What is a Bluetooth Beacon and How Can It be Used Effectively?
What is a Bluetooth Beacon and How Can It be Used Effectively?
Bluetooth® beacons are devices that have distinctive characteristics that make them applicable to many industrial and business settings. We are going to look at what a Bluetooth beacon is, how it works, and why it is an excellent solution in many Internet of Things (IoT) use cases that require some type of navigation, proximity measurement or low power sensing.
What is a Bluetooth Beacon?
A Bluetooth beacon is a small radio transmitter that often runs on battery power. Its purpose is to mark a location, Point of Interest or PoI by transmitting identity (ID) and in some cases sensor data with a Bluetooth-enabled radio. The receiving application, which is typically running on mobile devices, processes the data received, and in some cases characteristics of the signal (power, angle of arrival), and cross references the ID received with a digital map in order to establish the location of the receiving device. It may then perform an action or initiate an activity based on the location that has been calculated and in some cases the sensor information received.
Bluetooth beacons can be obtained in a variety of form factors designed to address the requirements of different usage scenarios. The term beacon is primarily used in relation to devices that remain stationary, such as when they are used to provide indoor navigation information to nearby individuals. When Bluetooth transmitters are attached to or embedded in a moveable item such as a supply chain component, they are then referred to as Bluetooth tags (not beacons). In some discussions, the term “beacon” and Bluetooth tags are used interchangeably. However, for the purposes of this article, we are specifically speaking of Bluetooth beacons, as described above.
How do Bluetooth Beacons Work?
Bluetooth Low Energy or BLE beacons work by transmitting data to apps running on Bluetooth-enabled devices. The term Bluetooth Low Energy beacon is used because of the device’s reduced energy requirements and the Low Energy variant of the Bluetooth protocol that is used to to achieve this. It operates on the same 2.4 GHz unlicensed radio band as the original Classic version of the Bluetooth protocol but requires substantially less energy.
A Bluetooth Low Energy beacon sends data with minimal energy consumption of 0.01 to 0.5 watts. That’s less than half the power required by Classic Bluetooth. The reduced power requirements and resulting longer operating life, lower maintenance (less need to change batteries), smaller battery size, the resultant smaller device size and lower cost make Bluetooth Low Energy beacons an attractive solution for IoT implementations.
A common analogy used to describe the way Bluetooth Beacons work is to compare a beacon to a lighthouse. A lighthouse, whose location is at a known place, continuously broadcasts the same signals that can be received by anyone within range. It is only used to send information, not to receive it. Because it broadcasts, any number of receivers can use it simultaneously. This allows beacon applications to support very large numbers of users using a single beacon device. Similarly, a stationary Bluetooth beacon broadcasts the same data to any compatible smart devices within range and does not receive any information in return. No connection or pairing is required. All receiving devices will obtain the same information, typically an identifier, from the beacon.
One major difference in the way a lighthouse and a Bluetooth Low Energy beacon work is that the lighthouse is always turned on. One of the characteristics of Bluetooth Low Energy beacons is that they obtain additional energy efficiency by remaining in sleep mode a significant proportion of the time, only ‘waking up’ to transmit a signal at a regular time interval. Typically they broadcast ten times a second, although this can be increased in the case of tracking fast moving objects or reduced when battery life needs to be extended.
The real functionality of Bluetooth beacons comes from their associated applications running on smartphones or other Bluetooth-enabled devices. Often the beacon itself is not capable of modifying its signal. The receiving app can use the information the beacons send for multiple purposes based on the signal’s location or proximity to the receiver.
What are Some Business Uses for Bluetooth Beacons?
Bluetooth beacons have consumer, enterprise and industrial uses. Based on how they are used, and the use case they are deployed to solve, dedicated applications are required to obtain the necessary functionality from the deployment of Bluetooth beacons. The applications receive and act on real-time data generated from beacons. Following are some of the business uses for Bluetooth beacons.
There are use cases where a precise X/Y location is not required, and a simple notification that a phone or reader is near a known location is all that is needed. Bluetooth beacons provide an excellent solution for this requirement. Examples are alerts when a shopper is near a certain display in a store, or a billboard outside. Apple has used this technique in their Apple Store app to encourage shoppers near the accessory section of their stores to self-checkout, so their staff can concentrate on helping visitors considering bigger ticket purchases of laptops and desktop computers. Advertisers have used this technique to estimate “impressions” from members of the public traveling past billboards.
This can be done relatively simply. Detailed site survey mapping of a venue isn’t necessary. All that is required is a list of beacon IDs associated with a list of assets (a billboard or an endcap store display). The longitude and latitude (X/Y) is not required.
Indoor navigation (also sometimes called wayfinding) can be facilitated through the use of Bluetooth beacons. Navigation can be provided to humans via smartphones and mobile devices in shopping malls or airports for instance, or to robots or other automated devices through built-in readers. Bluetooth beacons can be a useful tool when implementing industrial automation systems.
The Beacon is used to establish the mobile reader position relative to a map that uses beacons as points of interest that anchor specific locations on the map.
The reading device may use the signal from multiple beacons, that are ‘hearable’ at any one time, to triangulate or trilaterate to establish its location on the map. Trilaterateration is a process where the relative proximity to three different beacons is used to establish an X/Y location.
Proximity can be estimated using a variety of techniques, the most common of which is the Received Signal Strength Indicator (RSSI) value. This is a measure of how loud the signal is, in fact the received signal strength is measured in decibels. If you receive a strong signal from a beacon by the door of a store, while receiving a medium strength signal from a beacon known to be by the changing rooms at the side of the store, and a weak signal from a beacon known to be at the back of the store, the relative location of the receiver can be approximated.
The location accuracy obtainable in this way varies and is not highly accurate (2-3 meters). This low cost technique is often sufficient to guide someone to another location on the map.
A more accurate technique is “trilateration”, where the angle of arrival of signals from multiple beacons (“I see a given beacon is 33 degrees north of where I am") is used to locate the position of the receiver (similar to navigating by the stars on a boat). This can yield sub-meter accuracy, but this technique requires more specialized antennas on more expensive IoT devices and is currently not possible on regular phones.
Bluetooth beacons can also be used in retail stores to promote loyalty programs and enact marketing campaigns tailored to a customer’s current physical location. Retailers can offer customers a free smartphone app that communicates with beacons within the establishment.
Wiliot’s Versatile Bluetooth Beacons
Wiliot’s Battery Assisted (IoT) Pixels are an example of versatile Bluetooth Low Energy beacons in a sticker format that can be used to address a wide range of usage scenarios related to proximity and indoor positioning. They work in conjunction with the Wiliot Cloud to obtain actionable insights that can change the way your company does business.
A major advantage of Wiliot’s IoT Pixels is the availability of battery-powered or battery-free models. The battery-powered IoT Pixel uses a printed battery that is smaller, lower cost and more environmentally friendly than other beacons. They are smaller than a credit card and have a battery life of up to four years. Battery-free IoT Pixels that harvest energy from ambient radio waves have an effectively limitless lifetime. This makes them a superior choice in many use cases where the ambient radio energy that is required to power the battery free version is available, lower cost, long-term performance is required and where battery replacement is inconvenient.
Wiliot’s IoT Pixels are cost-effective and distributed as stickers on rolls for easy installation. Their small size and extended operational lifetime allow them to be used in countless ways. They offer businesses multiple opportunities to improve supply chain management and compete more effectively in their market.