On 2019-03-13 15:11, Tom Psyborg wrote: > On 13/03/2019, Felix Fietkau <nbd@xxxxxxxx> wrote: > >> The reason why we add 3dBm is because using two chains to transmit in >> the worst case (from regulatory point of view) doubles the transmit >> power (= +3dBm). > > An absurd idea that probably came from some misinformed regulatory > boys. There is no way to have 3dBm higher output power just because an > additional antenna exist. Even with 3x3 case it already proves as > inconsistent since there is no 6dB decrease but 5dB. Why would it be 6dB for 3x3? It's logarithmic: 2x2: 3dB 3x3: ~4.5dB 4x4: ~6dB 8x8: ~9dB You may not get +3dB actual output, but you do get some boost from the extra chain. - Felix
