Depending on the building construction, and assuming you are using DFS channels, running 40Mhz and even 80Mhz is very likely with no downside. 5GHz does not propagate very well, so a static 20Mhz plan in anything but big open spaces is IMHO unnecessary.
If you are a Cisco customer, enabling DFS (Dynamic Bandwidth Selection) is likely the best choice for maximizing the use of the 5Ghz space. DFS will dynamically adjust width based on the client make up and other factors, and I’ve found it to be far better than a human design since the environment is never static. I have a newly completed 110-bed residential hall with a very dense deployment of APs (105 AP’s total), most are in-room/suite. With DFS enabled, a clear majority of the in-room APs run at 80MHz. In more public and/or open spaces, they tend to adjust to 20Mhz or 40Mhz. Most of the clients in this residence hall are 11.ac and report a 1300 or 1170 Mbps connection speed. Jeff From: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> on behalf of "Trinklein, Jason R" <trinkle...@cofc.edu> Reply-To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> Date: Tuesday, November 29, 2016 at 1:35 PM To: "wireless-lan@listserv.educause.edu" <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> Subject: [WIRELESS-LAN] 5GHz Channel Width Hi All, I was just reading a blog article that heavily recommends not to use 40Mhz channel width in multi-floor environments, particularly where many 5GHz radios are used (particularly in our case with Xirrus multi-radio APs). Our campus presently uses 20MHz channel width in all buildings. We are testing and considering 40MHz width because of the bandwidth benefits for clients. What do you use on your campus? Have you found that setting a 40MHz channel width on your 5GHz radios has caused too much interference? Here is the article: http://divdyn.com/dual-5ghz-radio-aps/ Your thoughts are appreciated. -- Jason Trinklein Wireless Engineering Manager College of Charleston 81 St. Philip Street | Office 311D | Charleston, SC 29403 trinkle...@cofc.edu<mailto:trinkle...@cofc.edu> | (843) 300–8009 ********** 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/.
