Wireless Access

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Frequent Contributor I
Posts: 66
Registered: ‎02-18-2013

Avoid interference on same channel

Hello to all.

We have a highly dense network with multiple access points near and including the signal leakage between floors ends up affecting our use of channel time that is an AP with a high TX directly affects the others that are on the same channel, the next time or not. The fact is that even decreasing the power of the ARM have the co-channel interference, as can be seen in the attached figure. My question is: Is it possible to use the RX Sensitivity Tuning Based Channel Reuse to try to mitigate this interference? Sometimes we have 90% occupancy of the channel in one area so the RX received.
We have enabled the ARM with the Client Aware enabled and no longer used the HT-40 just to avoid the aggregation of channels. We have 14 controllers 3400 and 500 AP's model AP125 connected, is our version of ArubaOS 6.2.1.3
thank you

MVP
Posts: 4,269
Registered: ‎07-20-2011

Re: Avoid interference on same channel

[ Edited ]

 

One thing I noticed is that all those APs have the same channel, are those neighbor APs ?

 

What's the density of your deployment ? if it is too dense then you should decrease the minimum to 9 and max to 15  ,you should test   this first to make sure that you don't leave any holes .

Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
Frequent Contributor I
Posts: 66
Registered: ‎02-18-2013

Re: Avoid interference on same channel

Exactly, they are neighbors and are on the same channel ARM is who is managing, but as the client is aware active, they do not change the channel, sometimes we have 3 ap's online and on the same channel :smileyfrustrated:

Frequent Contributor I
Posts: 66
Registered: ‎02-18-2013

Re: Avoid interference on same channel

[ Edited ]

Hi Victor

Once tested with the EIRP power 9dBm and the result was not very encouraging, several customers complained of lack of signal in your area. We have a very complicated environment before trying to reposition access points I want to exhaust all possible configurations.

MVP
Posts: 4,269
Registered: ‎07-20-2011

Re: Avoid interference on same channel

 

Can you please run this command to check if you have the other channels available under the regulatory domain attached to the AP-Group those APs belong to?

 

(controller) #show  ap regulatory-domain-profile <profile name> 

Regulatory Domain profile "default"
-----------------------------------
Parameter Value
--------- -----
Country Code US
Valid 802.11g channel 1
Valid 802.11g channel 6
Valid 802.11g channel 11

 

Can you pleas share your ARM config ?

Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
Frequent Contributor I
Posts: 66
Registered: ‎02-18-2013

Re: Avoid interference on same channel

Country Code BR
Valid 802.11g channel 1
Valid 802.11g channel 6
Valid 802.11g channel 11

 

 

-------------------------------------------------------

Adaptive Radio Management (ARM) profile "RF_PROFILE_G_A4"
---------------------------------------------------------
Parameter Value
--------- -----
Assignment single-band
Allowed bands for 40MHz channels None
Client Aware Enabled
Max Tx EIRP 127 dBm
Min Tx EIRP 15 dBm
Rogue AP Aware Disabled
Scan Interval 10 sec
Aggressive scanning true
Active Scan Disabled
ARM Over the Air Updates Enabled
Scanning Enabled
Multi Band Scan Enabled
VoIP Aware Scan Enabled
Power Save Aware Scan Disabled
Video Aware Scan Enabled
Ideal Coverage Index 10
Acceptable Coverage Index 4
Free Channel Index 25
Backoff Time 240 sec
Error Rate Threshold 50 %
Error Rate Wait Time 30 sec
Noise Threshold 75 -dBm
Noise Wait Time 120 sec
Minimum Scan Time 8
Load aware Scan Threshold 1250000 Bps
Mode Aware Arm Disabled
Scan Mode all-reg-domain

 

----------------------------------------

Profile 802.11g

 

