The Bluetooth Beacon

Bluetooth beacons are small, wireless devices that use the Bluetooth Low Energy (BLE) communication protocol to transmit radio signals at short, regular intervals to portable Bluetooth-enabled devices nearby. These signals can be received by smartphones, tablets, gateways, or other compatible devices to trigger actions, deliver information, or provide location-based services. All modern smartphones are Bluetooth LE-enabled.

Bluetooth LE beacons are also called BLE trackers. They are usually fixed on strategic locations within a facility or building. They are placed on walls, ceilings, or on objects. These beacons can determine the proximity of a receiving device via a ranging process, as will be explained in the sections below.

Trackers with BLE come in different forms. These include cards, wristbands, stickers, USBs, key fobs, and badges. These beacons are either battery-powered, USB-powered, or plug-powered.

Bluetooth beacons functions similarly to a lighthouse. Just as lighthouses emit light signals to help ships determine their location, Bluetooth beacons transmit advertising data packets that other devices can detect. It is important to note that beacons cannot track users or mobile devices. Their only function is the transmission of advertising packets.

The data contained in these advertising packets can vary depending on the standard being used. It usually includes a unique identifier (UI) and namespace identifiers. Namespace identifiers are numbers that designate specific locations and areas within those locations. For instance, a namespace identifier might indicate a particular city, building, or even a specific floor or aisle within a building.

A Bluetooth-enabled device with a dedicated mobile app acts as the scanner that detects the advertising packets that are transmitted from the beacon. The mobile app interprets the data, identifying the location of the beacon and its assigned area. Additionally, the app can determine the proximity of the beacon based on the Received Signal Strength Indicator (RSSI) of the signals it receives. This enables for precise location detection.

The two leading standrads for Bluetooth beacons are the iBeacon standard from Apple and the Eddystone standard from Google. Another beacon standard is the AltBeacon protocol from Radius Networks. Many beacon hardware suppliers support multiple, if not all, standards. This results in increased flexibility for customers that may wish to implement these standards.

The iBeacon Standard

Introduced in iOS 7.0 in 2013, iBeacon was the first mainstream standard for Bluetooth beacons. This standard specifies the structure of the advertising packets transmitted by the beacons, which include a 16-byte UUID, a 2-byte major number, a 2-byte minor number, and a transmission power (Tx Power) of 1-byte. The iBeacon standard is compatible with both Android and iOS.

The UUID is a unique identifier that is assigned to an app. A specific region within the UUID is specified by the major number. The minor number specifies a sub-region within the major region. For instance, in a chain of retail stores, the UUID would be the same across all stores. Each individual store has a unique major number. Minor numbers specify the particular floor or aisle of each individual store.

To officially use the iBeacon name and claim compatibility, developers must sign a licensing agreement with Apple. However, it is possible to develop and utilize beacons that transmit iBeacon packets without this agreement; such devices just cannot be marketed as iBeacon-compatible.

The iBeacon standard also includes iOS APIs. These allow developers to create applications that can interact with devices that are compatible with the standard. These APIs allow for the detection of a device’s estimated proximity to the beacons.

The process of determining proximity is known as ranging. There are four distinct proximity states. The first is the immediate state, which indicates with high confidence that the beacon is very close to the mobile device. The near state signifies that the beacon is approximately 1-3 meters away, provided there is a clear line of sight.

The far state signifies the detection of the beacon. However, the detected signal cannot be assigned to the immediate or near states. This could be the result of interference and obstacles between the mobile reading device and the beacon. The unknown state is where proximity cannot be determined, or where the ranging process is still being initialized.

The Eddystone Standard

Google introduced the Eddystone standard in 2015. This standard had additional features that expanded on the iBeacon standard. These features beacon configuration and management, improved privacy and security measures, the ability to directly broadcast a URL to a reading device, and the elimination of the need for a specific mobile app. The standard is integrated within the Chrome browser on the reading device. Unlike iBeacon, which has a single packet type, Eddystone has four distinct packet types:

1. Eddystone-UID: This packet contains a unique static ID that has a 10-byte namespace and a 6-byte instance component.
2. Eddystone-URL: This packet type broadcasts a compressed URL that can be easily parsed and decompressed by the client.
3. Eddystone-TLM: This packet provides status data about the beacon. It is often used for fleet management and maintenance tasks.
4. Eddystone-EID: This packet type enables enhanced privacy and security. It data packet is time-varied and can only be resolved by clients that have valid authorization.

Bluetooth beacons are mainly used for applications in location tracking and proximity awareness. They are increasingly being utilized across various industries. In retail marketing, beacons can present customers with coupons and rewards as they approach a beacon that is located within a store. This enhances the shopping experience for customers.

In the events sector, beacons are used in small business gatherings and in large-scale events like sporting competitions and musical concerts. These beacons provide real-time updates to event attendees. Another application is asset tracking within buildings, where beacons help monitor the location of valuable items.

Beacons also play an important role in indoor location services and indoor navigation. They are used to guide people inside buildings where GPS is ineffective. In the tourism industry, beacons optimize visitor experiences in museums and guided tours by providing contextual information and interactive content as they approach the installed beacons.