I have asked almost the same question before and got the answer to buy Apples gear. When I went to an Apple store i found out that 1/ you have to have a router an USB to.......adapter..... 2/ The cost is almost like hireing a "soundman".
When looking at the brillinat video of how to connect the Ipad and the mixer he uses only 1 (one) USB dongle. That is what I want. The problem is that the dongles that are mentioned in the advanced guide are long by gone. They stoped manufacuring them years ago.
PLEASE LET ME KNOW WHAT DONGLE TO BUY (that still are on the market). Would be great if I can have an alternative one also. I live in Europe wich might be a problem. HELLLLLP!