AT&T disappointed Wall Street with its fourth quarter results, while Verizon exceeded expectations, though both carriers’ figures had some causes for concern – in AT&T’s case, a slowing of the postpaid mobile and U-verse TV subscriber bases and wireless revenue; in Verizon’s, falling wireless ARPU and some analysts’ fears that it will run short of capacity before its rivals do. AT&T reported total revenue of $42.12bn and net income of $4.01bn. For the year, the figures were $146.8bn and $13.35bn. But its wireless revenue for the quarter was down 4.9% year-on-year to $18.9bn. This was mainly because of lower equipment sales, as wireless services revenue fell by just 1.7%. The Dallas-based carrier picked up a total of 2.2m wireless customers,…