Re: [WIRELESS-LAN] Two RF Questions

[GT Hill]

Jeff,

I completely understand. And I have to be careful because this would quickly 
become a vendor pitch and that isn’t my intent. 

And I have to go back to the original question because I may have forgotten the 
context. :-) 


I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?



I think its obvious now that it wasn’t such a simple question. :-) 

But it is really fun! 

GT



From:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of "Jeffrey D. Sessler" 
<j...@scrippscollege.edu>
Reply-To:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date:  Tuesday, September 26, 2017 at 2:21 PM
To:  <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject:  Re: [WIRELESS-LAN] Two RF Questions

GT,

 

A better conclusion to draw may be, “Many wireless deployments suffer from 
questionable design choices and execution, often leading to less-than-optimal 
configuration decisions.” That I can get behind.

 

In the case of the university with 20/40 channelization, would the same 
improvement been possible by enabling the vendor’s dynamic bandwidth selection? 
The conclusion drawn is problematic given there is no detail in what the 
environment looked like before, or what was attempted.

 

Jeff

 

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of GT Hill <g...@gthill.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:52 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

I’m a Wi-Fi guy first and foremost but I work for a vendor and that’s where I 
get that information, not from a user survey. 

 

My point was to show that I’ve seen quantifiable data showing that excessive 
use of 40 MHz channels can have negative effects. Of course everyone’s mileage 
will vary but in my experience larger channels are overused in many 
environments, not just EDU. 

 

I suppose another way to summarize would be this: Default to 20 MHz channels 
and go UP to 40 MHz on a case by case basis when channel utilization exceeds a 
threshold. Off the cuff I’m saying 40% channel utilization but I’d need to do 
some more research on. 

 

If channel utilization isn’t excessive all that 40 MHz buys you is higher noise 
and fewer available channels. 

 

GT

 

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of "Jeffrey D. Sessler" 
<j...@scrippscollege.edu>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 1:41 PM
To: <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

 

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

 

For example:
If 1/3 of my users had a device that could not associate because of how the 
primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
If my buildings are open-concept (no walls/doors), and I have 24 AP’s on a 1000 
sq/ft floor plan, and statically set to 80 MHz channels, then the end-user WiFi 
experience is going to be really poor. If I then switch all those APs to 20 Mhz 
only, of course it’s going to be a huge improvement. Clearly, it was a poor 
design, and less about the channel width and more about the person who thought 
they knew better.
 

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down. 

 

Jeff

 

 

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of GT Hill <g...@gthill.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS

RE: [WIRELESS-LAN] Two RF Questions

[Chuck Enfield]

BTW, people on this list who know me will confirm that I'm an idiot.  You
might want to consider that if you're ever inclined to agree with me.

-Original Message-
From: Chuck Enfield [mailto:chu...@psu.edu] 
Sent: Tuesday, September 26, 2017 4:22 PM
To: The EDUCAUSE Wireless Issues Constituent Group Listserv
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: RE: [WIRELESS-LAN] Two RF Questions

"More channels means more capacity" is not true.  Because the number of
null subcarriers is fixed and independent of channel width, wider channels
will make more efficient use of the spectrum.  You'll get the most
capacity out of the 802.11ac spectrum by using (6) 80MHz channels and (1)
20MHz.  Of course, a variety of conditions and design choices affect
capacity, not just channel width.  That's why we don't build networks that
way.

It's no surprise that this contention was generated by a couple very
generalized questions.  The topic is way too complex to for a thorough
discussion in this format.  Any answer of reasonable length is going to
leave a host of assumptions unstated.  If yours are the same as mine we'll
probably agree.  If yours are different from mine you'll think I'm an
idiot.

-Original Message-
From: The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Curtis K. Larsen
Sent: Tuesday, September 26, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

>From the Cisco/Apple Design Guide Here:  https://goo.gl/5bGWks

"It is therefore not yet recommended to use 80 MHz channel width design.
If necessary, it should only be considered for low AP density deployments
where co-channel interference can be easily avoided."

I personally like the approach here:  https://goo.gl/FcPHFq

- More channels means more capacity
- 80MHz - small deployment with no interference - 40MHz - with thick
walls, one floor, and/or small deployments - 20MHz - by default


Thanks,

Curtis


From: The EDUCAUSE Wireless Issues Constituent Group Listserv
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jeffrey D. Sessler
<j...@scrippscollege.edu>
Sent: Tuesday, September 26, 2017 1:08 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jake,

GT's statement doesn't speak to the quality of the university's WiFi
design, only that this change made a difference. Again, without the
context, I still assert it's meaningless.

Jeff

From: "wireless-lan@listserv.educause.edu"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder
<jsnyde...@gmail.com>
Reply-To: "wireless-lan@listserv.educause.edu"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:49 AM
To: "wireless-lan@listserv.educause.edu"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jeff,
Take in context that GT works for a company that builds a tool to quantify
wireless problems based in depth packet analysis.  So when he says he sees
35% improvement, there's a lot of data that goes into it.
Sent from my iPhone

On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:
"After a switch to 20 MHz only, there was a 35% improvement in end-user
Wi-Fi experience."

I would argue that this is a meaningless statement without context, and
probably a bad question to ask a user in the first place. What does the
user think "experience" means i.e. the ability to connect or how well
their speedtest performs? It's not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of
how the primary channel was selected in a 40 or 80 MHz wide deployment,
then those people would not be happy. If I then change to 20 MHz only,
allowing those users with the problematic device to connect, there will
obviously be a significant improvement in those user's WiFi experience.
The other users may still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24
AP's on a 1000 sq/ft floor plan, and statically set to 80 MHz channels,
then the end-user WiFi experience is going to be really poor. If I then
switch all those APs to 20 Mhz only, of course it's going to be a huge
improvement. Clearly, it was a poor design, and less about the channel
width and more about the person who thought they knew better.

Of course, if the survey questions were more specific, and had questions
like, "Do you consistently receive the highest 4K stream rate from
NetFlix", the satisfaction for this question may trend down.

Jeff



From:
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.
edu>"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.E

RE: [WIRELESS-LAN] Two RF Questions

[Chuck Enfield]

"More channels means more capacity" is not true.  Because the number of
null subcarriers is fixed and independent of channel width, wider channels
will make more efficient use of the spectrum.  You'll get the most
capacity out of the 802.11ac spectrum by using (6) 80MHz channels and (1)
20MHz.  Of course, a variety of conditions and design choices affect
capacity, not just channel width.  That's why we don't build networks that
way.

It's no surprise that this contention was generated by a couple very
generalized questions.  The topic is way too complex to for a thorough
discussion in this format.  Any answer of reasonable length is going to
leave a host of assumptions unstated.  If yours are the same as mine we'll
probably agree.  If yours are different from mine you'll think I'm an
idiot.

-Original Message-
From: The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Curtis K. Larsen
Sent: Tuesday, September 26, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

>From the Cisco/Apple Design Guide Here:  https://goo.gl/5bGWks

"It is therefore not yet recommended to use 80 MHz channel width design.
If necessary, it should only be considered for low AP density deployments
where co-channel interference can be easily avoided."

I personally like the approach here:  https://goo.gl/FcPHFq

- More channels means more capacity
- 80MHz - small deployment with no interference - 40MHz - with thick
walls, one floor, and/or small deployments - 20MHz - by default


Thanks,

Curtis


From: The EDUCAUSE Wireless Issues Constituent Group Listserv
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jeffrey D. Sessler
<j...@scrippscollege.edu>
Sent: Tuesday, September 26, 2017 1:08 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jake,

GT's statement doesn't speak to the quality of the university's WiFi
design, only that this change made a difference. Again, without the
context, I still assert it's meaningless.

Jeff

From: "wireless-lan@listserv.educause.edu"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder
<jsnyde...@gmail.com>
Reply-To: "wireless-lan@listserv.educause.edu"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:49 AM
To: "wireless-lan@listserv.educause.edu"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jeff,
Take in context that GT works for a company that builds a tool to quantify
wireless problems based in depth packet analysis.  So when he says he sees
35% improvement, there's a lot of data that goes into it.
Sent from my iPhone

On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:
"After a switch to 20 MHz only, there was a 35% improvement in end-user
Wi-Fi experience."

