The Wi-Fi Alliance says that nearly 100 handsets are certified: The group has certified 82 dual-mode handsets and 10 Wi-Fi-only phones. The idea of certifying voice handsets that incorporate Wi-Fi allows the alliance to ensure both interoperability and better performance. Frank Hanzlik, the alliance's executive director, said in an interview that this testing helps the manufacturer produce devices that function better in difficult RF environments, as well as align the phone's function relative to Wi-Fi gateways. The alliance has also been working closely with the CTIA, the cell industry's trade group.
Hanzlik said that he has been working to raise awareness of the WMM (Wireless Multimedia) extensions that allow 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 through better management of unnecessary communications with a gateway. Hanzlik expects over time to see WMM and WMM Power Save in more gateways. WMM Power Save could be a simple upgrade for most routers, as it requires no changes in the radio. Incompatible power save modes can actually waste power, and the alliance would like all makers to move towards their certified version.
For large-scale hotspot networks, moving to WMM Power Save could dramatically improve the experience of mobile users making Wi-Fi calls. "When you look at these very, very large operators like T-Mobile here in the US, or some of the folks in the Wireless Broadband Alliance [a worldwide consortium of hotspot operators], we're trying to get the word out to these folks" to upgrade their networks or plan to include WMM Power Save from the beginning.