T-Mobile USA offloads 5M Wi-Fi callers

BARCELONA, Spain--T-Mobile USA said 5 million of its 34 million subscribers route some of their cellular calls over a Wi-Fi network, and that around 1.25 million of those subscribers use the carrier's new Wi-Fi Calling Android application.

Click here to see how T-Mobile’s Wi-Fi Calling service works.Further, the carrier said its subscribers place around 40 million calls per month over Wi-Fi--a significant figure considering the world's wireless carriers continue to seek ways to reduce traffic on their wide-area cellular networks.

T-Mobile in 2007 debuted its [email protected] Wi-Fi calling service, which relied on technology from partner Kineto Wireless. The effort was intended to replace users' landline phones. Handsets supporting the service included select Nokia(NYSE:NOK)  and Research In Motion (NASDAQ:RIMM) BlackBerry gadgets. In the intervening years, however, T-Mobile adjusted the program from a landline replacement play into an offload and coverage enhancement technique. Late last year, the carrier introduced its Wi-Fi Calling application for Google's (NASDAQ:GOOG) Android phones from Kineto, which allows Android phone users to route their calls and text messages through a Wi-Fi connection.

And it seems subscribers are interested in the service. T-Mobile said it counts a total of 5 million Wi-Fi calling subscribers, around 3.75 million of whom subscribe to its legacy [email protected] service and around 1.25 million of whom use its new Wi-Fi Calling offering.

Joshua Lonn, director of product development at T-Mobile, said the carrier is positioning its Wi-Fi Calling service as a coverage enhancer--he said it's essentially T-Mobile's version of a femtocell (he said T-Mobile is focusing on the Kineto-powered Wi-Fi Calling service now, though it hasn't ruled out the sale of standard femtocell products). Lonn said the Wi-Fi Calling app for Android phones allows users to route their cellular calls and text messages over a Wi-Fi access point, thus broadening the carrier's coverage area to anywhere with a Wi-Fi hotspot.

Interestingly, Lonn said calls made over T-Mobile's Wi-Fi Calling app count toward a user's bucket of minutes, and that users aren't able to hold onto a call while moving from a Wi-Fi access point to the carrier's cellular network (and vice versa). Instead, users will have to hang up and place a new call when moving from one type of network to the next. Lonn explained that there are technical challenges to such a handoff, and T-Mobile found that such functionality wasn't an important feature among users.

Lonn said T-Mobile expects to offer its Wi-Fi Calling app on all of its Android phones this year, and is working to move the service onto its Microsoft (NASDAQ:MSFT) Windows Phone 7 devices at some point in the future. He said T-Mobile also hopes to work with Kineto to refine the service so that users won't have to actively manage the app via their handsets--instead, the carrier is working toward a version of the service that would automatically route users' calls over suitable Wi-Fi access points. Lonn said such a function would require cooperation among T-Mobile, Kineto and T-Mobile's handsets suppliers.

For more:
- see this Kineto release
- see this Connected Planet article

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