Well, according to TechHive, AT&T still has LTE service in the US. The site conducted a test of all the networks for its Wireless Week and found that T-Mobile LTE is catching up and service is pretty fast as well. Verizon LTE is reasonably quick, while Sprint LTE lacks speed.
AT&T LTE service has an average download speed of 13.5Mbps and average upload speed of 6.45Mbps. Verizon came in 2nd with download time of 9.61Mbps and an upload time of 5.47Mbps. T-Mobile was 3rd beating out Sprint this year with 9.01Mbps and an average upload rate of 2.65Mbps. Sprint came in last, its average download rate is 4.32Mbps and an upload rate of 2.76Mbps.