Last year we certified 52 that were dual-mode and just six that were WiFi-only, said managing director Frank Hanzlik, and this year we expect many more dual from manufacturers like Sony Ericsson, NEC, and BenQ.

The WiFi Alliance, which comprises vendors of WiFi infrastructure and other parties interested in the development of 802.11 networking, will make the announcement at the 3GSM World Congress in Barcelona. This is the premier event in the GSM world, and arguably the biggest shindig in cellular technology globally, so the move is designed to underscore the importance of WiFi is assuming in the mobile industry, thanks to fixed-mobile convergence, FMC, for voice traffic.

FMC covers any of a number of techniques enabling cellular phones that use wireless WAN technology to transfer their traffic to a fixed-line connection, which can be made possible wherever one is available or, depending on the business model, in pre-determined locations like home or the office, in order to benefit from the lower cost of wireline voice.

One way of doing this is via WLAN technology, WiFi. Based on the IEEE’s 802.11 standard, WiFi had been enjoying explosive growth even before the buzz began about voice over WiFi, as both residential and business users deployed it for the convenience, and in the case of businesses, productivity of wireless data access. The possibility of using 802.11 infrastructure as an enabler for FMC intensifies its attraction to users, and because many of the big players in WiFi are not traditional voice vendors, they see it as another string to their marketing bow.

Analyst houses have picked up on the trend, and Hanzlik quoted a recent study by ABI Research that suggests as many as 23% of all the mobile phones shipped by 2011 will be dual-mode with WiFi, which it estimates will be some 325 million units.

However, the WiFi camp faces challenges in proliferating and popularizing VoWiFi. First is the power management issue, to which end the Alliance came up with its Wi-Fi Multimedia Power Save, WMM-PS, certification program to encourage manufacturers to leverage power management technologies contained in the 802.11e QoS specification. We see it as enabling on average a 15%-40% improvement in talk time, said Hanzlik. We need to address the fact that eight hours of talk time is users’ expectation now, and we’re not there yet.

He said another opportunity lies in seamless handover between the two radio access modes, where there are already a variety of initiatives. We have a task group looking at handover in collaboration with the FMCA, the CTIA, and the GSMA, he said. Unlicensed Mobile Access is a cellular-centric way of doing it, but there may be other ways of handling identity.