Converged Wi-Fi/cellular phones will outstrip today's Wi-Fi-only VoIP handsets pretty soon after they launch, according to analysts.

"We're not predicting when the cross-over point will be," said Richard Webb, of Infonetics Research. "But we believe that by 2009, four or five percent of all cellphones will have Wi-Fi." That could mean around 40 million converged phones a year, which is likely to be higher than the more specialised Wi-Fi only devices.

Both markets are still small, but Wi-Fi only handsets, from vendors such as Spectralink, established a $54.7 market by 2004, in specialist markets such as healthcare and warehousing, according to an Infonetics market report on wireless VoIP.

Converged phones are virtually non-existent, with a market of $6.7 million in 2004, mostly for early enterprise prototypes, but they will be sold heavily to consumers when they arrive. The growth rate of converged phones will eclipse the Wi-Fi only products, according to Webb, even though the current crop of Wi-Fi phones are beginning to look more usable.

"Single mode phones are looking sleek and elegant," said Webb. "It will take a bit longer to get there with dual mode phones." However, the consumer focus in converged phones will lead to faster product developments, when they arrive, he said. "Wi-Fi capability will eventually become a common feature in cell phones, just as it is becoming standard in laptops today."

Consumers will take up converged phones for use with home wireless gateways, public hotspots and VoIP services such as Vonage, said Webb. Enterprise products, that link through corporate PBXs will allow business users wide roaming too.

If, as seems likely, converged devices are eventually cheap consumer products, future single-mode Wi-Fi phones may simple be SIM-less versions of the dual-mode devices.