Hello,

anyone knows what happened to antenna-gain in 6.46.8 or how to make it work again? It was working in 6.45.8 and most probably in 6.45.9,
it is not in 6.46.8, the option is missing totally - both in winbox and terminal.



thanks

antenna-gain is now a CLI-only parameter.

Antenna-gain is now a CLI-only parameter.

Why?

antenna-gain is now a CLI-only parameter.

that's unfortunate :-/ How do I display it? detail does not show it, I didn't find it anywhere

/interface wireless set antenna-gain=x


one more thing
i've been asking multiple times about Spectral scan, i want that features to be implemented on 5 mhz

Seeing current antenna-gain value ?

Use CLI:

i've been asking multiple times about Spectral scan, i want that features to be implemented on 5 mhz

Spectral scan is function of wireless radio chip. Mikrotik uses the cheapest versions of the chip that simply can't do it, no amount of software can fix that.

Why?

I assume because 1) most Mikrotik devices have fixed antennas (with corresponding gain) and 2) it is no longer required for "tx power abuse", as tx power can be set manually.

Devices with fixed (built in) antenna should not allow gain changes. Gain is the property of the antenna, so why would you change it? This parameter is only so that you can specify what kind of external antenna you have connected.

Isn't it also the only way to reduce TX Power? By specifying a higher antenna gain? Yes, there are situations where you might want to lower TX Power.

Isn't it also the only way to reduce TX Power? By specifying a higher antenna gain? Yes, there are situations where you might want to lower TX Power.

No, it is not. In advanced mode on your wireless interface you can specify TX Power. No need (anymore) to use the gain setting.

You can adjust Tx-power by selecting "all rates fixed" in Tx Power Mode and afterwards setting a lower Tx power.

"Antenna gain" It is not the only way, but it was the "better" and "easier" way to do it.
"Better" because it correctly calculates the max TX power for every MCS to comply with the EIRP emission requirements. (Higher MCS'es have broader RF sidelobes and need to transmit at a lower TX power). TX-power setting according to those "card rates" does not work with many devices. "All rates fixed" works but does not moderate for the MCS spectrum differences.
"Easier" because you do not need to do the math with the antenna gain. The current/default value is hidden quite deep even with CLI.

The GUI could at least have shown the antenna gain, and the corresponding max TX power (which is now in the status tab). Or could have added a "TX power DELTA" parameter, or that fuzzy "% power" of other brands ("fuzzy" because this is logarithmic).

And the "DELTA" is not a signed number, so cannot increase the TX power, just as the minimum antenna gain is prohibiting the setting of a higher TX power.

Changing tx-power-mode to all-rates-fixed and altering tx-power does nothing unless we also set frequency-mode to manual-txpower which isn't allowed for the country selected that I'm currently in.
Atleast that's what I get on a hAP ac2.
And changing the country to something else you wouldn't be bounded by the reglementations of that country (max tx power and frequencies allowed), trusting the user to not break that.
So altering antenna gain was/is the only easy and "decent" way to decrease TX Power and still be bounded by reglementations.
Just my thoughts on this.

Your regulation forbids increasing power. If you use this setting to lower the power and you are operating within the legal allowed total EIRP, I don't see why a certain mode would not be allowed to use

Altering "All rates fixed" power level is the wrong way to do this. That's why there was "Card rates" option instead, but that stopped working with 802.11ac hardware.

Why is "All rates fixed" bad? Let me explain:
802.11 uses various modulations, from classic BPSK/QPSK to OFDM with QAM. Increasing modulation complexity requires more linearity in power amplifier. So it's very important to follow hardware specifications on maximum power level for various modulations. If you don't, signal will be distorted and it will actually worsen the SNR, produce unwanted interference outside of channel mask and it will make device non-compliant.
What antenna gain did it emulated the "Card rates" power option, where the antenna gain was subtracted from power levels at each modulation. So if by default you had 20dBm for 802.11b and 16dBm for 802.11n MCSx, it would decrease both proportionally.
But now, if you try to do the same with "All rates fixed" power, you are limited by maximum power level defined by most complex modulation. You can't go above that otherwise signal gets distorted as described above. If you are lowering power by say 10dBm, this may not be an issue as you will be below even most complex modulation level. But if you just want to lower power output by a few dBm, you can't.
Using same example with 20dBm/16dBm power levels, if I wanted to lower it by 2dBm, I can't. If I set fixed power to 18dBm, higher MCS levels will be distorted and device will not be compliant and power levels at different modulations will be affected differently.

What most people really want is to enter simple value that lowers the gain proportionally for all modulations by a specified number. If I want 5dBm weaker signal, I just enter "5" and I get 5dBm less signal over all modulations and modes. Irregardless of regulation domain settings, MIMO chain settings, different radios and products and all the other mess, keeping things simple and always working.

