Use of Bluetooth®LE Sensor in Location and Positioning

Minew Oct 12, 2021

BLE (Bluetooth Low Energy) is RF (radio frequency) technology that helps us track and detect the location of assets, devices, and people. This technology focuses on wireless communication and is suitable for various indoor positioning applications. Some of the application areas of a BLE sensor include proximity services, indoor navigation, and asset tracking, etc. Bluetooth technology is incredibly accessible and widespread and is a go-to technology for most modern-day devices. Like other protocols of communication including UWB and WiFi, we can also use BLE for transmitting data among devices via radio waves.

BLE Temperature Humidity Sensor

BLE Temperature Humidity Sensor

In today’s article, we will take a look at the evolution and use of Bluetooth Low Energy sensor technology. We will also take a quick look at Bluetooth Beacons and how BLE positioning works.

BLE Sensor Technology Evolution

With the invention of Bluetooth Low Energy technology, we experienced some fundamental changes to the worldwide Bluetooth ecosystem. After that, we saw hundreds of thousands of Bluetooth-supported devices entering the indoor spaces. Today, there are approximately 8 billion+ Bluetooth-enabled devices available globally. With the most recent Bluetooth-enabled tools and infrastructures, we now have many improved location-aware capabilities.

After 2013, we saw the very first beacon BLE communication protocol by the Apple Company. Such devices made it possible to connect with wire-free devices at a close distance.  In 2015, Google also came with its first beacon protocol. It enabled the use of BLE sensor technologies, like location tags and tracking, for an assortment of indoor location and positioning services applications. It just transformed the way devices and people communicate with indoor areas.

There is a continuous advancement in overall BLE communication protocol and such technologies. The new Bluetooth version 5.0 came in 2016. In 2019, we saw another upgrade known as Bluetooth 5.2 with better abilities. This update leads to highly precise and accurate location detection through DF (direction finding). This can result in accuracy of centimeter-level.

BLE has unique characteristics, making it a highly popular RF technology for indoor location and positioning. This technology is rising in popularity and has become a must for many wireless devices. It is an easy to implement, low-cost, and low-power technology that is ideal for various location-based applications.

BLE Beacons

Bluetooth Low Energy beacons are low-power, versatile, and small Bluetooth transmitters that wireless devices can detect. We can deploy beacons in fixed locations like mounted on structures or walls, or on mobile for providing location references. It supports BYOD (bring-your-own-device) concepts which allow you to communicate with BLE-supported applications. You can use embedded devices or smartphones to interact with BLE-enabled applications. We can use BLE beacons to find the location of a device and provide relevant content, including apps, videos, documents, and more. BLE sensor technology also guides on the user’s location or time, keeping them engaged and informed.

BLE beacons transmit signals regularly that other BLE-supported devices can detect. A Bluetooth Low Energy device collects beacons location data and pushes it towards the IPS for determining the location of the device. It supports several location-aware apps and also runs specific actions. Beacons are available in all sizes and shapes. Most beacons come with long-lasting batteries. These batteries can work for many years and you can power them via USB connections.

When compared with other radio frequency technologies, BLE is usually a low-cost solution to produce. It requires low maintenance and is suitable for various deployments to meet your specific requirements. A few beacons can be beyond Bluetooth Low Energy and combine extra technologies, like temperature sensors or accelerometers for improved results.

Virtual Beacons

With virtual beacons, organizations can add Bluetooth Low Energy technology without extra hardware. Virtual Bluetooth beacons allow us to add antennas to supported WiFi access points. Moreover, you can also leverage them with extra software tools amid several indoor positioning apps. Most enterprise-grade WiFi access points like both sensors and beacons can locate and detect transmitting Bluetooth Low Energy devices. They do not require a secondary infrastructure set.

How Does BLE Positioning Work?

Indoor BLE positioning solutions utilize either BLE-supported beacons or sensors for detecting and locating transmitting Bluetooth devices, like tracking tags or smartphones. The location data received from a beacon or BLE sensor is then consumed by several location applications. This data helps in powering various multiple location-aware applications.

1. BLE Sensor Positioning

BLE sensor positioning uses BLE-supported sensors deployed in the fixed position in an indoor area.  Such sensors locate and detect transmissions passively from BLE tracking tags, smartphones, wearable, personnel badges, and other PT devices. After that, this data is moved to the IPS or RTLS. A location engine examines this data and utilizes multilateration algorithms for determining the position of a transmitting device. You can use those coordinates for visualizing the asset or device location on indoor maps of the space.

2. Beacons BLE Positioning

Bluetooth Low Energy beacons pulse out Bluetooth Low Energy signals repeatedly. Surrounding devices, such as a BLE sensor and smartphone can detect these signals. Signals produced by beacons contain unique identifiers. Identifying codes are sent occasionally with other data, according to the communication protocol of the beacon. Wireless devices, such as smartphones will get and analyze signals from the BLE beacon when they are in the range. This detection between a device and one beacon allows for proximity-based positioning services.

It is also possible to use multiple beacons in an indoor area to communicate between multiple beacons and one wireless device for positioning the device through RSSI multilateration. The device’s determined location triggers the unique action for many services or applications. We can also deploy BLE beacons on a mobile object. It is also possible to detect and locate BLE beacons via fixed BLE-supported sensors that will be helpful in an asset tracking case.

The accuracy of BLE sensor positioning varies according to the hardware selections, deployed sensor/beacon density, and system architecture. Both BLE beacons and sensors can provide location accuracy within five meters range. Bluetooth relies on RSSI (signal strength) for estimating device locations. Bluetooth Low Energy is not the most accurate radiofrequency technology at the moment for indoor location services. However, it is still known as the most demanded and highly effective technology.

If you have any questions or ideas on the BLE sensor, leave us your comment below.

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