Wireless Access

Reply
Occasional Contributor II
Posts: 16
Registered: ‎10-28-2010

Reference spectrograms for healthy networks

Is there any place that has a library of healthy spectrograms and fft's, particularly for high density deployments?

 

I'm wondering because in the attached image, channel 11 had a pretty solid red line where no other channels have that problem, and I suspect it's causing some interference issues.

 

Any suggestions?

Contributor II
Posts: 40
Registered: ‎01-21-2011

Re: Reference spectrograms for healthy networks

There is Aruba document ( I think whitepaper) for this but I can't find it right now.

 

You can also google out this document, it's slightly more desriptive: "airmagnet spectrum xt user guide pdf"

Guru Elite
Posts: 20,777
Registered: ‎03-29-2007

Re: Reference spectrograms for healthy networks

May I ask, is this a problem that you are dealing with?  The spectrogram tells a certain part of the story, but by itself it does not mean the network is "bad".



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor II
Posts: 16
Registered: ‎10-28-2010

Re: Reference spectrograms for healthy networks

We were having an issue with bandwidth availability and packet loss in that section of the building, particularly in that classroom. It was likely an overload issue and has since been resolved (upgraded from single radio to dual radio with N), but it still appears there is some interference in channel 11 on the 2.4 ghz band (hence the red line). I'd like to get it cleaned up, if possible, but I want to make sure that it actually is interference. 

 

In the originally attached image, there is a pretty solid red line in the center of channel 11 that does not appear in other channels, so I was wondering if it was normal to appear that way or was it something worth investigating as possible interference. That's why I wanted to see a healthy spectrogram, for comparison.

 

 

 

Guru Elite
Posts: 20,777
Registered: ‎03-29-2007

Re: Reference spectrograms for healthy networks

Agreed.

 

With your spectrum analysis tool, does it indicate what devices are on channel 11 that are wifi, vs. non wifi?  You have to identify what is causing it to possibly do something about it...



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor II
Posts: 16
Registered: ‎10-28-2010

Re: Reference spectrograms for healthy networks

It's the built-in spec analyzer on the aruba controller (running latest 6.2) with an ap135 scheduled in spectrum mode, in case you were wondering... great tool.

 

It lists a freq-hopper (cordless base) in the channel, but there isn't anything like anywhere in the viscinity of the ap, so I don't know... we'll keep looking.

 

 

Guru Elite
Posts: 20,777
Registered: ‎03-29-2007

Re: Reference spectrograms for healthy networks

Okay,

 

Spectrum provides part of the picture, but that might not be the sole issue affecting your network.

 

What is your primary issue?  Are your clients using encryption?  When did it start happening?

 



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Search Airheads
Showing results for 
Search instead for 
Did you mean: