This reminds me of a line from an early Star Trek episode: "Ugly sacks of mostly water" to describe human beings. And 2.4 GHz is quite susceptible to water absorption, especially at 2.45 GHz.
Also remember that some things *reflect* RF, which can make a mess of those nice antenna patterns that you thought you were getting out of that directional antenna. At $WORK we have a regular pattern of access points on the ceiling of every floor (in typical concrete/steel buildings). It still took the network crew quite some time to get things adjusted, but the difference between a typical office and a conference is that *everyone* at the conference is vying for wireless access, in the office most of the devices are wired with only a small percentage wireless. Rather than trying to customise every antenna pattern, using a regular pattern of omnidirectional APs with the power down low and the channels designed like a typical cellular system with no adjacent use of the same channel (tougher than it sounds!) is likely the best that you can do. And about the SSID - yes, make it the same everywhere. You don't want to have to explain about multiple SSIDs to the users. I would also configure all of the APs for 'b' only (no 'g') to get the maximum use of your channel space. Mixing AP types as you have suggested may cause you more headaches, but then since $WORK builds our own, it's easy for us to use all the same AP everywhere - but it sure does make WiFi roaming between the floors (and buildings) less troublesome. Especially if this is one, big convention room floor (or even a few big cavernous halls), expect to be 'the guy' getting cursed at for the lousy wireless service - it's part of the gig, y'know! ;-) - Richard Chuong Dao wrote: > I've setup a fairly large wireless system. The event was at a conference for > about 10K of people. I the test setup went well at my work location. It did > not perform well at the event. Later, I found out that human bodies absorb > signals. You might want to read up on that. > > -CD > > -----Original Message----- > From: discuss-boun...@lopsa.org [mailto:discuss-boun...@lopsa.org] On Behalf > Of da...@lang.hm > Sent: Tuesday, January 12, 2010 2:17 AM > To: LOPSA Discuss List > Subject: [lopsa-discuss] high density wireless > > When attending confrences in past years I have been frustrated at the > quality/reliability of the wireless access. In many cases it's been clear > that the person setting things up did not understand the effects of many > computers in a small area.. > > Well, I now have a chance to show that I can do a better job. > > I believe I have a good handle on managing the RF side of things (set the > access points to low power, use directional antennas to get coverage of the > rooms without overlapping other access points, I have a wifi spectrum > analyser to be able to measure coverage and the effect of the walls, etc) > > However, I can't think of anything particularly special on the IP side of > things that I need to do. I can rate limit individual connections, use > something like packetfence to watch for machines that look like they are > infected and try and isolate them. > > I can police the vendor area with the scanner and ask booths that bring up > their own access points to disable them (a major problem in past years) > > The access points available are a combination of 3com 7760 and WRT54GL > (changing the firmware on the WRT APs is an option), I may buy a couple more, > possibly picking up a couple N capible devices (not for the speed, but for > the extra channels to try and releive the RF congestion) > > Should I try and put smarts in the APs? or just let them be a flat net with > one SSID and do everything at the gateway/DHCP server? > > > > So what am I not thinking of? > > David Lang > _______________________________________________ > Discuss mailing list > Discuss@lopsa.org > http://lopsa.org/cgi-bin/mailman/listinfo/discuss > This list provided by the League of Professional System Administrators > http://lopsa.org/ > > _______________________________________________ > Discuss mailing list > Discuss@lopsa.org > http://lopsa.org/cgi-bin/mailman/listinfo/discuss > This list provided by the League of Professional System Administrators > http://lopsa.org/ > _______________________________________________ Discuss mailing list Discuss@lopsa.org http://lopsa.org/cgi-bin/mailman/listinfo/discuss This list provided by the League of Professional System Administrators http://lopsa.org/