I would argue that this is a meaningless statement without context, and
probably a bad question to ask a user in the first place. What does the
user think "experience" means i.e. the ability to connect or how well
their speedtest performs? It's not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of
how the primary channel was selected in a 40 or 80 MHz wide deployment,
then those people would not be happy. If I then change to 20 MHz only,
allowing those users with the problematic device to connect, there will
obviously be a significant improvement in those user's WiFi experience.
The other users may still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24
AP's on a 1000 sq/ft floor plan, and statically set to 80 MHz channels,
then the end-user WiFi experience is going to be really poor. If I then
switch all those APs to 20 Mhz only, of course it's going to be a huge
improvement. Clearly, it was a poor design, and less about the channel
width and more about the person who thought they knew better.

Of course, if the survey questions were more specific, and had questions
like, "Do you consistently receive the highest 4K stream rate from
NetFlix", the satisfaction for this question may trend down.

Jeff



From:
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.
edu>"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.
EDU>> on behalf of GT Hill <g...@gthill.com<mailto:g...@gthill.com>>
Reply-To:
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.
edu>"
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.
EDU>>
Date: Tuesday, September 26, 2017 at 8:47 AM
To:
"wireless-lan@listserv.educause.

Re: [WIRELESS-LAN] Two RF Questions

[Jeffrey D. Sessler]

GT,

A better conclusion to draw may be, “Many wireless deployments suffer from 
questionable design choices and execution, often leading to less-than-optimal 
configuration decisions.” That I can get behind.

In the case of the university with 20/40 channelization, would the same 
improvement been possible by enabling the vendor’s dynamic bandwidth selection? 
The conclusion drawn is problematic given there is no detail in what the 
environment looked like before, or what was attempted.

Jeff


From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of GT Hill <g...@gthill.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:52 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I’m a Wi-Fi guy first and foremost but I work for a vendor and that’s where I 
get that information, not from a user survey.

My point was to show that I’ve seen quantifiable data showing that excessive 
use of 40 MHz channels can have negative effects. Of course everyone’s mileage 
will vary but in my experience larger channels are overused in many 
environments, not just EDU.

I suppose another way to summarize would be this: Default to 20 MHz channels 
and go UP to 40 MHz on a case by case basis when channel utilization exceeds a 
threshold. Off the cuff I’m saying 40% channel utilization but I’d need to do 
some more research on.

If channel utilization isn’t excessive all that 40 MHz buys you is higher noise 
and fewer available channels.

GT

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of "Jeffrey D. Sessler" 
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 1:41 PM
To: 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of how 
the primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24 AP’s on 
a 1000 sq/ft floor plan, and statically set to 80 MHz channels, then the 
end-user WiFi experience is going to be really poor. If I then switch all those 
APs to 20 Mhz only, of course it’s going to be a huge improvement. Clearly, it 
was a poor design, and less about the channel width and more about the person 
who thought they knew better.

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down.

Jeff



From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of GT Hill <g...@gthill.com<mailto:g...@gthill.com>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience.

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps.

And to just stir the pot a bit, I wish there were

Re: [WIRELESS-LAN] Two RF Questions

[GT Hill]

Jeff,

I think your statement is fair. And it is just one data point. 

And I agree with other statements that in some environments 80 MHz channels 
work great. In fact, I have an environment (my missile silo) where 160 MHz 
would be a rock star. :-)

My overall points are:
I don’t trust software to make RF decisions. It can be ok and at scale its 
tough to manually do channel planning. 
When in doubt, 20 MHz is the place to start. Larger channels should be used 
with caution.
GT

From:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of "Jeffrey D. Sessler" 
<j...@scrippscollege.edu>
Reply-To:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date:  Tuesday, September 26, 2017 at 2:08 PM
To:  <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject:  Re: [WIRELESS-LAN] Two RF Questions

Jake,

 

GT’s statement doesn’t speak to the quality of the university’s WiFi design, 
only that this change made a difference. Again, without the context, I still 
assert it’s meaningless. 

 

Jeff

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of Jake Snyder <jsnyde...@gmail.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:49 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

Jeff, 

Take in context that GT works for a company that builds a tool to quantify 
wireless problems based in depth packet analysis.  So when he says he sees 35% 
improvement, there’s a lot of data that goes into it.

Sent from my iPhone


On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler <j...@scrippscollege.edu> 
wrote:

“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

 

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

 

For example:
If 1/3 of my users had a device that could not associate because of how the 
primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
If my buildings are open-concept (no walls/doors), and I have 24 AP’s on a 1000 
sq/ft floor plan, and statically set to 80 MHz channels, then the end-user WiFi 
experience is going to be really poor. If I then switch all those APs to 20 Mhz 
only, of course it’s going to be a huge improvement. Clearly, it was a poor 
design, and less about the channel width and more about the person who thought 
they knew better.
 

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down. 

 

Jeff

 

 

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of GT Hill <g...@gthill.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience. 

 

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps. 

 

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-) 

 

GT

 

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder 
<jsnyde...@gmail.com>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 9:39 AM
To: <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection

Re: [WIRELESS-LAN] Two RF Questions

[Curtis K. Larsen]

>From the Cisco/Apple Design Guide Here:  https://goo.gl/5bGWks

"It is therefore not yet recommended to use 80 MHz channel width design. If 
necessary, it should only be
considered for low AP density deployments where co-channel interference can be 
easily avoided."

I personally like the approach here:  https://goo.gl/FcPHFq

– More channels means more capacity
– 80MHz – small deployment with no interference
– 40MHz – with thick walls, one floor, and/or small deployments
– 20MHz – by default


Thanks,

Curtis


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jeffrey D. Sessler 
<j...@scrippscollege.edu>
Sent: Tuesday, September 26, 2017 1:08 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jake,

GT’s statement doesn’t speak to the quality of the university’s WiFi design, 
only that this change made a difference. Again, without the context, I still 
assert it’s meaningless.

Jeff

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of Jake Snyder <jsnyde...@gmail.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:49 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jeff,
Take in context that GT works for a company that builds a tool to quantify 
wireless problems based in depth packet analysis.  So when he says he sees 35% 
improvement, there’s a lot of data that goes into it.
Sent from my iPhone

On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler 
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:
“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of how 
the primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24 AP’s on 
a 1000 sq/ft floor plan, and statically set to 80 MHz channels, then the 
end-user WiFi experience is going to be really poor. If I then switch all those 
APs to 20 Mhz only, of course it’s going to be a huge improvement. Clearly, it 
was a poor design, and less about the channel width and more about the person 
who thought they knew better.

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down.

Jeff



From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of GT Hill <g...@gthill.com<mailto:g...@gthill.com>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience.

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps.

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-)

GT

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jake Snyder <jsnyde...@gmail.com<mailto:jsnyde...@gmail.com>>

Re: [WIRELESS-LAN] Two RF Questions

[Jeffrey D. Sessler]

Jake,

GT’s statement doesn’t speak to the quality of the university’s WiFi design, 
only that this change made a difference. Again, without the context, I still 
assert it’s meaningless.

Jeff

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of Jake Snyder <jsnyde...@gmail.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 11:49 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

Jeff,
Take in context that GT works for a company that builds a tool to quantify 
wireless problems based in depth packet analysis.  So when he says he sees 35% 
improvement, there’s a lot of data that goes into it.
Sent from my iPhone

On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler 
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:
“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of how 
the primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24 AP’s on 
a 1000 sq/ft floor plan, and statically set to 80 MHz channels, then the 
end-user WiFi experience is going to be really poor. If I then switch all those 
APs to 20 Mhz only, of course it’s going to be a huge improvement. Clearly, it 
was a poor design, and less about the channel width and more about the person 
who thought they knew better.

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down.

Jeff



From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of GT Hill <g...@gthill.com<mailto:g...@gthill.com>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience.

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps.

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-)

GT

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jake Snyder <jsnyde...@gmail.com<mailto:jsnyde...@gmail.com>>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 9:39 AM
To: 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many c

Re: [WIRELESS-LAN] Two RF Questions

[Jeffrey D. Sessler]

All of this comes with the obvious statement, “It depends on your environment.”

