Wireless Access

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MVP
Posts: 1,111
Registered: ‎10-11-2011

Improving SNR & Speed

In an effort to improve client RF Performance, specifically SNR and speed, I would like to consider all the configurable options I have.  First off, a bit of background:

 

Client Connectivity

  • The majority of clients connecting are 5Ghz/HT-40Mhz
  • All others are 2.4GHz/HT-20MHz.
  • The environment is somewhat mobile (by foot) but would not be described as highly mobile.

 

Client RF Performance - SNR
12% < 20 SNR

38% 20 <> 30 SNR

50% > 30 SNR

 

Client RF Performance - Speed

25% < 54 Mbps

75% > 54 Mbps

 

Client Issues

  • Client roaming sometimes results in worse connection when just sitting at desk
  • Random drops from the network

 

Airwave flags potential connectivity problems for clients with an SNR of 35 or below.  So I use this as my baseline for determining if clients are underperforming.  Looking at the SNR numbers above, I would say that at least half of my clients do not have ideal SNR.  However, the speeds look good - not sure how the SNR and speed actually relate to eachother.  That being said, I think that the network could be tuned a bit to increase SNR and speed.

 

I understand there are several options that could be tweaked, but I am not sure where to start.  I believe I have the following options:

 

  • Adjust transmit EIRP (15 currently)
  • Tweak A & G transmit rates
  • Set local probe threshold

I've done some basic research on each of the options, but I'm not sure where to start if looking to increase RF Performance.  Any suggestions for where to start?

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MVP
Posts: 3,009
Registered: ‎10-25-2011

Re: Improving SNR & Speed

Hello

There is a documentation specifically for roaming and what aruba recommends for it... configurations and things you need to take in mind.

 

http://www.arubanetworks.com/wp-content/uploads/DG_Roaming.pdf

 

I dont nkow if you have read this before?

 

you can get good ideas of this pdf....

 

Cheers

Carlos

----------------------------------------------------
Product Manager - Aruba Networks
Alternetworks Corp
MVP
Posts: 1,111
Registered: ‎10-11-2011

Re: Improving SNR & Speed

I'm more concerned with the issues we have with laptops associating with APs that result in poor SNR or low bandwidth, which occurs when devices are not roaming.   I was hoping to get some information specific to improving SNR.  I don't think there are any docs that mention specifically how that's achieved.  I was hoping for a concise explanation, if that's even possible ;)

=======================================
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MVP
Posts: 3,009
Registered: ‎10-25-2011

Re: Improving SNR & Speed

Can you try enabling 802.11d/802.11h  to test on that SSID?

IF your clients support it, one of the things it does is that it negociate de output power of the AP and the client... which result en less noise and better performance.

----------------------------------------------------
Product Manager - Aruba Networks
Alternetworks Corp
MVP
Posts: 1,111
Registered: ‎10-11-2011

Re: Improving SNR & Speed

[ Edited ]

We've seen some significant and measurable improvements after working with Aruba ACE. The following changes have been implemented:

 

  • Set min/max EIRP on 2.4GHz to 9/15
  • Disabled 40MHz channels on 5GHz
  • Disabled .11b basic/transmit rates

 Also, looking at setting local probe threshold to 21.

 

We have about 20% more clients now connected with 30+ SNR.  I'm very happy with the results so far.

=======================================
If a reply adequately addresses your issue, please click on the "Accept as Solution" and "Give Kudos" button so this information can benefit other users.
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