Ruckus Power Settings

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Trying to work in Ekahau and figure this out. So if I set an AP power to 4dBm or 3dBm in Rukus what would that equate to?

Am
I taking the full power value of the band for instance 20dB and then if I choose -3dBm in Ruckus that would change to 10dB and if I want 4dBm I can do -7dBm approximately?

Also I can't seem to find a command that will give me the EIRP in the AP.  Tried this:

rkscli: get txpower wifi0
 wifi0 transmit power set to -3 dB from max power


So is that telling me that the AP power is 17dBm?
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Ali

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Posted 3 weeks ago

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Abilash P R

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Hi Ali,

Please let me know the AP Model/Country Code that you are using; I would find the Max Tx power of that AP.

Regards,
Abilash PR.
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Ali

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R610 and using it in the US.  However that still won't answer my question.  Need to know how Ruckus does its calculation?
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Abilash P R

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Hi Ali,

"I taking the full power value of the band for instance 20dB and then if I choose -3dB in Ruckus that would change to 10dB and if I want 4dB I can do -7dB approximately?"

If this is your question ? (Correcting the dBms to dB.)

You are correct, lets assume that when Tx power is set to auto/full it is 20dB, when you reduce it to -3dB then the power would be half'd which is 10dB, so if you want 4dB then it is -7dB by rules of 10's & 3's (-10+3 = 20 dB/10 = 2dB * 2 = 4dB).


Regards,
Abilash PR.
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Ali

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Thanks so much for that information and correction.  So using what you explained above if I plan AP's with 4dB in Ekahau I will change the value in the VSZ to -7dB.  Similarly the chart below makes sense?

But that ads some confusion too.  What is Min then and I'm guessing Full/Auto would be 20dB?  Also looking at the chart below 15dB to 19dB there is no way to set that as the option is not available in Ruckus?

Also is there no way to see in the dashboard what each AP is transmitting at?  All I see is the Tx Power Adjustment -3dB but it would be nice to be able to see it in a normal way if it is at 14, 17 or 20 etc.



 
(Edited)
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Mitchell Axtell

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-3dB on a radio is not 10dB, it is -3dB from peak, so 17dB.  As dB is a logarithmic unit, -3dB is effectively half of the noise.  It is not half of the dB value.

dB and dBm cannot be compared directly.  dB is an absolute value- the strength of a noise source independent of the antenna gain/loss, interference and other values.  dBm is the received power level of a signal in reference to 1 milliwatt, which is why it is shown in very low numbers in site survey programs like Ekahau (-10 to -100, usually).  Halving the dB level of a radio is not necessarily going to halve the dBm figure the client displays, as there are other factors at play that affect this.
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Ali

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Thank you that's what I am trying to understand how Ruckus does it. If the values in the figure are simply subtract from the peak value like you said -3dB will be 17dB and similarly -4dB will be 16dB and so on or is it actually adding the attenuation (BTW read that some where that is why asking). So far I haven't been able to find any official documentation on this which is pretty surprising. If you know of any would you kindly share the link? Thank you
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Abilash P R

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Hi Ali,

I am sorry, Mitchell is right; I got wrong with Units; which changed entire calculation.

AP:R610, Country Code US; Firmware:3.5.1.

Auto/Max 2.4Ghz Radio 18dBm 
Auto/Max 5Ghz Radio 20dBm 

Min 5Ghz Radio 2dBm
Min 2.4Ghz Radio it is usually 1dBm; this should still need verification.

Now, you could calculate your Tx accordingly, say if you set the Tx power -1dB then your Tx power of AP would 17dBm in 2.4Ghz Radio and 19dBm 5Ghz Radio.

Please note, this would vary according to country code and MCS rate.

Regards,
Abilash PR.