AT&T turned off its 2G network on January 1st; spectrum will be used to expand 4G LTE capacity
The nation's second largest carrier says that it will use the spectrum over the next few months to expand its LTE network. Eventually, some of it will be used for future technologies including 5G service. Currently, AT&T's 3G and 4G LTE signal cover 99% of the U.S. population. Adding the spectrum to its 4G LTE network will allow AT&T to carry more traffic without purchasing additional capacity.
Over the more than four years that has passed since AT&T first announced its plans to close the 2G network, the carrier used various techniques in order to help subscribers migrate to 4G and prevent them from being stranded. To accomplish this, AT&T gave away devices and offered discounts to certain customers. Subscribers making the jump from 2G to 4G LTE will get to experience faster data speeds, and will benefit from smoother video streams.
source: AT&T via Phonescoop