So basically, you have someone who’s livelihood depends on charging you for 
site surveys and design, telling you why using a simple one AP per room is a 
bad idea. I certainly wouldn’t disagree with some of his findings when when 
designing around 2.4, but when designing around 5 GHz, and especially .11ac, 
many of the concerns necessitating comprehensive surveys (even in one AP per 
room deployments) tend to evaporate.

Focusing on 5-GHz:
His argument is then about installing more AP’s then necessary and wasting 
money, which is 100% valid, but does that theoretical waste exceed the cost of 
the survey? Is the one AP per classroom over designed for the legacy, current, 
or future standards?

The write up also shows how quickly best practices change when new standards 
emerge e.g. where -65 dB was sufficient for the top rate in 802.11n (20-MHz 
channel), in .11ac that requirement is now -59 dBm in 20-MHz, and -49 dBm in 
160-MHz. This is why I say it’s inevitable that we’ll get to one (or more) APs 
per room if the desire is to maximize performance. It’s a really interesting 
conversation especially if one starts to consider tuition cost per minute of 
class time as a factor in a design.

Last but not least, some of his assumptions don’t necessarily hold up in 
higher-ed, and more so between private/public. I’ll also go out on a limb and 
say that with the advent of flex-radios, we’re well on our way to solving 2.4 
GHz problem. 2.4-GHz can gracefully ride into the sunset while those one AP per 
classroom devices slowly transition to running fulltime as two 5-GHz radios.

Jeff


From: "[email protected]" <[email protected]> 
on behalf of Samuel Clements <[email protected]>
Reply-To: "[email protected]" 
<[email protected]>
Date: Friday, May 27, 2016 at 7:25 AM
To: "[email protected]" <[email protected]>
Subject: Re: [WIRELESS-LAN] Beacon Intervals

Sure, but there is a great writeup on that exact topic that does a good job in 
my stead:
http://www.wlanpros.com/wp-content/uploads/2014/04/Why-One-AP-Per-Classroom-Approach-is-Wrong-.v3.pdf

In short, that may be a design you end up with, but assuming it's correct to 
begin with is a premise that should not be used. Proper WiFi design (including 
disabling radios or converting them to 5GHz radios if you have hardware that 
can do that) is of paramount importance in any environment that believes their 
network is of any measurable importance. Remember that disabling lower data 
rates & changing beacon intervals can *mitigate* poor design - but there is 
always a trade off (client compatibility being chiefest). I don't necessarily 
disagree that in some environments, one AP per classroom is what you would net, 
but I've seen far too many environments where they over bought and a 1.5 
classroom per AP (or some other measure) would have supported the load just 
fine. I hate to see people waste money when it could have gone to some other 
area of technology to further the end goal - education.
  -Sam

On Fri, May 27, 2016 at 9:18 AM, Jeffrey D. Sessler 
<[email protected]<mailto:[email protected]>> wrote:
Sam, would you please explain your position on one AP per classroom being a 
mis-design? Do you have data on this you could share?

In my environment, I’ve found that in order to properly deploy 5 Ghz and .11ac, 
it’s pretty much inevitable that we’ll get to one AP per room, especially if 
one desires consistent and universal coverage. Data from existing spaces 
clearly show gaps in 5GHz coverage when using an every-other room scheme.

Now if you are talking about 2.4 GHz I may agree with you, but even there, with 
removal of lower data rates, and a low-power microcell design, the data 
suggests it’s working very well.

Jeff

From: 
"[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>> 
on behalf of Samuel Clements <[email protected]<mailto:[email protected]>>
Reply-To: 
"[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Thursday, May 26, 2016 at 6:38 PM
To: 
"[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: [WIRELESS-LAN] Beacon Intervals

Remember folks, there is such a thing as too much RF and in the edu space, this 
occurs quite commonly due to the One AP per Classroom mis-design advice that 
was making the rounds some time ago...
  -Sam
********** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/groups/.

********** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/groups/.

**********
Participation and subscription information for this EDUCAUSE Constituent Group 
discussion list can be found at http://www.educause.edu/groups/.

Reply via email to