Now that AT&T has taken its lumps from competitors and users over the size of its 3G network, the company is determined not to be caught flat footed again.

Just one day after Apple announced that its new iPad tablet would be available on both AT&T and Verizon, AT&T began touting investments in its 3G HSPA network that the company believes will give it the ability to handle increased traffic from mobile devices. During a conference call Thursday, AT&T COO John Stankey said that the company was investing $2 billion in improving its wireless network in 2010 and that it would construct roughly 2,000 new cell sites to expand its coverage.

AT&T says that a big part of its wireless network upgrade will come through its transition to HSPA 7.2 technology that the company expects will cover 90% of its 3G network by the end of 2011. HSPA 7.2 is a variation of the GSM-based HSPA technology that has a peak speed of 7.2Mbps, although AT&T cautions that most users are unlikely to see data rates approaching theoretical peak speeds.

In addition to switching its 3G network to HSPA 7.2, AT&T is also hoping to boost network capacity by utilizing more spectrum on the 850MHz band. The company is hoping that deploying its 3G network over the 850MHz spectrum will solve some of the big capacity and propagation problems it has encountered in major markets such as New York and San Francisco.