Classic Bluetooth vs BLE #

Bluetooth is a short-range radio protocol used for communicating between devices. The first 3 versions are called “BR/EDR” for “Basic Rate/Enhanced Data Rate.”

Versions 4 and 5, known as “Bluetooth Low Energy,” or BLE, broke hardware compatibility with classic Bluetooth, but increased the data rate while lowering energy consumption, crucial for battery-powered devices like phones. As of 2020, the latest release of Bluetooth is release 5.2.

BR/EDR and BLE use the same physical antenna at 2.4 GHz, and both use FHSS (frequency hopping spread spectrum), but with different allocations of frequency bands.

BR/EDR used 79 channels, each 1 MHz wide, but BLE uses 40 channels, each 2 MHZ wide.

Both versions use frequency shift keying, which means that bits are encoded with two nearby frequencies.

BLE uses Gaussian frequency shift keying, which is similar, but the transistions between frequencies are less abrupt, which spews less noise at other frequencies.