Note to readers: I’m writing a series about iBeacon. This is the second installment in the series, explaining just how iBeacon works.
An iBeacon is a simple device, based on Bluetooth. To extend Bluetooth beyond the realm of audio devices, the Bluetooth SIG created Bluetooth Low Energy (BLE), sometimes called Bluetooth Smart. Compared to “classic” Bluetooth, BLE uses lower power and lower data rates, as well as reducing the latency of sending data between BLE devices.
An iBeacon is a BLE device. Many are battery-powered, though quite a few are powered by standard USB power. One of the many device types defined by BLE is called a beacon, which broadcasts information to receivers. An iBeacon is a special case of a BLE beacon that uses the contents of the beacon’s transmissions in a way specified by Apple.
There are three main fields in an iBeacon’s transmissions:
- The Universal Unique Identifier (UUID)
- The major number
- The minor number
There is no formal requirement for these fields to be used in any particular way, but the development framework on iOS treats them as hierarchical. The most important number is the UUID, which will typically identify an organization. Depending on the application, it might be a company (say, like, the Hilton hotel company), a single brand within the company (Hilton Garden Inn), or, depending on the application, a service provider that deals with many organizations (a hotel’s Wi-Fi service provider).
The major and minor number are used to represent subdivisions of everything covered by a UUID. Although every hotel in the world may be represented by a single UUID, if you want to have your phone recognize the hotel where you have a reservation and assist with the check in process, you want to trigger actions only when entering a specific hotel. The major number is typically used as the main division between locations. It can represent an office or a building identifier, such as Aerohive’s headquarters in California rather than our Hangzhou development center. Within the context of retail or restaurant chains, it might be a restaurant or store number.
To further subdivide the physical space, there is also a minor number, which represents still further subdivisions. In offices, it might be an office number or conference room. In hotels, it could be a room number. In a retail store, it might be a particular display, such as shoes (which I choose in deference to a colleague who I won’t name here, but might be obvious to you anyway).
An iBeacon also includes information that helps a receiver figure out how far away it is from the iBeacon, but we’ll discuss that in a future post.
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Read more on iBeacons
iBeacon Part 1: What the heck is it?
iPhone 6 + iBeacons + Wi-Fi: In-store shopping ups its game
iBeacon + Wi-Fi: Finally, "opting in" can be a win-win