How Bluetooth Angle of Arrival (AoA) Technology Modernizing The World

This article is a complete guide talking about Bluetooth Angle of Arrival (AoA) technology, its difference between AoA and AoD, AoA locator hardwares using AoA technology and its difference with hardware using BLE RSSI, AoA locator use cases , and product recommendation. Read further to know details.
Angle of Arrival Bluetooth Locators
Table of Contents

BLE Angle of arrival Technology and productized AoA locators are revolutionizing the reliability of Bluetooth technology and promoting adoption across nearly every industry. From smart homes to smart buildings, virtually every industry that relies on IoT devices and their capability to communicate with each other, or track specific assets or people, can benefit from AoA locators.

AoA locators aim to revolutionize industries ranging from manufacturing to retail. Today’s smart buildings and smart factories can benefit from the enhanced accuracy of AoA locators for tracking packages, products, personnel and equipment.

Dusun IoT published a new Bluetooth AoA demo kit that can be deployed within 10 minutes and the RTLS software can be used permanently. Orders placed before May 26th will enjoy preferential pricing. Don’t miss it!

Hospitality, retail, transportation and shipping can also benefit from AoA locators. They are also being used in health care for more reliable internal management. Prisons can use Bluetooth Angle of Arrival technology to track and position personnel where they are needed most, with fewer false alarms. In one smart city, according to an IEEE case study, AoA locators and BLE AoA technology were used to help manage the flow of pedestrian traffic to create safer streets.

So, What is Bluetooth Angle of Arrival Technology?

Since the early iterations of Bluetooth in the mid-1990s by Swedish engineer Jaap C. Haartsen, the exact positioning of singles between devices has been a challenge. Previous Bluetooth technology could only achieve an accuracy of roughly five meters using a process called “trilateration” to determine the positions of devices.

In early 2019, the Bluetooth Alliance SIG (Special Interest Group) introduced the Direction Finding in the Bluetooth standard specification 5.1, pushing Bluetooth positioning technology has also entered the field of high-precision positioning.

Difference between Angle of Arrival and Angle of Departure

High-precision Bluetooth positioning technology is divided into AoA angle of arrival and AoD Angle of Departure according to the different uplink and downlink modes of the positioned terminal. However, whether it is AoA or AoD, the basic principle of angle detection is the same.

The phase difference of the signal on different array elements is obtained through the antenna array, and then the direction of arrival information is obtained through the signal angle estimation algorithm.

The AoA Angle of Arrival uses a single antenna to transmit a direction-finding signal, and the device at the receiving end has a built-in antenna array. When the signal passes through, there will be a phase difference due to the different distances received in the array, and then the relative signal direction is calculated.

bluetooth angle of arival

AoD The departure angle rule is the opposite. The signal is sent by a device with an antenna array in a fixed position and transmitted to a terminal with a single antenna. The terminal can calculate the direction of the outgoing wave based on the received signal, and then locate it. As shown in Table 1, the positioning characteristics of the AoA method and the AoD method at the transmitter and receiver are compared.

angle of departure

See the following table: signal at the receiving end needs to be sampled by I/Q, and the data processing is more complicated; compared with the AoA method at the transmitting end, the AoD method at the transmitting end uses base station positioning and antenna array, and the system cost and technical complexity are higher . Therefore, the current Bluetooth indoor positioning system gives priority to Bluetooth AoA positioning.

AoA and AoD Transmitter and Receiver Comparison
Types Transmitter Receiver
AoA Positioning Terminal, Single Antenna Locating Base Stations, IQ sampling
AOD Locating Base Stations, Antenna Arrays Positioning Terminal, IQ sampling

Frequently Asked Questions of Bluetooth Angle of Arrival

What is Bluetooth 5.1 Angle of Arrival?

From Bluetooth 5.1 Core Standard, the Angle of Arrival (AoA) technology has been used with BLE for Direction Finding. Compared to received signal strength indicator (RSSI), it aims to boost location accuracy. In order to obtain significantly better location accuracy, the Bluetooth Angle of Arrival (BLE AoA) method measures the direction of a signal broadcast by a BLE beacon as it approaches a Bluetooth gateway.

How Accurate is Bluetooth 5.1 Direction Finding?

