AT&T is the second-largest carrier in the U.S., having over 100 million wireless subscribers. It is run as a subsidiary of the larger company AT&T, which also operates wireline internet, TV and phone services across the country as well. First gaining massive customer market share after being the exclusive carrier for the iPhone for multiple generations, AT&T has since branched out to being one of the biggest carriers for supporting Android devices. Though it wasn't the first to do so, AT&T quickly launched and expanded its LTE network after Verizon and now covers a vast majority of the country with its LTE service.
AT&T operates its network with GSM and LTE technology for both voice and data, primarily on 700, 850, 1700 and 1900MHz spectrum. In early 2014, AT&T also announced VoLTE (Voice Over LTE) service and compatible devices, though it will be some time before it becomes a mainstream service.
In what would have been one of the biggest shake-ups to the wireless industry in history, AT&T attempted to purchase fourth-place competitor T-Mobile for $39 billion in 2011. The deal eventually fell through due to regulatory disapproval, requiring AT&T to pay a breakup fee to T-Mobile north of $4 billion in cash and spectrum holdings. Since then, AT&T scooped up what was left of Alltel for $780 million in early 2013. It also casually acquired Leap Wireless (which operated the Cricket carrier) for $1.3 billion in mid-2013, bringing in spectrum and roughly five million customers to the carrier. In a huge deal that could have mobile implications in the future, AT&T acquired DirecTV for a whopping $48.5 billion.
AT&T has some of the highest wireless prices in the business, often pricing its plans almost comically identical to Verizon. With a big push towards so-called "Mobile Share" plans throughout 2013, AT&T hopes to increase the number of connected devices — phones, tablets and hotspots — per account all using the same data bucket. It has also started to expand further into the lower-cost and prepaid arena, however, with the improvement of its GoPhone prepaid brand and recently-renamed Cricket Wireless value-based carrier subsidiary.