Speaking only to our residential, the construction is such that with 
life/safety and occupant comfort high on the list, our residential building, 
including those constructed in the mid-late 1920’s (with renovations), tend to 
use materials that have high attenuation properties. Fire-rated doors, walls, 
and ceilings. Concrete, concrete block, metal studs, metal lath/plaster, rock 
or mineral wool, and high-performance window glazing.

Our residential construction means that those APs, with few exceptions, can use 
the wider channels with no consequences. It also means we’re installing nearly 
one AP per room. It’s not a terrible place to be, as it leads to WiFi nirvana 
where we have few devices per AP, excellent signal quality, and little CCI. 
Coupled with our 80% Apple population, and those 3SS 11ac clients are pretty 
happy.

Jeff

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of Chuck Enfield <chu...@psu.edu>
Reply-To: Chuck Enfield <chu...@psu.edu>
Date: Tuesday, September 26, 2017 at 9:37 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

Your experience is consistent with ours Jeff.  We get good use of 40MHz 
channels in most areas.  That said, complaints about basic connectivity greatly 
outnumber complaints about speed, so I recommend that when in doubt people 
should use 20MHz.  However, we currently have locations where speed is an 
issue, and I’m expecting those to increase with time.  Once your APs are close 
enough together to provide an SNR of 30dB or more (See GT’s contributions for 
reasons why this is important), adding 20MHz APs is more costly and less 
effective effective than enabling 40 MHz.

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Tuesday, September 26, 2017 11:43 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

For your residential, is that concern rooted in belief/assumption or proven by 
testing in production? I remember channel-width discussions with the advent of 
11n, and people here advocated sticking to 20 MHz for the same reasons, only 
our in-field testing said it was a bad assumption, reaffirmed by our vendor and 
SEs. We’re been using 40 MHz-wide channels since 2008, and adopted DBS with the 
deployment of 11ac.

Unless our campus and/or residential is unique in some way, shape, or fashion – 
our dense deployments overwhelmingly prefer 80 MHz wide channels, and data on 
both sides (client and infrastructure) reaffirms the software is making the 
right decision.

Jeff

From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Rob Harris 
<robert.har...@culinary.edu<mailto:robert.har...@culinary.edu>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 7:33 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

While there are performance gains to be sure (by going to 40, or 80), there are 
other concerns as well. We use 20 in our dorms because of the density of APs 
and users, we need those additional channels (even with dfs in use). We use 40 
in our public spaces when there’s adequate capacity for it, and 80 in our 
theater area since we designed for it.

[e Culinary Institute of America]
Robert Harris
Manager of Network Services
Culinary Institute of America
1946 Campus Drive
Hyde Park, NY
845-451-1681
www.ciachef.edu<http://www.ciachef.edu/>
Food is Life
Create and Savor Yours.™

Please consider the environment before printing this e-mail.

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Tuesday, September 26, 2017 10:20 AM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn.

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the

Re: [WIRELESS-LAN] Two RF Questions (channel width)

[Kees Pronk]

Really like this convo (popcorn ;-)

This podcast really is interesting for people who believe big channels and 
smart software solve all problems :

http://www.cleartosend.net/cts-084-channel-widths-devin-akin/

-Kees

On 26 Sep 2017, at 20:49, Jake Snyder 
<jsnyde...@gmail.com<mailto:jsnyde...@gmail.com>> wrote:

Jeff,
Take in context that GT works for a company that builds a tool to quantify 
wireless problems based in depth packet analysis.  So when he says he sees 35% 
improvement, there’s a lot of data that goes into it.

Sent from my iPhone

On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler 
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:

“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of how 
the primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24 AP’s on 
a 1000 sq/ft floor plan, and statically set to 80 MHz channels, then the 
end-user WiFi experience is going to be really poor. If I then switch all those 
APs to 20 Mhz only, of course it’s going to be a huge improvement. Clearly, it 
was a poor design, and less about the channel width and more about the person 
who thought they knew better.


Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down.

Jeff



From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of GT Hill <g...@gthill.com<mailto:g...@gthill.com>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience.

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps.

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-)

GT

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jake Snyder <jsnyde...@gmail.com<mailto:jsnyde...@gmail.com>>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 9:39 AM
To: 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

Remember that spectrum is our constraining resource.

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you the most smiles/hour on 
your la

Re: [WIRELESS-LAN] Two RF Questions

[GT Hill]

I’m a Wi-Fi guy first and foremost but I work for a vendor and that’s where I 
get that information, not from a user survey. 

My point was to show that I’ve seen quantifiable data showing that excessive 
use of 40 MHz channels can have negative effects. Of course everyone’s mileage 
will vary but in my experience larger channels are overused in many 
environments, not just EDU. 

I suppose another way to summarize would be this: Default to 20 MHz channels 
and go UP to 40 MHz on a case by case basis when channel utilization exceeds a 
threshold. Off the cuff I’m saying 40% channel utilization but I’d need to do 
some more research on. 

If channel utilization isn’t excessive all that 40 MHz buys you is higher noise 
and fewer available channels. 

GT

From:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of "Jeffrey D. Sessler" 
<j...@scrippscollege.edu>
Reply-To:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date:  Tuesday, September 26, 2017 at 1:41 PM
To:  <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject:  Re: [WIRELESS-LAN] Two RF Questions

“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

 

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

 

For example:
If 1/3 of my users had a device that could not associate because of how the 
primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
If my buildings are open-concept (no walls/doors), and I have 24 AP’s on a 1000 
sq/ft floor plan, and statically set to 80 MHz channels, then the end-user WiFi 
experience is going to be really poor. If I then switch all those APs to 20 Mhz 
only, of course it’s going to be a huge improvement. Clearly, it was a poor 
design, and less about the channel width and more about the person who thought 
they knew better.
 

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down. 

 

Jeff

 

 

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of GT Hill <g...@gthill.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience. 

 

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps. 

 

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-) 

 

GT

 

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder 
<jsnyde...@gmail.com>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 9:39 AM
To: <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo. 

 

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

 

Remember that spectrum is our constraining resource.

 

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you 

Re: [WIRELESS-LAN] Two RF Questions

[Jake Snyder]

Jeff,
Take in context that GT works for a company that builds a tool to quantify 
wireless problems based in depth packet analysis.  So when he says he sees 35% 
improvement, there’s a lot of data that goes into it.

