Wireless Access

Hi,

 

Controller - 7210(Master-Local) AOS 6.5.4, IAP325(Campus AP mode) managed by controller.

In our office thre are 8 AP(AP1- AP8) on cubical + cabin floor. We observed AP7 has associated with 47 clients(mostly n phy, radio status --> poor) and AP8 has associated with 42 clients.

We are trying to divert some clients to nearby AP by decreasing AP7 and AP8 and increasing neighbour AP power.

 

I have followed below URL to change AP power level

http://community.arubanetworks.com/t5/Controller-Based-WLANs/How-to-change-the-Transmit-power-of-a-specific-AP-s-in-an-AP/ta-p/185876

 

below are the query(in our setup AP is working on default power)

1) can i change power for AP so that will be applicable for a, b, g and n band instead of changing power for band(as per above url)

2) Is there any commnad(Webui) to check client Rx and Tx power.

 

Thank you...

---

@nik-mh wrote:

 

1) can i change power for AP so that will be applicable for a, b, g and n band instead of changing power for band(as per above url)

2) Is there any commnad(Webui) to check client Rx and Tx power.

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1, The URL shows you how to change power on the bands you've mentioned. 

2, No. It's not possible to change the client Rx and Tx from the controller.

 

Hi James,

 

Sorry for the confusion.

I want to know below information.

 

1) How can we check client Tx and Rx rate. so we can assigned the same power level for respective radio band.

2) Under AP specific ARM profile if we set Assignement --> Single-band

and 160 Mhz support --> Auto    what will be benifits and impact or its better to set Assignement --> disable

 

Thank you..

 

1, You would need to look at the specification of the particular device to find it max Tx and Rx rates.

2,  I'm not sure. If your aim is to reduce the AP power on 2 particular APs to attempt to balance clients more evenly then, just do that. Leave the ARM settings as they were and just change the min & max Tx power on the 2 APs.

 

Do you have clinet match enabled?

 

James,

 

I am in a similiar situation, I want to lower power and I assume do to so I would need to create a new AP group for those specific aps? I do have client match currently enabled but even with that, I have to much coverage so to speak looking at Visual RF.

 

My client devices won't stay associated to one access point longer than 1-2min before moving to one close by.

 

Thanks

but how to change the min/max tx power for a specific AP via the cli on the controller ArubaOS (MODEL: Aruba7210-IL), Version 8.4.0.4 ?

 

tnx,

ams

A couple of quick thoughts. First off, you probably should be using 20 MHz or 40 MHz, or possibly 80 MHz channel widths. If you have multiple APs on the same channel and AP1 and/or it's clients can hear the RF from any other AP or client on the same channel, you will have co-channel interference, which will decrease the performance of your network. Often, more APs at lower channel width is better.

 

Also, remember that it is important to remember that the power of the client transmission is typically less than that of the AP. So you need to make sure that the station is able to communicate with the AP. Also, if the signal is less, the client or AP will drop down to a lower data rate, which takes more time to transmit data, which could be worse.

 

Just some thoughts. I hope this helps.

tnx 4 ur rapid reply.
bandwidth is set to 20mhz for the 2.4ghz band and 80mhz for 5ghz band.

i am wondering why u mention the matter of the client tx power.
lowering the ap's tx power may cause the client to boost its tx power since
it will be receiving a weaker signal.
but...
whats worse? (or is it the same?)
a) ap's high tx power
]b) client high tx power

they can both have the same effect of causing interference to nearby
connections
using the same or adjacent channels.

my situation is that we have lots of nearby ap's in lecture rooms and dorms.
(by 'nearby' i means within 10 meters, usually less. i've even seen some on
opposite side of the same air-cavity block walls.)
at some locations i get lots of complaints of slow downloads and even
disconnects. since a pic is worth more that 1000's of words, i'll attach
some screenshots from the analysis tool in run on my cellphone.

btw, tnx lots for the useful information and insights, but.. why didn't u
answer my
question? how to fiddle with the tx power (min/max tx power) via the cli?

tnx
ams

avraham shir-el (arthur m. sherman)
computing center (tikshuv)
jerusalem college of technology - machon lev, naveh, tal, lustig
p. 972-2-675-1163

I did not see an attachment.

 

2.4 GHz should ALWAYS be at 20 MHz, which you have, which is good. If you have that many APs near each other, you may want/need to go down to 20 MHz wide channels to minimize co-channel interference (CCI). More channels with less interference will be more productive.

 

APs can transmit at up to 100 mW of power. Client devices are typically 25 mW or less. If the AP is screaming at 100 mW and the client device is only talking back to the AP, then the AP can't hear the client. Lowering the AP power will not cause the client to boost it's tx power. The client power does not fluctuate, it is set at what it is. The AP power only changes if ARM decides to set it at a lower power, or if it is manually set at a lower power.

 

In 5 GHz, you can experience CCI, but would not experience adjacent channel interference (ACI) since the 5 GHz channels do not overlap (the 2.4 GHz channels do/can overlap).

 

With lot's of APs near each other, they should all be on different channels. If you can do that with 80 MHz wide channels, great. If not, dan you do it with 40 MHz wide channels, then great. If not, then go to 20 MHz wide channels. Avoiding CCI at all cost and having clients connect at the highest data rate possible (typically achieved with higher density AP placement, that you have) are the top two items in design that will provide the best performance for the entire network.

 

I didn't answer your specific question because I don't remember exactly how to do it on OS 6.

 

I would suggest buying one of the CWNA Study Guides (I'm partial to the Sybex book) or sitting in on a CWNA class to learn about 802.11 and RF, so you can better understand and support your environment.

 

I hope this helps,

apparently the attachments go lost when the aruba website xfered my email response to theairhead community website.

i a not running OS6. i am running:

ArubaOS (MODEL: Aruba7210-IL), Version 8.4.0.4

 

yes, i've been reading up a bit on rf matters.

btw, a few years ago we switched from cisco to aruba lock, stock and barrel. although the mobility master is much more intuitive that the cisco prime for managing the wifi network, i never had to manually adjust rf param on the cisco wifi network.

tnx 4 the advice,

ams

For some reason I thought you were on version 6.x

 

To manually configure AP radio setting on ArubaOS 8 you can use the "airmatch ap freeze" command. This allows you to statically configure channel, bandwidth, or power for one or more APs. For example

 

#airmatch ap freeze ap-name AP2 band 5GHz channel 36 EIRP 10

 

This will set AP2 5 GHz radio to channel 36 with an EIRP value of 10 dBm.

 

#show airmatch debug static-radios

 

This will show radios that have been statically set, along with their settings. You can undo the settings by using "airmatch ap unfreeze"

 

Airmatch will continue to function, but will not change any frozen settings.

 

Make sure to carefully document what settings you make. It is easier to  track and modify if you have a documented list.

 

I hope this helps,

please excuse the delay in my reply.
i have reduced the tx power of abt a dozen ap's (dual radio) in hope of
reducing cci in 1 particular room. according to my measurements, there is
reduced cci, but...
we're in exam period until today, so i will be able to get user feedback
during the next few days. i have reduced the tx power across the board on
those ap's which i have modified, to 6. in this case, there is an ap in
each lecture room.
the next case will be more tricky. in the dorms, we have ap's in the
hallways, 2/floor, abt a dozen rooms/floor.

tnx,
ams
avraham shir-el (arthur m. sherman)
computing center (tikshuv)
jerusalem college of technology - machon lev, naveh, tal, lustig
p. 972-2-675-1163