Bluetooth direction finding offers accuracy at centimeter level. In actuality, the accuracy varies depending on elements like the hardware quality of the AoA locator, radio signal noise, surfaces that reflect radio waves, the precision with which the AoA locator is placed, and beacon orientation. Accuracy can also be increased by using location engine software that is sophisticated enough to mitigate some of the aforementioned problems. Dusun IoT’s BLE AoA positioning hardware ware solution can reach accuracy of 0.3-1 meter. Welcome to Quote.

What is Angle of Arrival/AoA Locator?

Bluetooth Angle of Arrival Positioning Technology leads to the invention of AoA Locator. The Bluetooth devices are able to achieve an average accuracy from 0.1 meters to 0.5 meters, and item-finding and point-of-interest information services become even more useful. In a word, This more accurate AoA positioning technology makes Bluetooth wireless systems more efficient and effective while increasing the possibilities for their use.

Bluetooth Triangulation Accuracy

AoA locators allow Bluetooth signals to track and locate other Bluetooth-enabled devices using triangulation rather than trilateration. Where trilateration relies on signal strength, triangulation uses the timing differences in the reception of tags’ signals to increase Bluetooth positioning accuracy. This makes Bluetooth triangulation technology far more reliable for locating Bluetooth signals, and vastly enhancing the accuracy of positioning capabilities for Bluetooth devices.

AoA locators send signals to a public cloud from cards, indoor or outdoor beacons, smart watches and mobile devices to a user’s private cloud. In addition to serving as a positioning gateway, an AoA locator can also support WiFi, BLE5.2, Z-Wave and Zigbee protocols to connect sensors and devices.

Beacon Gateway vs AoA Locator

Both BLE beacon gateway and AoA locator are Bluetooth Gateways. They all serve for Bluetooth location service.

BLE Beacon Gateway

Bluetooth Beacon is usually placed in a fixed position indoors and continuously advertises to the surroundings, and all advertising data is arranged under specific rules. The BLE beacon gateway can be used to scan BLE Beacon devices, and then send data to the cloud to realize remote cloud management. The most commonly used function of the BLE gateway is reverse positioning. The reverse positioning is to use the BLE beacon gateway to upload the scanned Bluetooth data to the cloud server through the network, and use the RSSI in the Beacon device data to determine the distance or range between the Beacon device and the Bluetooth beacon gateway, so as to peform location tracking. At the same time, the scanning range of the Bluetooth beacon gateway can also be marked as a safe area. Once the Beacon device leaves the safe range, it can trigger a security alarm in the background. This is also the key to achieving safe care and material management in industrial uses.

AoA Locator

While AoA locator adds the AOA positoining technology on the basis of RSSI, improving the original Bluetooth positioning accuracy to the accuracy of centimeter, easy to operate and low cost. AoA locators send signals to a public cloud from cards, indoor or outdoor beacons, smart watches and mobile devices to a user’s private cloud. In addition to serving as a positioning gateway, an AoA locator can also support WiFi, BLE5.2, Z-Wave and Zigbee protocols to connect sensors and devices. Meanwhile, an AoA Locators can be used in conjunction with other AoA Locators for a larger positioning coverage space and even greater accuracy. A single AoA Locator can obtain the actual heading angle, or pitch angle of a Bluetooth tag and retrieve an absolute spatial coordinate. Multiple AoA Locators can increase accuracy across a larger area. Therefore, AoA locator can bee seen as a groundbreaking breakthrough for indoor positioning.

AoA Locator Design

The Bluetooth Angle of Arrival algorithm is able to transmit a specific direction-finding signal by a antenna. The receiving device has an array of antennae that read the signal phase difference between the signal transmitting antenna and its many antennae. By using sample data, the receiving device can calculate the relative signal direction.

BLE AoA Positioning vs BLE Beacon Solution

Positioning Accuracy

The BLE AoA positioning system adopts the latest Bluetooth 5.1, and can improve the positioning accuracy to the sub-meter level or even the centimeter level, based on the positioning principle of the BLE angle of arrival AoA. While the traditional Beacon positioning solution is based on the RSSI three-point algorithm. Since the RSSI value is not a reliable judgment value, the positioning accuracy will be relatively poor, generally within 3 to 5 meters.

Active/Positive Location

BLE AoA positioning adopts a passive positioning method. It only needs to locate two positioning devices including the base station and the positioning terminal. the positioning terminal transmits, and the positioning base station scans and receives. While BLE beacon positioning is an active positioning method, which requires three parts of the positioning device: the positioning beacon, the positioning terminal and the smart Bluetooth gateway. The positioning beacon advertise the signal, the terminal scans, processes and forwards the signal, and the Bluetooth gateway transmits the positioning data to the server.