Sent from my iPhone

> On Sep 26, 2017, at 12:41 PM, Jeffrey D. Sessler <j...@scrippscollege.edu> 
> wrote:
> 
> “After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
> experience.”
>  
> I would argue that this is a meaningless statement without context, and 
> probably a bad question to ask a user in the first place. What does the user 
> think “experience” means i.e. the ability to connect or how well their 
> speedtest performs? It’s not specific enough to draw a conclusion.
>  
> For example:
> If 1/3 of my users had a device that could not associate because of how the 
> primary channel was selected in a 40 or 80 MHz wide deployment, then those 
> people would not be happy. If I then change to 20 MHz only, allowing those 
> users with the problematic device to connect, there will obviously be a 
> significant improvement in those user’s WiFi experience. The other users may 
> still be happy because they can still connect.
> If my buildings are open-concept (no walls/doors), and I have 24 AP’s on a 
> 1000 sq/ft floor plan, and statically set to 80 MHz channels, then the 
> end-user WiFi experience is going to be really poor. If I then switch all 
> those APs to 20 Mhz only, of course it’s going to be a huge improvement. 
> Clearly, it was a poor design, and less about the channel width and more 
> about the person who thought they knew better.
>  
> Of course, if the survey questions were more specific, and had questions 
> like, “Do you consistently receive the highest 4K stream rate from NetFlix”, 
> the satisfaction for this question may trend down.
>  
> Jeff
>  
>  
>  
> From: "wireless-lan@listserv.educause.edu" 
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of GT Hill <g...@gthill.com>
> Reply-To: "wireless-lan@listserv.educause.edu" 
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
> Date: Tuesday, September 26, 2017 at 8:47 AM
> To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
> Subject: Re: [WIRELESS-LAN] Two RF Questions
>  
> I know that this is just one example, but I was at a large university site 
> (Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
> only, there was a 35% improvement in end-user Wi-Fi experience. 
>  
> Jake – One feature that I think many people agree is missing in FRA is the 
> ability to dynamically turn off a radio. In some cases an extra radio in 
> either band hurts more than it helps. 
>  
> And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
> channelization. In many high density environments 20 MHz is just too big. 
> Give me some more radios at smaller channel sizes and I’ll show you a 
> spectacular Wi-Fi network. :-) 
>  
> GT
>  
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder 
> <jsnyde...@gmail.com>
> Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
> Date: Tuesday, September 26, 2017 at 9:39 AM
> To: <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
> Subject: Re: [WIRELESS-LAN] Two RF Questions
>  
> My challenge, as I’ve stated on this list before, is that Mac OS X 
> preferences width in its AP selection criteria.  So while you may get more 
> capacity, in a large Mac environment you lose most of that with Macs hanging 
> onto APs linger and having to rate-shift down to slower PHY speeds due to 
> that AP having a wider channel than its neighbors. Yes, it’s dumb.  But he’s 
> the driver of that lambo.
>  
> Also, couple that with increasing the noise floor by 3db every time you 
> double the channel width and there are many cases where your lambo just spins 
> it’s tires.  All that power and you can’t hook it up.
>  
> Remember that spectrum is our constraining resource.
>  
> Figure out what width of channel you can run in a building, and run that.  
> That’s the best use of spectrum and sure to give you the most smiles/hour on 
> your lambo.
>  
> I really like what cisco did with FRA.  Give me the ability to see what it 
> thinks the overlap is.  I would LOVE to see the same with DBS, and give me 
> what width it thinks all the APs in the building can pull off.
>  
> Sent from my iPhone
> 
> On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler <j...@scrippscollege.edu> 
> wrote:
> 
> It’s surprising to me that anyone would purchase a Lamborghini, then 
> disc

Re: [WIRELESS-LAN] Two RF Questions

[Jeffrey D. Sessler]

“After a switch to 20 MHz only, there was a 35% improvement in end-user Wi-Fi 
experience.”

I would argue that this is a meaningless statement without context, and 
probably a bad question to ask a user in the first place. What does the user 
think “experience” means i.e. the ability to connect or how well their 
speedtest performs? It’s not specific enough to draw a conclusion.

For example:

  1.  If 1/3 of my users had a device that could not associate because of how 
the primary channel was selected in a 40 or 80 MHz wide deployment, then those 
people would not be happy. If I then change to 20 MHz only, allowing those 
users with the problematic device to connect, there will obviously be a 
significant improvement in those user’s WiFi experience. The other users may 
still be happy because they can still connect.
  2.  If my buildings are open-concept (no walls/doors), and I have 24 AP’s on 
a 1000 sq/ft floor plan, and statically set to 80 MHz channels, then the 
end-user WiFi experience is going to be really poor. If I then switch all those 
APs to 20 Mhz only, of course it’s going to be a huge improvement. Clearly, it 
was a poor design, and less about the channel width and more about the person 
who thought they knew better.

Of course, if the survey questions were more specific, and had questions like, 
“Do you consistently receive the highest 4K stream rate from NetFlix”, the 
satisfaction for this question may trend down.

Jeff



From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of GT Hill <g...@gthill.com>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 8:47 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience.

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps.

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-)

GT

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jake Snyder <jsnyde...@gmail.com<mailto:jsnyde...@gmail.com>>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 9:39 AM
To: 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

Remember that spectrum is our constraining resource.

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you the most smiles/hour on 
your lambo.

I really like what cisco did with FRA.  Give me the ability to see what it 
thinks the overlap is.  I would LOVE to see the same with DBS, and give me what 
width it thinks all the APs in the building can pull off.

Sent from my iPhone

On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler 
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:
It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn.

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t al

RE: [WIRELESS-LAN] Two RF Questions

[Chuck Enfield]

Your experience is consistent with ours Jeff.  We get good use of 40MHz 
channels in most areas.  That said, complaints about basic connectivity 
greatly outnumber complaints about speed, so I recommend that when in doubt 
people should use 20MHz.  However, we currently have locations where speed 
is an issue, and I’m expecting those to increase with time.  Once your APs 
are close enough together to provide an SNR of 30dB or more (See GT’s 
contributions for reasons why this is important), adding 20MHz APs is more 
costly and less effective effective than enabling 40 MHz.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Tuesday, September 26, 2017 11:43 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions



For your residential, is that concern rooted in belief/assumption or proven 
by testing in production? I remember channel-width discussions with the 
advent of 11n, and people here advocated sticking to 20 MHz for the same 
reasons, only our in-field testing said it was a bad assumption, reaffirmed 
by our vendor and SEs. We’re been using 40 MHz-wide channels since 2008, and 
adopted DBS with the deployment of 11ac.



Unless our campus and/or residential is unique in some way, shape, or 
fashion – our dense deployments overwhelmingly prefer 80 MHz wide channels, 
and data on both sides (client and infrastructure) reaffirms the software is 
making the right decision.



Jeff



From: "wireless-lan@listserv.educause.edu 
<mailto:wireless-lan@listserv.educause.edu> " 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> > on behalf of Rob Harris 
<robert.har...@culinary.edu <mailto:robert.har...@culinary.edu> >
Reply-To: "wireless-lan@listserv.educause.edu 
<mailto:wireless-lan@listserv.educause.edu> " 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> >
Date: Tuesday, September 26, 2017 at 7:33 AM
To: "wireless-lan@listserv.educause.edu 
<mailto:wireless-lan@listserv.educause.edu> " 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> >
Subject: Re: [WIRELESS-LAN] Two RF Questions



While there are performance gains to be sure (by going to 40, or 80), there 
are other concerns as well. We use 20 in our dorms because of the density of 
APs and users, we need those additional channels (even with dfs in use). We 
use 40 in our public spaces when there’s adequate capacity for it, and 80 in 
our theater area since we designed for it.





Robert Harris
Manager of Network Services

Culinary Institute of America

1946 Campus Drive

Hyde Park, NY
845-451-1681

www.ciachef.edu <http://www.ciachef.edu/>

Food is Life

Create and Savor Yours.™



Please consider the environment before printing this e-mail.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Tuesday, September 26, 2017 10:20 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions



It’s surprising to me that anyone would purchase a Lamborghini, then 
disconnect ten of the twelve cylinders and drive it at 25 mph on the 
autobahn.



When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a 
Cisco customer running 8.1 or above, and not using DBS (Dynamic Bandwidth 
Selection), then it’s the equivalent of the Lamborghini above running on 
only two cylinders.



Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for 
something the software doesn’t already do far better at. I promise, DBS won’t 
hurt a bit and your users will thank you a hundred times over.



Jeff





From: "wireless-lan@listserv.educause.edu 
<mailto:wireless-lan@listserv.educause.edu> " 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> > on behalf of "Street, Chad A" 
<cstr...@emory.edu <mailto:cstr...@emory.edu> >
Reply-To: "wireless-lan@listserv.educause.edu 
<mailto:wireless-lan@listserv.educause.edu> " 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> >
Date: Tuesday, September 26, 2017 at 6:59 AM
To: "wireless-lan@listserv.educause.edu 
<mailto:wireless-lan@listserv.educause.edu> " 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> >
Subject: Re: [WIRELESS-LAN] Two RF Questions



What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utiliza

Re: [WIRELESS-LAN] Two RF Questions

[James Andrewartha]

How did you measure the 35% improvement?

--
James Andrewartha
Network & Projects Engineer
Christ Church Grammar School
Claremont, Western Australia
Ph. (08) 9442 1757
Mob. 0424 160 877

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of GT Hill <g...@gthill.com>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, 26 September 2017 at 11:47 pm
To: "WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience.

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps.

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-)

GT

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jake Snyder <jsnyde...@gmail.com<mailto:jsnyde...@gmail.com>>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 9:39 AM
To: 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

Remember that spectrum is our constraining resource.

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you the most smiles/hour on 
your lambo.

I really like what cisco did with FRA.  Give me the ability to see what it 
thinks the overlap is.  I would LOVE to see the same with DBS, and give me what 
width it thinks all the APs in the building can pull off.

