AT&T customers who were anticipating the launch of a WiFi calling feature on iPhones will have to wait a bit longer: though the carrier had expected to roll out the option to iPhone users with the recently released iOS 9, it now says it’s going to take a little more time to deploy it, while it waits on approval from the Federal Communications Commission.

Sprint and T-Mobile currently offer WiFi calling, a handy option if you happen to be somewhere with poor service but a steady WiFi network, but AT&T and Verizon have yet to offer that feature on their networks.

There’s no launch date yet, Phone Scoop reports (h/t The Verge), but those who had beta tested iOS 9 before it was released and therefore were already able to use the feature will still be able to do so.

“AT&T tested WiFi Calling through the iOS 9 beta and we are prepared to support commercial launch of the service once approved by the FCC,” the carrier said in a statement provided to Phone Scoop.

It’s also unclear when WiFi calling will be ready for devices other than the iPhone, though it would seem that it won’t be before the FCC approval comes through.

So what’s the hold up? AT&T needs approval for features for hearing impaired users, which involves a system called real-time text (RTT). It’s similar to the traditional TTY (which stands for Text Telephone) phone technology, but is more reliable than TTY is on WiFi networks.

AT&T Hopes to Launch WiFi Calling On iPhone Soon [Phone Scoop]

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