Remember when we used to transfer photos between phones using Bluetooth? Those days seem ancient now. What started as a clunky way to share files has evolved into an essential technology we use daily without thinking about it – from our wireless earbuds to our keyboard and mouse setups. The game really changed when Bluetooth Low Energy (BLE) came along.
Back in 2016, Bluetooth 5.0 was released with several new features targeting that booming IoT world. Most recently, the Bluetooth SIG has just released Bluetooth 6.0 on September 3, 2024. This time, it’s bringing some new upgrades and the tech world is racing to adapt to the new specifications. We are excited to take a look at how Bluetooth 6.0 will affect Bluetooth location-based services and the new opportunities ahead of us.
What is Bluetooth and Bluetooth 6.0
Bluetooth basically consists of two standards with the same name: the “Classic” Bluetooth developed in the 1990s and Bluetooth Low Energy (BLE). Classic Bluetooth was originally used for audio streaming and data transfer, and it is now also widely used in device localization technologies to meet the growing demand for indoor positioning solutions.
Today there are over 8.2 billion Bluetooth devices worldwide. Thus, Bluetooth is the most widespread short range wireless communication protocol. In particular, BLE has emerged as a crucial short distance IoT connectivity for low power and efficient communication between devices. Bluetooth 5.0 introduced better tracking capabilities, and now, with the release of Bluetooth 6.0, we’re seeing another major leap forward in high-precision positioning.
Bluetooth 6.0 isn’t just a minor update. Like previous major updates, Bluetooth 6.0 builds on rather than replaces Bluetooth 5.4, 5.3 and earlier versions. Instead, it expands on several new features. The focus this time? Enhanced security and significantly improved distance measurement accuracy.
Key features of Bluetooth 6.0
The standout innovation in Bluetooth 6.0 is Channel Sounding, but the specification includes several other important enhancements:
- Bluetooth Channel Sounding: previously known as HADM, enables high-accuracy distance measurement between Bluetooth devices through phase-based ranging (PBR).
- Decision-Based Advertising Filtering: This enables more efficient device scanning by allowing selective secondary channel scanning based on primary advertising channel content.
- Monitoring Advertisers: A new capability that enables devices to track when advertisers move in and out of range through Host Controller Interface (HCI) events.
- ISOAL Enhancement: The improved Isochronous Adaptation Layer introduces a new framing mode that can reduce latency for time-sensitive applications while improving reliability.
- LL Extended Feature Set: Enables devices to exchange supported link-layer feature information more effectively.
- Frame Space Update: Introduces negotiable interval to replace the fixed 150 μs interval for connections and connected isochronous streams.
How Bluetooth Channel Sounding works
Channel Sounding, previously known as high-accuracy distance measurement (HADM), represents Bluetooth’s latest innovation in distance measurement. It is a way for two Bluetooth devices to measure their distance from each other with greatly improved precision. While traditional RSSI methods offered 3-5 meter accuracy, and Bluetooth 5.1’s AoA/AoD achieved sub-meter precision, Channel Sounding takes a quantum leap forward – bringing accuracy down to less than 10 centimeters and rivaling UWB technology. This is a fundamental shift in what’s possible with Bluetooth positioning.
The magic lies in its dual approach to measurement:
- Phase-based ranging (PBR): Calculates precise distances using phase differences
- Round-trip time (RTT): Measures exact signal flight time between devices
Ranging happens either with one method or the two working together to coordinate 72 channels in the 2.4 GHz spectrum. It supports up to four antenna paths between devices with eight possible antenna combinations.
Bluetooth Channel Sounding and precise positioning
The tech world is buzzing about the many improvements in Bluetooth 6.0, but by far the most notable feature is Bluetooth Channel Sounding. This breakthrough feature is set to transform how we approach location and distance-awareness services. We’re excited to see what’s possible for users and solution providers. Here are some key takeaways.
Bringing accuracy to UWB territory
This new technology features centimeter-level accuracy through phase-based ranging, and that will have huge implications in competing with UWB solutions. UWB has long been known for its precision positioning capabilities, but will that dominance hold on?
For Bluetooth-based location applications, the dual PBR and RTT measurement can provide highly accurate positioning while reducing infrastructure. The current popular UWB and Bluetooth AoA positioning may require complex antenna arrays or extensive infrastructure. Now, secure and precise positioning only needs standard Bluetooth hardware.
More importantly, in challenging environments with multiple reflective surfaces (like modern offices or warehouses), Channel Sounding’s PBR provides reliable measurements utilizing multiple antennas. The implementation of these solutions will also be significantly simpler.
Essentially, positioning accuracy is greatly improved while implementation remains cost-effective and simple. This development could make Bluetooth one of the preferred choices for precise tracking applications.
Ubiquitous adoption in tracking devices
By 2028 we will have nearly 7.5 billion Bluetooth devices shipped and there will be a large number of devices that may integrate Bluetooth channel sounding over time. The technology is positioned for rapid adoption thanks to its compatibility with existing Bluetooth LE hardware in many cases. Some devices available today can even be upgraded to enable this feature.
Some existing devices can be upgraded to support Channel Sounding–creating an instant network of positioning anchors.
