How does iBeacon use BLE communication?
With iBeacon, Apple has standardized the format for BLE Advertising. Under this format, an advertising packet consists of four main pieces of information.
UUID: This is a 16-byte string used to differentiate a large group of related beacons.
For example, If Coca-Cola maintained a network of beacons in a chain of grocery stores, all Coca-Cola beacons would share the same UUID. This allows Coca-Cola’s dedicated smartphone app to know which beacon advertisements come from Coca-Cola-owned beacons.
Major: This is a 2-byte string used to distinguish a smaller subset of beacons within the larger group.
For example, If Coca-Cola had four beacons in a particular grocery store, all four would have the same major. This allows Coca-Cola to know exactly which store its customer is in.
Minor: This is a 2-byte string meant to identify individual beacons.
For example, A beacon at the front of the store would have its own unique Minor. This allows Coca-Cola’s dedicated app to know exactly where the customer is in the store.
Tx Power: TX power is defined as the strength of the signal exactly 1 meter from the device. This has to be calibrated and hardcoded in advance. Devices can then use this as a baseline to give a rough distance estimate.