AT&T has turned on its 4G LTE service in Northwest and Albany, GA and Norfolk-Virginia Beach, VA, and expanded 4G LTE in parts of Philadelphia and Baltimore. Operator expended LTE network in Bucks County, Pennsylvania and Cecil County, Maryland.

With this announcement, AT&T 4G LTE is now available in 141 markets.

According to AT&T, its 4G LTE, HSPA+ network covers 288 million people. and almost 90 percent of AT&T's mobile data traffic now runs over enhanced backhaul that supports both HSPA+ and 4G LTE data traffic.

AT&T expects its 4G LTE network to cover 300 million people by year-end 2014.