Access point power level is maximum with good RSSI

[mina_raouf]

Hello

I have a cisco controller 5520 with more than 300 access points joining it, I found that most of the access points like 250 out of 300 are working on the maximum power level 1 on 5g band only, while on 2.4 bands the power level is within normal levels, the power is set to auto 

I checked random clients attached to those Access points I found that they are getting a very good signal with RSSI above 60dbm and SNR above 30 

coverage hole detection values are all set to default -80

Any recommendation that might cause the Access point to radiate on power level 1 on the 5G band only?

[patoberli]

You can check the neighbors, if you have enabled DCA. DCA is the part that does the channel-power adjustment and needs/should be enabled on 2.4 and separately on 5 GHz. If the DCA algorithm doesn't see the neighbor APs with a strong enough signal (can happen with some antennas or very high ceiling, for example) they are set to full power.
So first, check your DCA settings for 5 GHz.
How is the channel load on a busy day?
Are you using mostly 20 MHz?

[mina_raouf]

Hi 

The DCA is enabled on both band and also set to auto, I am using  channel bonding of 40Mhz on the 5g band 

[patoberli]

Then it's well possible that you have enough channels and wide enough spacing between the APs to run at full power.

Do you actually have a problem in the network, like high channel load or very slow speeds?

[mina_raouf]

Till now (this is a new implementation) nothing was reported as slowness or  bad performance, but it is a bit confusing for me why the access points are working on the highest power level although the distance between access points are not that far 

[Leo Laohoo]

The only reason why the WLC has automatically set full power to 5.0 Ghz is because there is not "enough" co-channel interference to warrant the power to be scaled back.

[Haydn Andrews]

First question I have is what was the wireless requirements that it was designed to? Was there a requirement for -60 RSSI?

When I design the wireless I design it at power levels normally around 25mW (based on clients i am using). I then us RF profiles to limit the power the APs can auto tune to to one or 2 above and below this after I have verified the deployment.

DCA and TPC will be setting the power to power level 1 as it is not seeing the 5GHz neighbours close enough. 

[mina_raouf]

The wireless design was designed on -67db during the predictive survey, the APs were also placed on the lowest power levels (10W) during the survey 

"DCA and TPC will be setting the power to power level 1 as it is not seeing the 5GHz neighbors close enough."

so do you see if there is no performance issue reported, that will be good from a design perspective?  what should be the best power levels for the AP to guarantee that there is no interference and no coverage holes as well 

[patoberli]

That's up to the wireless design/site survey. This actually depends on the used AP and antenna and varies wildly between different structures.