SAN JOSE, Calif. — Buzz about the new iPhone — expected to be released in June — has less to do with the phone itself than its use of AT&T's 3G network.

That 3G network, which refers to a third generation of wireless networks, would dramatically improve the performance of some iPhone features, such as Web browsing. Apple's current iPhone uses AT&T's Edge Network, a 2.5G network that undermines some of the device's most appealing technology — such as the display of full Web pages — because of relatively slow download speeds.

Experts say a 3G network is best defined by the applications it makes possible with 3G-compatible phones and other devices, rather than by the download speeds that vary depending on the user's location and connection.

Research officials at CTIA-The Wireless Association say 3G can be described as a network with sufficient bandwidth to provide a Web browsing experience. A more elaborate definition could include the ability to use applications such as music downloads, some video services and more robust video games.

AT&T says its 3G network covers 275 markets, but declines to state what percentage of the nation that represents. A major competitor, Verizon Wireless, uses a different kind of talking point: a 3G network covering 240 million people.

Bob Roche, vice president of research for CTIA, cites a Federal Communications Commission report, released early this year, showing that 82 percent of the U.S. population lives where there is at least one service provider offering 3G mobile access. It is available in Hawai'i.

Roche noted that 3G is widely used to describe current wireless networks, but that previous mobile eras were named retroactively. As far as the 1G voice-only analog period of the 1980s and the subsequent 2G digital era that began in the 1990s, "no one called them that until much later," Roche said.

AT&T says its 3G network can be thought of in terms of its video and multimedia capabilities.

For instance, spokesmen point to the company's video share service, which allows some customers to send live or recorded video during mobile-to-mobile calls, depending on the models of phones being used.

The network also provides the ability to look at data such as PowerPoint slides on the phone's screen — assuming you have the right phone model — while also holding a conversation via Bluetooth.