Max Tx Power Not Achievable on RB911G-5HPnD (SOLVED-ish)

[yottabit]

The RB911G-5HPnD [u]product page[/u] states the radio has a 1000 mW output power (+30 dBm).

Couple problems here:

• 802.11a/n 5 GHz operation in the United States specifies a maximum power level of 50 mW (+17 dBm), 250 mW (+24 dBm), or 1000 mW (+30 dBm) for different channels ([u]U-NII 1/2/3[/u]) in the band, and these rules are not enforced by the regulatory domain setting in the AP
• The default Tx power level in the AP is 50 mW (+17 dBm)
• Even specifying a higher Tx power level manually has no effect, even with regulatory domain unset (all rates still show +14 dBm in Current Tx Power, with +17 dBm Total including the +3 dBi antenna gain that also cannot seem to be adjusted properly) (see attachments)

Is the advertising on the product wrong? Or is there a software problem (noticed no difference running 5.26 v. 6.5)?

[uldis]

most likely your radar-detect found the lower channel frequency as suitable and there output power is lower. Check the Status page to see what frequency the wireless interface uses.
If you use frequency-mode=regulatory-domain you can’t override the tx-power above the regulatory-limit.

[yottabit]

Nevermind, I just figured it out. But there might be a bug involved here, too?

After running a sweeper I noticed my frequency selection never took effect. The lowest channel (#36, 5180 MHz) was always being used, regardless what the RB was configured to use.

Turns out, when DFS Mode is set to anything except “none” the RB will only use #36, 5180 MHz. I believe this is a bug? Because DFS is specifically meant to help with radar interference in the middle and upper part of the band, not the lower part. The Unites States regulatory domain even requires the use of DFS in the middle and upper band, but not the lower band.

However, when I set DFW Mode = none, and then select a high channel (#161, 5805 MHz), I see the Tx power levels increase to +27 dBm (with +30 dBm including the +3 dBi antenna gain, which btw is still not working correctly because I have the gain set to 0 dBi).

So it seems to me there is a bug where DFS isn’t working properly when selecting any but the lower channel. And in the United States regulatory domain this should be required.

It would also be nice if the antenna gain setting worked properly.

Thank you!

[ofca]

Antenna gain works in regulatory-domain setting, since regulatory requirements refer to EIRP, which includes antenna gain in calculation.