A Day at the Beach  - Pushing Bluetooth Range to the Extremes

Tue, 02/25/2020 - 14:11

Supercharging the Personal Area Network - An Exercise in Bluetooth Range

Bluetooth, now approaching its 12th generation at Bluetooth 5.2, has been carefully developed and segmented to cater to a growing number of use cases and applications. Bluetooth Class is the categorization which separates Bluetooth products by their transmit power, which has an effect on power consumption and overall range. They range from Class 1 (with an average range of ~320 feet) to Class 3 (~1.5 feet), and they have very different purposes and uses for different customers.

Most consumer products fall into Class 2, which requires a maximum permitted power of up to 4dBm (1.5 mW) and achieves a typical range of 65 feet. This is the Bluetooth Class which most of us associate with the devices we use daily: headsets, wireless keyboards and mice, and other typical consumer items that occupy the Personal Area Network (PAN).

But other applications outside the consumer space, such as those found in medical and industrial environments, often require higher range and therefore higher power consumption to push Bluetooth data across larger environments, or to overcome signal loss in harsher RF  environments.

We wanted to see what the absolute limits of our BL654 Bluetooth LE module, and to do so, we set up a highly specialized test to push those traditional boundaries. One fine day in North Somerset, UK, we brought loads of RF / test equipment to Brean Down with the goal of seeing exactly how far we could sustain a Bluetooth LE link, and the conditions that would maximize that range.