You could say that the idea of wirelessly transferring information evolved from short range passive Radio Frequency Identification (RFID) tags embedded in displays and signs or in the readers in POS terminals. Users exchange information between a reader and their device or using their device’s reader to exchange information with an object. For example, an employee scanning their badge (RFID tag) to gain entry at an access point (reader). But the drawback of RFID is the need for the device or object to be very close to the reader which means within a few meters for UHF-tags or a few centimeters for NFC-tags to establish a connection.
The idea of a beacon builds on this to provide a stationary, one-way communication to transmit data for longer range applications. Using Bluetooth® Low Energy (LE) protocols, a beacon broadcasts a code over a range of 30 to 50m. The achievable range depends on environmental factors such as objects blocking the beacon’s signal path like people, walls, or cars.
With further advancements in technology came the development of the Bluetooth LE tag, which improves on the beacon, by adding two-way communication between the tag and a host device such as a smartphone, gateway or monitoring device for an even broader variety of applications. Tags are not limited to close-range applications like beacons or RFID tags, which makes them also ideal for locationing and tracking.
Take Dialog’s Wireless Ranging (WiRa™) SDK as an example. This SDK enhances the existing DA1469x family of Bluetooth LE System on Chips (SoCs), with new, highly accurate and reliable distance measurement capabilities. The WiRa™ SDK’s 2.4 GHz radio interweaves Bluetooth Low Energy data packets with constant tone frequency exchanges to generate phase-based ranging signals. The high-resolution of on-chip radio wave sampling provides high quality IQ samples, which form the input for distance determination. Data processing algorithms then filter the data for noise, interference and multi-path reflections. This process outputs the shortest distance over-the-air signal path length, providing the application with an accurate distance measurement.
By using Bluetooth low energy, designers have the option to choose if they want to operate their application as a beacon or a tag. It is a tag if it programmed to open the receiver and wait for a known transmission. It is a beacon if it is programmed to transmit data regardless of who or what is receiving. Such a device can be both by adding a beacon to a two-way Bluetooth LE communication capability and the ability to switch between. For example, if you have a Bluetooth LE equipped food quality sensor in a perishable foods shipment, such as a gas sensor, the Bluetooth LE device can change its mode of operation depending on the situation. As long as the food quality is within the target gas range, it would operate as a tag and log data until the data is actively requested by a reader. If programmed accordingly, it could become a beacon and notify its surrounding to dispose of the box in the shipment once the food quality has deteriorated.
The importance and urgency of locationing in recent years has further increased the number of applications for beacons and tags. With smaller mechanical size and lower power consumption of the latest Bluetooth single chip SoCs the evolution of beacons and tags continues to grow. While the underlying technology is the same, the way beacons and tags are used is quite different, and understanding those differences leads to powerful new applications for consumers.