Armed with a waiver from the FCC, AT&T recently introduced functionality that adds the long-awaited WiFi calling feature to newer iPhones capable of running iOS 9. Unfortunately, owners of the iPhone 5 and earlier models are out of luck.

The new WiFi calling functionality became available on October 8, so if you are interested in making calls over your WiFi connection, check out this CNET article that shows you how to enable the feature. It may take a while for the WiFi indicator to display after activation.

Here’s a closer look at AT&T’s new WiFi calling functionality.

WiFi Calling Helps When Carrier Signal is Weak 

WiFi Calling is a godsend for many travelers encountering a weak or nonexistent carrier signal, but are able to access a WiFi hotspot.

AT&T WiFi Calling now available

AT&T WiFi Calling

Additionally, if AT&T’s 4G or 3G signals aren’t strong inside your home, you can now leverage your residential Internet account to make calls. Bandwidth usage is minimal — especially compared to video chat — but run a quick speed test to ensure everything is running smoothly.

The person receiving your call doesn’t need a third-party app or any similar WiFi calling feature. It works like any normal mobile phone call. You are able to call a landline or mobile phones with no issues, provided your Internet signal is active.

AT&T Following T-Mobile and Sprint’s Lead with WiFi Calling

T-Mobile and Sprint previously introduced WiFi calling on their networks. AT&T’s recent launch of the feature leaves Verizon Wireless as the only major American wireless company holding out. Google’s nascent Project Fi phone service focuses on WiFi calling, but it piggybacks on top of T-Mobile and Sprint’s networks if a suitable hotspot isn’t available.

AT&T complained that the FCC was unnecessarily delaying the approval of the required waiver. The company wanted to introduce the feature with the rollout of iOS 9.

With customers now expecting WiFi calling as a standard feature on their smartphones, Verizon is likely to add similar functionality soon. Big Red had hoped to rollout the feature this summer, but missed that date. It isn’t a big priority for them, considering the company’s status as the largest 4G LTE network in the country.

There’s no denying that more and more calls will be using WiFi bandwidth over the next few years. App-free video calling is likely to follow with no Skype or Facetime needed.