Despite predictions of victory for converged Wi-Fi/cell phones, single-mode Wi-Fi phones are set for strong growth, according to a new report.

Despite fast growth, both kinds of voice on WLAN phones will add up to around three percent of the total mobile phone market, according to VOWLAN Business Models, a report from Disruptive Analysis. This is much slower than the growth predicted by Infonetics, which reckons dual-mode phones on their own will have reached four or five percent of the mobile market by that time.

Disruptive Analysis predicts a big role for single-mode Wi-Fi phones, despite the expectation that dual-mode devices made for a mass market can trump them on cost and functionality. Around 17 million single-mode phones will be sold in 2009, alongside about 29 million converged phones, says Dean Bubley, the author of the Disruptive Analysis report.

"I'm quite a believer in single mode VoWLAN, in both corporate and consumer
Markets," said Bubley. "In consumer, it'll be driven by Vonage, Skype and the like giving away customised phones. Over time they'll probably get cheap enough to compete with ordinary cordless phones, and they'll also have applications on them such as SMS, MMS, a browser, e-mail and games."

In the business market, meanwhile, Wi-Fi only phones will be good enough for employees spend their time on-site, or work in hospitals where cellphones are not allowed. "They will be positioned as DECT replacements, which are more suited to IP-PBXs than current DECT phones," said Bubley. "They will also be much less complex - and therefore cheaper- than dual-mode smartphones."

Vertical market such as warehousing will continue to need ruggedised Wi-Fi phones, a product variation not worth making on consumer-grade dual-mode phones. Also, they will come into their own with IP PBXs: the PBX makers are launching their own-brand phones (already the case with Cisco, Siemens, Zultys and others), and others sell Spectralink handsets and Vocera badges.

"Also as SIP-based IP-PBXs become more popular, it should be more possible to
use cheap generic SIP WiFi phones," said Bubley.