Wireless Access

I have 2 vaps one corporate users with Dell latitude laptops and guest users which are smart phones tablets, and other devices. My wireless system has been managed by several different employees so the configuration is not always best practice. What we are seeing is a classroom of laptops all connected to 2.4GHZ and all personal devices on 5.8GHZ. The 2.4GHZ corporate laptops slow down or drop. When I look at the configuration the corp VAP has band steering check box UN Checked but the VAP for guest wireless it is checked set to A radio preferred. Client match is enabled for ARM A and G radios it appears the guest network is working correctly by steering users to the A radio where more channels are available. but the Crop users where band steering is disabled are only connecting to G Radio. Reading the guide best practice says use client match and not band steering and don't use both one or the other. We are on Code level 6.4.3.7 

Are you sure that those laptops can even see or connect to the 5ghz  band?

 

The AP-225 is right above them in the center of the classroom. In the past we have had isseus with an older driver and since Dell has come out with a newer driver but the problem had nothing to do with this issue. It seems that the guest VAP is working much better by putting most of the devices on the 5.8 radio. I verified the personal devices are the same users which have the laptops. 

I should add that it's possible these dell laptops have that older driver with the problems we did not push out an update to all laptops it was replace as people complained. 

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@kell490 wrote:

I have 2 vaps one corporate users with Dell latitude laptops and guest users which are smart phones tablets, and other devices. My wireless system has been managed by several different employees so the configuration is not always best practice. What we are seeing is a classroom of laptops all connected to 2.4GHZ and all personal devices on 5.8GHZ. The 2.4GHZ corporate laptops slow down or drop. When I look at the configuration the corp VAP has band steering check box UN Checked but the VAP for guest wireless it is checked set to A radio preferred. Client match is enabled for ARM A and G radios it appears the guest network is working correctly by steering users to the A radio where more channels are available. but the Crop users where band steering is disabled are only connecting to G Radio. Reading the guide best practice says use client match and not band steering and don't use both one or the other. We are on Code level 6.4.3.7 

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The most important thing is the transmit power of the AP on the 2.4ghz and the 5ghz band.  The 2.4ghz band propagates further than the 5ghz band at the same power, so you need to make the maximum transmit power on the 5ghz 3 to 6 db higher than the 2.4ghz so that clients will prefer the 5ghz band.  Forget Client Match and forget Band Steering.  Start with the principles.

You could be right because the location where we are having the issue is using the default ARM profile with power settings for both A and G radios

Max Tx EIRP 127 dBm
Min Tx EIRP 15 dBm

 

Where my other locations I have min of 9 dBm for G radio and 21 for max A and G radios most of my laptops at other locations are working correctly. 

The min and max should be no more than 6db in difference. Ideally the range should match the range of output of your clients. Your max should be no more than 18. I would open a TAC case to have your settings reviewed.

When you mean match the range of output to your clients what you mean is the distance from the AP to the client I'm assuming? 6 DB range is that because client match can only very the signle strenth by 6 DB?

Your TX power min should be 12 and your TX power max should be at 18 to start on the 5ghz band.  That would roughly match the output power of your clients on the wireless.  In many situations you would have to make the 2.4ghz arm min 9 or 12 and the max 12, to make it lower than the 5ghz and because you have to avoid more cochannel interference on the 2.4ghz band.

What about outdoor areas where a few buildng mounted AP's are flooding 300-500 feet away from the antenna would you still only do 12-18 range on 5GHZ?

RF goes much further outdoors.  You can get 300 foot coverage depending on the type of access point and whether or not you use external antennas with the same transmit power.  Outdoor coverage requires special planning and is not covered by what I mentioned above.  I was assuming that it was indoors with medium to high density.

I was only asking because I wanted to know if we could just use one ARM profile for everything or if we should break it up. I did make 3 profilies high density, Med, outdoor. Most of our outdoor AP's are 114's with flat panel antenna's have wide angle of covfrage I get what you mean that the antenna gain will compensate for lower power output. I guess what I'm asking is that really nesscary in real world situation in your experince to even have more then one power level just set everything to the same lower power leveles. Is there any plan to allow the controller to have more control over power output then 6 DB? 

To be clear, you should have different ARM profiles for different locations.  The recommendation to have a range of power of only 6 is only a recommendation so that the power does not vary too much from AP to AP.  You can configure a broader range...it is just a recommendation.  If in a space your AP transmit power varies by more than 6, you can have an AP that has low transmit power and one that has much higher transmit power.  The clients will want to stick to the AP with the higher transmit power and refuse to roam in many circumstances; that could cause issues.  AP transmit power should be as uniform as possible in an environment where you want smooth roaming.

That's what we will do then thanks.