BT has finally launched the Wi-Fi version of its Fusion converged phone, offering a choice of dual-mode handsets to customers using its broadband service.

Aimed at small businesses, the system now includes Wi-Fi data, so applications can go faster than GPRS, as well as the existing "cheap calls" which sets the price of Wi-Fi calls at landline rates. Calls can now be made at BT Openzone hotspots as well as on the office Wi-Fi network.

To start with, BT is offering the Nokia 6136 and the Motorola A910, with the Samsung P200 coming next month. The price starts at £15 a month - on top of the BT Business One Plan for fixed line and broadband. This include the handset and a Wi-Fi hub; calls over Wi-Fi cost 5p a minute for up to 60 minutes to UK landlines, and 25p to mobiles. The mobile rate, provided through an MVNO deal, is 25p.

Analysts are more positive about this version of Fusion than the previous one, which used Bluetooth for the indoor portion: "Our view was that many small enterprises would wait for a Wi-Fi product before delving into convergence and that adoption of the first product would be slow," said Ovum analyst Jeremy Green. "Now the WiFi version is here, we still think small businesses need to do a few calculations before deciding whether FMC is for them."

Any existing Fusion customers can upgrade to the Wi-Fi version, since BT put a Wi-Fi access point in the original Bluetooth hub. The service still uses the same UMA (unlicensed mobile access) technology to tunnel VoIP calls across the Internet to the PSTN.

The offering will only appeal to very small business, because calls to fixed lines on the same site cost the same as calls to landlines outside the office, points out Green: "This flavour of Fusion will appeal to very small companies, possibly start-ups, with little or no fixed infrastructure and a fairly 'mobile' workforce who make long calls on the move, and particularly in Wi-Fi hotspots such as airports."

At the moment, BT has around 2000 Openzone hotspots, but is planning to build wireless networks in twelve cities in the early part of 2007, where Fusion users will be able to get Wi-Fi calls at Openzone rates.

The service has a 20MB GPRS data allowance, and free messaging service.