Alternative mobile service provider Truphone launched a service today that automatically “re-routes” international calls that begin on incumbent operator networks and delivers them via the Internet and the Truphone network.

Truphone’s core offering is a mobile calling service that leverages smartphones, such as Nokia E-Series devices, that can run its client software and access the Internet via integrated WiFi – essentially a WiFi-enabled mobile VoIP solution.

The new service, dubbed Truphone Anywhere, detects when a mobile user is making an international call out of range of a local WiFi hotspot. In that situation, the Truphone software makes a local call – over the telco network – to the nearest Truphone server. Truphone then uses its network to route and terminate the call over the Internet.

Customers pay for the local Truphone call – typically “free” if part of a bundled minutes plan. They also pay for the Truphone portion of the call, but at much lower rates than a typical mobile international call. For example, a typical 10-minute call through a US carrier to a Chinese landline phone would cost $34.90 using AT&T International Dial Standard rates; the same call would cost $0.60 using the Truphone Anywhere approach.

While few callers would pay the full rate for a US-to-China call – using cheaper avenues such as calling cards instead – the Truphone Anywhere solution makes placing cheap overseas calls much easier, the company said.

The default setting for the Truphone Anywhere client software routes international calls made from a user’s home country only. The software can also be set to check tariffs when roaming abroad and placing international calls.

Truphone is one of a new breed of “new mobile service providers” that Telephony profiled earlier this year. Its charter is to leverage a wide array of access technologies – including WiFi, WiMax, 3G data and more – to provide software-enabled calling via its voice-over-IP network, according to James Body, Truphone’s research director.

“If you look at people like us, we’ll do a number of deals with access players who own spectrum,” Body said in an interview earlier this year. “Some will be WiFi, others will have licensed spectrum, but there will be more operators piling in, and prices will keep going down. It will be our role to aggregate together wireless transmission means and make it work for the end user.”