US carrier AT&T has announced plans to upgrade its 3G network with High Speed Packet Access (HSPA) 7.2, as it paves the way for a roll out of LTE in 2011.

AT&T, knocked into second place in the US market following Verizon’s acquisition of Alltel, said it will begin upgrading its network to support HSPA later this year, with a view to completing the roll out in 2011, just as it starts looking at the next stage of its network evolution.

The carrier said it plans to enhance its 3G coverage by almost doubling the amount of wireless spectrum dedicated to delivering mobile broadband in most metropolitan areas, which should beef up in-building reception. Backhaul will also be upgraded with fibre at thousands of cell sites, with AT&T claiming that the enhanced network platform could allow for theoretical peak rates of 7.2Mbps, although real world users are unlikely to get these speeds.

AT&T’s 3G network is currently available in about 350 major metropolitan areas in the US, with about 20 additional metro areas planned for deployment in 2009. Femtocells and a push behind wifi-enabled handsets also feature on the carrier’s plans to drive its mobile broadband strategy forward.

The company plans to begin LTE trials in 2010, with deployment beginning in 2011.

Capital investment for these projects fits in 2009 fits within AT&T’s previously outlined targets of $17bn to $18bn.