The nation's biggest cell phone company provided few details with Tuesday's announcement except to say it would launch the service in a "substantial" number of markets by the end of 2005 and "most" major markets by the end of 2006.

Cingular already offers the new service in six cities where it had been launched by AT&T Wireless before its acquisition by Cingular in late October - Dallas, Detroit, Phoenix, San Diego, San Francisco and Seattle - but had yet to move beyond trials itself due to capacity constraints before the merger.

The Atlanta-based company said the wireless technology it is using, known as third-generation or 3G, will offer average data speeds between 400 kilobits per second to 700 kilobits per second - on par with entry-level DSL and cable broadband connections.