Reality Check: A long horizon in store for VoLTE

Editor’s Note: Welcome to our weekly Reality Check column where C-level executives and advisory firms from across the mobile industry share unique insights and experiences.
The industry is abuzz with the promise that voice over LTE can bring. Carriers are seeing it as an effective means to gain spectrum efficiency and reduce the cost of service delivery. While all the business rationale is there to proceed, full-scale adoption of VoLTE faces a number of significant hurdles.
Why is VoLTE becoming so important? On a basic level, it’s another component that will allow carriers to build a broader base of services on a common platform. While the theory holds merit, the execution of VoLTE is a long way off. There is a veritable laundry list of logistics that must be sorted out before it can reach critical mass, ranging from specifications and standards to the availability of handsets to support it.
The advent of LTE for data services is already raising the bar in terms of expectations for data speeds. Yet voice is still in the 2G and 3G realm. Add to that the fact revenues for voice services are diminishing, making it difficult for carriers to affordably offer the features and functions their customers are demanding. It comes as no surprise therefore that VoLTE is being seen as a potential game changer in delivering voice services.
By way of explanation, here’s how things look today. To create a complete mobile experience, carriers need to combine voice and data channels. This can be done in a number of ways. Using a 3G network for example, the combination is to use UMTS for voice and HSPA or high-speed data access for data.
Because voice is managed as a completely separate network layer, carriers simply can’t deliver tightly integrated services as efficiently. At the same time, voice and video calls are demanding an increasing amount of bandwidth as more people are seeking greater engagement with their mobile devices.
As a pure data play, LTE does not have a voice component. Therefore carriers are having to layer LTE onto their UMTS channel. So even though LTE in and of itself is extremely efficient when it comes to spectrum usage, having to combine it with inefficient services such as UMTS for voice negates that advantage and increases service delivery costs in the process.
Spectrum efficiency is one of the biggest selling points for VoLTE. Because it enables voice to be transmitted over data packets, it promises to deliver the same capabilities for mobile that voice over Internet Protocol has done for the Internet. Adding voice capability to LTE would increase efficiency exponentially while freeing up precious spectrum as it would eliminate the need for a dedicated voice network.
However, the hurdles in reaching the finish line are substantial and will involve a complex network of multiple players. One issue is infrastructure and the natural latency associated with rolling out new capabilities nationwide and internationally. This is not a trivial exercise by any means. In fact, deferrals in the LTE rollout have put carriers close to two years behind initial completion dates.
Another sticking point is the hardware itself. Delivering voice in data packets requires different codec chips in handsets in order to work, which translates into a significant and costly change requirement. In other words, if both endpoints of a call do not have an upgraded chip set and codec, all the benefits of VoLTE would be lost.
A key issue for carriers and manufacturers therefore will be implementing a handset evolution strategy that will encourage a subscriber base to move to VoLTE-enabled handsets. That will entail a plethora of marketing and logistics headaches.
Next to latency and interoperability, perhaps the biggest challenge facing carriers will be continuity of calls. What happens when a person using a VoLTE-compatible phone moves outside of an LTE supported area? How do you ensure that calls are not lost? The key will be in enabling the ability to sustain calls when leaving LTE zones.
This issue is something that may be resolved with the development of the enhanced single radio voice call continuity specification within the LTE standards. But as we all know, when it comes to specifications and standards, 10 stakeholders can read the same specification and come up with 10 different interpretations. It takes time and effort to get everyone going in the same direction.
These challenges may be significant, but they’re not enough to stem the tide of carrier interest in VoLTE. Ultimately the ability to un-clutter and integrate spectrum currently used for dedicated voice networks will open up tremendous opportunities. Carriers can then take advantage of the unused voice allocation to increase overall capacity and expand services. At the end of the day, that’s a very big deal.
VoLTE for its part however may not be such a big deal in the minds of the consumer base, who may not care or even notice if VoLTE gives better voice quality. It will take time and persuasion to get that audience to understand the experience and the benefits as the migration takes place. One message they will understand clearly is they will get better data rates and service for less money.
So where do things stand today? First, we can comfortably assume that we are looking at a multi-year rollout of LTE in core urban regions. Ultimately everything – including outlying areas – will move to LTE, but it will take some time. Only then will VoLTE follow in any significant way.
VoLTE may only be a dot on the horizon, but when the time comes that every single network is LTE, everyone will be ready to get on board with the voice part of the equation.
There’s a reason why it’s called Long Term Evolution.
Werner Sievers is CEO of Nextivity, a San Diego-based developer of the Cel-Fi Smart Signal Booster (www.cel-fi.com). Sievers is a veteran of the wireless industry and experienced leader of technology-centric, venture-backed startups.