Power Consumption

The base station of Bluetooth AoA positioning adopts PoE or DC power supply, and also adopts the low power consumption technology of BLE, so the power consumption is quite low. The Bluetooth beacon only needs to advertise data, coupled with the low power consumption technology of BLE, so the power consumption of the beacon is also very low.

However, in the Bluetooth Beacon positioning solution, the positioning terminal needs to continuously scan the broadcast signal of the beacon, and also needs to perform some data processing, calculation and forwarding, so the power consumption of the beacon positioning terminal is often relatively high, and the frequency of positioning charging and maintenance costs are accordingly higher.


Because the BLE AoA positioning base station uses multiple antenna arrays to improve positioning accuracy, it needs some positioning data processing and calculation through PoE power supply and data return, so there is a wiring cost, and the deployment will be relatively higher. While the Bluetooth Beacon positioning solution generally uses battery-powered beacons and does not require cables, so the cost of deployment is relatively low, but the cost of battery replacement and maintenance for replacing new positioning beacons will be relatively high.

Therefore, If yo want to choose a Bluetooth positioning solution, it is necessary to comprehensively consider the cost based on you project requirements, positioning accuracy requirements, maintenance costs, and project budget. Also, when select a positioning solution, you can take consideration of consider an integrated positioning solution when appropriate. Contact Dusun IoT to get customized Bluetooth positioning!

AoA Locator Uses

Improve Supply Chain Efficiency

By accurately tracking “last mile” deliveries, AoA Locators are already making it easier to solve supply chain issues. In supply chain and logistics, quickly identifying the location of specific pallets or containers in a crowded shipyard can help move them to the correct destination faster and more accurately

Improve Shopping Experience

AoA Locators can also be used to make brick-and-mortar shopping experiences easier and more personalized by tracking the position of goods and shopping carts for better consumer navigation. Combined with big data analysis, AoA locators can guide shoppers to the right product aisles and deliver coupons to their smartphones for a seamless shopping experience.

Prevent the Elderly and Childern from Going Missing

AoA locators can also be used in conjunction with wearables and smartphones for real-time tracking of older adults and children. Both groups are at risk of becoming lost or disoriented, so AoA locators can provide peace of mind to their caregivers.

In essence, any industry that requires improved logistics, personnel tracking and better asset management can benefit from an AoA locator and Bluetooth-enabled devices or tags.

Dusun IoT AoA Locator for Recommendation

In addition to their increased accuracy, AoA locators have a number of benefits. Usually they have a battery life of up to five years for long use. And thanks to the Bluetooth ecosystem, they are a cost-effective way to create more accurate tracking for devices inside and out. An AoA locator can support a high tag density without using much power.

Multiple Bluetooth manufacturers have developed AoA locators, so it’s important to choose the right one to meet your needs and your specific application to realize the full benefits.

Dusun DSGW-200 gateway, can support Internet of Things (IoT) anchor capabilities for compatibility with a broad range of devices for Bluetooth 5.1 applications and higher versions. The DSGW-200 AoA Positioning locator works for indoor Bluetooth positioning with an accuracy of 0.3-1 meters for personnel tracking and real-time positioning of assets. 

Dusun AoA locators also support a multitude of tags, including:

  • Smartphones
  • Bracelets
  • Smart watches
  • Beacons
Dusun angle of arrival locator

AoA Locator Future

Bluetooth technology has come a long way and continues to evolve. In any situation where managers want to track people or assets, AoA locators can streamline the process with incredible accuracy.

As smart buildings and smart cities gain momentum, AoA locators can be the key to connecting all of the devices and technologies to keep them running smoothly. Several key factors may keep angle-of-access technology at the front of the line. The ability to handle various protocols, including Zigbee and other IoT devices, along with its backward compatibility with Bluetooth 4.0 bodes well for angle-of-access technology.

Its accuracy, low cost and low power consumption make applying AoA technology virtually a no-brainer for many industries. It’s worth considering for commercial, retail, manufacturing and home applications where greater location capabilities are required. Contact us today to see how angle of arrival technology can support your needs.


National Inventors Hall of Fame (NIHF) – Jaap C. Haartsen

Bluetooth – How AoA and AoD Changed the Direction of Bluetooth Location Services

IEEE Xplore – AoA-Based Localization System Using a Single IoT Gateway: An Application for Smart Pedestrian Crossing

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