AT&T Inc. T, -0.58% is bringing back unlimited wireless data plans, a reversal after more than five years of moving customers away from such plans onto those that charge for data use.

The new plans are only available to customers who subscribe to its recently acquired satellite television service, DirecTV, or its older U-verse TV service. They come at a competitive time in the industry that has carriers looking for new ways to attract customers, and retain their existing ones, without simply cutting prices.