What indoor positionning technology to choose?

Which geolocation techniques?

They all generally use the same technical principle: triangulation or trilateration.

This consists of squaring a more or less large area with antennas.

The antennas communicate with geolocation badges. By comparing the angles, power or communication time between the badges and the antennas, it is possible to know the position of each of the badges.

This is comparable to GPS (Global Positioning System) technology for outdoor geolocation.

Nevertheless, each technology has its own specificity. They differ, for example, in their communication protocols and frequencies, their range, their accuracy and their cost. Discover our comparative table of the 4 technologies at the end of the article!

WiFi technology

It is very well known for the communication between several computer devices at a distance.

WiFi allows an important flow of information but is not optimized for its energy consumption.

WiFi is ideal for communicating a large amount of data very quickly at medium range (from 0 to 300 m in theory).

• The protocol is governed by the standards of the IEEE 802.11 group. It uses the frequency bands of 2,4Ghz or 5Ghz.
• The precision of localization is of the order of the meter in a simple environment. The signal interferes easily with metallic environments.
• The quality of localization deteriorates very quickly depending on the environment. It is therefore complicated to use WiFi to precisely geolocalize flows in industrial environments.

The advantage for industrialists is in the use of existing WiFi antennas.

The antennas are generally already present in the company and therefore do not require new installations. It is simply a matter of using WiFi sniffing methods.

Ultra Wideband for precise location

Ultra Wideband has been gaining momentum for a few years. Due to its technology, the data transmission consumes little and has a high throughput.
But its greatest strength is its accuracy (between 10 and 30 centimeters depending on the environment).

The range is also interesting since it allows to geolocate a badge on a surface of several hundreds of m²!

At Zozio, we often use this technology to offer you our indoor geolocation badges. Currently, no other technology can offer such accuracy with such low energy consumption!

Bluetooth Low Energy (BLE)

This protocol is based on the classic Bluetooth. It was created by Nokia in 2006 to reduce the consumption of Bluetooth communication between two devices. The BLE has an equivalent speed but consumes 10x less. Thanks to its reduced consumption, companies have developed badges (beacons) to locate any object for several years.
In return for its low energy consumption, the range is lowered from 100m to 50m in theory.

In reality, we must expect a range between 10 and 30m to have a guaranteed location.

The protocol uses the 2.4Ghz frequency band.

This frequency band is not ideal for complex environments. The emitted signals will interfere with objects in their environment. The travel time will be extended and some signals will not reach their destination.  The communication will not be ideal.

This technology is particularly suitable for a space with a low occupancy rate.

ZigBee, an innovative solution?

This technology was developed to meet the growing need of the Internet of Things (IoT). The high-level protocol allows data to be transmitted between thousands of nodes very easily and at low power.
The 802.15.4 protocol used by ZigBee defines three usable frequency bands: 868Mhz in Europe, 915Mhz in the Americas and Australia, and 2.4Ghz worldwide.

The Sub-Ghz frequency bands are particularly interesting to limit interference with the environment.

The range is estimated at 100m in a lightly occupied environment. Its location accuracy is of the order of a meter and will be less impacted by the environment than Wifi or BLE protocols.  In an industrial environment, ZigBee seems more appropriate.

Comparison of WiFi, BLE, UWB and ZigBee solutions

The four technologies do not have the same characteristics. They differ in range, power consumption, accuracy, communication rate and cost. The table below summarizes all the characteristics of WiFi, BLE, UWB and ZigBee protocols.

Depending on the use, a different geolocation accuracy is required. Ultra Wideband is the most accurate protocol but will have a higher cost than BLE for example. No solution is ideal! For each project, a different solution should be considered.