Apple has approved an official Vonage VoIP application to give iPhone users the ability to make voice calls over WiFi, as does the Skype app for iPhone.
The restriciton to "WiFi only" is part of an agreement with AT&T to not allow customers to use their network to initiate VoIP sessions using the AT&T 3G network.
The decision does not go as far as many would like, but as far as the current agreement with AT&T will allow. But change will come, though not fast enough to suit some. Over a 10-year period between 1997 and 2007, for example, U.S. communication service providers replaced the nearly 50 percent of revenue derived from long distance charges with an equivalent amount of wireless revenue.
It would be reasonable to suggest that IP services and mobile broadband likewise will, over a possibly similar amount of time, also transition from reliance on voice revenues to a reliance on mobile broadband and data services. In fact, such a transition is virtually required, as 3G and 4G networks do not support the existing voice format for technical reasons.
That said, it is no so clear that all voice will be consumed using any particular VoIP business model. Some portion will be provided by third parties, while some will be provided by the carrier themselves. Over time, though, there is little debate about the relative importance of the voice revenue stream declining while the relative importance of the data streams increases.
Given the already-reasonable retail cost of domestic U.S. calling, VoIP might have the most obvious impact in the global calling market, where per-minute prices are much higher.
That said, a mobile voice capability actually is a bundle of several values. The simple ability to make and take local or domestic calls is analogous to the function of a voice fixed line. Most mobile plans, and most VoIP plans, alrready eliminate the distinction between local and domestic long distance calling. The difference between "unlimited" plans, and "buckets of minutes" also already is being narrowed, at least for domestic U.S. calling.
The ability to place international calls has many product substitututes, including VoIP, but also including calling cards, for example. Email, instant messaging and text messaging are functional, if not complete substitutes as well.
It might take a while, but relatively standard use of mobile VoIP is coming, as it likewise ultimately will come in the landline business as well. But complete change will take quite some time.