Bluetooth Channel Sounding: What It Is and How It Will Enhance Your Connections

September 16, 2024
Jason Marcel
Access Control, Bluetooth Low Energy, Broadcast, Channel Sounding, Connected Device, Digital Key, Item Finding, Location Services

2408 Event IMG Update Channel Sounding 3

For more than a decade, developers have leveraged Bluetooth^® RSSI (received signal strength indicator) as a coarse-ranging feature capable of estimating the distance between two devices, helping Bluetooth devices better anticipate user needs and become more intelligent, responsive, and intuitive. Bluetooth^® RSSI has ushered in a wide range of novel use cases, including Find My networks and digital key solutions, offering a glimpse into what can be achieved when a device can understand its location in relation to another. That potential inspired a group of key Bluetooth Special Interest Group (SIG) members to come together to enhance the accuracy and security of Bluetooth device ranging capabilities.

This effort led to the introduction of Bluetooth^® Channel Sounding, an entirely new protocol stack, including a new PHY (physical layer) designed specifically to enable secure, fine ranging between two Bluetooth devices.

“Extending an already rich ecosystem, the Bluetooth® Channel Sounding standard enables connected devices to more precisely and securely locate each other, paving the way for the design of new low-cost, energy-efficient, location-aware solutions,” said Kyle Golsch, senior RF system engineer at DENSO. “It also has the potential to provide a more secure and convenient user experience for automotive digital key solutions and we look forward to leveraging this technology inside and outside of automotive areas to enable more seamless user experiences for all.”

“The Bluetooth® Channel Sounding standard enables connected devices to more precisely and securely locate each other, paving the way for the design of new low-cost, energy-efficient, location-aware solutions.”

– Kyle Golsh, DENSO

Bluetooth Channel Sounding

Bluetooth^® Channel Sounding brings true distance awareness, introducing transformative benefits across various applications. The user experience of Find My solutions can be greatly improved, making it easier and faster to locate lost items. In digital key solutions, Bluetooth Channel Sounding will add a robust layer of security, ensuring that only authorized users within a specified range can unlock doors or access secure areas.

“Bluetooth® Channel Sounding will apply to consumer, enterprise, and industrial settings alike.”

– Andrew Zignani, ABI Research

“Bluetooth® Channel Sounding will apply to consumer, enterprise, and industrial settings alike,” said Andrew Zignani, senior research director at ABI Research. “Imagine Bluetooth mice, keyboards, and game controllers that can automatically switch between active and inactive states based on their distance from a laptop. In industrial settings, distance aware Bluetooth human-machine interface (HMI) solutions can increase personnel safety by only allowing usage from a safe distance. Meanwhile, Bluetooth device networks, such as those used for networked lighting control, can more easily self-configure to enhance system performance using this innovative technology. With 1.35 billion Bluetooth connected devices forecasted to ship in 2024 alone, the opportunities are significant.”

By infusing billions of everyday devices with true distance awareness, Bluetooth^® Channel Sounding unlocks a world of possibilities for developers, freeing them to imagine and create innovative experiences that will continue to enhance our connection with our devices, one another, and the world around us.

Bluetooth^® Channel Sounding: A Technical Overview

This paper provides an overview of the forthcoming update to the Bluetooth^® Core Specification. The update adds Bluetooth Channel Sounding, a new feature that enables secure fine ranging between two Bluetooth devices.

LEARN MORE

Higher Accuracy, Greater Security, and Trusted Ubiquity

By combining the inherent accuracy and security of this new feature with the prevalent ubiquity of Bluetooth technology as a whole, Bluetooth Channel Sounding promises to be the easy, safe choice for adding a fine-ranging capability to Bluetooth connected devices.

Accurate: Bluetooth^® Channel Sounding leverages multi-channel, phase-based ranging (PBR) to enable highly accurate fine ranging between Bluetooth connected devices. When performed between two devices, Bluetooth^® Channel Sounding offers centimeter-level accuracy over considerable distances, meeting the needs of the vast majority of applications and allowing even the simplest connected devices to take advantage of true distance awareness.
Secure: As the number of connected devices grows, so does the importance of maintaining the integrity of those connections. Bluetooth^® Channel Sounding deploys robust, multi-layer security that includes a secondary ranging method, round-trip time (RTT) secure distance bounding, to add an extra layer of protection to counter sophisticated man-in-the-middle (MITM) relay attacks.
Ubiquitous: One key reason for the incredible success of Bluetooth® technology is the tremendous flexibility it provides developers. Bluetooth® technology is already embedded in all major consumer platform devices, including smartphones, tablets, and laptops.

“This technology (Bluetooth® Channel Sounding ) will open up a wide range of new opportunities to create new product types and greatly improve the user experience of existing devices with location aware user interfaces.”

– Oyvind Storm, Nordic Semi Conductor

With Bluetooth^® Channel Sounding, developers will now be able to add true distance awareness to Bluetooth connected devices without having to design in an additional radio technology.

“Nordic Semiconductor is extremely excited by the release of Bluetooth® Channel Sounding,” said Oyvind Strom, executive vice president of the short-range business unit for Nordic Semiconductor. “This technology will open up a wide range of new opportunities to create new product types and greatly improve the user experience of existing devices with location aware user interfaces.”

To learn more about the intricacies of this new Bluetooth feature, check out the Bluetooth^® Channel Sounding Technical Overview.

Bluetooth® Channel Sounding: A Technical Overview

This paper provides an overview of the forthcoming update to the Bluetooth® Core Specification. The update adds Bluetooth Channel Sounding, a new feature that enables secure fine ranging between two Bluetooth devices.

LEARN MORE