VoLTE Gets Real: But the Number of Devices Supporting It Is Really Limited

By Paula Bernier, Executive Editor, TMC  |  September 24, 2014

After years of talk about voice over LTE (News - Alert), cellular service providers in recent months have finally begun to roll out LTE services. 

“VoLTE and HD voice will start to grow and play a larger and more important role in the wireless industry going forward,” says industry analyst Jeff Kagan. “This lets users place voice calls over the data portion of the wireless network.”

Not only does VoLTE enable cellular carriers to deliver HD voice, it also enables them to move away from their legacy networks, notes Doug Mohney, editor in chief of HD Voice News, and a TMC (News - Alert) contributor.

“VoLTE is the last necessary piece before carriers start shutting down the legacy mess of 2G and 3G networks and refarming spectrum,” says Mohney. “Guaranteed quality of service is the edge VoLTE offers over OTT best effort solutions, along with the fallback ubiquitous voice solution when people disagree on what OTT clients they want to use.”

On May 15, AT&T (News - Alert) introduced what it calls VoLTE-based High Definition Voice service to Samsung Galaxy S 4 mini users in select areas of Illinois, Indiana, Minnesota, and Wisconsin, adding more markets are to come. Hong Kong Telecom the same day announced its launch of VoLTE, which it is supporting via Huawei core infrastructure, and delivering to Samsung Note 3 users.

About a month later, T-Mobile revealed it had VoLTE live in 15 markets reaching more than 107 million people, and that it supports VoLTE on four devices – the most recently added being the Samsung Galaxy S 5. In a June 18 blog, T-Mobile CTO Neville Ray wrote that the company was the first to roll out VoLTE and that it expects to make VoLTE available nationwide by the end of the year. Ray also boasted about the HD voice capabilities T-Mobile can deliver via VoLTE.

“Because our network has been designed for data, we’re now able to nearly double the data that supports voice calls for superior, crystal-clear HD voice,” Ray wrote. “In fact, we offer the highest fidelity HD voice possible – 23.85kbps voice codec rate. VoLTE also offers faster call set-up times than a non-VoLTE call, and customers are able to access our LTE network during a voice call.”

Bouygues Telecom in France and Verizon in the U.S. also plan to roll out VoLTE and related HD voice services this year. In announcing its selection of Ericsson (News - Alert) as its VoLTE vendor, Bouygues Telecom said its LTE network will deliver the first VoLTE calls later this year and will go commercial in 2015. Verizon, meanwhile, said VoLTE is slated to roll out on its nationwide network later this year. Verizon didn’t specify what handsets on its network would support VoLTE functionality.

But a May 20 Verizon blog said this: “…more and more customers across the country will be able to use VoLTE as select handsets will be VoLTE-enabled through a software update leading up to the roll out of the service, with new devices VoLTE-enabled at the time of purchase later this year. For a customer to make or receive a VoLTE call, both parties must have VoLTE-enabled devices and be in an area where VoLTE is available.  

“Verizon’s VoLTE will also offer video calling options, including making and receiving video calls directly from contact lists. As part of the VoLTE video calling experience, customers have the ability to change their calls instantly from voice-only to voice and video. The rollout also sets the stage for future enhancements through Rich Communications Services, which enable things like including large file transfer, more robust group messaging, and more location sharing.”

These rollouts and announcements come after years of debate on how best to support voice on LTE networks, and work on VoLTE by the major cellular carriers and their suppliers.

The long time to implement VoLTE is due to its huge technical complexity, the need for excellent LTE radio coverage and enough backhaul, the need for devices supporting VoLTE, and the lack of a clear business model around this technology, among other issues, says Dean Bubley (News - Alert), director and founder of London-based research and consulting firm Disruptive Analysis.

“[VoLTE] is complex and expensive, and does not obviously generate any new revenues,” Bubley says. “As such, the business case is highly questionable – and with

the additional network complexity, testing, etc., may actually increase risks significantly.”

Edited by Maurice Nagle