UWB vs Bluetooth Channel Sounding – which is better for distance measurements?
The idea
Both Ultra WideBand (UWB) and Bluetooth are two of the leading wireless technologies on the market. Bluetooth is making a significant move into UWB's territory, leveraging its new specification and Channel Sounding feature in distance measurement-related scenarios.
Main differences between these two technologies are understandable, but what about the real-life comparison of how they work, or maybe in other words, could they be a digital measuring wireless tape or a virtual ruler? Our team of QA engineers from Comarch set up experiments in the company’s offices to find the answer to this question.
Test environment
The experiment was performed in a usual IT office with fabric carpets, glass-aluminum doors, several floors, furniture, and a continuous queue to the coffee machine. In addition to the radio traffic from the experiment, there were other wireless signals in the building from various other projects that we work on, such as smart IoT (Z-Wave and Thread), audio devices (UWB audio and BLE audio), and common UWB and Bluetooth activities (ranging and mesh as well) – which is nothing unusual. However, the conditions in this ecosystem are far from ideal and slightly harder for packet propagation than, for example, in the countryside, where there is barely any interference.
Although conducted in a noisy environment, the measurements remain highly relevant. This is because in public spaces there are lots of wireless devices like hotspots, headphones, and other devices, so our results reflect the conditions we face every day.
When it comes to the experiment setup, modules were taken out of the box and firmly attached to a plastic plate to avoid random or accidental movements. Measurements were taken along the same path and under the same conditions.
The “contenders”
At Comarch, we, the engineering team, know these technologies very well, as we develop and use semiconductor leaders' products every day. We know their issues and limitations, as well as their advantages and capabilities. For our experiment, we have selected two modules — one for UWB and one for BT — from a range of solutions designed by industry leaders available on the market. Given how quickly the technology is changing — with new Bluetooth specifications emerging every few months — our objective was a purely technical assessment of its current state as of the beginning of June 2025, without promoting or criticizing any specific company. The selected duo presented the best results of measured values in terms of:
- accuracy – in terms of the overall average value (which in most cases was a value in between min and max read values) read within a couple of seconds for each distance;
- stability – determined by the difference between min and max values from the average value and by the frequency with which these edge values appeared in the readings.
With a read procedure and a definition of the above metrics, we have focused more on the user experience rather than theoretical methodology. To avoid random issues and ensure accuracy, we repeated any measurement that appeared unusual or highly inaccurate. However, if these values were repeated in every case, we claimed them as true and not a propagated interference or other radio disturbance.
Configuration of the modules
UWB configuration
In terms of UWB module configuration, we selected 20 ms of UWB active radio time, and 1 s of an interval between measurements and Two-Way-Ranging (TWR) mode as a middle ground between power and accuracy efficiency that we usually use in applications for our products, demos, and development for customers.
For UWB, with the configuration presented above, we measured average current (for Tag) of 0,75 mA and 98,5 mA (peak values). We achieved such results because the radio remained in the sleep mode for most of the measurement time.
Bluetooth Channel Sounding configuration
There were a lot more parameters to configure on the Bluetooth side. However, we focused on those that seemed to have the most significant impact on the discussed functionality, such as:
number of connection events between consecutive Channel Sounding procedures,
- connection interval,
- the suggested duration for each Channel Sounding subevent,
- number of used antenna paths,
- algorithm to calculate the distance from the data,
- the method used to perform measurements (phase-based ranging (PBR) or round-trip time (RTT)).
It is possible to combine those parameters to achieve current consumption ranging from 0,6 mA to even 3 mA average. Of course, with better accuracy and stability comes bigger current. After some testing, we decided not to care about power consumption, since at this point, we wanted to compare accuracy rather than power efficiency. Then, we selected a set of parameters to reach the best measurement values:
- 30 connection events,
- 7.5 ms connection interval,
- duration between 1250 µs and 4 s,
- 2 antenna paths,
- default algorithm, with the module delivered by the vendor,
- PBR mode.
This is the point where some challenges begun. We ended up with two BT modules that had the best results. The first demonstrated higher accuracy but with greater current consumption (1.8 mA average, 31 mA peak). The second was more power-efficient (0.97 mA average, 16.9 mA peak) but showed a 20–30% error at shorter distances, escalating to 60% at longer ranges. As a result, we chose the more accurate (but more power-thirsty) first module in our experiment.
Measurements
The results are presented in the table below (click here to download the table). The average read value is in most cases average of min and max value. All values are in centimeters.
End comments
After the analysis of the collected data, we were able to directly compare the performance of Ultra WideBand and Bluetooth Channel Sounding in real-world scenarios. Here are our key conclusions:
- UWB demonstrates better stability in its distance readings, with edge values appearing less frequently than with Bluetooth Channel Sounding.
- In terms of the error of the average value to the real value, UWB technology provides better accuracy.
- The accuracy of Bluetooth Channel Sounding is notably improving with successive SDK releases.
- While Bluetooth can yield very good results, it often comes with higher current consumption.
- While the initial purpose of UWB was distance measurement, it is now evolving to include new features such as audio streaming and enhanced car security.
- Bluetooth is already designed with multiple features, and Channel Sounding is just another valuable and useful enhancement to an already advanced and universal protocol.
Ultimately, the choice of communication protocol for your project comes down to your specific needs. By understanding the pros and cons of each technology, you can balance the trade-offs between accuracy, stability, cost, and power efficiency to find the right solution for you or your customer.
Comarch’s experience in wireless technologies
With over 6,000 skilled technical employees worldwide, Comarch is a globally recognized and stable provider of comprehensive software and hardware services. Our teams comprise specialists and engineers who deeply understand client needs across various domains, including software development, connectivity, integration, quality assurance, interoperability, and cross-platform services.
Our extensive knowledge of modern technologies, including Bluetooth and UWB, supported by a combination of hardware and software, is one of the main factors in delivering a comprehensive and individual approach to each project. Through several years of cooperation with market leaders, Comarch has gained the experience needed to equip the company with the desired solutions.
To discover more about how Comarch’s expert and high-quality services can be tailored to meet your specific business requirements contact us. Comarch’s dedicated team is prepared to offer personalized assistance and lead you through the potential of leveraging their innovative solutions for your organization’s prosperity.