Back to the future of mobile voice

Vodafone Germany this week showed us the future of mobile voice and it is strikingly familiar: voice-over-IP. We'll be seeing a lot more mobile VoIP in the future and its impact on users and the mobility industry will be strong.

The German cellular operator is making VoIP available to its customers with devices that can connect to the Internet via technologies such as Wi-Fi. The benefits are compelling: no roaming fees for international travelers and voice access where it otherwise isn't available, such as indoors. In other words, converging VoIP with cellular offers great convenience and flexibility.

However, convenience and flexibility aren't the strong suites of many cellular operators, particularly in the U.S. Cellular carriers have been, at best, reluctant to offload their traffic to VoIP because, for the most part, carriers don't control the networks that would carry the VoIP traffic. It doesn't take a Wharton MBA to understand that, if customers can easily switch to VoIP using any ISP's pipe, the cellular operator loses those revenue-producing minutes.

Sure, in the abstract, it would benefit the carriers to offload voice traffic from their cellular networks because it would save money in network build-out costs. After all, why put in more base stations when VoIP can offload traffic? At its inception, Vonage used that logic to try to convince carriers to partner with them, but the carriers obviously believed the greater harm (to them) was offloading customers and revenue-producing minutes to somebody else's network.

But make no mistake: mobile VoIP is the way of the future. For now, T-Mobile has its HotSpot@Home program for consumers that enables users to seamlessly switch between cellular and voice in their homes. This program has its attractions, but users can't really get access to VoIP after they've left home.

And the carriers agree that, long-term, voice traffic over 4G networks will be VoIP. The carriers seem to be lining up behind LTE technology for their 4G service, which we can expect to see, if all goes well (which it often doesn't) in, maybe 2011. Maybe.

Which brings me to Sprint's WiMax effort, which has the potential to be available to many customers this year, three full years before its competitors can offer similar 4G technologies. One reason WiMax could be disruptive, if it ever gets off the ground, is that it will encourage mobile VoIP. Because Sprint would own both the cellular and IP networks, the company could easily devise plans that would converge cellular and VoIP voice in a single device. And converged devices definitely will be available since Nokia, Motorola and Samsung, which are providing the infrastructure for Sprint's WiMax network, have committed to creating the devices.

In the best of times, it would be a bold move for Sprint to roll out its WiMax network. But Sprint is crippled and crippled publicly-traded companies typically don't have the luxury of being bold. Still, if it can figure out a way to roll out its WiMax network, it would not only change the nature of mobile voice, but it likely would be well rewarded, eventually, for its boldness.