AT&T has added St. Louis to its growing 4G LTE network, bringing to 32 the nationwide total of cities with access to the carrier's fastest service.
In addition to St. Louis, AT&T also announced Wednesday that it has expanded its 4G LTE network in Staten Island, N.Y.
The carrier also released a new infographic (download PDF) about its LTE deployments, listing all 32 cities.
AT&T hasn't reported an average download speed for its 4G network, but it has said that LTE mobile Internet speeds are as much as 10 times faster than those available with its 3G service. Testers in markets such as Houston have seen AT&T LTE speeds in the 7Mbps to 20Mbps range, depending on how many users were crowding the network.
An AT&T spokeswoman Wednesday said AT&T "expects average LTE speeds will be in the 5-12Mbps downlink and 2-5Mbps uplink speed range."
AT&T noted that LTE offers lower latency, meaning Web pages load faster and responses in video calls are more immediate. The company on Sunday began selling the new Nokia Lumia 900 for use on its 4G LTE network. AT&T also offers the Samsung Galaxy Note and the Pantech Element tablet for use on the network.
AT&T is considerably behind Verizon Wireless in launching LTE service. Verizon's 4G service is available in more than 200 cities. Still, AT&T said it is able to reach more than 74 million U.S. residents with 4G LTE.
Among its other claims, the carrier said that when customers are unable to reach 4G LTE, they can revert to its existing HSPA+ service, which is faster than 3G -- though AT&T has not specified how fast it is on average.
AT&T said that HSPA+ "enables 4G speeds" but only when HSPA+ is combined with enhanced backhaul, which means that a cell tower has been provisioned with a fiber-optic connection and other infrastructure improvements.
AT&T didn't say how many of its HSPA+ cell towers are backhaul-enhanced, although it claims in its infographic that 80% of mobile data traffic runs over enhanced fiber backhaul.
According to figures in the infographic, AT&T has undertaken five wireless performance upgrades in recent years, with the carrier's service progressing from UMTS, HSDPA, HUSPA and HSPA+ to LTE. Those five upgrades were designed to "provide our customers with consistently fast speeds before, during and after LTE deployment," the infographic says, adding: "Other carriers can't say the same."
AT&T's largest competitor, Verizon, has jumped from EV-DO service to LTE, without several other upgrades, the infographic notes in a chart.
Matt Hamblen covers mobile and wireless, smartphones and other handhelds, and wireless networking for Computerworld. Follow Matt on Twitter at @matthamblen, or subscribe to Matt's RSS feed. His email address is firstname.lastname@example.org.