AT&T today announced they have purchased Dobson Communications, which operates the Cellular One network in most regions. AT&T will buy Dobson for $13 per share, as well as assuming the regional carrier’s debt, which will cost the nation’s largest carrier about $5.1 billion total. Dobson was first rumored to be for sale earlier this week, making this a very fast or at least well guarded acquisition. The companies have not announced when they expect the buyout to be complete.