I'm researching this question and can't find an answer. The question is, how many simultaneous wireless IP phone calls can be supported by the internal AP on a UC540W? I'm not sure there is an answer to this, but I'm trying to cover all my bases.
Many things play a factor and you can never know for sure without testing, but here are some theoreticals. Pg 37 and 38
The only test that I am aware of was with the AP541 running at 802.11G, G.711 codec. You could only use 8 WiFi IP phones simultaneously. If you used 9 or more, the call quality would degrade severely.