That’s exactly what Duetsche Telekom, T-Mobile parent and one of the world’s largest mobile operators, is doing.

Duetsche Telekom, which until today had banned access to VoIP services over their wireless networks, has announced new plans that will allow it’s users to pay an additional fee for the ability to place VoIP calls. The plans, which start at EUR 9.99, will be tiered based on usage.

This news is a victory for consumers (and mobile VoIP providers) who’ve been snubbed by carriers and a sign that the “tides are continuing to change” with respects to mobile carrier bans on VoIP services. Some may argue that VoIP is just an application or utility, like Google, and thus shouldn’t have to pay extra to use it.

I say take what you can get.

And while it’s still not the end goal, paying $10 for access is a small price when compared to the fees one could rack up making international calls at Duetsche Telekom’s rates.

TCM Mobile, a relatively unknown outfit, has launched the first ever VoIP based cellular system right down the road from VoIP Supply in Syracuse, New York.

Officially announced last week, TCM Mobile’s patent-pending technology utilizes unlicensed 2.4 GHz spectrum to provide cellular service using VoIP (2.4 GHz is typically used for Wi-Fi networks) . The technology, which overcomes the challenges of interference, seamless roaming and network performance was recently put to the test in down town Syracuse.

According to TCM Mobile officials the testing went better then expected.

“TCM Mobile has resolved the major challenges associated with developing this type of system, such as eliminating interference, roaming seamlessly (seamless hand-off) and creating a successful network architecture. We are proud to announce that we have achieved our goals and look forward to demonstrating our technology to the world.”

Now one must take the news of a new, patent-pending technology from an unknown company deployed in a low density population with a bit of skepticism, but it is entirely possible that they’ve created the secret sauce that has the potential to make wide spread VoWiFi possible.

You’re not likely to see TCM Mobile networks pop-up in major markets or the national stage any-time soon. It seems more likely that TCM Mobile’s will partner with existing carriers, municipalities and even offer service  directly to consumers in rural markets.  It’s still early, but this is definitely a company to keep on your radar in the future.