Wifi is just plain bad for crowded venues
Wifi is just plain bad for crowded venues. Why?
The *original* wifi spec had an option that was called "point coordination function", the access point itself would coordinate access to the given channel between itself and everything associated to it. This option has never actually been implemented AFAIK; so, instead, the access point and stations attempt to wait for the channel to be clear then transmit. On a busy channel this means collission city, frequent collissions mean a increasing fraction of the time on the channel transmits no useful data, and eventually you get congestion collapse (connections retransmit and time out without useful information making it through.)
Wifi also has no power control. In a dense environment with many APs, the power on each access point should be turned down since the goal is no longer maximizing range, but covering a specific area with different APs covering the neighboring areas. But the APs typically have no way to tell the client to transmit at reduced power; so usually they don't, they broadcast full power and crap up the channel for everyone else.
Nevertheless, the rudimentary fixes are: 1) Use as many channels as possible (5ghz channels as well as 2.4ghz). 2) Set power control on APs relatively low, since you have many APs and want to reduce overlap. 3) To the extent possible, keep APs on the same channel as seperate as possible. 4) High end APs have various other black magic, best practices, proprietary options, and so on, to try to maximize throughput in a heavy usage environment.