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I have to put 4 AP in a big sports arena
How far apart should the AP be placed.
there is 25 meters from wall to wall
Kind regards Jerry
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Jerry Sørensen

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Posted 8 months ago

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Hi Jerry
It depends, a site survey should give you the answers. First you have to determine the requirements (capacity, RSSI sensitivity of the devices, applications supported over the wifi,..). The hight of the access points deployment is also an important factor. Then you use the requirements to conduct a site survey and create the design. If the wifi support Voice for example, best-practice there is a good signal (depending on the sensitivity of the devices used) from at minimum 2 access points, if the environment has to support location based features, a minimum of three access points must be available from any location. As you can see there is no real standard deployment guide, it depends... .
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Fabien Gaille

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Hi Jerry,

It depends on several things actually. Are you going to use mesh mode or will all your AP be connected to your infrastructure ?

Moreover, placing an AP is not really a question of distance but a question of needs. Will all our guests be able to connect ? Is it a network for the staff ? 2.4GHz, 5GHz ? In an open environment you may have issues with 2.4GHz and channels. 

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Jerry Sørensen

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It is at a school, and we are going to have a exams test with 85 client spread out on 25 x 25m area.
There are going to use both 2,4 and 5 GHz.
I use to disable one of the 2,4 GHZ but then i always get hit by some of them with only 2,4 GHz in 5 GHZ area.

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Terence Fleming ThinkWireless, Champ

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So I am guessing that this is the gym at the school?  I'm guessing for exams ...

By the way, your picture only shows 80 desks - is this an incentive to turn up on time?  ;-)

In terms of coverage, one of your APs can cover the area.  What you want to be sure of is Capacity, and Resilience (cannot have the network go down mid-exam).  Hence multiple radios

So, run the 2.4 GHz radios on the four  APs on channels 1,6, 11 and Off  (Unless you have AP250s and can run the second radio on another 5 GHz channel)

40 MHz wide channels on 5 GHz, channels 36, 44 149 and 157

Mount your APs high enough to have line of sight across the students (around 3m high is ok, will still be accessible from a set of steps)

Run cable to all of your APs, don't want to rely on Mesh during exams

If possible, run them to different switches so you don't have a switch as a single point of failure, but your biggest nightmare is going to be losing the Internet.

So you could rent, or invest in, a Branch router with a mobile SIM card as potential backup to an Internet outage.  Rest of the school goes down but the students are still ok.

Have a different Network Policy for the Gym so you don't get people outside camping on the connection and if necessary you can manage this network differently from the rest of the school

Just a few ideas
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Jerry Sørensen

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Hey Terence
That its very helpful. Yes it is in a gym at our school and the 80 was just for illustration. 

I normal  run the 2.4 GHz radios channels on auto and disabled 2,4GHz on the last one.
And 5 GHz active on all of them. And they are connected directly to a HP 2530-24G Switch.
I will of course change the 2,4 GHz channels to 1,6,11 

Why 40 MHz on 5 GHz and Which one should i select 40 MHz above or 40 MHz below. ?

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Jan Boje

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Hej Jerry
We have use Aerohive for exam on our Gymnasium here in Roskilde for 3 years. My suggestion is to set 2.4 manual. Sometimes automatic is not ok, it depends on what you have around your Gym. We are using 20 Mhz on 5 GHz and channel is set to automatic.
Under exam we are keeping an eye on how many is connected to each accesspoint. If there is to many on one accesspoint, we maked some correction on the power DBm.

/Jan Boje
PS. My guess is that you a danish, you are welcome to give me a call. I should be easy  to Google :)
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Jerry Sørensen

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Hey Jan

Yes i am from Denmark, Stenløse Privatskole.
Normal it works fine, but i just wanted to optimize the settings before the exam.
We use channel 1,6 and 11 on the 3 of them and had disabled the 4 AP and 5Ghz is set to all auto.
I maybe will contact i the future, just to hear about your experience with Aerohive.
We have had Aerohive for 6 years and have about 32 Access Points