What most people really want is to enter simple value that lowers the gain proportionally for all modulations by a specified number. If I want 5dBm weaker signal, I just enter "5" and I get 5dBm less signal over all modulations and modes. Irregardless of regulation domain settings, MIMO chain settings, different radios and products and all the other mess, keeping things simple and always working.

THIS! All rates fixed is NOT a good solution.

What most people really want is to enter simple value that lowers the gain proportionally for all modulations by a specified number. If I want 5dBm weaker signal, I just enter "5" and I get 5dBm less signal over all modulations and modes. Irregardless of regulation domain settings, MIMO chain settings, different radios and products and all the other mess, keeping things simple and always working.

Yes!

normis says: You can adjust Tx-power by selecting "all rates fixed" in Tx Power Mode and afterwards setting a lower Tx power.

Would it be possible to bring back Antenna Gain or something similar? I need a simple way to lower power.

+1!

Seeing current antenna-gain value ?

Use CLI:

Code: Select all

/ interface wireless export verbose
/ interface wireless print advanced

wow - i have hundreds of various RBs, but this is the first time I see the advanced option, I thought detail was for this.. thanks bpwl, man never stops learning :-)

I use antenna-gain exactly as many people mentioned here and that is why I miss it, some of our APs move frequently and if I see bad wireless conditions / interference etc on the spot, I just lower power by setting antenna-gain, without bothering about different powers, changing country regulations etc - very fast and comfortable, and I remember the default antenna-gain values for most of our routers

+1

bring back the antenna-gain feature within GUI on future releases.. Let MikroTik OS calculate proper TX and regulatory EIRP settings.... Mucking with all-card-rates-fixed is not the answer.

i'm keeping my devices on 6.45.9

now it gets interesting.. 6.46.8 on cAP (arm) - no antenna gain - the reason this topic was created.

Now I looked at 6.46.8 RB912UAG-2HPnD (mipsbe) and... guess what? Antenna gain is there.

So I tried RB2011 6.46.8 - no antenna gain.

What is the logic in this? It was removed on devices with integrated antennas?

Yes, exactly that. Since it knows the gain of the integrated antenna it uses a hard coded value instead of being set from user input. So if you have any device with integrated antenna, there is no good way to reduce TX power.

Reason is probably FCC or other similar regulator spotted "antenna gain" to be adjustable in one of the Mikrotik boxes with internal antennas and went full "YOU CAN'T LET USERS DO THAT!!!" and so Mikrotik removed/hidden it from GUI.

I'm fine with that, as long as there is new feature with same functionality of lowering power evenly.

Hey, Mikrotik, if you are listening, just make something like this:
Under TX power, add new Tx power mode, call it something like "lower power for all rates" or "decrease power evenly" or whatever you want to call it, and let us enter the value there.
As long as it works the same way (ie. adjusts power down evenly for all modulations) I'd be perfectly happy with it.

And NO, "all rates fixed" is definitely NOT what we need or even usable in our cases, as described above.

Yes, what r00t says is what is being considered.
Also yes to the other posters above, it was removed from user input, because "antenna gain" is a hard parameter of the antenna itself. Adjusting it makes no sense, if antenna is non removable.

@normis

but that feature works on both types of antenns.
when you saying non removable, you mean Internal antenna vs external antenna, is that correct?

but that feature works on both types of antenns.

Radio doesn't know the difference between antennae, only your friendly local RF inspector does.

The problem with unrestricted antenna gain settings is that it is possible to set it lower than actual value and the resulting EIRP is higher than allowed. So hardcoding antenna gain for "permanently attached" antennae is the correct way of doing it, the only problem is the resulting awkwardness of the way to reduce Tx power. Hopefully MT will come up with some great idea how to do it and with even better name for the new setting.

So hardcoding antenna gain for "permanently attached" antennae is the correct way of doing it,

Actually the "minimum antenna gain" is hard coded when regulatory domain is used for built-in antenna. So hiding this from the GUI was not really needed to be compliant. with RF certification.
But it is/was very confusing for novice users that setting the antenna gain was not altering the antenna gain, as intuitively expected from the wording, but telling RouterOS to take that amount of antenna gain into account.

Short wording is difficult, but should express something like: "TX Power reduction compensating for antenna gain".
Still the need to give a higher number to further reduce the transmit power can be contra-intuitive, and that minimum should be visible somewhere then.

I hope they find a way out of this. I'm not the only one who holds all his AP functioning devices in the 6.45.x version. They all have specific antenna-gain setting by tuning iterations.

It's becoming an old story. viewtopic.php?f=21&t=154662&#p774279
And I'm still uncertain about the actual transmit power used: viewtopic.php?f=21&t=154662&#p775439 when using other settings.

I would like to repeat the main issue with this. Antenna gain is a fixed physical parameter of an antenna. Like weight. If antenna is fixed and permanently attached, why would you need to edit this value?

The field needs to be edited only if the system doesn't know what antenna you have attached.

If you need to lower transmit power, there are / will be other ways to correctly do it.

