Belgian research lab Imec claims that a software change to the Bluetooth specification has the potential of adding distance measurement with up to 30 cm accuracy.

The change Imec says works with a standard Bluetooth transceiver at each end ort the radio link, hence should be workable on existing smartphones. So far, accurate location and high security could only be achieved by using high-end solutions based on ultra-wideband [UWB] radios.

Imec lab’s ranging technique uses phase-difference-on-arrival, and has been demonstrated on existing evaluation boards for Bluetooth and IEEE802.15.4 chips, needing less than 32 Kbyte ROM and 64 Kbytes of RAM on an Arm Cortex-M4F and taking under 50 ms per measurement running at 120 MHz. “It is extremely robust for multi-path reflections, which are typically a challenge for RSSI based solutions operating in indoor environments,” said Imec.

Applications are foreseen in building access and car entry as well as location-based data access services where accuracy and privacy are important. The technology can be used anywhere two IEEE802.15.4 transceivers are communicating. It is being developed to meet Imec partner applications, and is available for commercial licensing. It is also applicable to ZigBee and Wi-Fi transceivers.