Parameter Value
--------- -----
Radio enable Enabled
Mode ap-mode
High throughput enable (radio) Enabled
Channel N/A
Transmit EIRP 15 dBm
Non-Wi-Fi Interference Immunity 2
Enable CSA Disabled
CSA Count 4
Spectrum Monitoring Disabled
Spectrum Monitoring Profile default-g
Advertise 802.11d and 802.11h Capabilities Disabled
Spectrum Load Balancing Enabled
Spectrum Load Balancing Mode channel
Spectrum Load Balancing Update Interval (sec) 30 seconds
Spectrum Load Balancing Threshold (%) 20 percent
Spectrum Load Balancing Domain N/A
Beacon Period 100 msec
Beacon Regulate Disabled
Advertized regulatory max EIRP 0
ARM/WIDS Override OFF
Reduce Cell Size (Rx Sensitivity) 0 dB
Management Frame Throttle interval 1 sec
Management Frame Throttle Limit 20
Maximum Distance 0 meters
RX Sensitivity Threshold 0 dB
RX Sensitivity Tuning Based Channel Reuse disable
Protection for 802.11b Clients Enabled
Adaptive Radio Management (ARM) Profile RF_PROFILE_G_A4
High-throughput Radio Profile default-g
AM Scanning Profile default

 

thx Victor

Guru Elite
Posts: 21,010
Registered: ‎03-29-2007

Re: Avoid interference on same channel


Rafap wrote:

Hello to all.

We have a highly dense network with multiple access points near and including the signal leakage between floors ends up affecting our use of channel time that is an AP with a high TX directly affects the others that are on the same channel, the next time or not. The fact is that even decreasing the power of the ARM have the co-channel interference, as can be seen in the attached figure. My question is: Is it possible to use the RX Sensitivity Tuning Based Channel Reuse to try to mitigate this interference? Sometimes we have 90% occupancy of the channel in one area so the RX received.
We have enabled the ARM with the Client Aware enabled and no longer used the HT-40 just to avoid the aggregation of channels. We have 14 controllers 3400 and 500 AP's model AP125 connected, is our version of ArubaOS 6.2.1.3
thank you


I would:

 

1.  Uncheck Client-Aware

2.  Change the ARM Max TX Power to 18

3.  Change the ARM Min TX power to 12

4.  For now, do not use the RX sensitivity Tuning Based Channel Reuse, just to see what happens.  It seems like all of your APs are at 15, which means they could go lower.  12 or 9 is probably the lowest that you want them on.

5.  Disabling 40 MHZ channels is good, but it will not do anything for 2.4ghz (b/g) channels; it would only help with 5ghz (a) channels.

6.  Are you using "Drop Broadcast and Multicast" on all of your Virtual AP profiles?

7.  How far apart are your access points?

 

 

How far apart are your access points?



Colin Joseph
Aruba Customer Engineering

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

Aruba
Posts: 233
Registered: ‎11-19-2009

Re: Avoid interference on same channel

Please make sure we enable BCMC on all VAP`s to reduce the air congestion especially on 2.4 GHz.

May I know the type of clients connected to the network ? Disable the multi-band scanning and band-steering if the clients are swithcing between "a" and "g". 

 

From the Screen shot I see one of the AP shows up "56%" of Channel busy and other AP`s are less than 30 %.

Enable AMON on the controller pointing to airwave to capture the live report of RF utilization, client report and it`s history.

Find below link.

 

http://community.arubanetworks.com/t5/Community-Tribal-Knowledge-Base/Why-you-should-always-enable-AMON-on-your-Aruba-Controller-when/ta-p/72104

 

Also please attach show ap debug radio-stats and show ap arm rf-summary to look at mac errors etc...

Is the clients are dropping when they roam or being stationary or are we facing ping loss on 2.4.GHz.

 

It would be great if you can provide little bit of more info.

 

Thx.

 

Frequent Contributor I
Posts: 66
Registered: ‎02-18-2013

Re: Avoid interference on same channel

Hello cjoseph

I'll have to perform these tests by the parties, even to have a better understanding and control of changes, I will begin the same way you put it, in the same sequence.

The question of distance between access points on average have 10 access points allocated in a hall of about 200 meters, with a single account would be one access point every 20 meters, assuming all are below the ceiling and targeted.
thank you

Guru Elite
Posts: 21,010
Registered: ‎03-29-2007

Re: Avoid interference on same channel

You should have no more than 4 access points in an open hall with no obstructions, because they can all see each other..

Try turning off all but 4.


Colin Joseph
Aruba Customer Engineering

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

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