What are Beacons?

Bluetooth beacons are primarily used to allow other Bluetooth devices such as smartphones or Bluetooth-WiFi gateways to determine their location and associated sensor information. In terms of working distances, beacons fit between NFC and GPS and provide a solution to the problem of GPS not working indoors. Bluetooth beacons also use much lower receiving device battery power than GPS. Some beacons have sensors that can provide extra information such as temperature, movement, light level, humidity, magnetic detection, barometric pressure and generic switch on/off detection.

Beacons allow apps to do innovative and seemingly clever things based on location. For example, they can be used in retail to provide more timely information or in visitor spaces to increase participation. Apps that better use the external context can increase engagement and, in turn, usefulness. Increased engagement and usefulness can in some situations be used for commercial gain.

In IoT scenarios, beacons can provide remote proximity detection (of people and things) and sensor data to web servers, IoT platforms and the cloud.

Technically, beacons use Bluetooth Low Energy (LE) to repeatedly transmit a unique id or web address without having to pair devices as was the case with previous versions of Bluetooth. The range is typically 50m but can reach up to 100m outdoors for some beacons. We also stock some specialist beacons that can reach up to 4000m. The range is significantly less indoors when there are walls.

Physically, beacons are small computers typically packaged in a small plastic box, usually powered by one or more coin batteries. Some models can be powered by USB or packaged as a USB dongle.


Beacon with coin battery

The small chip on the circuit board is a System on a Chip (SoC) provided by one of four manufacturers : Dialog, Nordic, Texas Instruments and NXP. The use of these SoC devices simplifies circuit designs and ensures beacons transmit standard Bluetooth radio signals that, in turn, ensures compatibility with receiving devices such as iOS/Android phones and Bluetooth WiFi gateways.

The id in the beacon advertising data can be formatted as either an Apple iBeacon id (UUID, major and minor), Google’s Eddystone-UID or for tracker-type beacons the MAC address (that's turned into a peripheral id on iOS) is used. Google's Eddystone also has the facility to broadcast a URL (Eddystone-URL) that can be launched via Android (OS) or with the Physical Web app (on iOS and Android). The supported advertising format, iBeacon and/or Eddystone, depends on the manufacturer implementation.

Here's a screenshot from the Android iBeaconDetector app showing advertising data from both Eddystone-UID and iBeacon:
 


The Eddystone data has a Namespace and an Instance. The namespace is intended to uniquely identify your company and the instance identifies the beacon within your company. See the Eddystone specification and our article for more details. The UUID, major and minor can be seen in the iBeacon advertising data.

The ids and other configurable data such as power and the transmit period are usually set up via a free manufacturer-supplied Android and/or iOS app. Unlike the usual passive detection of beacons ids where the beacon doesn't know or care who is seeing the advertised data, setup of configurable data in the beacon requires that the app connect to the beacon, via Bluetooth Generic Attributes (GATT), to change values. This setup is usually password protected.

The main differences when comparing beacons are:

  • Whether it's an iBeacon, Eddystone, Sensor or Tracker Bluetooth beacon. Some support multiple transmission types simultaneously.
  • The power and corresponding maximum range.
  • The battery size and hence life.
  • The CPU type which can significantly affect battery use. For the same transmit power and advertising interval configuration, the Dialog DA14580 provides 2x to 3x battery life of the Nordic nrf51822 that's used in many beacons and up to x6 the battery life of TI CC254x based-beacons.
  • Physical aspects such as waterproofing, the size and colour of the box and how it will be mounted.

Most beacons allow battery health to be read via the connected settings mode and a few offer this via advertising data. Google Eddystone has an Eddystone-TLC broadcast that can transmit data about the beacon.

As previously mentioned, some beacons also have additional sensors such as temperature, humidity and acceleration. The acceleration is sometimes linked to other beacon features, for example, the initiation of connectable mode to change settings or, on a few beacons, motion-triggered broadcasting. Temperature and acceleration is also, in some beacons, visible in the advertising data so that it can be easily read without connecting. Fitness devices are essentially Bluetooth sensor beacons in a wristband form factor. A few beacons have buzzers and/or switches to provide additional interaction possibilities.

Read: Ways to Use Beacons

Tags: ibeacon, eddystone