Wireless and RF

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Occasional Contributor II
Posts: 67
Registered: ‎06-04-2009

Outdoor planning

Hi all,

I want to know what is the max. distance that should be between the AP and the client in the outdoor environment?

also i use Aruba outdoor planner with the default client model which is 2dbi antenna with max. power 12dbm,

it gives me coverage of the 6 Mbps speed a circle with radius about 200 meter when using AP 125 and 13 db margin

does this result accurate?

should i use another client model?

is there any issues i must take care of?

thanks in advance
Aruba
Posts: 760
Registered: ‎05-31-2007

Outdoor planning

In terms of distance and RF Parameters, the goal is to ensure you have a
symmetrical link (AP to Client, and Client to AP). You mention the use
of an AP125, which for outdoor applications is not necessarily the best
choice. If you have outdoor applications that require 802.11n, I would
recommend the use of the Aruba AP124, due to it's ability to support
external antennas(the AP125 cannot).

If you substitute in the AP124 you are then free to set up the antennas
that you will put into the model, which should enable you to support the
desired radius of coverage.

On a related topic, when you are doing planning here is one of my
favorite planning utilities... I typically pull it up when I want to run
a few quick scenarios, or doing a 'simple' point to point link
calculation.

Thought I would pass along for your bookmark collection:
http://www.afar.net/rf-link-budget-calculator/

JF
Occasional Contributor II
Posts: 67
Registered: ‎06-04-2009

Re: Outdoor planning

Hi Jason Fernyc,

thanks for your reply, you are right regarding AP 125 usage for outdoor, but the only antenna model available in Aruba outdoor planner for AP 12x is the AP 125 integrated antenna,

anyway what i needed to know :

is the default laptop model in the Outdoor planner is practical?

should i consider the coverage of 6 Mbps circle as it gave me about 200 meter radius?
should i consider another data rate circle from the outdoor planner to calculate the coverage?

thanks in advance
MVP
Posts: 1,357
Registered: ‎11-07-2008

Re: Outdoor planning

If you want to model coverage using the 12x and an external antenna, you would just choose the AP12x from the AP type and then whatever external antenna you wish to model. Modeling using the integrated omnis in the AP125 is there to help model the rare cases where an AP125 is used for warehouse or large building coverage models. We differentiate between the AP12x and the 85 due to rx/tx sensitivities at different rates, but you can use and model any of the antennas on both APs.

I would ask though why are you using a 13dB margin? Is the outdoor area in question heavily wooded or obstructed? If this is more an open area (like a campus quad, football field, etc) then a 6-9dB margin would be better and would likely increase your coverage a tad.

Keep in mind that the AP125 needs multi-path to work well, so performance in wide open areas isn't as good as you might find with a legacy AP. Also, AP and antenna alignment and placement would likely improve performance as well. All of these factors, unfortunately, cannot be predicted or accounted for.

The default laptop model is the most average laptop model to date. However, if you know you have clients that are well below that (some HHTs or ruggedized laptops with internal antennas inside titanium or metal cases) or perform better (laptops with 100mw cards and external antennas), you can adjust accordingly. Usually the client is the limiting factor in the coverage model, since that is taken in to account as much as the AP power and antenna gain.

If you want, send me the KMZ you're working with and I can take a peek and make any other recommendations as to antenna type and model it, etc. jhoward-at-arubanetworks-dot-com
Jerrod Howard
Sr. Techical Marketing Engineer
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