Truphone enables internet calls over GSM

The VoIP company Truphone has launched a new service that will enable users to make internet calls over a standard GSM network.

Truphone Anywhere routes calls made outside of internet coverage onto the mobile network, making it possible to make international calls at local rates. The service, launched on Wednesday, is integrated into the recently released version 4.0 of the firm's client.

James Tagg, the company's chief executive, told ZDNet.co.uk at last week's Wireless08 event in London that calls made over the service become an "out-of-bundle [local] call when phoning anywhere in the world". He added that calls to landlines in 40 countries are supported, and calls can be made to mobiles in 15 countries.

Calls made over the service go through to Truphone's server, which then rings the recipient. A text message then gets sent to the company's server containing the caller and recipient's numbers, and the server then calls both parties and connects the calls.

Tagg said business adoption of Truphone's client, which until now has been a VoIP service installed on handsets and running over Wi-Fi, had mainly been in the SME and lone-worker sectors. He said, however, that Truphone had "a couple of very big companies as customers", who he could not name, that were using the service in their IT departments and slowly moving it out to a wider user base. He claimed these companies had "hundreds of thousands of employees", but could not say how many of these workers were using the service.

Tagg also said a version of the Truphone client would be demonstrated on the iPhone next month. "Apple is happy to support VoIP products over Wi-Fi but not 3G," he said. "We hope to get into the iTunes distribution system".

Truphone's client is still not available on Windows Mobile handsets, said Tagg, because the company is "still not happy" with the battery life of such devices. He also claimed that Truphone had a "full Linux stack" that was built for Nokia's N810 internet tablet, but has not yet been fully launched.

The company effectively became a fully-fledged mobile operator in its own right in April, when it bought a global pay-as-you-go mobile network called SIM4travel. Truphone said it intends to launch a "single, global SIM card" at some point in the future.