GSMA has adopted One Voice as the official solution for its Voice over LTE (VoLTE) initiative, effectively shutting out rival industry group VoLGA.
One Voice is the initiative formed in November 2009 by a number of operators and vendors as a way of dealing with legacy circuit-switched voice and SMS traffic over LTE’s all-packet network.
The GSMA waded into the LTE voice debate last year, announcing an initiative to evaluate and back a VoLTE standard to avoid fragmentation.
One Voice – which backs an IMS-based approach – was vying for the blessing of the GSMA and 3GPP in competition with VoLGA (Voice over LTE via Generic Access), which was spearheaded by T-Mobile and Kineto Wireless last year as an alternative to CS (circuit-switched) fallback, another solution that allowed operators with legacy 2G networks to use them to serve LTE’s voice/SMS requirements.
GSMA chief technology and strategy officer Alex Sinclair said it was One Voice’s adherence to IMS that won the day.
“In the end it has to be IMS-based because that is the standard for LTE going forward,” Sinclair said, adding that One Voice’s membership is “a broad representation of the industry that backs up that conclusion”, in reference to One Voice’s heavy operator support.
One Voice has
AT&T, Orange, Telefonica, TeliaSonera, Verizon Wireless and Vodafone onboard, while T-Mobile is the only operator to officially back VoLGA.
As for IMS, VoLGA’s proponents have argued that many cellcos have no definite plans to adopt IMS and need a solution now that doesn’t rely on deploying it.
But Verizon Wireless CEO Dick Lynch said regardless of short-term needs for voice and SMS support on LTE, cellcos had to take a long-term view on their LTE voice strategy.
“We felt from the beginning that it was a necessity to have a standard voice API set,” he said. “You also have to think about what will happen in the long term if your voice service is not IMS-based. You’d be constantly transcoding traffic, so the efficiency is much lower.”
Operator support for One Voice also highlights the fact that cellcos’ initial vision of LTE as a data-only service has changed drastically in the last year, said Vivek Badrinath of Orange, which backed the GSMA’s decision.
“The initial device focus was on dongles, but LTE handsets are coming down the pipeline much faster than we anticipated, so there’s a definite need to sort out a standard approach to this now,” he said.
Ovum analyst Jeremy Green said the GSMA’s decision “strengthens the business case for LTE, because it makes it a stronger candidate for the wholesale replacement of the existing mobile network.”
Meanwhile, Kineto Wireless isn’t giving up on VoLGA just yet, at least as an interim solution and an alternative to CS Fallback. On the MWC exhibition floor, Kineto is demoing VoLGA and promoting recent test results with Deutsche Telekom that claim VoLGA delivers call-setup times up to 65% faster than “alternative LTE voice technologies” such as CS Fallback.
“Our testing has already shown quantitative improvements over CS Fallback in the areas of faster call-setup times, lower dropped call rates, and the ability to talk and surf the Internet at the same time,” said Patrick Tao, Kineto’s vice president of technology.