As demand for location services in all areas of the Internet of Things (IoT) grows, so too has the requirement for precision location. For many applications, especially those that need to scale to cover large areas, providing ”proximity zone” types of location is simply not accurate enough. That means the old way of determining location—primarily using Bluetooth beacons—is no longer sufficient.
Bluetooth beacons have been the go-to solution for determining location for years, but they have three limiting factors:
- Beacons only work with smartphones, not tags, which limits how they can be used
- They are able to locate objects in best case within 3-4 meters, which is fine for determining a general location, but is not refined enough to meet the requirements for many of today’s applications
- Beacons are battery-operated, which impacts their ability to deliver real-time location; frequent transmissions drain the device’s battery, meaning frequent replacements are necessary
The shortcoming of beacons and other location technologies that rely on smartphones has spawned an industry shift to a more network-centric approach, with the intelligence moving to the receiver antenna and a centralized software application, rather than the intelligence residing in a smartphone app. That, in turn, has launched the development of a wide range of active, low-cost Bluetooth Low Energy (BLE) tags with long battery life and possible on-board sensors.
Another shift occurring is a change in how signals from these tags are measured to determine location. The traditional method—using signal strength to estimate location—does not take into consideration how the signal will be impacted by its environment. While a weak signal could indicate an object is far away from a beacon, it’s also possible a physical object, such as a concrete pillar or wall, is impacting the signal.
Two new approaches are emerging for BLE angle estimation. The first is based on the signal’s Angle of Arrival (AoA)—the precise direction the device is from the receiver antenna arrays. With AoA, multiple antennas are used within the same devices to measure the signal. This allows the antenna to locate a tag or smartphone with accuracy of 10 to 20 centimeters, not meters.
The second approach considers the signal’s Angle of Departure (AoD). In this approach, the location intelligence is moved back to the mobile devices. The AoD approach works like "indoor GPS," where the fixed infrastructure devices (aka Locators) are only broadcasting and are not aware of the receiving devices, similarly to how a GPS Satellite works. This means the capability to locate an unlimited amount of devices, and no privacy issues.
As the use cases for indoor location services continue to grow, with every industry from manufacturing and logistics to healthcare and retail, to law enforcement and beyond clamoring for more precision, new approaches beyond Bluetooth beacons need to be considered. The AoA and AoD methodologies are quickly gaining momentum as the next generation of location technology.
Guest post by Antti Kainulainen is CTO & cofounder of Quuppa. Before Quuppa, he was with Nokia Research Center (NRC) during 2005-2012, where he was the lead engineer in several projects related to indoor positioning. He also took part in the standardization work of the Bluetooth Wireless technology. Antti received his M.Sc. degree in technology from Helsinki University of Technology in 2007. He has 16 granted patents and 22 pending patent applications. More at www.quuppa.com