Sent from my iPhone

On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler 
<j...@scrippscollege.edu<mailto:j...@scrippscollege.edu>> wrote:
It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn.

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t already do far better at. I promise, DBS won’t hurt a bit 
and your users will thank you a hundred times over.

Jeff


From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of "Street, Chad A" <cstr...@emory.edu<mailto:cstr...@emory.edu>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 6:59 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu<mailto:chu...@psu.edu>> 
wrote:

1.  Enable it in places to check 

Re: [WIRELESS-LAN] Two RF Questions

[GT Hill]

I’ve been reading more of the conversation and wanted to add another statement:

The ONLY reason to have channelization above 20 MHz is budget. Which, is a 
valid reason. But, Wi-Fi networks ALWAYS perform better at smaller channel 
widths. Keep in mind, overall throughput per device is not the real concern. An 
11ac 20 MHz system can provide a massive amount of throughput. 

- Larger channels LISTEN to more interference 
- Your SINR will always be lower with larger channels
- Larger channels typically means more devices per AP 
- More devices per AP means higher retry rates which means degraded performance 

Just some thoughts. :-) 

GT

From:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of GT Hill <g...@gthill.com>
Reply-To:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date:  Tuesday, September 26, 2017 at 10:47 AM
To:  <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject:  Re: [WIRELESS-LAN] Two RF Questions

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience. 

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps. 

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-) 

GT

From:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder 
<jsnyde...@gmail.com>
Reply-To:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date:  Tuesday, September 26, 2017 at 9:39 AM
To:  <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject:  Re: [WIRELESS-LAN] Two RF Questions

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

Remember that spectrum is our constraining resource.

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you the most smiles/hour on 
your lambo.

I really like what cisco did with FRA.  Give me the ability to see what it 
thinks the overlap is.  I would LOVE to see the same with DBS, and give me what 
width it thinks all the APs in the building can pull off.

Sent from my iPhone

On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler <j...@scrippscollege.edu> wrote:

It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn. 

 

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

 

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t already do far better at. I promise, DBS won’t hurt a bit 
and your users will thank you a hundred times over. 

 

Jeff

 

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of "Street, Chad A" <cstr...@emory.edu>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 6:59 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

 

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu> wrote:

1. Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the only 
issue.

Re: [WIRELESS-LAN] Two RF Questions

[GT Hill]

I know that this is just one example, but I was at a large university site 
(Cisco Wi-Fi) that was running 20/40 channelization. After a switch to 20 MHz 
only, there was a 35% improvement in end-user Wi-Fi experience. 

Jake – One feature that I think many people agree is missing in FRA is the 
ability to dynamically turn off a radio. In some cases an extra radio in either 
band hurts more than it helps. 

And to just stir the pot a bit, I wish there were SMALLER than 20 MHz 
channelization. In many high density environments 20 MHz is just too big. Give 
me some more radios at smaller channel sizes and I’ll show you a spectacular 
Wi-Fi network. :-) 

GT

From:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of Jake Snyder 
<jsnyde...@gmail.com>
Reply-To:  The EDUCAUSE Wireless Issues Constituent Group Listserv 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date:  Tuesday, September 26, 2017 at 9:39 AM
To:  <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject:  Re: [WIRELESS-LAN] Two RF Questions

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

Remember that spectrum is our constraining resource.

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you the most smiles/hour on 
your lambo.

I really like what cisco did with FRA.  Give me the ability to see what it 
thinks the overlap is.  I would LOVE to see the same with DBS, and give me what 
width it thinks all the APs in the building can pull off.

Sent from my iPhone

On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler <j...@scrippscollege.edu> wrote:

It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn. 

 

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

 

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t already do far better at. I promise, DBS won’t hurt a bit 
and your users will thank you a hundred times over. 

 

Jeff

 

 

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of "Street, Chad A" <cstr...@emory.edu>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 6:59 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

 

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

 

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu> wrote:

1. Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the only 
issue.  Some clients don’t probe on DFS channels, and will only respond to 
beacons.  Make sure 2.4 is usable for the small number of incompatible devices.

2. No.  Don’t even consider 40MHz unless you’re using almost all the DFS 
channels, but even then you’ll probably have to disable it in some high density 
areas.

 

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Two RF Questions

 

Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best practice?

 

Our wireless infrastructure:

 

3 Cisco 5508s running 8.2.141.0

 

20 - 3800 APs

368 - 3700 APs

414 - 3600 APs

8 - 3500 APs

7 - 1810 APs

32 - 1142 APs

 

Prime 3.1.0

 

Thanks for your input.

David

*

Re: [WIRELESS-LAN] Two RF Questions

[Jeffrey D. Sessler]

For your residential, is that concern rooted in belief/assumption or proven by 
testing in production? I remember channel-width discussions with the advent of 
11n, and people here advocated sticking to 20 MHz for the same reasons, only 
our in-field testing said it was a bad assumption, reaffirmed by our vendor and 
SEs. We’re been using 40 MHz-wide channels since 2008, and adopted DBS with the 
deployment of 11ac.

Unless our campus and/or residential is unique in some way, shape, or fashion – 
our dense deployments overwhelmingly prefer 80 MHz wide channels, and data on 
both sides (client and infrastructure) reaffirms the software is making the 
right decision.

Jeff

From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of Rob Harris <robert.har...@culinary.edu>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 7:33 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

While there are performance gains to be sure (by going to 40, or 80), there are 
other concerns as well. We use 20 in our dorms because of the density of APs 
and users, we need those additional channels (even with dfs in use). We use 40 
in our public spaces when there’s adequate capacity for it, and 80 in our 
theater area since we designed for it.

[he Culinary Institute of America]
Robert Harris
Manager of Network Services
Culinary Institute of America
1946 Campus Drive
Hyde Park, NY
845-451-1681
www.ciachef.edu<http://www.ciachef.edu/>
Food is Life
Create and Savor Yours.™

Please consider the environment before printing this e-mail.

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Tuesday, September 26, 2017 10:20 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn.

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t already do far better at. I promise, DBS won’t hurt a bit 
and your users will thank you a hundred times over.

Jeff


From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of "Street, Chad A" <cstr...@emory.edu<mailto:cstr...@emory.edu>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 6:59 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu<mailto:chu...@psu.edu>> 
wrote:

1.  Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the only 
issue.  Some clients don’t probe on DFS channels, and will only respond to 
beacons.  Make sure 2.4 is usable for the small number of incompatible devices.

2.  No.  Don’t even consider 40MHz unless you’re using almost all the DFS 
channels, but even then you’ll probably have to disable it in some high density 
areas.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: [WIRELESS-LAN] Two RF Questions



Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best practice?



Our wireless i

Re: [WIRELESS-LAN] Two RF Questions

[Jake Snyder]

My challenge, as I’ve stated on this list before, is that Mac OS X preferences 
width in its AP selection criteria.  So while you may get more capacity, in a 
large Mac environment you lose most of that with Macs hanging onto APs linger 
and having to rate-shift down to slower PHY speeds due to that AP having a 
wider channel than its neighbors. Yes, it’s dumb.  But he’s the driver of that 
lambo.

Also, couple that with increasing the noise floor by 3db every time you double 
the channel width and there are many cases where your lambo just spins it’s 
tires.  All that power and you can’t hook it up.

Remember that spectrum is our constraining resource.

Figure out what width of channel you can run in a building, and run that.  
That’s the best use of spectrum and sure to give you the most smiles/hour on 
your lambo.

I really like what cisco did with FRA.  Give me the ability to see what it 
thinks the overlap is.  I would LOVE to see the same with DBS, and give me what 
width it thinks all the APs in the building can pull off.

