12 users for 1 WAP sounds like a lot, but I wouldn't dismiss that just yet...

There might be some low hanging fruit, maybe you already have looked at these things....(sorry if I am underestimating here)

Q1) What are your syptoms ? is just everyone going slow, or are users getting kicked off ? Does the router need reset/power cycled frequently ?

1) Is anyone doing any serious upload/downloading. grabbing large files (over 500meg) regularly ? streaming Netflix while in the office ?

2) Is your wireless in range of a public place or other nearby business where other people could be getting on ?
2a) Are you using WPA2 turned on and the password protected ? (ie: not shown in public) (Earlier versions of Wi-Fi security are more hackable...)

3) Are people connecting their personal devices ? (phones, tablets, personal laptops..)

4) are there other nearby wireless networks that could be interfering ? In the old days, there were like 6(?) Wi-Fi channels and if 2 networks were on the same channel, they could interfere with each other and produce abnormal results. I'm not sure if this is still possible with the latest routers though.

-John

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