A total of 20 mobile operators have joined the GSM Association’s forum to harmonise standards for carrying voice services over LTE.
In a statement due to be made on the first day of the 2010 Mobile World Congress in Barcelona, the trade association said that its One Voice initiative, first announced in November 2009, is gathering wider support.
The informal alliance appears to indicate widespread support for using IMS — IP multimedia subsystem — for carrying voice over the new fourth-generation mobile technology, which is likely to start going into service this year.
However, the downside for the GSMA is that it is dropping the One Voice name for the project — as BT had already claimed it as a trademark. “Now it will be VoLTE,” said Dan Warren, the GSMA’s director of technology.
The move means that “the LTE voice standard will be a target”, he added. “It means terminals will be able to roam and will be able to connect up to networks.”
Makers of network equipment and terminals will be able to certify their products as adhering to the eventual VoLTE standard.
The original One Voice initiative had the support of a number of major operators — including AT&T, Orange, Telefónica, Verizon Wireless and Vodafone. Equipment vendors backing the move included Alcatel-Lucent, Ericsson and Nokia Siemens Networks, plus terminal makers Nokia, Samsung and Sony Ericsson.
“The idea was to catalyse the market to adopt a single system for voice over LTE,” Warren told Global Telecoms Business.
At the same time a number of fallback options have been considered for what has been designed as a 4G standard mainly for data, including a circuit-switched system and an approach called VoLGA — voice over LTE via generic access.
“They are interim solutions,” says Warren. “Now we can make the step to voice over LTE direct. We can now minimise the use of interim solution: the problem with them is that they’re hard to move on from.”
The new supporters of VoLTE, due to be announced at MWC, include some of the biggest operators in the world, including China Mobile, NTT DoCoMo, Deutsche Telekom, Softbank and SK Telecom, as well as Telecom New Zealand.
In addition the GSMA has won the support of more equipment and handset makers, including Cisco, Fujitsu, Huawei, LG and NEC — but not yet Apple, BlackBerry maker RIM or ZTE.
VoLTE is intended to control network-to-network interfaces and roaming interfaces, said Warren. “It’s fundamental to LTE to have the sort of fully roaming ecosystem that we have today. And voice is still the major market for mobile communications.”
VoLTE is being designed to offer the option of high-definition voice, which will be compatible with the audio standards that are being introduced on a number of fixed VoIP services as well as audio and video conference systems. “The key to all this is to have an end-to-end ecosystem,” he added.
Two of the major LTE standards and development organisations, 3GPP and the NGNM, the Next Generation Mobile Networks alliance.
The GSMA is telling companies in the industry that in order to take part in VoLTE meetings and exchanges they will have to agree to “fair, reasonable and non-discriminatory” exchange of related intellectual property. GTB