topic Re: Odd looking heatmap in Wireless

Odd looking heatmap

A_Marquez — Mon, 05 Jul 2021 18:36:18 GMT

Good morning,

We use Cisco Prime v3.1.0 and I got a report about a classroom having issues staying connected to the wireless. When I checked the heatmap I noticed this odd pattern where the signal seems fine on the bottom half of the ap but then has this irregular shape on the top where it's like something is suppressing the signal. Attached is a picture of what I'm seeing on our heatmap. The AP is a 3502.

Re: Odd looking heatmap

patoberli — Tue, 28 Jan 2020 15:15:57 GMT

I don't trust PI heatmaps at all, as they are a weird guesswork of formulas. Those are even less correct if the walls aren't correctly drawn. Then some Prime versions had various bugs to the mapping feature.
Can you check with a signal strength measurement tool (a mobile phone with an app for example) and check how the signal strength actually is in the room?
Have you rebooted the AP already? Sometimes a radio can get stuck or some other firmware bug happens and the AP will stop to perform correctly. A reboot typically fixes that.

Re: Odd looking heatmap

A_Marquez — Tue, 28 Jan 2020 15:21:53 GMT

Here lately I've been really questioning how accurate the heatmaps are as we've had a few similar complaints about clients dropping even though the heatmap shows that the signal in the rooms is good. I did reboot the AP yesterday after making this post and so far that seems to have helped but I'll have to physically check the room later. Are there any apps you'd recommend for checking signal strength?

Re: Odd looking heatmap

patoberli — Tue, 28 Jan 2020 15:55:18 GMT

Currently I use the app "WiFi Analyzer (open-source)" on Android, by VREM Software Development.

Re: Odd looking heatmap

Scott Fella — Tue, 28 Jan 2020 20:03:21 GMT

You should only reference the heat map, but it’s predictive on how the AP’s hear each other. Sounds like you need to be onsite to investigate what the issue really is. Clients dropping isn’t always due to your coverage.