Apple users are familiar with FaceTime. It is Apple’s proprietary VOIP service. You can make voice or video calls between iOS devices.
What is nice about FaceTime is that it works over cellular and Wi-Fi transparently. The handoff between Wi-Fi and Cellular is instantaneous and transparent. [insert crashing train wreck sound effect and photo here]
What if Apple entered into a plan to buy data capacity wholesale from carriers such as T-mobile? No phone numbers, just pure data. Let’s say they just went to T-Mobile and other carriers and said: We will buy cell-tower data in bulk for iPhone users.
Then, Apple could make the smallest and most straightforward of changes…
Apple could implement FaceTime PSTN gateways. People could port their phone numbers to those gateways and Apple could route the call as a FaceTime call to the iOS device. Likewise, iOS could allow people to call others via email or via a phone number. If the called phone number was not known to be another iOS user, then the call would be sent out the FaceTime PSTN gateway into the public network.
Apple could, quite simply become the largest bypass operator in the world.
Since something like about half of all smartphones are iOS devices, it would mean that half of the phone calls between people with phone numbers would never touch the PSTN network. They would be straight FaceTime calls. It would be a massive unloading of traffic from the classic (doomed) wireline carriers.
Apple is poised to do this today. If they implemented a PSTN FaceTime gateway people could have a public phone number that would call them on their iPhone or iPad or iMac computer. From there it is a trivial matter to allow calls to originate on an iPhone via FaceTime and be spilled onto the PSTN network.
Heck, I would probably subscribe to a FaceTime PSTN phone number even now, so that I could get phone calls via FaceTime globally, anywhere.
This raises the question of the future of cellular carriers. The answer is plain and simple: they are utterly doomed. They are about to become commoditized data carriers who transport no-value-add data when people are out of the range of a WiFi Hotspot 2.0 access point.