da...@lang.hm wrote: > On Tue, 12 Jan 2010, Richard Chycoski wrote: > >> 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. > > this is why I intend to get in there a few weeks ahead of time to > measure the effect. > >> 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. > > given that there are only three useable b/g channels, this isn't > possible with omnidirectional antennas. > >> 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. > > b and g use the same channels, just at different speeds. I would > expect that everyone would be using g nowdays, and the more people who > use g the shorter the transmissions, and the less cluttered the airwaves g uses groups of b channels. If you restrict the network to b, you get more channels to work with, and providing a cell structure is more practical. Besides, if any b devices come onto the net, it becomes b anyway. Any g device can operate as b, and I think that throughput is going to be the least of your worries - channel overlap and contention are likely to render g pretty well useless. > >> Especially if this is one, big convention room floor (or even a few >> big cavernous halls), > > I'm not that lucky. I have one middling size convention room floor on > one floor, and a bunch of smallish rooms spread out on the second floor That may actually work out to your advantage. Large, single areas are the most difficult to service. Individual rooms have those nice walls that attenuate the signals, so you may be able to put the rooms in groups of two or three with a single access point between them. I do suggest that you look at putting the APs on the ceilings, or at least above crowd level, to minimise 'ugly bag of mostly water' absorption. > >> expect to be 'the guy' getting cursed at for the lousy wireless >> service - it's part of the gig, y'know! ;-) > > yep, I just hope to do better than I've seen before. I wish you luck with the install, but if you end up resorting to Scotch at the end of the week, we'll all understand! > > David Lang
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