Author(s): Raghu Gopal
This week AT&T announced the rollout of its Wi-Fi Calling service across Android devices for post-paid subscribers. AT&T users with compatible smartphones will receive a notification from the operator. The LG G4 is the first phone eligible for the service.
Wi-Fi calling is an architecture that allows mobile subscribers to use Internet connections for voice calls and texts, retaining the same phone number as the identifier. This makes AT&T's initiative distinct from third-party services such as Skype or Viber, which require a separate identity.
Wi-Fi calling is not based on geographic location, meaning any Wi-Fi access point in the world is essentially treated as a cellular base station. Wi-Fi calling is also a way to bring artificial cellular coverage to areas where signals are weak, such as rural areas and basements.
The service is certainly not new to the US market, nor to AT&T. It was first made available to AT&T iOS subscribers late in 2015. Wi-Fi calling is now available from all major US operators, with other providers including Rogers Wireless in Canada and EE in the UK.
The specifications to support unlicensed mobile access — the mingling of open Internet connections to operator core networks — were completed more than 10 years ago, but there has been resistance to its implementation. In particular, there was the very real potential of interference with voice-related revenue, especially from roaming charges as it would lead to more calls over Wi-Fi rather than cellular. However, new flat-fee business models, combined with the recognition that users are moving to third-party apps for voice calls, is leading to a realization of the need to offer Wi-Fi calling.
There's an interesting paradox that Wi-Fi is now being used to extend cellular services into hard to reach places while so-called "Wi-Fi first" services such as Project Fi, FreedomPop and Republic Wireless use cellular signals as a complement to Wi-Fi. Both Wi-Fi calling providers and Wi-Fi-first operators advertise seamless hand-offs between the two wireless domains.
For consumers, this is a win. Implementations of unlicensed mobile access and a Wi-Fi-centric service are also addressing expectations from the audience. Why distinguish between wireless access types? It's a reasonable question. Now two separate technologies are being brought into a formal partnership. We also note the growing support among operators to provide users with alternative ways of accessing services seamlessly across networks.