We know what it means and what it does, adjusting TX Power by that amount to comply to the regulatory-domain limits for the country set.
Its long definition in the case above would be: "antenna-gain=substract this amount from the maximum EIRP of the country set and use the result for TX Power." or something like that.
We also know that a setting can't make the internal antennas from our hAP ac2s for example, bigger or smaller, and adjusting that value thinking that this would be the result is pointless, BUT:
We also said for what we were actualy using that setting for, except the obvious stated above, it was an easy way to reduce TX Power even more without much headache, and that's what we want to be able to do in the future also without much headache.
We know that it wasn't meant to be used that way, but it served for that purpose very well.
We'll wait for the new implementation of a similar setting with a new name or whatever, to be able to do exactly that.
Thank you for listening to us!

OK, we will have to update the manual, there is a lot of stuff there, that applies to very old Atheros 5xxx chips only.

The mode all-rates fixed, however misleading its name, never transmits with power higher than cablibrated for compliance. You should be using this mode to reduce the power.

Examples of what happens with different approaches:

calibrated power: mcs0=20dbm mcs7=16dbm
regulatory limit: 19dbm

1) if you will set antenna-gain=1, tx-power=default:
actual tx power mcs0=18dbm (regulatory - antenna-gain), mcs7=16dbm

2) if you will set antenna-gain=0, tx-power=18:
actual tx power mcs0=18dbm, mcs7=16dbm

3) if you will set antenna-gain=5, txpower=default:
actual tx power mcs0=14dbm, mcs7=14dbm

For each modulation, the minimum of 3 values is used as "tx power": 1 - regulatory limit minus antenna gain, 2 - configured tx power in all-rates-fixed mode, 3 - calibrated power for modulation.

The problem with unrestricted antenna gain settings is that it is possible to set it lower than actual value and the resulting EIRP is higher than allowed. So hardcoding antenna gain for "permanently attached" antennae is the correct way of doing it, the only problem is the resulting awkwardness of the way to reduce Tx power. Hopefully MT will come up with some great idea how to do it and with even better name for the new setting.

not true - too low values threw errors, something like "minimal antenna gain for this country is xx" . So it was checking antenna gain value vs EIRP/country

I would like to repeat the main issue with this. Antenna gain is a fixed physical parameter of an antenna. Like weight. If antenna is fixed and permanently attached, why would you need to edit this value?

MKT,Normis, trying to justify what they did. Removing a parameter called "antenna gain" from the GUI.

"Antenna gain is a fixed physical parameter of an antenna." Yes it is and that is baked into hardware (the physical structure of the antenna).
The parameter called "antenna gain" is a parameter that can be set. It is not physical at all, it is not related to the physical antenna in any way. It does not adjust the working characteristics of the antenna. It is just a variable used in calculating and setting the TX Power of the radio. Unfortunately it bears the same name, ( what leads to a lot of confusion, ) because the value must be equal or larger than the physical antenna gain to be compliant with regulation. That simple compliance test is in place already for a long time. Removing that parameter from the GUI is not helping to enforce this compliance.

Once again, MT showing off their ability to ignore users or understand uses or understand wifi terminology they use.
Why they have not hired bpwl to clean up their wifi mess is inexcusable.
Impeach the bloody lot of them ;-)
Did I say Bpwl make MT Wifi Great Again LOL.

Whatever is decided I want to be able to reduce maximum allowable output in decibels (single digits).
Since we are talking fixed internal antenna units, it should be
A. TX power reduction by rate selections
B. TX power reduction across all rate selections (as stated above).
(in most consumer routers one can select the TX power in decibels up to the max available for that unit)

I really dont care how its done but the wording above is not ambiguous or confusing.
As a user I expect the default to be max power and then I can lower it to suit my needs.

Maybe some people are not able to think they could do something contra-productive, just by refusing to undo it , they think they are right, even if many people ask for it.to be undone.

- That "antenna gain" parameter (not the antenna gain physical characteristic) is a relative power adjustment. The TX Power setting is an absolute power adjustment. An absolute setting cannot just replace a relative setting in many many systems.
- Even the cheap devices from Edimax, TP-link, D-link, Engenius, Draytek, .... let's say all equipment I have ever seen has a possible relative setting.
- Advantage of this parameter is also it is giving at least a (very) little feedback in the 'status' line of the interface.: 5220/20-Ce/ac/P(21dBm) , while the "Current TX Power" is empty. I know that "Current TX Power" used to come from the wireless chip and is not there with the newer chips. But that's no reason to take away ALL information from the operator.

Do we have to do the math ourselves every time ? regulatory domain, set antenna gain (which is hidden from the gui and from the default export or print) , TX power set, calibrated power .

What ^^^ said!!

Yes at the end of the day I want a relative reduction in power from the max setting, in single DB digits as required (by rate or by all).

hAP Ac3 have removable antennas, but there is missing antenna Gain in 6.47.7.