Sent from my iPhone

> On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler <j...@scrippscollege.edu> 
> wrote:
> 
> It’s surprising to me that anyone would purchase a Lamborghini, then 
> disconnect ten of the twelve cylinders and drive it at 25 mph on the autobahn.
>  
> When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
> wonder what’s behind the purposeful neutering of the system. If you are a 
> Cisco customer running 8.1 or above, and not using DBS (Dynamic Bandwidth 
> Selection), then it’s the equivalent of the Lamborghini above running on only 
> two cylinders.
>  
> Don’t miss out on the significant advancements in bandwidth management. Free 
> those resources spent doing point-in-time simulation and surveys for 
> something the software doesn’t already do far better at. I promise, DBS won’t 
> hurt a bit and your users will thank you a hundred times over.
>  
> Jeff
>  
>  
> From: "wireless-lan@listserv.educause.edu" 
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of "Street, Chad A" 
> <cstr...@emory.edu>
> Reply-To: "wireless-lan@listserv.educause.edu" 
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
> Date: Tuesday, September 26, 2017 at 6:59 AM
> To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
> Subject: Re: [WIRELESS-LAN] Two RF Questions
>  
> What is your reasoning behind not wanting 40 megahertz channels if you have 
> plenty of overhead with your channel utilization?  People saying you should 
> or should not do something without Gathering any type of metric worry me.
>  
> On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu> wrote:
> 1.  Enable it in places to check for radar events.  If you get few, then 
> yes.  Client devices are almost fully capable now.  Hidden SSID’s are the 
> only issue.  Some clients don’t probe on DFS channels, and will only respond 
> to beacons.  Make sure 2.4 is usable for the small number of incompatible 
> devices.
> 
> 2.  No.  Don’t even consider 40MHz unless you’re using almost all the DFS 
> channels, but even then you’ll probably have to disable it in some high 
> density areas.
> 
>  
> 
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
> Sent: Monday, September 25, 2017 3:17 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: [WIRELESS-LAN] Two RF Questions
> 
>  
> 
> Greetings,
> 
> I have two hopefully simple RF related questions:
> 
> 1.  Should I enable the extended UNII-2 channels campus wide?
> 
> 2.  Should I enable 40Mhz channel width campus wide?
> 
> In other words what are you doing on your campus and what is the "best 
> practice?
> 
>  
> 
> Our wireless infrastructure:
> 
>  
> 
> 3 Cisco 5508s running 8.2.141.0
> 
>  
> 
> 20 - 3800 APs
> 
> 368 - 3700 APs
> 
> 414 - 3600 APs
> 
> 8 - 3500 APs
> 
> 7 - 1810 APs
> 
> 32 - 1142 APs
> 
>  
> 
> Prime 3.1.0
> 
>  
> 
> Thanks for your input.
> 
> David
> 
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> 
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
>  
>  
> 
> This e-mail message (including any attachments) is for the sole use of
> the intended recipient(s) and may contain confidential and privileged
> information. If the reader of this message is not the intended
> recipient,

Re: [WIRELESS-LAN] Two RF Questions

[Jeremy Gibbs]

Couldn't have said it better myself.  That is exactly what we do.




*--Jeremy L. Gibbs*
Sr. Network Engineer
Utica College IITS

T: (315) 223-2383
F: (315) 792-3814
E: jlgi...@utica.edu
http://www.utica.edu

On Tue, Sep 26, 2017 at 10:33 AM, Rob Harris <robert.har...@culinary.edu>
wrote:

> While there are performance gains to be sure (by going to 40, or 80),
> there are other concerns as well. We use 20 in our dorms because of the
> density of APs and users, we need those additional channels (even with dfs
> in use). We use 40 in our public spaces when there’s adequate capacity for
> it, and 80 in our theater area since we designed for it.
>
>
>
> [image: The Culinary Institute of America]
>
>
> *Robert Harris **Manager of Network Services*
>
> *Culinary Institute of America*
>
> 1946 Campus Drive
> <https://maps.google.com/?q=1946+Campus+Drive%0D+Hyde+Park,+NY+%0D+845=gmail=g>
>
> Hyde Park, NY
> <https://maps.google.com/?q=1946+Campus+Drive%0D+Hyde+Park,+NY+%0D+845=gmail=g>
> 845-451-1681 <(845)%20451-1681>
>
> www.ciachef.edu
>
> *Food is Life*
>
> *Create and Savor Yours.™*
>
>
>
> *Please consider the environment before printing this e-mail.*
>
>
>
> *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:
> WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] *On Behalf Of *Jeffrey D. Sessler
> *Sent:* Tuesday, September 26, 2017 10:20 AM
> *To:* WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>
> *Subject:* Re: [WIRELESS-LAN] Two RF Questions
>
>
>
> It’s surprising to me that anyone would purchase a Lamborghini, then
> disconnect ten of the twelve cylinders and drive it at 25 mph on the
> autobahn.
>
>
>
> When I see static 20 MHz channels, or using 40 MHz in only limited areas,
> I wonder what’s behind the purposeful neutering of the system. If you are a
> Cisco customer running 8.1 or above, and not using DBS (Dynamic Bandwidth
> Selection), then it’s the equivalent of the Lamborghini above running on
> only two cylinders.
>
>
>
> Don’t miss out on the significant advancements in bandwidth management.
> Free those resources spent doing point-in-time simulation and surveys for
> something the software doesn’t already do far better at. I promise, DBS
> won’t hurt a bit and your users will thank you a hundred times over.
>
>
>
> Jeff
>
>
>
>
>
> *From: *"wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.
> EDUCAUSE.EDU> on behalf of "Street, Chad A" <cstr...@emory.edu>
> *Reply-To: *"wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.
> EDUCAUSE.EDU>
> *Date: *Tuesday, September 26, 2017 at 6:59 AM
> *To: *"wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.
> EDUCAUSE.EDU>
> *Subject: *Re: [WIRELESS-LAN] Two RF Questions
>
>
>
> What is your reasoning behind not wanting 40 megahertz channels if you
> have plenty of overhead with your channel utilization?  People saying you
> should or should not do something without Gathering any type of metric
> worry me.
>
>
>
> On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu> wrote:
>
> 1.  Enable it in places to check for radar events.  If you get few,
> then yes.  Client devices are almost fully capable now.  Hidden SSID’s are
> the only issue.  Some clients don’t probe on DFS channels, and will only
> respond to beacons.  Make sure 2.4 is usable for the small number of
> incompatible devices.
>
> 2.  No.  Don’t even consider 40MHz unless you’re using almost all the
> DFS channels, but even then you’ll probably have to disable it in some high
> density areas.
>
>
>
> *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv [
> mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>] *On Behalf Of *David Blahut
> *Sent:* Monday, September 25, 2017 3:17 PM
> *To:* WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> *Subject:* [WIRELESS-LAN] Two RF Questions
>
>
>
> Greetings,
>
> I have two hopefully simple RF related questions:
>
> 1.  Should I enable the extended UNII-2 channels campus wide?
>
> 2.  Should I enable 40Mhz channel width campus wide?
>
> In other words what are you doing on your campus and what is the "best
> practice?
>
>
>
> Our wireless infrastructure:
>
>
>
> 3 Cisco 5508s running 8.2.141.0
>
>
>
> 20 - 3800 APs
>
> 368 - 3700 APs
>
> 414 - 3600 APs
>
> 8 - 3500 APs
>
> 7 - 1810 APs
>
> 32 - 1142 APs
>
>
>
> Prime 3.1.0
>
>
>
> Thanks for your input.
>
> David
>
> ** Participation and subscription information for this EDUCA

RE: [WIRELESS-LAN] Two RF Questions

[Rob Harris]

While there are performance gains to be sure (by going to 40, or 80), there are 
other concerns as well. We use 20 in our dorms because of the density of APs 
and users, we need those additional channels (even with dfs in use). We use 40 
in our public spaces when there’s adequate capacity for it, and 80 in our 
theater area since we designed for it.

[The Culinary Institute of America]
Robert Harris
Manager of Network Services
Culinary Institute of America
1946 Campus Drive
Hyde Park, NY
845-451-1681
www.ciachef.edu<http://www.ciachef.edu/>
Food is Life
Create and Savor Yours.™

Please consider the environment before printing this e-mail.

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Tuesday, September 26, 2017 10:20 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn.

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t already do far better at. I promise, DBS won’t hurt a bit 
and your users will thank you a hundred times over.

