The Wi-Fi Alliance has certified nearly one hundred Wi-Fi phones, demolishing the argument that converged Wi-Fi/GSM services can't work because of a lack of handsets.

"A lot of these phones are undergoing final testing at carriers," said Frank Hanzlik, managing director of the Wi-Fi Alliance, an industry body promoting Wi-Fi compatibility, "but there is a wave coming out in the next six months."

In fact, the number of dual mode devices is still well short of 100. Of the 92 devices certified by the Alliance, ten are Wi-Fi only devices, and come of the others may have been counted twice - showing up under different product identities for different regions, Hanzlik admitted.

ABI Research has forecast that 325 million dual-mode 15 million single-mode Wi-Fi phones will be shipped by 2011. However, the requirements of a handset have only just begun to be considered. The alliance has been working with mobile groups including the CTIA and the FMCA (fixed mobile convergence alliance), and is promoting the use of trade group.

Certification to the basic Wi-Fi standard isn't enough to make a good Wi-Fi handset, however, since other things are useful, including the WMM (Wireless Multimedia) extensions that give voice packets to achieve priority across a network, WPA2 security, and the special WMM Power Save mode, which can extend battery life by 25 to 40 percent on a handset. The Wi-Fi Alliance also has a specification called CWG RF for measuring RF performance.

All this means there's potentially still confusion out there, leading to moves such as that by Aruba, to produce an industry specification for Wi-Fi handsets.

In the meantime, the Alliance's efforts should bring some unity to the situation. "WMM Power Save could be a simple upgrade for most routers, as it requires no changes in the radio," points out Glenn Fleishman of Wi-Fi Net News. "Incompatible power save modes can actually waste power, and the alliance would like all makers to move towards their certified version."

The full list includes vendors such as Acer, BenQ, Fujitsu-Siemens, HP, Motorola, NEC, Nokia, Samsung, Sanyo, Sony Ericsson and Toshiba, and others. The Wi-Fi Alliance has also published a white paper covering convergence issues.