July 05, 2013, 10:49 AM — The technology to implement Voice-over-LTE (VoLTE) is maturing, but mobile operators won't roll out telephony services in earnest until 2015. At the same time apps like Skype and Fring are growing quickly in popularity, according to Infonetics Research.
The main issues holding VoLTE back are business oriented, although there are also technical concerns such as integration with existing operations and business support systems, Infonetics said.
Alternative technologies are also allowing telephony over older networks to coexist with data over LTE.
"Operators are using another solution called circuit-switched fallback CSFB, and my understanding is that has worked better than operators had dared hope for. So what they are asking themselves is what VoLTE can do for them from a commercial perspective, and as it stands today that is not clear," said Mark Newman, chief research officer at another research firm, Informa Telecoms & Media.
CSFB allows smartphones to turn off their GSM or 3G radios to save battery while the 4G network is in use for Internet browsing, turning them on again to receive an incoming call when notification is received over the 4G network.
Adoption of VoLTE has been faster in some countries than in others. In South Korea, SK Telecom's VoLTE service had 3.6 million subscribers in April. Infonetics now expects 12 commercial VoLTE networks and 8 million subscribers by year-end, with about three-quarters of those in Asia Pacific, it said.
The market research firm isn't alone in thinking that the success of VoLTE in South Korea will help accelerate the implementation of the technology. Per Narvinger, head of equipment vendor Ericsson's LTE radio products division, said in a recent interview that the Koreans have showed it works well, and that has in turn increased interest globally. The Korean operators were helped by their national coverage, which meant they didn't have to rely on protocols such as Single Radio Voice Call Continuity (SRVCC) to hand over between the 4G network and older networks, according to Narvinger.
While VoLTE services find their feet, Internet-based voice services are becoming more popular. Such services, also known as over-the-top (OTT) services, include Skype, Fring, KakaoTalk, Line, Nimbuzz, WeChat and Viber. The number of mobile subscribers for these services shot up more than 550 percent last year to over 640 million, and is expected to approach the 1 billion mark this year, according to Infonetics. However, most are making very little money per user. In 2012, the average annual revenue per mobile user was a meager US$7.13, Infonetics said.
What operators are hoping for is that a combination of VoLTE, HD Voice and RCS (Rich Communications Suite) will turn out to be a more attractive proposition to consumers than just voice on its own, according to Informa's Newman.