Jeff


From: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of "Street, Chad A" <cstr...@emory.edu<mailto:cstr...@emory.edu>>
Reply-To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Tuesday, September 26, 2017 at 6:59 AM
To: 
"wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: Re: [WIRELESS-LAN] Two RF Questions

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu<mailto:chu...@psu.edu>> 
wrote:

1.  Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the only 
issue.  Some clients don’t probe on DFS channels, and will only respond to 
beacons.  Make sure 2.4 is usable for the small number of incompatible devices.

2.  No.  Don’t even consider 40MHz unless you’re using almost all the DFS 
channels, but even then you’ll probably have to disable it in some high density 
areas.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: [WIRELESS-LAN] Two RF Questions



Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best practice?



Our wireless infrastructure:



3 Cisco 5508s running 8.2.141.0



20 - 3800 APs

368 - 3700 APs

414 - 3600 APs

8 - 3500 APs

7 - 1810 APs

32 - 1142 APs



Prime 3.1.0



Thanks for your input.

David

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




This e-mail message (including any attachments) is for the sole use of
the intended recipient(s) and may contain confidential and privileged
information. If the reader of this message is not the intended
recipient, you are hereby notified that any dissemination, distribution
or copying of this message (including any attachments) is strictly
prohibited.

If you have received this message in error, please contact
the sender by reply e-mail message and destroy all copies of the
original message (including attachments).
** Participation and subscription info

Re: [WIRELESS-LAN] Two RF Questions

[Jeffrey D. Sessler]

It’s surprising to me that anyone would purchase a Lamborghini, then disconnect 
ten of the twelve cylinders and drive it at 25 mph on the autobahn.

When I see static 20 MHz channels, or using 40 MHz in only limited areas, I 
wonder what’s behind the purposeful neutering of the system. If you are a Cisco 
customer running 8.1 or above, and not using DBS (Dynamic Bandwidth Selection), 
then it’s the equivalent of the Lamborghini above running on only two cylinders.

Don’t miss out on the significant advancements in bandwidth management. Free 
those resources spent doing point-in-time simulation and surveys for something 
the software doesn’t already do far better at. I promise, DBS won’t hurt a bit 
and your users will thank you a hundred times over.

Jeff


From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> 
on behalf of "Street, Chad A" <cstr...@emory.edu>
Reply-To: "wireless-lan@listserv.educause.edu" 
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Tuesday, September 26, 2017 at 6:59 AM
To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Two RF Questions

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu> wrote:

1.  Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the only 
issue.  Some clients don’t probe on DFS channels, and will only respond to 
beacons.  Make sure 2.4 is usable for the small number of incompatible devices.

2.  No.  Don’t even consider 40MHz unless you’re using almost all the DFS 
channels, but even then you’ll probably have to disable it in some high density 
areas.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Two RF Questions



Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best practice?



Our wireless infrastructure:



3 Cisco 5508s running 8.2.141.0



20 - 3800 APs

368 - 3700 APs

414 - 3600 APs

8 - 3500 APs

7 - 1810 APs

32 - 1142 APs



Prime 3.1.0



Thanks for your input.

David

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




This e-mail message (including any attachments) is for the sole use of
the intended recipient(s) and may contain confidential and privileged
information. If the reader of this message is not the intended
recipient, you are hereby notified that any dissemination, distribution
or copying of this message (including any attachments) is strictly
prohibited.

If you have received this message in error, please contact
the sender by reply e-mail message and destroy all copies of the
original message (including attachments).
** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/discuss.

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

RE: [WIRELESS-LAN] Two RF Questions

[Chuck Enfield]

If you’re responding to my comments, I don’t think I said what you think I 
said.



From: Street, Chad A [mailto:cstr...@emory.edu]
Sent: Tuesday, September 26, 2017 9:59 AM
To: Chuck Enfield <chu...@psu.edu>
Cc: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions



What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should 
or should not do something without Gathering any type of metric worry me.



On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu 
<mailto:chu...@psu.edu> > wrote:

1.  Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the 
only issue.  Some clients don’t probe on DFS channels, and will only respond 
to beacons.  Make sure 2.4 is usable for the small number of incompatible 
devices.

2.  No.  Don’t even consider 40MHz unless you’re using almost all the 
DFS channels, but even then you’ll probably have to disable it in some high 
density areas.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: [WIRELESS-LAN] Two RF Questions



Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best 
practice?



Our wireless infrastructure:



3 Cisco 5508s running 8.2.141.0



20 - 3800 APs

368 - 3700 APs

414 - 3600 APs

8 - 3500 APs

7 - 1810 APs

32 - 1142 APs



Prime 3.1.0



Thanks for your input.

David

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

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





  _


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Re: [WIRELESS-LAN] Two RF Questions

[Street, Chad A]

What is your reasoning behind not wanting 40 megahertz channels if you have 
plenty of overhead with your channel utilization?  People saying you should or 
should not do something without Gathering any type of metric worry me.

On Sep 25, 2017 3:28 PM, Chuck Enfield <chu...@psu.edu> wrote:

1.  Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the only 
issue.  Some clients don’t probe on DFS channels, and will only respond to 
beacons.  Make sure 2.4 is usable for the small number of incompatible devices.

2.  No.  Don’t even consider 40MHz unless you’re using almost all the DFS 
channels, but even then you’ll probably have to disable it in some high density 
areas.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Two RF Questions



Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best practice?



Our wireless infrastructure:



3 Cisco 5508s running 8.2.141.0



20 - 3800 APs

368 - 3700 APs

414 - 3600 APs

8 - 3500 APs

7 - 1810 APs

32 - 1142 APs



Prime 3.1.0



Thanks for your input.

David

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

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




This e-mail message (including any attachments) is for the sole use of
the intended recipient(s) and may contain confidential and privileged
information. If the reader of this message is not the intended
recipient, you are hereby notified that any dissemination, distribution
or copying of this message (including any attachments) is strictly
prohibited.

If you have received this message in error, please contact
the sender by reply e-mail message and destroy all copies of the
original message (including attachments).

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

RE: [WIRELESS-LAN] Two RF Questions

[Yahya M. Jaber]

Try to simulate your AP location in Ekahau, see what it tells you.
I use almost 40Mhz channels everywhere, and some 80Mhz which was based on the 
design.


Yahya Jaber.
Sr. Wireless Engineer
IT Network & Communications – Engineering

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Entwistle, Bruce
Sent: Tuesday, September 26, 2017 12:11 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Two RF Questions

We have a similar configuration and have begun using the additional channels 
but continue to use 20MHz channel width.

Bruce Entwistle
Network Manager
University of Redlands


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 12:17 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: [WIRELESS-LAN] Two RF Questions

Greetings,
I have two hopefully simple RF related questions:
1.  Should I enable the extended UNII-2 channels campus wide?
2.  Should I enable 40Mhz channel width campus wide?
In other words what are you doing on your campus and what is the "best practice?

Our wireless infrastructure:

3 Cisco 5508s running 8.2.141.0

20 - 3800 APs
368 - 3700 APs
414 - 3600 APs
8 - 3500 APs
7 - 1810 APs
32 - 1142 APs

Prime 3.1.0

Thanks for your input.
David
** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/discuss.
** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/discuss.


This message and its contents including attachments are intended solely for the 
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**
Participation and subscription information for this EDUCAUSE Constituent Group 
discussion list can be found at http://www.educause.edu/discuss.

RE: [WIRELESS-LAN] Two RF Questions

[Entwistle, Bruce]

We have a similar configuration and have begun using the additional channels 
but continue to use 20MHz channel width.

Bruce Entwistle
Network Manager
University of Redlands


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 12:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Two RF Questions

Greetings,
I have two hopefully simple RF related questions:
1.  Should I enable the extended UNII-2 channels campus wide?
2.  Should I enable 40Mhz channel width campus wide?
In other words what are you doing on your campus and what is the "best practice?

Our wireless infrastructure:

3 Cisco 5508s running 8.2.141.0

20 - 3800 APs
368 - 3700 APs
414 - 3600 APs
8 - 3500 APs
7 - 1810 APs
32 - 1142 APs

Prime 3.1.0

Thanks for your input.
David
** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/discuss.

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

Re: [WIRELESS-LAN] Two RF Questions

[Kenny, Eric]

Hi Dave,

I personally would not enable 40+ MHz wide channels without already having the 
UNII-2 channels enabled as it will cut down on your available channels.

