iBeacon is the name for Apple’s technology standard, which allows Mobile Apps to listen for signals from beacons in the physical world and react accordingly. In essence, iBeacon technology allows Mobile Apps to understand their position on a micro-local scale, and deliver hyper-contextual content to users based on location. The underlying communication technology is Bluetooth Low Energy.
In laymen language
iBeacons can help a phone show notifications of items nearby that are on sale, and it can enable payments at the point of sale where customers don’t need to remove their wallets or cards to make payments.
How it works?
iBeacon is Apple’s version of the Bluetooth-based beacon concept, which allows Bluetooth devices to broadcast and receive tiny information within short distances. In simplistic words, it consists of two parts: a broadcaster (beacon device) and a receiver (smartphone app). The broadcaster is always advertising “I am here, and my name is…”, while the receiver detects these beacons and do whatever it needs to do based on how close or far it is from them.
It uses BLE for detection.
What is Bluetooth Low Energy (BLE)?
Bluetooth Low Energy is a wireless personal area network technology used for transmitting data over short distances.
Reported Distance between a Mobile Device and a Single Beacon
While ranging the Beacons (measuring the distance between your smartphone and a Beacon), you might notice that reported distance fluctuates heavily. That’s because the signal is simply a 2.4 GHz radio wave, which makes it susceptible to external factors, like multipath propagation, diffraction, absorption and interference.
Also, keep in mind that the fluctuations will be more visible and generally greater on Android. That’s because Apple’s CoreLocation framework for iOS already has noise reduction methods implemented. Android Bluetooth stack, on the other hand, still lacks those.
There are three static zones that surround each beacon.
Zones are not adjustable; they are preset boundaries that fit within the confines of the radio signal’s reach. As an example, if the range is reduced to 10 m, all three zones remain available. If the range is further reduced, to just 1.5 m, two zones remain available; immediate and near.
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. Keeping with the Coca-Cola 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: This is used to determine proximity (distance) from the beacon. 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.
A beacon broadcasts the following packet
A device receiving this packet would understand it’s from the Coca-Cola Beacon (UUID) in the Target on 1st Street (Major) at the front of the store (Minor).