Australian telcos aren't the only ones upgrading their third-generation mobile networks to get faster speeds. Now their US counterparts Sprint Nextel and Verizon are getting in on the act.

On Thursday, Verizon Wireless announced it is upgrading its third-generation wireless network using a CDMA-based technology called Evolution Data Optimized (EV-DO) Revision A (Rev. A) in six markets: Boston; Richmond, Virginia.; Chicago; Gary, Indiana; Salt Lake City; and parts of Florida.

Sprint Nextel has also been upgrading its 3G network with EV-DO Rev. A since October 2006. And last week the company said it offers the service in 24 markets, including some in which Verizon says it will operate, such as Boston, Salt Lake City and southeastern Florida.

The main benefit of upgrading to EV-DO Rev. A is an increase in upload speeds. EV-DO Revision Zero, the first version deployed, offers downloads between 400 kilobits per second and 700kbps with upload speeds of about 50kbps to 70kbps.

The new version of the technology is likely to offer average speeds from 450kbps to 800kbps for downloads and 300kbps to 400kbps per second for uploads, the companies said. This means that customers on their network could use their laptops or personal digital assistants to download a 1MB e-mail attachment, the equivalent of a small PowerPoint presentation or a large PDF file, in less than 15 seconds, and upload the same size file in less than 25 seconds. Verizon said this was a marked improvement over earlier generations of the technology.

AT&T's Cingular Wireless has also made several announcements over the past week highlighting the expansion of its 3G wireless network, which is based on a technology called HSDPA (high-speed downlink packet access). On Thursday, Cingular said it is deploying major enhancements to its service on the campus of Louisiana State University, as part of the company's nearly US$165 million investment in the state.

The company also announced an US$86 million investment to upgrade its network around Las Vegas. And it is launching the new 3G service in Connecticut.