Wireless VoIP?

By Jonathan Tombes

With CTIA Wireless 2008 approaching - the event opens next week in Vegas - wireless is in the air, so to speak.

In the air are not just voice, but also data. That's nothing new per se: mobile broadband is a hard reality to some 14 million Blackberry subscribers and growing ranks of mobile PC users. What is blowing like a wind of change is the realization that these higher throughputs can carry voice.

While over-the-top providers, such as Skype, already have launched mobile VoIP applications, this prospective shift among facilities-based providers is noteworthy.

"It probably makes sense for wireless operators to move to VoIP, just as the cable operators have," said Randy Fuller, VP business development for Camiant. "The economics for VoIP work better."

A provider of policy control and application service assurance technologies, Camiant will be represented at a CTIA "Mobile VoIP" panel on April 1 (no joke) billed as providing insight into a "multi-vendor mobile VoIP trial."

Other companies slated to appear on this panel include Ericsson, Motorola, Sprint Nextel, Nortel and Qualcomm.

The wireless broadband technology behind the trial in question is known as EVDO (Evolution-Data Optimized) Rev A, which is the CDMA way of handling data. The equivalent technique on the GMS side of the wireless industry is known as UMTS (Universal Mobile Telecommunications System.) (For some insight into what happened at last month's GSM event in Madrid, see this interview.

Looks familiar

The rationale behind a wireless shift to VoIP should be familiar to anyone who has followed the way in which early providers of cable telephony - Cablevision, Cox Communications, and the old AT&T Broadband - "capped" their investment in circuit-switched technology and correspondingly "grew" their use of the softswitches that drive VoIP deployments.

Fuller explained this shift in the wireless domain as being that whereas in an existing mobile switching center (MSC) one finds an "integrated hardware and software device, once you move to VoIP, most of what you get is software."

What Camiant offers to this mix is policy control and charging rules function (PCRF), the component within an IMF framework that "makes sure that the session should be allowed to set up," Fuller said.

"We specialize in that PCRF piece," Fuller said. "The reason that we do that is the PCRF can be used for a whole lot of other things before VoIP gets going."

That story tracks with how some cable operators have deployed policy servers for applications, such as high-speed data speed previews, well in advance of any formal IMS rollout. "It can be used in the same way in mobile broadband networks," Fuller said.

As for when a carrier-grade, mobile VoIP service would appear, don't hold your breath. "There are still a good couple of years to go," he said.

- Jonathan Tombes