The stage has been set for Web services to start playing a vital role in mobile applications for enterprise networks.

Web service development tools are growing more sophisticated as wireless networks become more pervasive and powerful.

This combination will make it easier for enterprise network groups to tie together mobile clients with back-end applications and data.

The potential was illustrated at last week's annual TechEd conference in Orlando, where Microsoft announced the latest pre-beta release of Indigo, the next Windows communications framework for Web services. During a session devoted to Indigo, Microsoft's Ari Bixhorn, lead product manager for Web services, created a device-based chat application with Indigo in about 5 minutes. In another demonstration, an Indigo-based application, working with Microsoft's Media Center software, sent an alert to Bixhorn's PocketPC smartphone whenever his son turned the TV set to "The Jerry Springer Show."

Some pioneers aren't waiting for Indigo (the beta release is due this summer) to launch mobile applications that use Web services. But it means building from scratch many of the services Indigo will provide as callable class libraries, such as reliable messaging, transaction features and security

"You can do [a service-oriented architecture] without Indigo. And we did," says Furrukh Khan, associate professor at Ohio State University's college of engineering in Columbus. He led a team in creating a Web services architecture (see graphic), using Microsoft's earlier Web Services Enhancements (WSE) 2.0 software, for operating rooms at the OSU Medical Center.

He wouldn't do it again.

"You have a federation of Web services, that need security, reliable messaging, transactions and a lot of things besides simple HTTP," he says. "Almost all this was missing from WSE 2.0, which focused mainly on security. Indigo combines all this functionality into one unified model for SOA."

Khan's team is at work now replacing large chunks of custom written code with Indigo's class libraries.

As handheld devices gain still more powerful processors and more memory, and as wireless data nets offer greater throughput and reliability, Web services become increasingly attractive for enterprise users.