Wireless Access

Reply
Contributor II
Posts: 59
Registered: ‎02-17-2012

Channel hopping & Interference on 5Ghz

Hi,

 

I am seeing a number of my APs hop excessively throughout the day (10+ times).  This doesn't seem right, but looking over the AirWave states reasons such as Empty Channel and Interference.

 

Additionally, I am seeing high Interference >20% on some 5Ghz channels which seems to correspond the times of actual channel utilization.  This, too, doesn't seem right unless Interference is somehow related to channel use.

 

Guru Elite
Posts: 20,976
Registered: ‎03-29-2007

Re: Channel hopping & Interference on 5Ghz

Try to use 20 mhz channels if possible.  If any channel in a bundle shows interference, it will change channels.  Statistically it is more likely to notice interference when you are bonding channels.



Colin Joseph
Aruba Customer Engineering

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

Contributor II
Posts: 59
Registered: ‎02-17-2012

Re: Channel hopping & Interference on 5Ghz

That makes total sense.  

 

Aside from doing that, is there an automated way to get controller or airwave to pick up what the source and location of the interference is?  If not, what do peope usually recommend to get this information?

 

Also, is there a particular reason why AP moves from one channel to another just because it's free. I get the reasoning behind channel switching for interference but simply change a channel because its free doesn't seem right.

 

Thanks.

Guru Elite
Posts: 20,976
Registered: ‎03-29-2007

Re: Channel hopping & Interference on 5Ghz

Free channel < interference than a channel with devices. You should use client aware if you don't want access points to change channels when users are connected.


Colin Joseph
Aruba Customer Engineering

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

Guru Elite
Posts: 20,976
Registered: ‎03-29-2007

Re: Channel hopping & Interference on 5Ghz

To track things down typically a handheld spectrum analyzer is the best way to find something that is in a fixed area. Even with something like a spec-an with a directional antenna it is difficult to locate. ARM is designed to avoid interference so that your clients can have relief sooner.


Colin Joseph
Aruba Customer Engineering

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

Contributor II
Posts: 59
Registered: ‎02-17-2012

Re: Channel hopping & Interference on 5Ghz

Thanks a lot, Colin!

 

Does anyone have any opinions on using wi-spy for finding the source of interference?  Or, perhaps some other tool that can give me both 2.4 & 5 coverage?

 

Also, returning back to my original question, why do I see corelation between channel utilization and interference?

Guru Elite
Posts: 20,976
Registered: ‎03-29-2007

Re: Channel hopping & Interference on 5Ghz

There are users that use the wi spy and get good results. It would be good to hear what other users use and their experiences. I don't have much experience with the with wi spy.

Channels that have more traffic will have more sampling vs. Channels that are only sampled as part of an off-channel scan, so it stands to reason that there will be more DATA about that channel.


Colin Joseph
Aruba Customer Engineering

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

Contributor II
Posts: 59
Registered: ‎02-17-2012

Re: Channel hopping & Interference on 5Ghz

[ Edited ]

Frequent sampling of the used channels makes perfect sense.  What doesn't make sense is fhe fact that interference moves in lock-step with the utilization, unless of course interference implicitely implies utilzation.

Guru Elite
Posts: 20,976
Registered: ‎03-29-2007

Re: Channel hopping & Interference on 5Ghz

Channel utilization is a total of everything including interference.


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: