Wi-Fi-only phones will have been almost wiped from the market within five years, according to a report from Juniper Research.

The company predicts that the world-wide market for voice-over-Wi-Fi handsets will grow to almost $70 billion by 2012, but that only 2% of this will be WLAN-only handsets. The vast bulk will be dual-mode handsets, able to operate as both WLAN and cellular phones.

"The handset market is moving to a stage where no one wants to carry two or three devices in their pocket, so the ability to have a single device for all calls is a compelling proposition," said Basharat Hamid Ashai, the report's author.

This could change the Wi-Fi map considerably, as networking suppliers who have invested in developing WLAN phones must now develop cellular phones or get shouldered aside by the mobile phone developers -- and of course it is the latter who have the expertise, the brand recognition and the connections to operators.

"Most single mode VoIP over Wi-Fi handset manufactures are actively either designing or planning to ship dual mode phones," Ashai noted.

Juniper predicts that VoIP-capable enterprise WLAN access points and switch/mobility controllers will add another $13 billion to the annual voice-over-Wi-Fi business by 2012, for a total of $82 billion. It says North America will be the biggest market, at $35 billion, but Europe, Middle East and Africa will be the second largest with $23 billion, ahead of Asia Pacific with $21 billion.

The report adds that another growth trend will be the use of wireless mesh technology for VoIP. "Currently these networks are in their infancy and are being used primarily for data applications," it said. "However this market will be ripe for wireless VoIP during the coming years. VoIP using Wireless Mesh will be a key move."