Enterprises adopting Windows Mobile 5.0 Smartphone Edition for road warriors can now integrate a VPN system, certified by Microsoft, for secure and stable access to their applications.

Microsoft has certified NetMotion Wireless's Mobility XE for use with its OS for advanced mobile phones such as the Cingular Wireless 2125 model.

The VPN product, a combination of client and server software, encrypts data exchanged during enterprise application sessions and keeps the server sessions alive when the phone leaves a coverage area or roams to another network. The employee can then return to the task at hand when the wireless link is re-established.

Smartphones may be smaller than full-blown PDAs, but they still offer the ability to use enterprise applications while on the road, staying connected via a high-speed cellular network.

Security worries frequently snag corporate plans for offering employees mobile access to applications, even though there are much more common hazards, such as Windows PCs without the latest patches, according to Ovum analyst Roger Entner.

"Whenever a CIO doesn't want to do anything, they say, 'Oh, it isn't secure enough,'" Entner said. A mobile VPN can help ease the CIO's mind, he said.

Although Research in Motion's BlackBerry still dominates handheld enterprise deployments, Microsoft is making some inroads, Entner said. One advantage of Windows Mobile is that it takes less training to get a current Windows PC user up to speed on the handheld OS than with a BlackBerry, he added.

Mobility XE offers AES encryption in three grades, 128-bit, 196-bit and 256-bit, said John Knopf, director of marketing at the Seattle company.

A version of the software for Windows Mobile 5.0 Smartphone Edition will begin shipping later this week, Knopf said.

NetMotion already offers client software for Windows Mobile 5.0 Pocket PC Edition and Windows CE, as well as for notebook PCs. As the company expands from its North American base into Europe, it is exploring a future version for the Symbian operating system, he said.

Mobility XE is priced starting at about $150 per seat license for small enterprises. In large enterprise deployments, after the first 1,000 clients, NetMotion charges $55 per seat.

NetMotion recently merged with rival Padcom. The company will base its future development on Mobility XE but will continue to support Padcom's Total Roam product for at least two more years, according to Knopf. Features of Total Roam will be integrated into Mobility XE, he said.