Single SSID – anything else just adds confusion for the end-user. Then again, I was recently visited a spot where they had a different SSID for every building. :)
Thinking more about this… If residence halls (academic buildings too) are well designed around 5 GHz and use in-room AP placement, the issues with 2.4 tend to melt away (or you can ignore them), with clients only falling back to 2.4 when they transition outside of a building. If you’re a Cisco shop (I assume Aruba has something similar), their automatic RRM (radio resource management) and TPC (Transmit Power Control) tend to result in very tiny cells where there is a lot of 2.4 radios talking (which is a good thing - tiny cells). Of course, this can be really problematic if the AP layout design is not-optimal such as in a typically budget-driven “down the center of the hallway” methods of deployment where adjacent AP’s tend to have clear line-of-sight of each other. In cases such as these, the reduction in radio output to reduce AP channel overlap can result in client connection troubles i.e. The clients are probably behind fire–proof metal clad doors, brick walls, etc. Coupled with coverage hole detection (where AP power is increased for client connectivity), you now have an environment that’s in constant chaos, where someone has to do a lot of manual adjusting of AP radios or disable the auto-adjusting. On the other hand, if AP layout is optimal where you’re deploying AP’s in-room, lower on the wall, avoiding line-of-sight, etc. then you get the benefit of the room’s construction (doors, floors, walls, what inside the walls, bed, desks, etc.). All of which help promote small cell isolation and reduce the number of adjacent neighbor AP’s you’ll see, resulting in less 2.4 GHz channel overlap. Now then, the same issues can crop up in 5 GHz, but it doesn’t propagate as far, so if you're using the in-room deployment method, it’s likely not as big of an issue even in dense deployments. That said, if you do have dense 5 GHz deployments, Cisco’s 8.1 code introduces 5 GHz dynamic channel-width allocation, somewhat eliminating the issue by dynamically moving between 20, 40, and 80 MHz channels. In my opinion, 2.4 GHz is slowly marching to its demise, and I’m focusing all of my attention on 5 GHz. We have the luxury of of a robust Mac population (~80% of the students), and Apple laptops and desktops have long since had access to 5GHz, so I’m not sure how much effort should be put into maintaining 2.4 if it’s ultimately only being used by old phones, devices that move little data, or have alternative data paths such as cellular, why expend a lot of effort on it? Jeff From: "wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" on behalf of Stephen Oglesby Reply-To: "wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" Date: Wednesday, August 12, 2015 at 9:41 AM To: "wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs Paul, We're an Aruba shop and, as Bruce of Liberty mentioned, for dense deployments we turn 2.4 ghz radios off on every other AP (typically edge of building APs). Our main performance issues were due to interference and channel utilization on the 2.4 ghz spectrum. We attempted reducing 2.4 ghz (20 mhz channel) transmit power but still had issues. I also agree with keeping to the simplicity of a single SSID if at all possible. I can't imagine the number of issues that would be reported to me simply because the user exited the ideal range for 5ghz spectrum. Our student and staff networks support a wide range of client wireless cards, antenna configurations, and spectrum compatibility (many are including 2.4ghz only). Having users manually switch networks as needed may cause HelpDesk to become very popular. Good Luck, Stephen Oglesby Network and Telecommunications Architect Aims Community College 5401 W. 20th Street Greeley, CO 80634 970.339.6350 (Office) stephen.ogle...@aims.edu<mailto:stephen.ogle...@aims.edu> IT staff will never ask you for your username and password. Always decline to provide the information and report such attempts to the help desk (x6380). On Wed, Aug 12, 2015 at 8:24 AM, Philippe Hanset <phan...@anyroam.net<mailto:phan...@anyroam.net>> wrote: Paul, Dorm design is an animal of itself and each school has its own set of challenges based on locations and policies. As much as I agree that 2.4 GHz and 5 GHz shouldn’t be on separate SSIDs for main campus, I have really changed my mind for dormitories. Those buildings are really micro houses stacked on top of each other with people bringing anything and everything they want which is quite different than academic buildings. We all spend our summers designing the best coverage that we can for those residential areas, and as soon as students move in, the interference in 2.4 GHz makes our entire effort look pointless in the eyes of the complaining student who is actually partly responsible for the problem. So, in dormitories only, I would have the regular set of SSIDs that the campus provides plus and extra 5 GHz only called something like "residential-preferred". But I wouldn’t use “fast” or “5GHz” in the SSID name. Best, Philippe Philippe Hanset www.eduroam.us<http://www.eduroam.us> On Aug 11, 2015, at 4:22 PM, Paul Sedy <rps...@masters.edu<mailto:rps...@masters.edu>> wrote: Hello everyone, We are a Cisco shop and have, up until now, employed a single SSID for students, supporting both 2.4 Ghz and 5Ghz connections. During this summer, we have been working to develop sufficient AP density to ensure good 5Ghz cells throughout our dorms. In the past, we have seen numerous instances of poorer performance on the 2.4 Ghz spectrum, but up to this point, have relied on the client to make the decision between these two options. We are thinking of deploying two separate SSIDs, a 5Ghz network and a 2.4 Ghz network, that are exclusive in order to promote a better experience for the students with devices capable of 5Ghz connectivity. We would probably use the original SSID name with an appended (5 Ghz) or (2.4 Ghz). Are any of you currently employing this type of configuration and how well has it worked for you? We would appreciate any insights that anyone might have. Paul Sedy The Master’s College Director of IT Operations 21726 Placerita Canyon Rd, Santa Clarita, CA 91321 661.362.2340<tel:661.362.2340> | rps...@masters.edu<mailto:rps...@masters.edu> ********** 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/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
