AT&T – Wi-Fi Calling
AT&T - WiFi Calling
AT&T just announced Wi-Fi calling is available starting October 8th, 2015. While AT&T isn't the first to support Wi-Fi calling as both T-mobile and Sprint have Wi-Fi calling available today. Verizon is in the process of deploying as well. This does mean that AT&T will remain on par with its competitors.
There are two important uses cases that I see with this announcement. The first is for casual international travelers. They will be able to use their telephone number on public Wi-Fi when abroad making it easy to touch base at home. The second are those business customers that have spotty in building coverage but can't justify a distributed antenna system (DAS). Hospitals are the top of my list but I'm sure there are others as well. Post your thoughts in the comments.
There are some caveats to using AT&T Wi-Fi calling that aren't immediately clear to consumers. It only allows switching between Wi-Fi and LTE when in a voice over LTE (VoLTE) coverage area. Calls that drop back to 3G/4G, which are circuit switched, will drop.
As of October 2015 the only platform supported is the Apple iPhone 6/6s variations. You also must have iOS 9. Must have Voice over LTE (VoLTE) coverage.
There is no class of service (COS) over Wi-Fi but it does use an adaptive wide-band codec. This means that based on the amount of available bandwidth the codec and can use more or less data. The amount of data used will correspond to the overall voice quality. AT&T is conservative about network quality. It is safe to assume they are using COS over the VoLTE network and you may notice better quality with VoLTE vs Wi-Fi.
Whether or not it is a problem is hard to say. We have become used to dropped calls with mobile phones. What is exciting is that you may not even know when your phone switches between VoLTE and Wi-Fi. For business customers that is huge benefit. It also extends your range to allow making Wi-Fi calls when travelling internationally. That is a positive step in the right direction for a seamless mobile experience.
Android devices will become supported but need code updates to support the switching between VoLTE and Wi-Fi.
Please read my DISCLAIMER as this NOT an AT&T sponsored post but my own description and opinions.