What's the best way to set up the broadcast channels? Overlapping on identical channels, or alternating channels? Seamless wireless service rollover when moving from one end of the building to the other is key.
I know for home setups, I've always heard to find and use a channel none of your neighbors are using to avoid interference (or set to auto channel). Since all the WAPs in this building are for the same network, and will all have identical SSIDs, does this rule of thumb still apply? Or should they all be set to the same channel, since it's the same network they'll be using?
Multiple WAP's must be on separate channels and should not overlap. In North America only 3 channels meet that criteria (1, 6, 11). Virtually everything sold today is defaulted to channel 6 so it's best to avoid if possible. What you should do first thing is a site survey to see who else may be on the air. You can use inSSIDer ( http://www.metageek.net/products/inssider/ ) for this task.
Seamless wireless service rollover when moving from one end of the building to the other is key.
Good luck on that one. PC by default will stay withe AP they associated with until the signal drops below a certain level (you can change). They then go though the process to find the strongest signal and re associate. Depending on how you configure things you may actually get prompted for a password. Even if they don't it must go though the whole key exchange process. Users will defiantly see a couple second drop. The more common problem is that the PC does not switch when you want it to. Because it is still getting what it thinks is a good enough signal from the first AP it will stay with it even though the response time will be much better if it would switch. You most the time must force the switch manually.
This type of feature is only available on commercial systems that have a controller. Part of the wireless protocol does allow the AP and the PC to transfer the associates from AP to AP transparently for reason like signal strength or even to rebalanced users density on AP. Cisco has a video showing them walking down a hallway with a wireless camera and even getting into elevators and getting out on different floors with no packets loss.