Silicon Labs Bluetooth® Channel Detection Technology Delivers Sub-meter Accuracy, Enabling Safe and Precise Distance Measurement

Breakthrough hardware and software improves Bluetooth device ranging accuracy and security

Beijing, China – September 9, 2024 – Silicon Labs, a global leader in secure, intelligent wireless connectivity for a more connected world, today announced support for Bluetooth® Channel Sounding technology on the xG24 platform.

Bluetooth Channel Probe is a new protocol stack designed to enable secure and accurate distance measurement between two Bluetooth Low Energy connected devices. By providing true distance awareness, Bluetooth Channel Probe improves the accuracy and security of the ranging function of Bluetooth devices.

“Bluetooth Channel Sounding revolutionizes proximity and location capabilities, ushering in a new era for Bluetooth technology at a time when location awareness is critical,” said Ross Sabolcik, senior vice president of the Industrial and Commercial Business Unit at Silicon Labs. “Silicon Labs has always enabled developers to realize the full potential of Bluetooth technology, and our latest hardware and software also create a path for them to accelerate the development of breakthrough Bluetooth products equipped with Bluetooth Channel Sounding.”

Bluetooth channel detection improves the accuracy and safety of distance perception

By helping to estimate the distance between two devices, the Bluetooth Received Signal Strength Indicator (RSSI) has opened the door to a new wave of applications. From solutions that help locate devices such as phones or tablets to digital security enhancements such as geo-fencing, Bluetooth technology has improved the convenience and ease of everyday activities. However, the challenge is that Bluetooth RSSI relies on estimates to determine location. At the same time, RSSI is susceptible to problems such as multipath and obstacles, which can greatly reduce accuracy. Bluetooth channel sounding can solve these problems by increasing accuracy to sub-meter levels and enhancing the security of Bluetooth device ranging capabilities.

Bluetooth channel detection uses Phased-Based Ranging (PBR) technology to achieve accurate distance measurement between two devices, and uses an auxiliary ranging method called Round Trip Time (RTT). Independent distance measurements from RTT can be used to verify and cross-check PBR measurements. This cross-validation process helps detect anomalies and ensures the security of the application, which is critical when developing access control solutions for hospitals and industrial buildings, as these solutions must grant or deny access based on proximity.

With PBR and RTT technology, Bluetooth channel detection can be used for home and life applications such as smart locks, consumer electronic device positioning and pet trackers, as well as industrial and commercial applications such as geo-fencing, vehicle keyless entry and access control, while providing accurate, secure and reliable Bluetooth ranging services. With advanced distance estimation technology, Bluetooth channel detection can also be used to triangulate the location of commercial infrastructure such as wireless access points or lighting equipment to meet regulatory requirements or save manpower and costs.

In addition, Bluetooth channel sounding provides a more convenient and flexible ranging solution for applications that already use Bluetooth low energy. In this case, it can be implemented without additional hardware and design space.

Silicon Labs' New xG24 and Antenna Hardware Solutions Support Channel Sounding Technology

Silicon Labs' new xG24 radio board and professional kit are now available for order, providing a fast and efficient way to create and prototype products that use Bluetooth channel sounding for accurate distance estimation. The radio board kit includes a BRD4198A EFR32xG24 2.4 GHz +10dBm radio board, a sleeve dipole antenna, and reference designs.

In addition, the new xG24 development kit will be generally available in December 2024. It features a dual-antenna PCB design and a channel detection visualization tool that enables customers to easily view distance measurement results in real time, thereby simplifying the implementation of Bluetooth channel detection in their products and applications.

Silicon Labs provides customers with new advanced hardware solutions for developing complex products that support Bluetooth channel detection:

• Single-antenna hardware has fewer antenna paths and limited multipath information, making it more suitable for basic Bluetooth channel sounding applications where lower power consumption and reliability in simpler environments are more important than accurate distance measurement.

• Dual-antenna hardware will be available for order and use starting December 2024. Dual-antenna hardware provides higher accuracy, better spatial performance, and enhanced multipath resolution, making it ideal for advanced applications that require precise distance estimation, such as car keys and tags. The board’s small size makes it ideal for size-constrained applications. Additionally, antenna diversity improves signal quality and robustness.

Silicon Labs’ hardware solutions are AEC-Q100 qualified, making them a suitable choice for automotive applications such as Passive Entry and Passive Start systems.

The xG24 host stack and link layer are expected to be certified for Bluetooth Core Specification Version 6.0 by the end of this year. The certified protocol stack will support intra-event antenna switching for optimal non-line-of-sight performance and channel sounding when the xG24 is running in Network Co-Processor (NCP) mode with an external application microcontroller (MCU) or System-on-Chip (SoC) mode with an integrated application MCU.

Partnering with Silicon Labs to Enable Bluetooth Channel Detection

Silicon Labs customers can leverage comprehensive software and hardware solutions, along with patent-pending distance estimation algorithms, to develop products that use Bluetooth channel sounding technology for a variety of everyday applications in the home, industry, commerce or connected health.

At the "2024 Works With Conference Shanghai" to be held in Shanghai on October 24, Silicon Labs will showcase the Bluetooth channel detection technology, solutions and applications implemented on its xG24 platform, and will hold a special training event on this technology. In addition, special in-depth discussions will be held in four technical directions: Bluetooth, Matter, Wi-Fi and Sub-GHz, so that participants can gain insight into trends and receive on-site introductions from professional engineers.