AT&T has just revealed a new expansion plan -- one that involves crossing the border into Mexico. Apparently, the company's in the process of acquiring Mexican carrier Iusacell for $2.5 billion, which includes the amount needed to pay off the latter's debts. By snapping up this carrier, AT&T's gaining its network infrastructure, licenses, retail stores, 8.6 million subscribers and its potential to grow further. Iusacell's network covers 70 percent of the country's 120 million residents, and Ma Bell hopes it can take advantage of that fact by getting more people to sign up for smartphone plans, now that more and more affordable models are hitting the market. Subscribers will have to make do with 3G connections, though... at least until AT&T decides to expand its LTE service, as well.