Last week reports started popping up around the internet that some AT&T customers in New York City were starting to see evidence that the company’s long-rumored 4G LTE data network was up and running. There was no official statement from AT&T at the time, so the company was plainly only testing the network’s functionality.

That changed today with a press release from AT&T announcing that the new faster data network would officially be going live in New York and other markets this month. According to John Stephens, Senior Executive Vice President and Chief Financial Officer, the company plans to have 70 million customers covered by the network by year’s end.

The press release also notes that, thanks in large part to the iPhone 4S, of which it activated 1 million units in the first five days, AT&T has sold roughly 6 million smartphones so far in the fourth quarter. With eighteen shopping days left until Christmas and 24 days left in the year, that puts the company well on track to break its previous fourth quarter smartphone record of 6.1 million phones sold.

Though the announcement specifically mentions New York City, no other markets were mentioned by name, so it remains unclear who will be first to get access to the new, faster data network. BGR reported last week, however, that Phoenix area users were also seeing data speeds consistent with the LTE network, so we can probably expect that city to be among the first markets rolled out as well.