After delays, lodging official complaints about its competitors, and gaining a waiver from the FCC, AT&T has finally enabled Wi-Fi calling on its network. Wi-Fi calling helps close gaps in cellular networks by rerouting calls and texts over a Wi-FI network when cell reception is weak or unavailable. iPhone users on iOS 9 can begin using the feature today.

Last month, AT&T said the delay was due to a waiver it had not yet received from the FCC for TTY (teletypewriter) support, a feature relied on by those with impaired hearing. AT&T wrote the FCC asking it to amend its rules to allow it to use RTT (real-time text) solution, a newer technology that it developed, and claimed that competitors Sprint and T-Mobile launched their versions of Wi-Fi calling without the proper waiver from the FCC.

Despite the drama, Wi-Fi calling has finally made its way to AT&T customers. If you're using an iPhone 6, 6 Plus, 6S, or 6S Plus, you can turn on the feature today by opening the Settings app, clicking on "Phone," and clicking on "Wi-Fi Calling."