Is the time right for FaceTime over 3G?

The Verizon version of the iPhone 4-due to arrive early at once month-will include a personal hotspot feature that will let users share their phone's 3G connection with up to five other devices. Pending carrier approval, the hotspot feature could in the end make its way into every device-possibly as before long as the however-in-beta iOS 4.3 update arrives. And not surprisingly, that's generated a lot of positive buzz: users see the hotspot capability as a way to both reduce the number of devices they need to carry around and lower their cellular bills by sharing a single connection among multiple devices.

The introduction of this new capability

The introduction of this new capability, now, does raise a few interesting questions about FaceTime, another innovation that Apple has touted as revolutionary in spite of the fact that it is severely limited by its reliance on Wi-Fi connectivity.

When Apple CEO Steve Jobs previewed FaceTime last year, he mentioned that the video-calling system would only work across a Wi-Fi connection, presumably due to the limited reliability of cellular networks, or maybe because wireless operators were reluctant to embrace a research that could possibly eat into their core revenue stream.

It's difficult to say whether the situation has changed enough in the intervening six months to warrant a reversal of this policy. Nevertheless there are a few indications that things are, meanwhile, moving in the right direction. First, AT&T has invested heavily in its network, particularly in areas where the coverage suffers from a combination of regulatory hurdles and unfavourable topography, like New York City and San Francisco.

What's more, although the iPhone 4 won't use Verizon's faster LTE (Long Term Evolution, latest standard in the mobile network technology) network, the company is similarly positioned, with good coverage and plenty of time to upgrade their network since it started working with Apple on a CDMA version of the device.

Crucially, AT&T stopped offering unlimited data plans in 2010, and has been allowing VoIP (Voice over Internet Protocol) apps to operate for both audio and video calls over 3G for some time. This means that the company however has an incentive to allow FaceTime over its network, since it will cause users to consume more data and, presumably, pay higher monthly premiums.

What it does

AT&T has as well lifted many limitations on what it does and doesn't allow on its network. Take Skype, the voice-over-IP app that was restricted to making calls over Wi-Fi when it first debuted on the iOS platform. That changed in 2009, when AT&T agreed to let VoIP apps place calls on its 3G network. These days, you can even make a video call over 3G using Skype.

Users of jailbroken iPhone 4 devices have already been able to use FaceTime over a 3G connection for some time, thanks to a little utility that tricks the phone into thinking that it is connected to a Wi-Fi network at all times.

The increasing availability of personal hotspots

And given the increasing availability of personal hotspots, the line between Wi-Fi connectivity and 3G data gets increasingly blurred. Since there is no practical qualitative difference between a "traditional" Wi-Fi network in other words connected to a wired Internet link and one in other words created by a mobile hotspot, limiting FaceTime to a local wireless connection will make less and less sense.

If you try to make a FaceTime connection over a Wi-Fi hotspot that's relaying data over a 3G network, it works. The quality of a call depends heavily on the stability of the 3G data link and suffers from the occasional hiccup due to network lag or temporary congestion. Now, the same is true of a regular Wi-Fi link: if you're in the middle of a large download that eats up a considerable amount of your bandwidth, you can safely expect FaceTime performance to be less than stellar.

In short, my empirical experiments show that FaceTime over 3G is an in every respect feasible proposition. It uses large amounts of bandwidth-about 3MB per minute-however no more so than, say, streaming video off of a service like Netflix. Clearly, in the long run, only Apple will have the final decision on the matter. Yet it seems that all the necessary pieces may all things considered be there for iPhone and iPod touch users to view each other even when they're away from a traditional wireless hotspot.