The wireless network can also be used for routine police and fire investigations, and city officials said it will eventually be put to use for more mundane functions, including reading water meters and trying to smooth out traffic flows.

The first section of the Citywide Mobile Wireless Network to be activated serves lower Manhattan, the densely built area south of Canal Street that includes the site of the destroyed World Trade Center towers, a spokesman for New York Mayor Michael Bloomberg said.

Last September, when a US$500 million contract to build and maintain the network for five years was awarded to Northrop Grumman Corp., Bloomberg invoked the tragedy of the Sept. 11, 2001, terrorist attacks. "One of the most important lessons learned from the Sept. 11 attacks was that our emergency responders need better access to information and clearer lines of communication in the field," the mayor said at the time.

Lower Manhattan accounts for only a fraction of the 310 square miles that the cellular data network will cover when it's completed, said Paul Chelson, Northrop Grumman's program director. He added that the network should be fully activated by spring 2008. "The project is moving along rapidly and has a fast, accelerated buildout," he said.

According to Chelson, the project team has demonstrated in lower Manhattan that whatever a police officer or firefighter can do on a desktop PC can be done via the new network on a laptop in a moving vehicle. That includes launching streaming video, accessing e-mail, finding a photo of a criminal suspect and viewing building floor plans. About 100 laptops equipped with cellular modem cards can access the network now, but the number of end users will eventually reach "tens of thousands," Chelson said.