Prime Floor View Heatmaps show different Color for same Transmit Power

[derobbacher]

Hello Cisco-WLAN-Experts,

I have noticed that our Cisco Prime Heatmaps are confusing regarding the color representation of

WLAN APs with identical sending power.

Eventhough the WLAN APs are configured with same sending power, the Color representation

shows different intensity size  around the WLAN APs.

All APs are of same model and configuration and there are no obstacles configured on the floor area.

I have attached an example for Your appreciated examination.

What might be the reason for this confusing representation of identical WLAN-APs ?

Thank You for Your Input in advance

Greetings from Frankonia

Wini

[pwwiddicombe]

It can be confusing.  What channels are these on?  Is this A or G range?

A radios in the lower channels support a relatively low power output, while the high end channels to support much higher power, even if both are set to the same "power levels".

[derobbacher]

Hello pwwiddicombe

please find attached the same floor representation showing Channels and Transmit Power.

Why are there different sizes of Color with same channel and transmit power ?

Greetings

Wini

[pwwiddicombe]

Different model of AP, perhaps, or external antenna; we also can't see the types of walls that might be involved.

[patoberli]

You don't seem to use any DFS channels, you might want to consider start using them, if allowed in your country. This would offer many more channels on the 5 GHz band. Nearly all clients are compatible.

And yeah, I agree with the others, if you don't draw any walls, the representation is very wrong.

I also think, but ain't entirely sure, that the Prime doesn't use the information on how the other APs hear each other, I think it only uses static data, based on the used AP model, placement and drawn obstacles.

[Freerk Terpstra]

Prime's maps are ideal to get a quick overview of your access-point's health, channel utilization and configured powers. The heat-maps are based on how the access-points can hear each other based on the neighbor packets (which are always send on the highest power possible and lowest data-rate). This makes the heat-maps nothing more than a prediction and a lot of times not really useful. Due to that I always tell the customer to trust the site-survey data instead.

I did notice in your screenshot that all your access-points run on full-power which is most of the times a bad idea. Did you conduct a site-survey?