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wireless interference

Answered Question
Aug 8th, 2013
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  Hi,


I have a 5508 WLC installed in an area of 1500 sq m. There are  LAP which is active in that area. The users are complaining of weak signals in the area.


There is some iron construction going on in that area.


Would like to know whether that affects AP signal strength?                 

Correct Answer by Scott Fella about 4 years 1 week ago

You have AP's up? In the cli can you IAS a show advanced 802.11b summary and ski do one for 802.11a

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Leo Laohoo Thu, 08/08/2013 - 20:43
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Depends on how dense is the iron works.


Download inSSIDer and check out the wireless signal/propagation for yourself.

Pravin Pillai Thu, 08/08/2013 - 21:10
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The site is at remote location. I have asked the local to provide to S/N ratio


Need to know what is the threshold level for s/N ratio

Scott Fella Fri, 08/09/2013 - 04:16
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Well... If you have some sort of construction and they have equipment that naught cause interference and it might be blocking signal, then that's your issue. If it started when the construction began, then you have a good idea of why users are complaining. Unless you go out there and test, you will never know.

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Pravin Pillai Fri, 08/09/2013 - 04:35
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Could be due to power signal setting? The power the client is getting might be low?


How can i check the power which is allocated to client via some command on WLC

Scott Fella Fri, 08/09/2013 - 04:39
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Look at the GUI under the wireless tab. On the left side is 802.11bgn or 802.11an. That will show you what power level the ap is using. That's what you need to look at. Again, your troubleshooting something that really requires a site visit. Making changes to something that was working can affect the rf later. Power Level of 1 is the highest power setting for an ap. so you can manually set that if you want.

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Pravin Pillai Fri, 08/09/2013 - 04:50
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I cant see the power setting.. I can see noise profile and interference profile etc.


For me to go to the site is not feasible.

Scott Fella Fri, 08/09/2013 - 04:53
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You can see the power setting for the access points? It's in the GUI.

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Pravin Pillai Fri, 08/09/2013 - 04:58
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AP Name

Radio Slot#

Base Radio MAC

Sub Band

Operational Status

Load Profile

Radio Role

Noise Profile

Interference Profile

Coverage Profile

CleanAir Admin Status

CleanAir Oper





only these ar visible

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Scott Fella Fri, 08/09/2013 - 05:01
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You have AP's up? In the cli can you IAS a show advanced 802.11b summary and ski do one for 802.11a

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Pravin Pillai Fri, 08/09/2013 - 05:18
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Thanks got it. The Tx powr is as low as 2 dbm and -1 dbm for some LAP.


Is tht the cause?

Scott Fella Fri, 08/09/2013 - 05:20
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Yes that is low. You will want to set the min tx power to say 14 dbm.

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Pravin Pillai Sat, 08/10/2013 - 05:45
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thanks so much for the help


I wanna ask the power setting we apply to LAP is that same as Tx power or is there some other setting//


Is there any config command to increase or level the Tx power to 14 dbm frm as low as -1 dbm?

Scott Fella Sat, 08/10/2013 - 06:31
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You can set the max TX and the min tx for each band. Here is where you can set it. You want the min around 11 dbm to start with.

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Scott Fella Sat, 08/10/2013 - 06:35
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Rmember that this is in dBm and that is the value you need to enter.


Thanks,

Scott

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Pravin Pillai Thu, 08/15/2013 - 07:01
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Hi ,



I have not changed the min and max Tx power since RRM algo determines it. but for testing I changed the problematic LAP power to max TX power which is 1.



The client report that the client switches between different LAP even when they are in perimeter of coverage area.

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