What is TurboQAM and how to enable it ?
This technology makes it possible for the 2.4GHz band with 40 MHz channels to achieve a maximum transfer rate of 200 Mbps per data stream. Multiply that by three (the number of data streams) and we get 600 Mbps.
TurboQAM uses QAM-256 instead of QAM-64 .Maximum data rates are increased on the 2.4 GHz band through the addition of VHT Modulation and Coding Scheme(MCS) values 8 and 9, which support the highly efficient modulation rates in 256-QAM
This feature is supported from 6.4.2.x on AP 200 , 210 , 220 , 270 series and its disabled by default . We can enable it under the "g" radio profile
rf dot11g-radio-profile "default"
The majority of Broadcom 802.11ac clients are expected to support TurboQAM, but they may require an upgrade to the latest driver. Note that the 600 Mbps number applies to 40-MHz channels only. The 33% increase is valid at 20 MHz .