Increasing speeds and falling prices are adding to the appeal of 3G Evolution Data Optimized wireless data services, which deliver broadband speeds to mobile devices.

As availability expands, more businesses are eyeing EV-DO networks that let users with a wireless phone, laptop or other device access applications and services from anywhere they get a cell phone signal.

"EV-DO has really taken off. Laptops perform very well with EV-DO connectivity," says Rena Bhattacharyya, an analyst at research firm IDC.

The performance gain comes from EV-DO services' transmission rates, which are comparable to those of most home DSL or cable modem offerings. The current technology, called EV-DO Revision 0, supports upload speeds of 50K to 70Kbps and download speeds of 400K to 700Kbps.

"The two big applications driving this wireless data usage are e-mail and PC-cellular data connectivity," Bhattacharyya says. "E-mail performed just fine with 2G and 2.5G services, but you really needed higher-speed connections to get your PC laptop connection to have a compelling experience," she says.

In the United States, Sprint Nextel and Verizon Wireless are leading the charge to expand EV-DO coverage. Sprint says its 3G network is available in 220 markets and 8,700 cities and potentially can reach as many as 188 million customers. Verizon Wireless does not offer a market or city count, but says its EV-DO network potentially can reach as many as 150 million customers in the United States.

One early adopter is Pittsburgh-based Union Switch & Signal (US&S), which makes signaling and control equipment for railroads and mass transit industries.

US&S has been using EV-DO services for about 18 months, says Ted Davidson, the company's manager of network and computing infrastructure. US&S gets EV-DO through remote-access service provider Fiberlink Communications , which provides bundled versions of carriers' network offerings as managed services for enterprises.

Systems engineers, network support staff and project managers are among the US&S employees using the service. Adding EV-DO to the mix lets these users do their jobs more efficiently, Davidson says.

"We have system engineers that are physically at railroad sites at the tracks doing installation and testing," Davidson says. These employees can't come and go as they please because of security protocols. So in the past, if engineers got to a site and found they needed additional software or different drawings, they would have to wait until they got back to their hotel and then return to the site the next day. "With EV-DO they can download software and new drawings immediately. It saves a tremendous amount of time," he says.

Thanks to EV-DO services, network support staff, too, are more responsive to user issues. They run network troubleshooting applications from wherever they are, as long as they have a laptop and EV-DO card, Davidson says.

Likewise US&S project managers on the road visiting clients use the EV-DO network to tap into corporate resources, even when a client can't provide an office space with Internet connectivity. In addition, although many hotels offer these options, if Wi-Fi and Ethernet access aren't available or require an additional fee, employees use the Fiberlink service to connect to the Internet and corporate office, Davidson says.

Meanwhile, the high-speed wireless-data technology is making it easier for Davidson to deploy a virtual environment using VMware virtualization software. Combining VMware with EV-DO access will let employees establish a VPN connection with headquarters through which they access tools and applications just as if they were in the office, he says.

Part of this plan calls for creating a loaner-laptop pool, Davidson says. Such a pool will let US&S issue desktop computers for the majority of the staff and provide VMware-equipped loaner laptops as needed. Without the reliable, high-speed, ubiquitous access EV-DO technology provides, the remote access experience would be painful, he says.