Ericsson AB (Nasdaq: ERIC) is revoking its membership of the Voice over LTE via Generic Access (VoLGA) Forum , a sign that support for the group might be waning.

The move is significant because Ericsson's support, or lack of it, for mobile industry initiatives is important, given that it's the largest single global supplier of mobile infrastructure and one of the early movers in the emerging market for LTE systems.

Ericsson's move is made more notable because the Forum is promoting just one of a number of approaches to arguably the most important issue currently facing mobile operators: how to deliver legacy voice and messaging services over LTE networks. (See Voice Over LTE's Future Cloudy and Forum Tackles Voice Over LTE.)

LTE, as a packet-based network technology, doesn't support legacy, circuit-switched traffic, and that's an issue because, despite the growing popularity of mobile data services, legacy voice and SMS services currently account for 85 percent of the world's $800 billion-per-year mobile services market, according to Pyramid Research .

Support from major carriers and vendors is important if any single solution is to gain momentum and become adopted by the global mobile industry.

Cracks had already formed in the Forum's support in recent months as industry players leaned increasingly toward an alternative IMS (IP Multimedia Subsystem)-based approach to tackling the industry's voice-over-LTE challenge, and Ericsson's decision will only widen those cracks. (See Kineto Hedges on LTE Voice.)

The VoLGA Forum, though, says support for its efforts is strong, and that it is moving forward with the next stage of its specification development work.

Jumping ship
Ericsson, though, doesn't see much support amongst the operator community for VoLGA, and so has decided it's time to withdraw from the Forum.

When the Forum was formed, "we had the impression that VoLGA would become a global solution," says the vendor's VP of technology and industry, Erik Ekudden, who is responsible for industry standardization at Ericsson. (See New Forum Gives Voice to LTE .)

Now, though, "there are no signs that it [VoLGA] will be strongly supported" by mobile operators, Ekudden tells Unstrung.

Indeed, T-Mobile International AG is the only major carrier to speak out in support of VoLGA so far. (See T-Mobile: Voice Discord Threatens LTE.)

"Of course we will support it if required, but now there is more acceleration for support for packet-based voice -- that's where there is big momentum," states Ekudden.

He says the Forum's work is largely complete, and Ericsson doesn't expect the group to undertake any further specifications work, so "this is a good time for us to leave." (See New Specs Deepen LTE Voice Dilemma.)

VoLGA holds firm
The VoLGA Forum, though, says its work is far from complete. "We cannot comment on Ericsson's reasons to leave the Forum," states VoLGA Forum spokesman Kurt Bischinger, VP of Strategy and Process Coordination, International Standardization at Deutsche Telekom AG (NYSE: DT)/T-Mobile, in an email to Unstrung.

The Swedish vendor, states Bischinger, has been "a valuable member and we appreciated [Ericsson's] engagement in the development of the phase 1 specifications."

But there's more to come and more interest in the Forum, he says. "We do not recognize waning support. All remaining members are fully committed to proceed with the work and to develop the second phase of the specifications," states the T-Mobile man.

"The involved companies are busy with implementing and testing their solutions. We are in contact with several applicants for the forum and interested parties who consider VoLGA as [the] solution for voice and SMS in LTE," adds Bischinger.

Ericsson talks One Voice
Ericsson, though, is certainly turning its back on the Forum's ongoing efforts, believing that the main focus of carrier efforts will be behind two solutions endorsed by the 3rd Generation Partnership Project (3GPP) : circuit-switched fallback (CS fallback), which enables continued support for legacy voice and messaging by allowing handsets to leave the LTE network and "fall back" to the 2G/3G network to make and receive calls; and IMS, as outlined by the recently formed One Voice initiative.

Despite the immaturity of IMS (and the cost of implementing an IMS strategy), and the lack of sophistication of CS fallback, One Voice is backed by AT&T Inc. (NYSE: T), Orange (NYSE: FTE)'s Orange, Telefónica SA (NYSE: TEF), Telia Company , Verizon Wireless , and Vodafone Group plc (NYSE: VOD), as well as a selection of major equipment vendors, including Alcatel-Lucent (NYSE: ALU), Nokia Corp. (NYSE: NOK), Nokia Networks , Samsung Electronics Co. Ltd. (Korea: SEC), and Sony Ericsson Mobile Communications . (See Voice Over LTE & the 'IMS Gap' and Operators Rally Round IMS for LTE Voice.)

"That's where we see the bulk of the support. There may be others running in parallel, but those are the two solutions" that Ericsson believes will be backed by the majority of operators, says Ekudden.

Indeed, according to information provided by Ericsson for the recent Unstrung Insider report, "Voice Over LTE: Many Questions, No Easy Answers," the vendor believes commercial IMS-based voice over LTE services will be launched as soon as 2011.

According to the same report, the initiatives that might be running in parallel with CS fallback and IMS are: VoLGA; Fast Track, which is being pushed by NSN (though the vendor is also a supporter of One Voice); and a number of over-the-top VoIP solutions, such as the one being promoted by partners Acme Packet Inc. (Nasdaq: APKT) and Mavenir Systems Inc. . (See Mavenir, Acme Tackle LTE Voice and NSN Goes Solo for LTE Voice.)

The existence of a number of differing solutions won't necessarily lead to industry fragmentation, concludes the report's author, John Blau. However, he notes, it could. And "that is a problem: Fragmentation helps no one -- neither operators that seek standardized solutions to reduce capex and opex nor vendors that strive for economies of scale in their manufacturing," notes the analyst.

— Ray Le Maistre, International News Editor, Light Reading