This doc recommends 20 MHz wide channels for high density deployments but have 40 MHz channels campus wide. We especially wanted 40 MHz channels for large classrooms or auditoriums where we have 6 APs for 100 to 300 students. (With 2.4 GHz enabled on only 3 of the APs).
Our APs are not deployed densely enough to cause any channel overlap, even with 40 MHz channels. Even in our pilot project for the residence halls with an AP in every 3rd room (max one wall between client and AP) we don’t see any channel overlap with 40 MHz channels. In that building APs hear at most 1 other AP at -63 dB and the rest are -75 dB or lower. We have some res hall buildings that 5 GHz travels vertically very well compared to horizontally. Even in those buildings APs that are two floors apart hear each other at -71 dB to -76 dB. So in those buildings we might end up setting the 5 GHz power down or if that does not work then we would use 20 MHz wide channels. https://www.wjcomms.co.uk/wp-content/uploads/2014/11/Tuning-Cisco-WLC’s-for-High-Density-Deployments-v3.pdf On Apr 10, 2015, at 12:26 PM, Dan Brisson <[email protected]> wrote: > Just my 2 cents, but the "killer app" to me with 40mhz is that a client > operating at the higher data rates means less time on channel which means > better overall performance (lower channel utilization). > > We've been doing 40mhz for a LONG time now with no noticeable issues. > > -dan > > > Dan Brisson > Network Engineer > University of Vermont > (Ph) 802.656.8111 > > [email protected] > On 4/10/15 12:37 PM, Eric T. Barnett wrote: >> All 20 MHz here. I like not having to deal with channel interference and I’m >> not seeing a “killer app” for 40 MHz. >> >> Eric Barnett >> Wireless Administrator >> Information and Technology Services >> Arkansas State University >> 870 680 4243 >> >> >> >> From: The EDUCAUSE Wireless Issues Constituent Group Listserv >> [mailto:[email protected]] On Behalf Of Heath Barnhart >> Sent: Friday, April 10, 2015 11:10 AM >> To: [email protected] >> Subject: Re: [WIRELESS-LAN] 802.11ac AP Deployment >> >> Ruckus R700 for the APs. I aware of the possibility of saturation, but I'd >> rather have the devices in place and try pulling back the transmit power >> than find out later I need more APs. I don't have the dimensions in front of >> me, but I did take that into account when planning it. >> >> Out of curiosity how many people are running 20 Mhz channels on 5GHz? >> >> -- >> Heath Barnhart >> ITS Network Administrator >> Washburn University >> Topeka, KS >> On Fri, 2015-04-10 at 14:38 +0000, Hinson, Matthew P wrote: >> Just curious, how big are the rooms that you’re putting these in? What model >> APs, and what are the walls made of? >> >> >> >> Most places I’ve seen do this end up disabling the radios on 1/3 of the APs >> or sometimes half of them to combat co-channel interference. If you aren’t >> using UNII-2e/DFS channels, you’ve only got 4 non-overlapping 40MHz channels. >> >> >> >> It CAN work if your antenna selection and building layout/construction allow >> for it. >> >> >> >> From: The EDUCAUSE Wireless Issues Constituent Group Listserv >> [mailto:[email protected]] On Behalf Of Heath Barnhart >> Sent: Friday, April 10, 2015 10:07 AM >> To: [email protected] >> Subject: Re: [WIRELESS-LAN] 802.11ac AP Deployment >> >> >> >> >> We also have a new ResHall on the way. I'm putting an AP in every suite and >> will adjust power levels as needed. We are pulling two Cat6 to each >> location. Like many, I'm not seeing high utilization out of any of our >> existing APs, so I'm not too worried about overwhelming the link and >> therefore can't justify running Cat6a. At the moment the plan is to install >> Wave1 APs as well, and I'm staying with 40 MHz channels on 5Ghz, so the >> total bandwidth required would be below 1 Gbps anyways. >> >> >> >> -- >> Heath Barnhart >> ITS Network Administrator >> Washburn University >> Topeka, KS >> >> On Mon, 2015-04-06 at 23:28 +0000, Doug Burke wrote: >> >> >> >> All, >> >> Last year we cabled our campus classrooms and administrative offices with >> CAT6a preparing for the deployment of Wav 2 802.11ac. We are about to begin >> Phase II of the cabling project in our residence halls and we are looking >> for input from others on whether to plan for one AP per room or trust our >> survey tools. I expect most of you will say "it depends" and we understand >> the complexities of building construction. We have deployed 70 Wav 1 APs as >> a Proof of Concept (POC) testing them in different types of building >> construction but would like to hear other's experiences in particular to >> residence halls. Thank you for your help. >> >> Douglas Burke >> Senior Director '13 MSEL, BSBA >> Network Infrastructure Systems & Services >> University of San Diego >> >> ********** >> Participation and subscription information for this EDUCAUSE Constituent >> Group discussion list can be found at http://www.educause.edu/groups/. >> ********** Participation and subscription information for this EDUCAUSE >> Constituent Group discussion list can be found at >> http://www.educause.edu/groups/. >> > > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/groups/. > --- Bruce Curtis [email protected] Certified NetAnalyst II 701-231-8527 North Dakota State University ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
