Who says Wi-Fi offload is just for data?

Operators may be using Wi-Fi to move Internet-bound packets off of their 3G and 4G networks, but they could be shipping all kinds of mobile traffic via Wi-Fi, according to Kineto Wireless. On Wednesday, Kineto released a new version of its Smart Wi-Fi smartphone and network software designed to make the big world of Wi-Fi hotspots one big off-ramp for voice, SMS, MMS and other carrier services.

T-Mobile and Kineto’s other customers have used home, office and other private Wi-Fi networks to offload voice and SMS traffic for years, and, in fact, the public hotspot-access capabilities have been buried in T-Mobile’s Android(s goog) devices for some time. When traveling in Europe I’ve been able to make calls back to the U.S. over Wi-Fi by activating the Wi-Fi calling feature in my handset – while T-Mobile still charged me minutes, I bypassed the exorbitant international roaming and long-distance fees. The service sometimes gets a bit quirky on a public network, but Kineto believes it has now worked out all of the bugs enough to off a commercial-grade solution to its carrier customers.

It’s upgraded its Wi-Fi client to detect login or splash-page barriers on public hotspot networks and added features to help them easily navigate or bypass those obstacles. The new client can also let users set preferences on what types of traffic to offload. For instance, a customer could limit voice and SMS only to home or other private Wi-Fi networks, while using whatever free Wi-Fi is available for general application and Internet data. The idea is that customers may be willing to put up with a less-than-optimal Wi-Fi connection if they’re downloading e-mail or surfing the Web, but they want to ensure their calls and texts will always go through.

The reason carrier services are special is because voice and message traffic isn’t your typical IP bit stream that a Wi-Fi access point can just dump onto the public Internet. SMS and voice has to be converted to IP, which is then tunneled back to the carrier’s core network, where they become normal phone calls and text messages again. While many operators are perfectly willing to shunt YouTube and other Web traffic onto someone else’s broadband connection, they’re loath to give up control of their bread-and-better voice and SMS services for those brief moments when they cross unlicensed Wi-Fi connections and the byways of the Internet. That’s why T-Mobile is the only major U.S. operator to really embrace voice Wi-Fi as a means of offloading its principle mobile services. Other operators have either tried to solve the problem with femtocells or just keep all of the voice calls and text messages within their own networks.