Real Time Communications Featured Article

VoLTE Gets Real - But Should We Really Care?

July 07, 2014

After years of talk about Voice over LTE, cellular service providers in recent months have finally begun to roll out LTE services. 

On May 15, AT&T 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, with more markets 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.

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 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.

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.

RealTimeCommunications recently spoke to Dean Bubley, director and founder of Disruptive Analysis, a London-based research firm and consultancy, about what took so long, and what it means that VoLTE has finally arrived.

What is the telco strategy around VoLTE?

“For the most part, it is essentially business as usual – i.e., plain-vanilla

telephony. Yes, it's got HD voice, but that's already available with 3G

non-VoLTE telephony on 100 networks anyway. In theory, it is more spectrum-efficient than circuit voice. It also should help speed up the eventual end-of-life/switch-off of 2G

networks, especially for CDMA carriers. However, it is complex and expensive, and does not obviously generate any new revenues. As such, the business case is highly questionable – and with the additional network complexity, testing, etc., may actually increase risks significantly.”

How important – or not – will VoLTE be in enabling telcos to better compete with OTT players?

“There is zero new revenue from VoLTE specifically. It may help stem future

losses a bit, if it works well enough. In theory, the IMS platform which VoLTE demands may support other new services (either to end users or developers), but that is largely theoretical at this point.”

So will VoLTE allow telcos to differentiate their voice services on any front?

“No. It's just telephony again, in a shiny suit. It doesn't reinvent the

120-year old idea of telephony. Shorter call setup times are nice, though. Conceivably it might make it easier for third parties to innovate around voice-integrated applications, but that can be done with OTT VoIP as well anyway. In busy/congested networks it will probably work better than OTT VoIP. But really, is that important enough for many people? I doubt it. Notably, VoLTE is not expected to be good enough to support 911/999 calls for some considerable time. It is also not flexible enough for more advanced public-safety voice/video applications that go beyond telephony.”

What are your thoughts about the VoLTE rollouts? Are they widespread or

piecemeal in terms of markets? In terms of devices supported?

“Very limited to date. The only mass market rollouts are in South Korea. Other

launches in the U.S., Germany., etc., are often limited to certain geographic

regions and a handful of devices.”

How does VoLTE relate to WebRTC?

“Potentially, it is possible to extend VoLTE services to non-VoLTE

devices/networks via WebRTC to browsers, or potentially to OTT-style mobile

apps. Nothing has been commercialized yet, and this brings in various extra

complexities. Most operators will probably want to get their main VoLTE

rollouts sorted before looking at WebRTC as an enhancement.”

We've been hearing about VoLTE for several years, now it's finally seeing

commercial rollouts. What took so long?

“It’s huge technical complexity, the need for excellent LTE radio coverage and enough backhaul (including indoors), devices, [the fact that it has] no business model, the

length [of] test cycles needed (needs to be at least as good as old GSM), interoperability issues at various levels, and [the fact that] circuit-switched fallback [has been] good enough.”

Edited by Stefania Viscusi

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