Angle of Arrival – High-precision positioning with the AoA method

For use cases that require extremely precise positioning, Favendo uses the AoA method for positioning. AoA stands for Angle of Arrival is based on the principle of measuring angular directions (Azimuth and Elevation) from a device (aka Locator) placed at a known location. With angle it is meant the angle in which the signal meets the receiver. The angle is measured by computing the phase of the receiving radio signals.

Favendo is an official partner of Quuppa and uses Quuppa Locators, which are using proprietary angular estimation algorithms and advanced signal processing within their positioning engine. As a result, their AoA-based method provides high accuracy sub-meter positioning between 0.1 and 1 m.

The set-up costs for the infrastructure are slightly higher when using Quuppa Locators instead of Favendo’s Relay-Beacon Tracker due to the more complex planning and installation procedure, but still remain far below the costs of a UWB system.

Combined Positioning Software

A combination of both methods is possible, so for areas where centimeter-precise positioning is not necessary, the less expensive hardware can be used. In areas where this very precise positioning is necessary, Quuppa locators are used.

Mostly Asset Tracking solutions on proximity level use a combination of high accuracy positioning and low accuracy presence in different areas.

RSSI vs. AoA

Both terms denote methods for calculating a position based on Bluetooth technology. In the case of positioning based on the Received Signal Strength Indicator (RSSI), the Beacon Tracker measures the strength of the signal that the asset tags – the transmitters with which the assets to be tracked are equipped – permanently transmit. A simple picture to understand is the waves that a stone thrown into the water “emits” and which weaken with increasing distance. This type of position determination by means of distance measurement based on signal strengths is called lateration, the effect of decreasing signal strength, which is used here, is called attenuation.

A position calculation based on the Angle of Arrival (AoA) is a network-centric architecture based on angular estimation. In contrast to lateration, a Bluetooth device can make its location available by transmitting direction finding-enabled packets using a single antenna. The radio signal is then received by a multi-antenna device known as the Locator. For a two-dimensional identification of a position two angles computed from a Locator are needed. For three-dimensional identification, the position is computed by triangulation from at least two Locators.

However, the effort to set up the necessary infrastructure for the receiver is greater than with an infrastructure designed for RSSI. The method is currently not suitable for mobile indoor navigation.

Use cases for Angle of Arrival Positioning

High-precision asset tracking is at home in Industry 4.0, logistics and healthcare. It enables the fast and reliable location of tools, medical devices and production equipment as well as small parts. At the same time, AoA-Tracking also allows the secure identification of closely positioned assets, so that large parts can be tracked reliably and precisely in narrow environments.

• Centimeter accurate tracking
• Tracking assets of any size that are close together

Asset Tracking in production halls

For example, an aircraft engine manufacturer wants to identify and track the position of its unfinished engines in its manufacturing hall. Although the engines are very large, they cannot be tracked reliably using an RSSI-based method because the positioning is too inaccurate to identify the large objects stored next to each other. AoA positioning is sufficiently accurate to be able to distinguish the objects even in confined spaces and reliably identify the required workpiece.

Asset Tracking in hospitals

In a hospital, thousands of pieces of equipment must be reliably available and easy to find. Especially in those cases where time pressure plays a major role, it is important not only to get an approximate position like a certain storage location, but also to have exact information about where the item you are looking for is actually located.

High-precision people tracking

For staff working alone, high-precision tracking is a special safety factor, especially in critical situations in complex environments. For example, when a single worker has an accident in a petrochemical plant. In emergencies, help can be sent directly to the person and not just to the respective section. The Wearable is still an extremely reliable and basic Bluetooth transmitter.

The possibilities of tracking using Angle of Arrival technology are enormous and will increase significantly in the coming years. Even though AoA tracking is suitable for almost every area, a successful implementation of the project depends on professional planning – because every use case is individual. Favendo has particular expertise in the planning, installation and rollout of sensor infrastructures and was even named therefore by Gartner in the Magic Quadrant for Indoor Location Services, Global 2021.

So if you are already planning a specific project or just want to define your options, feel free to contact one of our experts for a free consultation on your use case or use the contact form below. Together we will surely find the best solution for your tracking project!

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