AT&T’s decision to aggressively push its 3G wireless services in 2008 is further proof that U.S. mobile operators are now banking on growing demand for wireless broadband to overcome slumping/stagnating voice revenues.

AT&T plans to expand its network to another 80 cities this year, bringing the total number of markets on their 3G network to 350. As part of the plan, the company will roll out its first High-Speed Uplink Packet Access (HSUPA)-enabled network by the middle of the year. “We’re also planning for the future by establishing a clear path to a 4G network that will meet the needs of our customers for years to come,” said Ralph de la Vega, president and CEO of AT&T’s wireless unit, in a press statement.

But there appears to have been a delay in the HSUPA rollout. After all, the company was making similar statements about a HSUPA-enabled rollout in a “few weeks” back in September 2007.

And AT&T is facing some serious competition from Sprint and Verizon, whose offerings have become popular with the road warriors, making it tough for AT&T to become a major player in the the 3G market. They all desperately need to offer higher speeds and better price plans in order to compete more effectively. For my money, Sprint has the best EVDO offering right now, and unlike Verizon, it doesn’t contain hidden bandwidth and data transfer caps.