Bluetooth SIG Launches Bluetooth 6.0 with "True Distance Awareness" via BLE Channel Sounding

The Bluetooth Special Interest Group (Bluetooth SIG) has announced a new version of the core specification that bears its name, Bluetooth 6.0 — bringing with it "true distance awareness" through a feature dubbed Bluetooth Channel Sounding.

"Bluetooth technology has become an ingredient of everyday life," claims Bluetooth SIG chief executive officer Neville Meijers. "When connected devices are distance-aware, a range of new possibilities emerge. Adding true distance awareness to Bluetooth technology exemplifies the ongoing commitment of the Bluetooth SIG community to continuously enhance our connection with our devices, one another, and the world around us."

Bluetooth Core Specification Version 6.0, to give the group's latest release its full title, has distance awareness as its core new feature. Bluetooth Channel Sounding, the Bluetooth SIG claims, delivers "true distance awareness," building on range-finding features added to previous versions of the standard but with "significantly better accuracy" through the use of either Phase-Based Ranging (PBR) or Round-Trip Timing (RTT) — or both, with PBR as the primary method.

PBR, the Bluetooth SIG explains, works by figuring the distance between two Bluetooth devices using the number of wave-cycles needed for the signal to go from the transmitter to the receiver — and is good to around 150 meters (around 500 feet) before accuracy issues crop up. RTT, meanwhile, measures the distance in time, and while it's less accurate can be used with PBR to "eliminate distance ambiguity" and extend the maximum measurable distance between devices.

While defined in Bluetooth 6.0, Bluetooth Channel Sounding is a Bluetooth Low Energy (BLE) feature — and requires support on both devices. It will work with a single antenna, the Bluetooth SIG has confirmed, but will be more accurate when devices have an array of multiple antennas — providing multiple signal paths and improving the accuracy of PBR measurements. As for use-cases, the Bluetooth SIG expects Bluetooth Channel Sounding to be of interest to those building "Find My" platforms and digital key products among others.

Other new features of Bluetooth 6.0 include a decision-based advertising filter for BLE, which allows a scanning device to use the content in a packet received on a primary advertising channel to decide whether to scan for related packets on secondary channels, the ability to filter out duplicate advertising packets, changes to the Isochronous Adaptation Layer (ISOAL) to reduce latency, the ability for devices to exchange information about supported extended link-layer features, and negotiable frame spacing that replaces the previous fixed 150µs spacing.

More information on Bluetooth Channel Sounding is available in the Bluetooth SIG's technical overview, while the Bluetooth Core Specification is available to download from the official website.