There is wireless, but it doesn't quite reach out to where the infantry barracks are in KAF.
The US have set up a network, but at a cost (I can't remember prices... some how $50 a month sound right... might be more.). Once you're there, you can enquire through the chain of command.
When I was there (the three days I was actually in KAF) we managed to pick up and unprotected network, but the speeds were pretty slow.
Honestly, I wouldn't count on internet outside of the welfare trailers set up by Canada House. Besides, if you're going over with an infantry company (unless you're in HQ or CQ) you won't be around KAF long enough to use any kind of wireless. But, there is internet out in the FOBs... some of them anyway.
Good luck... keep your head down.