Wireless Access

Hi...

In Aruba 275 outdoor Ap data sheet it indicate ..,

Maximum (aggregate, conducted total) transmit power (limited by local regulatory requirements):
-2.4-GHz band: +28 dBm (23 dBm per chain)
-5-GHz bands: +28 dBm (23 dBm per chain)

What's 23 dBm per chain means? and here in Sri Lanka it's restricted to import outdoor APs exeeding 23 dBm, since it indicate +28 dBm can we still justify maximum emitting poer as 23 dBm?

It would be limited to the max allowed for your regulatory domain, to ensure it is compliant

The above answers are correct, the regulatory setting on the controller will prevent APs from exceeding any regional regulatory limits.

To answer your question regarding the 28dBm max (23dBm per chain), the AP-275 is a 3x3 AP, which means there are up to three chains. Each chain being 23dBm, the second chain will add 3dBm to the total output, and the third chain will add another 1.8dB. 23dBm + 3dBm + 1.8dBm gives you 28dBm max (rounding up). 

Informative explanation… Thanks…. 

Hi Jerrow,

Why does the second chain add 3 dBm and the third chain 1.8 dBm? Why doesn't the third chain add another 3 dBm as the second chain? Why those numbers?

Regards,

Julián

2x corresponds with +3dB (10*log 2)

3x corresponds with +4.8dB (10* log 3)

4x : +6dB

10x: +10dB

1/10: -10dB