Moving an Entire Office to WiFi

Hey all -

Recently, a pre-sales engineer, suggested that I go wireless for a new office install - >150 users over a building spanning half a city block. He tells me that it’ll all work nicely using 160Mhz channels, etc. ‪ Let’s pretend that I have quiet neighbors (which I don’t).

Now, instinctively, this sounds like a horrible idea. Have any of you seen something like this work?