Bluetooth Transmission Speed
Version 1.1 and 1.2 use a variation of frequency
shift keying (FSK) called two-level Gaussian FSK (2-
GFSK) as a modulation technique, and
support max. speed of 1 Mbps
Version 2.1 adds 2 modulations: pi/4-DQPSK and 8-
DPSK to support max. speed of 2.1 and 3 Mbps,
respectively,
while maintaining full backward compatibility at 1 Mbps.
This feature is called Enhanced Data Rate (EDR)