Hi John, I knew I should have broken the rules and taken a few pictures! ;-)
If I remember right, they stayed with 1,6,11 (!). Although there was a time where the 4 channels worked (for 802.11b only). They just had huge overlapping cells. It's important to note that during many of the meetings, the huge ballrooms are closed off with large partitions so the actual working groups end up sharing smaller RF space. So it's not always that crazy and each one of these partitions add a 3dB loss but during the opening/closing, there is work being done and the partitions are all open. Worth the price of the admission if there is an IEEE meeting in your area (although I don't think the meetings are as well attended because there's nothing really pressing to fix these days but I could be wrong ;-) With 6 APs to service 90 people - you should be ok but it all depends on the applications.I should add that the bulk of the work being done was email, VPN, and file sharing to a server. Nothing fancy like time sensitive VOIP apps or video conference. That's when you would see possibly break down in that environment. I still remember some vendors recommending a max of 7 VOIP client per AP (!). Anything that doesn't tolerate retries would have a hard time in such a congested environment but for most apps, it just works (just more slowly but not an issue for most users). PS: As a rule of thumb, I'm a big fan of not playing around too much with AP power unless you can do the same on the client-side... Why let your client scream louder than your infrastructure? ... Jonn Martell On Thu, Apr 21, 2011 at 4:29 PM, John Kaftan <jkaf...@utica.edu> wrote: > That is a crazy story. How did they do it, just with managing cell size and > channels? I mean back in those days they only had 2.4 Ghtz. I have heard > of folks cranking down the power in tight big rooms and going with a 4 > channel plan. We have an event next weekend where we are going to have 90 > people in a 50' x 50' room and I am freaking out about that. Maybe I > shouldn't be. > > I was planning on putting in 6 APs and having only 3 radios going on 2.4 to > avoid co-channel interference. > > John > > On 4/21/2011 5:34 PM, Jonn Martell wrote: >> >> Absolutely possible to have a huge number of active clients in a single >> room. >> >> When I attended the IEEE plenary and interim meetings between 2001 and >> 2004, there were 500-800+ engineering types *all* with active laptops >> all downloading the latest versions of working group drafts. Back >> then, we started on 802.11b (DSSS) without the benefit of OFDM and >> some of the newer technology in 802.11n (that's the technology there >> were crafting up! :) .... >> >> It all worked even if the people installing the APs were an outside >> firm that did the site surveys when the rooms were empty! ;-) I was >> shocked to be at IEEE 802.11 engineering meetings and seeing APs on >> the floor. :) They fixed that in subsequent meetings but even with >> the APs on the floor and a room full of humans, the stuff still >> worked! >> >> Now, when everyone downloaded these huge documents simultaneously "the >> latest draft of TGi is up on the server..." when announced, the speed >> would drop but still downloaded fairly fast considering the number of >> people and temporary deployment of these meetings. >> >> No special sauce needed, these were autonomous Cisco APs with standard >> omni-directional antennas. There's a lot more you can do these days >> to optimize your setup. >> >> I wish we were allowed to take pictures! 700+ laptops all lined up >> and active on a ballroom floor is quite the scene! All I could do was >> stand at the back with a big smile on my face: "This stuff is >> amazing"! >> >> ... Jonn Martell >> >> On Thu, Apr 21, 2011 at 8:11 AM, Palmer J.D.F. >> <j.d.f.pal...@swansea.ac.uk> wrote: >>> >>> Hello, >>> >>> I've been posed a tricky question by someone on a planning committee for >>> a new campus building. >>> "...is it actually feasible for 500 simultaneous WiFi connections in a >>> lecture room?" >>> >>> I was hoping that there would be someone that might have experience of >>> answering (or providing a solution to) such a question who could offer >>> some input as to whether this is possible, or how close to the figure of >>> 500 could we realistically achieve with the technology currently >>> available? >>> >>> We are Cisco a site so ideally any solution would need to be one Cisco >>> is capable of delivering, but if there are other vendors that are proven >>> to be able to provide this kind of coverage to good effect, then I'd be >>> glad to hear of your experiences. >>> >>> All the best, >>> Jezz Palmer. >>> >>> ------------------------------------- >>> Jezz Palmer >>> Library& Information Services >>> Swansea University >>> Singleton Park >>> Swansea >>> SA2 8PP >>> ------------------------------------- >>> >>> ********** >>> 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/.
