Might be a stupid question, but why not use cell signal to fly with instead of wifi? Seems as long as you had a signal your range would be battery life. Same as the video.

http://newsoffice.mit.edu/2011/iphone-drone-control-1108

In most countries it is controlled which frequency's are used for RC models.
Some time ago 2,4 Ghz and 5,8Ghz was set to be used for RC and Video transfer.
As same as the Power of these systems. If it would be aloud by law you also could get more range out of 5,8 and 2,4 Ghz.
Also range wise the older 35Mhz technology was better you could easily achieve 2km legal.

Domo Kun Posted at 2014-11-26 00:27
In most countries it is controlled which frequency's are used for RC models.
Some time ago 2,4 Ghz a ...

This takes a step into another world and it is very active and in daily use......
Do some Google research and see it in use.....

Everybody who is using RC stuff should know this or at least have some interest to understand it.
It is a critical point of our hobby and cause serious issues if you disrespect it.

Domo Kun Posted at 2014-11-26 16:14
Everybody who is using RC stuff should know this or at least have some interest to understand it.
It ...

I'm referring to the control and flight of the unit via a gsm data connection (sim card) and advising the OP to research such...   

Sorry my English must be a bit relaxed, ill try and keep it very specific and explanatory.