I'd like to know the consensus on where the TX power 6dB offset 'rule' between 2.4GHz and 5GHz should be applied......
Should the 6dB off set between 2.4GHz and 5GHz, be designed for "in the air" (EIRP values) - as that is what the client device will be experiencing?
(And antennas often have different gain values for 2.4GHz and 5GHz - which would skew the offset, if set at TX out)
Can you explain what YOU mean by the 6dB "rule". It's not clear.
Do you mean the fact that dual mode antennas are"designed" to have higher gain in the 5 GHz range ? Although that is generally true, the difference is never that great.
Good PA's, power amplifiers, especially at higher frequencies are expensive. 6 dB is a very large difference from a PA perspective.
Newer 802.11n/ac radios are also configured with LOWER output, than were older installations. and because the FCC mandated that multi-stream radios must produce LESS power per stream.