The rollout of the 4G Network is an effort to catch up with rivals Sprint and Verizon. Earlier this year, AT&T began calling its upgraded 3G network 4G, although the service failed to meet expectations because of the slow expansion of infrastructure.
4G is faster, but for now it is not compatible with some AT&T devices, like the popular iPhone. Apple has not said if it plans to make a 4G device.
