon advertising function is transmit-only. Many iBeacon devices will implement a Bluetooth receiver for monitoring and configuration functions, but the protocol itself is transmit-only.
In the jargon of the Bluetooth specification, an iBeacon is a broadcaster, a type of device that is specific to Bluetooth Low Energy. Broadcasters transmit periodic advertising packets, which contain information used by the receivers. iBeacon advertising packets are designed to be transmitted, but receivers do not need to respond to them.9 In effect, iBeacon advertising packets are thrown out into the air, and receivers can act on them (or not).
iBeacons send advertising packets. When a device receives an advertising packet, it results in the creation of an advertisement event at the receiver. Sometimes, advertising packets and events ...