Also, stay away from any doppler radar frequencies used in Poughkeepsie ;-)

-Eric Kenny

> On Sep 25, 2017, at 3:16 PM, David Blahut  wrote:
> 
> Greetings,
> 
> I have two hopefully simple RF related questions:
> 
> 1.  Should I enable the extended UNII-2 channels campus wide?
> 2.  Should I enable 40Mhz channel width campus wide?
> 
> In other words what are you doing on your campus and what is the "best 
> practice?
> 
> Our wireless infrastructure:
> 
> 3 Cisco 5508s running 8.2.141.0
> 
> 20 - 3800 APs
> 368 - 3700 APs
> 414 - 3600 APs
> 8 - 3500 APs
> 7 - 1810 APs
> 32 - 1142 APs
> 
> Prime 3.1.0
> 
> Thanks for your input.
> David
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> 

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

Re: [WIRELESS-LAN] Two RF Questions

[Jeremy Gibbs]

I have been moving our less AP dense buildings to 40 Mhz channels.  In the
dorms, I stick with 20 Mhz, unless there is little to no CCI when I do my
testing.  I see RADAR events, but they are sparse.  I definitely see an
improvement with the 40 Mhz channels and keeping users connected and happy
in our academic areas.

On Mon, Sep 25, 2017 at 3:27 PM, Chuck Enfield <chu...@psu.edu> wrote:

> 1.  Enable it in places to check for radar events.  If you get few,
> then yes.  Client devices are almost fully capable now.  Hidden SSID’s are
> the only issue.  Some clients don’t probe on DFS channels, and will only
> respond to beacons.  Make sure 2.4 is usable for the small number of
> incompatible devices.
>
> 2.  No.  Don’t even consider 40MHz unless you’re using almost all the
> DFS channels, but even then you’ll probably have to disable it in some high
> density areas.
>
>
>
> *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:
> WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] *On Behalf Of *David Blahut
> *Sent:* Monday, September 25, 2017 3:17 PM
> *To:* WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> *Subject:* [WIRELESS-LAN] Two RF Questions
>
>
>
> Greetings,
>
> I have two hopefully simple RF related questions:
>
> 1.  Should I enable the extended UNII-2 channels campus wide?
>
> 2.  Should I enable 40Mhz channel width campus wide?
>
> In other words what are you doing on your campus and what is the "best
> practice?
>
>
>
> Our wireless infrastructure:
>
>
>
> 3 Cisco 5508s running 8.2.141.0
>
>
>
> 20 - 3800 APs
>
> 368 - 3700 APs
>
> 414 - 3600 APs
>
> 8 - 3500 APs
>
> 7 - 1810 APs
>
> 32 - 1142 APs
>
>
>
> Prime 3.1.0
>
>
>
> Thanks for your input.
>
> David
>
> ** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found at http://www.educause.edu/
> discuss.
> ** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found at http://www.educause.edu/
> discuss.
>
>


-- 


*--Jeremy L. Gibbs*
Sr. Network Engineer
Utica College IITS

T: (315) 223-2383
F: (315) 792-3814
E: jlgi...@utica.edu
http://www.utica.edu

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

Re: [WIRELESS-LAN] Two RF Questions

[Hunter Fuller]

We currently won't even touch 40MHz as we like having the ability to solve
problems by throwing more APs at them.

On Mon, Sep 25, 2017 at 2:28 PM Chuck Enfield <chu...@psu.edu> wrote:

> 1.  Enable it in places to check for radar events.  If you get few,
> then yes.  Client devices are almost fully capable now.  Hidden SSID’s are
> the only issue.  Some clients don’t probe on DFS channels, and will only
> respond to beacons.  Make sure 2.4 is usable for the small number of
> incompatible devices.
>
> 2.  No.  Don’t even consider 40MHz unless you’re using almost all the
> DFS channels, but even then you’ll probably have to disable it in some high
> density areas.
>
>
>
> *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:
> WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] *On Behalf Of *David Blahut
> *Sent:* Monday, September 25, 2017 3:17 PM
>
>
> *To:* WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> *Subject:* [WIRELESS-LAN] Two RF Questions
>
>
>
> Greetings,
>
> I have two hopefully simple RF related questions:
>
> 1.  Should I enable the extended UNII-2 channels campus wide?
>
> 2.  Should I enable 40Mhz channel width campus wide?
>
> In other words what are you doing on your campus and what is the "best
> practice?
>
>
>
> Our wireless infrastructure:
>
>
>
> 3 Cisco 5508s running 8.2.141.0
>
>
>
> 20 - 3800 APs
>
> 368 - 3700 APs
>
> 414 - 3600 APs
>
> 8 - 3500 APs
>
> 7 - 1810 APs
>
> 32 - 1142 APs
>
>
>
> Prime 3.1.0
>
>
>
> Thanks for your input.
>
> David
>
> ** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found at
> http://www.educause.edu/discuss.
> ** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found at
> http://www.educause.edu/discuss.
>
> --

--
Hunter Fuller
Network Engineer
VBH Annex B-5
+1 256 824 5331

Office of Information Technology
The University of Alabama in Huntsville
Systems and Infrastructure

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

RE: [WIRELESS-LAN] Two RF Questions

[Chuck Enfield]

1.  Enable it in places to check for radar events.  If you get few, then 
yes.  Client devices are almost fully capable now.  Hidden SSID’s are the 
only issue.  Some clients don’t probe on DFS channels, and will only respond 
to beacons.  Make sure 2.4 is usable for the small number of incompatible 
devices.

2.  No.  Don’t even consider 40MHz unless you’re using almost all the 
DFS channels, but even then you’ll probably have to disable it in some high 
density areas.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: Monday, September 25, 2017 3:17 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Two RF Questions



Greetings,

I have two hopefully simple RF related questions:

1.  Should I enable the extended UNII-2 channels campus wide?

2.  Should I enable 40Mhz channel width campus wide?

In other words what are you doing on your campus and what is the "best 
practice?



Our wireless infrastructure:



3 Cisco 5508s running 8.2.141.0



20 - 3800 APs

368 - 3700 APs

414 - 3600 APs

8 - 3500 APs

7 - 1810 APs

32 - 1142 APs



Prime 3.1.0



Thanks for your input.

David

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


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

RE: [WIRELESS-LAN] Two RF Questions

[Manon Lessard]

Hi

The answer is: it depends.
Extended channels depend on the presence of TDWR radars in your environment 
(ex: if you are near an airport, there are lists of TDWR radars in the US).
40 Mhz channels depends on your clients: do you need more small cells in 20Mhz 
or can afford less available channels and go 40?
Are there going to be more clients using 40 Mhz capacity or are they older 
clients which means your additional channel won’t be used by many VS the 
benefit of mitigating CCI...

Tell us more about your client devices and your environment. In the end, 
regardless of your APs’ capability it’s all about the client.

Thx

Manon Lessard
Technicienne en développement de systèmes
CCNP, CWNA, CWDP
Direction des technologies de l'information
Pavillon Louis-Jacques-Casault
1055, avenue du Séminaire
Bureau 0403
Université Laval, Québec (Québec)
G1V 0A6, Canada

418 656-2131, poste 12853
Télécopieur : 418 656-7305
manon.less...@dti.ulaval.ca<mailto:manon.less...@dti.ulaval.ca>
www.dti.ulaval.ca<http://www.dti.ulaval.ca/>

Avis relatif à la confidentialité | Notice of 
Confidentiality<http://www.rec.ulaval.ca/lce/securite/confidentialite.htm>



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From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of David Blahut
Sent: 25 septembre 2017 15:17
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Two RF Questions

Greetings,
I have two hopefully simple RF related questions:
1.  Should I enable the extended UNII-2 channels campus wide?
2.  Should I enable 40Mhz channel width campus wide?
In other words what are you doing on your campus and what is the "best practice?

Our wireless infrastructure:

3 Cisco 5508s running 8.2.141.0

20 - 3800 APs
368 - 3700 APs
414 - 3600 APs
8 - 3500 APs
7 - 1810 APs
32 - 1142 APs

Prime 3.1.0

Thanks for your input.
David
** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/discuss.

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