The best place to look would probably be CTIA and FCC sites. One can also check out the major wireless analysis companies such as Gartner, Yankee Group, Canalys etc. One should also look at where and when the GSM Association is holding events (probably in Asia/Pac and Europe but really global in nature).
Some other sites to get this information would be:
http://www.wowgao.com/ for government-oriented conferences on these subjects
http://www.mwwusa.com/ (Mobile & Wireless World - Computerworld Strategic Programs & Events )
As an advise though I would recommend that one should probably want to really think about why he/she wants to go to such an event, if he/she wants to market something then that's a good excuse BUT if you want to go to such an event to make solid industry contacts you really need to make sure that the meetings are set up in advance.
The worst thing to do is to go an industry event with no planning, preparation and no introductions to the right folks. You will just be bleeding money.