Optical/IP Networks

Voice Over LTE's Future Cloudy

If voice initially was not high on the priority list of vendors and operators transitioning to Long Term Evolution (LTE) technology, it is now moving up, as both camps prepare for some of the first LTE deployments in early 2010. Yet for all the promise inherent in its blazing speeds, LTE still needs a commercially and technically acceptable solution for dealing with the industry's cash-cow circuit-switched telephony service, which the mobile communications industry appears now to realize.

Legacy 2G and 3G networks, which are optimized for voice communications and extend to all corners of the globe, will continue generating the bulk of voice traffic even after operators have added LTE technology. So a big question facing operators is how they can most efficiently deliver legacy circuit-switched voice and text-messaging services over packet-switched LTE.

The 3rd Generation Partnership Project (3GPP) standards body envisioned that this functionality -- and other voice-enhanced multimedia applications -- would be solved by the use of IP Multimedia Subsystem (IMS) architecture. Unfortunately, this solution is taking longer to realize than originally envisaged. After many years of standardization, the technology has yet to move beyond the trial stage into mass-scale deployments in mobile networks, and many fear it may have become too complex.

As detailed in the latest edition of the Unstrung Insider, "Voice Over LTE: Many Questions, No Easy Answers," several interim solutions have emerged, and more could be on the way. So far, not all are standardized by 3GPP. The threat of fragmentation is real: Instead of agreeing to a common way forward to provide voice over a next-generation network -- an opportunity missed in 3G – the industry could find itself engaged in a new war over proprietary solutions.

Some expect the deployment of voice over the next-generation network to be "conservative," as operators seek to maximize the technology and infrastructure they use to provide voice services instead of moving aggressively toward a new solution. Others point to risks that operators could face if voice is not an integral part of their LTE offering from the beginning. These include the threat from Internet companies providing combinational voice and data services for little to no cost; and the expectations of users subscribing to next-generation services that, understandably, look forward to receiving something better than what they already have.

Beginning in 2010, consumers and businesspeople will begin to experience new LTE data services, and they are sure to like it. How many bells and whistles they can expect from the voice service remains to be seen.

— John Blau, Research Analyst, Unstrung Insider

The report, Voice Over LTE: Many Questions, No Easy Answers, is available as part of an annual subscription (12 monthly issues) to Unstrung Insider, priced at $1,595. Individual reports are available for $900. To subscribe, please visit: www.unstrung.com/insider.

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