Enhanced security and interoperability
Channel Sounding also has high security and better interoperability. It comes with built-in security against common threats to prevent man-in-the-middle attacks and relay attacks. That includes encrypted connections and distributed random bit generator (DRBG) and others. While this may not affect users daily, secure access control and asset tracking will be much more reliable.
Furthermore, Channel Sounding is designed to work with existing Bluetooth technology, meaning it can be combined with Bluetooth AoA/AoD for applications such as indoor positioning and asset tracking.
As a standardized Bluetooth feature, Channel Sounding is expected to see widespread use in new BLE products, including SoCs and positioning modules. This allows scalable, reliable tracking systems to be deployed without additional components or hardware space, all while reducing implementation costs and extending battery life.
Target applications of Bluetooth 6.0
The Bluetooth specification expands with each revision into ever more applications and scenarios. As the world is just beginning to explore Bluetooth 6.0’s new capabilities, we’re in the early stages of Channel Sounding applications. The coming years will reveal innovative use cases. Location services based key applications are as follows.
Find My Solutions
One of the most striking consumer applications is “Find My Solutions.” This includes using various personal tracking tags to locate valuable items such as wallets, backpacks, phones, luggage, keys, and even pets. The centimeter-level accuracy of Channel Sounding allows users to find lost items with much more precision than one would think.
More importantly, almost any Bluetooth LE device with compatible chipsets can now be tracked with high accuracy, without requiring extra hardware. While Apple’s “Precise Finding” has been using UWB technology in iPhone 11 and newer models for precise location of AirTags or AirPods charging cases, Bluetooth 6.0 not only enhances tracking precision for these devices but also brings similar positioning accuracy to devices without UWB capabilities.
Asset Tracking
Compared to previous solutions, Bluetooth Channel Sounding significantly improves indoor asset tracking performance while reducing deployment complexity.
In hospitals, staff can track high-value equipment such as ECG machines and infusion pumps much more easily. Place Bluetooth Channel Sounding tags on tools, trailers or equipment in busy warehouses or construction sites and you will be notified when assets are moved outside designated locations. Channel Sounding combined with electronic shelf labels facilitates product location in large shopping malls or retail centers. Wherever there are a lot of people moving (e.g. airports, train stations), it can offer clear navigation and wayfinding to which gates are your destination, simplifying itinerary.
Digital Keys and Access Control
Channel Sounding shines in digital key applications by combining enhanced security with precise positioning. When used alongside AoA and AoD technologies, it significantly improves proximity sensing for applications like smart locks. While AoA and AoD determine relative position, Channel Sounding measures distance – a combination perfectly suited for secure entry devices.
As a standardized feature, Channel Sounding enables Bluetooth devices to reveal their exact position to authorized devices without requiring UWB chips. With Bluetooth’s growing presence in IoT devices, we’ll soon have a powerful network capable of locating almost anything, anywhere.
Bluetooth 6.0 vs UWB for high-precision positioning
High-precision positioning technologies are getting more diverse with multiple options available in the market. It’s not just about UWB anymore—Bluetooth 6.0’s Channel Sounding brings new possibilities to the positioning landscape. From the above applications, it seems there’s some overlap in UWB and Channel Sounding, so what are the differences?
Accuracy Performance
According to Bluetooth SIG, Channel Sounding delivers centimeter-level accuracy over considerable distances. Both technologies can achieve sub-10cm accuracy within 150 meters—making Channel Sounding an attractive alternative to UWB fine ranging. More importantly, when considering UWB’s high cost and complexity, Bluetooth positioning meets most asset tracking needs.
Additionally, let it be said that current UWB combined with ToF can provide accuracy to centimeters and sometimes to sub-centimeters. For these applications which need that degree of accuracy, UWB is essential.
Power Efficiency
For Bluetooth, energy efficiency is well-known — especially in Low Energy (BLE) mode — and that holds true for Bluetooth 6.0 too. Although UWB chips are being optimized for less power consumption, on average they use more power than Bluetooth, especially for continual communication or tracking.
Market Adoption and Ecosystem
Considering the enormous Bluetooth ecosystem with about 5 billion shipped units a year, the technology clearly has a huge head start. Given its adoption, there will be greater speed to integrate Channel Sounding into various applications. UWB chips are increasingly available in high-end devices but are still seen as an add-on, rather than a Bluetooth alternative.
As a standardized feature, Channel Sounding isn’t trying to replace UWB—instead, it’s complementing existing positioning solutions with centimeter-level accuracy and enhanced security, particularly compared to Bluetooth positioning based on RSSI and Direction Finding.
When will we see Bluetooth 6.0
Bluetooth 6.0’s rollout is beginning, with Qualcomm’s Snapdragon 8 Elite among the first chips supporting the new standard. The iPhone 16 series remains on Bluetooth 5.3, but the upcoming iPhone 17 series will likely jump to Bluetooth 6.0. Early 2025 may see the first wave of Bluetooth 6.0 accessories with earbuds, fitness trackers, and tracking devices.
At MOKOSmart, we’re not just watching the Bluetooth 6.0 revolution—we’re building it. Our MK19 nRF54L15 module supports the new standard Bluetooth 6.0. As Bluetooth beacon manufacturers, we’re eager to see innovative applications, especially in IoT and Industry 4.0. As proof-of-concept deployment expands, more businesses will likely adopt Bluetooth-based tracking solutions.