Wireless Access

Reply
Occasional Contributor II
Posts: 12
Registered: ‎02-09-2017

30 students on 1 AP ?

Hi all,

 

i'm new to Aruba and to high density wifi as well. I read some good thing here and also found some formula, but i'd like to have some more info.

 

We will have some classrooms (with about 30 students) with a size of about 40m2 close to each other. Then it seem difficult to have more that one AP per classroom as it would result in channel collisions/congestion i guess, right ?

We are thinking of using AP embedded controller, there will be about 15 AP (about 15 classrooms)

I know that 310/320 serie AP could have a great density, but been able to have many connections do not mean been able to have speed for everyone.

One first thing i do not understand : 310 has 1x1Gbps link, 320 2x1Gbps link, why ? Wifi will never have such a throughput and then will never need such link, am i mistaking ?

 

use of the wifi will be citrix, then at least 2Mpbs is needed, 5 will be better.

 

But is one AP able to handle such thing ?

This also will be a BYOD system, we will have many different capability : 2.4 or 5 GHz, wifi b, g, n, ac ... and if everyone is speaking a different protocol will it result in congestion or so and if  a device is able a 5Ghz that should be important to "force" it to use 5GHz to leave 2.4 for others, right?

 

Any though about all of that is welcome

Thanks !

 

Guru Elite
Posts: 21,279
Registered: ‎03-29-2007

Re: 30 students on 1 AP ?

If you have not already, please see the blog entry here:  http://community.arubanetworks.com/t5/Technology-Blog/Choices-choices-which-Wave-2-AP-is-right-for-me/ba-p/279704



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor II
Posts: 12
Registered: ‎02-09-2017

Re: 30 students on 1 AP ?

Hi Colin,

 

thanks for this interesting link.

Our choice was between 315 and 325

But i can see differences that i can not understand :

 - 315 is doing 4x4:4SS MU-MIMO and 325 "only" 4X4:3SS

 - but 325 is also doing 4x4:4SS SU-MIMO

- 315 has 160Mhz channel, 325 is 80MHz 

 

-> i really can not tell what is better or not and why

 

 

Occasional Contributor II
Posts: 23
Registered: ‎09-02-2015

Re: 30 students on 1 AP ?

How are you planning AP redundancy? If the one AP fails what then?

The 315 is imho able to do 30 clients. But if you talk about 30 student the number of devices is more in the area of 90 then 30. Everybody has more then 1 device.

I would place 2 315 AP in one classroom. Having said that, I don't have all the details of the deployment so it is a guess.
Cheers,
Frank
Life off the wire
Occasional Contributor II
Posts: 12
Registered: ‎02-09-2017

Re: 30 students on 1 AP ?

Hi Frank,

 

You're right, redudancy is not planned.

In the classroom there will also have RJ45 and switch if needed.

I guess they will also have a spare AP to use when one is failing (one offline spare, just an AP on a shelf to take if needed).

This is not critical.

Also you're totally right, a student can have a smartphone, a tablet or so !

And we do not want that... we'd like only laptop for citrix use.

This is something i do not know how to manage.

 

Yes 2 AP seems the best thing, this is something we thought about but imagine :

 - they are many classrooms that will be side by side, size should be something like 5mx8m

 - if i put 2 AP, density of AP will be too important and we won't have enought channel, no ?

 

attached is a little drawing, not representing the reality, but giving a good idea of it.

Imagine 15 rooms of 5mx8m, if i put 2 AP per classroom (green circles) density seem to high, no ?

 

All your advices are welcome

Thanks a lot

 

 

Guru Elite
Posts: 21,279
Registered: ‎03-29-2007

Re: 30 students on 1 AP ?

What are your walls made of?

Do you have existing wireless?

Depending on how mission critical your deployment is, redundancy might just be a spare AP that you would deploy.

A student could have a smartphone and a tablet, but they would probably only be using one at a time, so 2 APs/classroom would be too high.

With regards to channels, if you turn on DFS, you would have 22 802.11a channels available, and depending on what your walls are made of and the transmit power, your APs might not go more than two classrooms down the hall.  The 2.4gz band you could tune lower so that it also does not go far.

 

That is a simple diagram, but you would probably need a mini-survey to determine how far your signal goes and what you should put where.

 

Please see the 802.11n(applies to 802.11ac as well) Survey VRD here: http://community.arubanetworks.com/t5/Validated-Reference-Design/Indoor-802-11n-Site-Survey-and-Planning/ta-p/155136 to get some ideas on what you could do..



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor II
Posts: 12
Registered: ‎02-09-2017

Re: 30 students on 1 AP ?

Thanks Colin,

 

this is a simple but very good idea to have 2 AP with lower range !!!

You're right channel congestion will be then reduced...

 

I just do not understand this sentence "With regards to channels, if you turn on DFS, you would have 22 802.11a channels available"

 

regards

Guru Elite
Posts: 21,279
Registered: ‎03-29-2007

Re: 30 students on 1 AP ?

Please see here:  http://community.arubanetworks.com/t5/Controller-Based-WLANs/What-is-Dynamic-Frequency-Selection-DFS-How-to-Enable-it-What/ta-p/179170



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor II
Posts: 12
Registered: ‎02-09-2017

Re: 30 students on 1 AP ?

Really interesting

But here, we are near military facility :)

But sure i can try that.

 

By the way you gave me many things to think about and many thanks for that

Guru Elite
Posts: 21,279
Registered: ‎03-29-2007

Re: 30 students on 1 AP ?

Even without enabling DFS, you have 9 802.11a channels if you use 20-mhz wide channels...



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Search Airheads
Showing results for 
Search instead for 
Did you mean: