What is the default Radio transmit power range (dBm)

[JohnDH]

Hey there,

I'm wondering what the default settings are for:

Wireless > Radio Settings > RF Profiles > Basic Indoor Profile > 5GHz
Radio transmit power range (dBm)

This is a range, so there are two values, one to the left and and one to the right. 

Transmit shorter distance: How low the AP might choose to set its transmit power.
Transmit farther: How high the AP can set its transmit power.

Mine was set between 8 and 30.
But I wonder if this is the default (recommend).

Reason is that i see my own Meraki AP's interfering on the same channels with a signal strength of -66 dBm

And channels are set to Auto.

Regards

John

[ww]

Yes 8 and 30 is default for the indoor profile.

If you create new profile you can choose another preset. F.e. classroom

If you have many ap's you could force them to 40 or even 20Mhz

[MerakiDave]

Hi @JohnDH. As @ww mentioned, those are the default values and AutoRF will tend to balance things out, but rarely would you want to leave the max set to 30dBm, that's one full watt of Tx power and no client device will ever match that anyway. 

In many many deployments I typically see customers leave the default of 8 and bring down the max to perhaps 23 to 25dBm for example.  Of course the proper answer is always found via site survey but as a rule of thumb remember that you DO need some cell overlap, for example your walk-through may reveal cell edges at -67dBm with minimum data rate of 12Mbps with 20% cell overlap, then use band steering to 5GHz, perhaps disable every other 2.4GHz radio, and then additional tweaks as needed.  If you get as far as adjusting RXSOP (which we say is like putting "ear muffs" on the AP) then do that LAST, that is only meant to be leveraged in a deployment that has already been fairly well tuned. 

Perhaps a first step would be for you to drop that RF Profile down 3dB at a time and observe your results over the course of a day.  Remember the AutoRF changes will not be immediate, there is an algorithm with timers and limits to how many dB can be increased/decreased in a given time, in order to prevent a ripple effect throughout the coverage area.  So even if you bumped an RF profile max Tx power from 30 all the way down to 20dBm, it would take some time to get there, by design. 

[WB]

@MerakiDavecan you confirm that the radio transmit values are just the value of the IR itself (the radio alone) and not the EIRP including the antenna gain?

So if I wanted to target a max. EIRP of 24dBm in the 5 GHz band on an MR46, I would set the slider to 18dBm as I have to take in to account the 6 dBi gain of the antenna?

[MerakiDave]

Confirmed @WB  that Tx power is the IR itself.  Hope that helps!

[WB]

Thanks for the confirmation!

[JohnDH]

Well thank you both for the reply.

The question was fairly straightforward asking for the default setting.

And the answer was also straightforward.

The underlaying reason of my question is of course more complex.

The issue i'm seeing in one of the many office locations is that even with the minimum power set to 5 - the Meraki Access Points still hear each-other very 'loud' (-54 to -62dBm) on the same channel. And all most all of them dropped transmit power to 5.

Even with the Radio Channel set to Auto, I get up to 5 Meraki AP's on the same channel. 
They keep changing channels - over and over again, but only choose the lower range UNII-1 channel range.

They do not use the other channel ranges although they are available.

For now, only one office location is showing this, and we have a felling this started after MR 28.7 - September 10th.

Anyhow, I have a ticket open with Meraki support on this issue.

I will follow up when I have some news.

Thanks

JohnDH