Yes, VoLTE is about HD voice, but also a lot more…

In fact, in an emerging country like India, the revenue share of voice invariably rises to dominant proportions. For example, mobile voice revenues for Bharti Airtel’s South Asia operations stood at 85.2 percent in the quarter ended June 30, 2013. This is way higher than some of the carriers in the US who would have voice’s revenue contribution in the range of 55 percent.

It is unlikely for the contribution of voice revenues to adjust anywhere near 50 percent mark, even if India experiences rapid data growth over the next five years or so. Yes, things would change more swiftly in favor of data as the internet of things (EoI) growth crosses a threshold, but that is not expected to happen in India in the next five-year period.

No wonder then, one of the greatest challenges facing the LTE operators in India is to offer voice to their subscribers. And in the absence of an in-built support for voice over LTE, operators have been exploring options like Circuit-Switched Fall Back (CSFB) to provision voice.

But then, CSFB is at best a patchwork approach to offering voice on an LTE network. It’s like going to a fine dining restaurant where the food is being served by a nearby dhaba, just because the restaurant doesn’t have a kitchen in place yet.

In other words, while CSFB does manage to deliver voice on an LTE network, it falls much short of what a VoLTE experience really should be.

Before we come to the benefits of VoLTE, let’s also look at yet another technology that delivers voice on an LTE network—Single Radio Voice Call Continuity (SRVCC). While even this is not anywhere close to VoLTE in terms of the overall benefits, it still offers significant improvements over CSFB—the chief one being ‘call continuity,’ as the name suggests.

To make the point more clear for the uninitiated, CSFB is inherently prone to drops in connection, which needs to be switched to a 3G or 2G network as a call comes in and switched back to the LTE network when the call session ends. Since LTE is an IP network while both 3G and 2G can be circuit-switched networks, even the data speed and hence quality would be significantly compromised during the switchovers.

SRVCC does manage to overcome the problem of connection drops by keeping the control for a voice-call session within the LTE’s IP plane, so it surely scores over CSFB in terms of overall user experience on an LTE network. However, as we will see, VoLTE is even more superior and offers a vastly improved user experience that telcos would certainly want to deliver, lest they were to lose a battle with the over-the-top (OTT) voice providers that are already a maturing threat:

1. HD Voice: I personally see this as a prime killer application of VoLTE, for the simple reason that voice continues to the dominant communication medium for users in India despite a quality that is often a pain to bear, so users would very likely lap up high-definition voice that makes communication a pleasurable experience. I personally also have a hypothesis that a reasonably significant cross-section of users would even be willing to pay a notional premium for HD voice. The improved quality of experience is also likely to increase the voice ARPU for telcos, which would be a once-in-a-generation kind of phenomenon.