I will be flying to Seoul through Shanghai. I have a new Pantech Crossover which has the required 2,100 mhz but am wondering if there is anything else I need to be able to make calls to my friends who are in Seoul from either airport (or need to know how to make those calls.
Don't forget to enable international roaming on your account. You can only do this over the phone (not online), and its NOT enabled by default on most people's accounts. International roaming is the actual feature that allows you to place calls while abroad. World Traveller is just the discount plan that makes the calls cheaper.