By 2009, one-third of all cellular voice devices will have Wi-Fi connectivity, and 18 percent of those will enable VoWLAN, predicts a report by the research firm In-Stat. Much of that growth already is occurring in the business market, the In-Stat report points out.

Out of 300 mid-size businesses surveyed, 23 percent of decision-maker respondents said they’ve already deployed wireless VoIP (Voice over Internet Protocol), and 30 percent said they were planning to add the technology.

The number of cellular/WLAN subscribers will reach 256 million worldwide by 2009, or 12 percent of all cellular users, the report continues. The most telling statistic, however, might be the 60 percent of respondents who said the integration of wireless VoIP with WWAN would be very beneficial.

“New alliances are being forged, and trials are in place. VoWLAN could change the wireless landscape as to how we use cell phones on the road,” says Allen Nogee, principal analyst for In-Stat.

CEA analyst Sean Wargo agrees. “It’s revolutionary and the pricing is right. It gives full area coverage in hot spot zones and hooks up wirelessly to the Internet. It provides good voice service and will have an impact on service providers.”

The first offering of a real-world VoWLAN test suite is underway. Aruba Networks, a provider of centralized network systems that enable wireless, security and mobility services, and VeriWave, a WLAN testing company, are trialing the service.

Yet, there is a caveat to the growth of VoWLAN, which most experts agree is reserved for the enterprise market. It currently is seeing low single penetration rates, with critical mass predicted to be in about two years, according to Jon Arnold, principal for J Arnold & Associates, an IP communications consulting firm.

“Existing end-points must have compatible handsets to roam between Wi-Fi and other cellular networks. Wireless is a more sensible alternative to wires, but enterprises must have the confidence in their wireless networks. If they do, VoWLAN will be faster, cheaper and easier to grow an organization. Once mobile devices can support Wi-Fi and roaming, there will be much greater adoption,” Arnold says.