AT&T has revealed the first five markets in which it will begin to rollout its next generation 4G LTE network: Atlanta, Chicago, Dallas, Houston and San Antonio. These cities will get access to the super-fast wireless service in the summer and will be joined by 10 additional U.S. markets before the end of 2011, as AT&T looks to reach 70 million potential customers.

The company's CTO John Stankey made the announcement this morning at a Barclays Capital conference, where he also announced plans to add 20 4G devices to AT&T's portfolio this year. Of course, it's unclear how many of those will actually support LTE as AT&T -- alongside T-Mobile -- has added some ambiguity to the term by branding their 3G HSPA+ service as 4G.

AT&T did not give an exact launch date nor did it mention what download and upload speeds users will get from its network.

GigaOM recently trialed AT&T's LTE network and was able to reach download speeds of 28.87 Mbps and upload speeds of 10.4 Mbps, although it should be noted that this was on a controlled test environment and those speeds will go down in real-world usage. By comparison, Verizon, during its own trials last year said it had reached download speeds of 40 to 50 Mbps, and peak upload speeds of 20 to 25 Mbps, but it promises customers 5 to 12 Mbps down and 2 to 5 Mbps up.

Donovan said that the company has invested $75 billion in its wired and wireless networks over the last four years, with plans to invest $19 billion more in those areas this year. Nevertheless, the AT&T's LTE rollout is significantly more modest than Verizon's, which launched with 38 markets late last year and will cover a total 76 markets by June.