LTE may be the future, but don't forget legacy services

LTE is being hyped as the next technological revolution, but we have yet to see concrete evidence of new services and revenues to support the business case. In an LTE world it is still voice with web access that provides the greatest revenues.

However, no technology has been defined as the clear winner to offer voice services. In addition, SMS will play a key role, not as a commercial messaging service but as an enabler for provisioning data services and roaming, and therefore should also not be forgotten.

Don’t forget about voice – it will remain your largest revenue generator in five years’ time

Ovum forecasts that global mobile revenues will reach $1.11 billion in 2014, of which 69% will come from voice. Even in developed markets such as Western Europe, voice will still account for 65% of revenues in 2014. Given the importance of voice, it is surprising that no clear technology path has been defined to date. We believe that voice will be important in an LTE world, as a data-only service will fast become a commodity. In addition, we believe that the business case is weakened if it is not supported on a single network.

Voice services need to be at least as good as they are today. A satisfactory voice solution must include:

• call quality and performance at least as good as existing 2G/3G voice
• interoperability across operators and technologies, including fixed and mobile - not forgetting legacy mobile technologies
• support for roaming
• quick call setup.

To date, mobile operators have four routes: IP multimedia subsystem (IMS); circuit-switched fallback (CSFB); voice over LTE via generic access (VoLGA); and Nokia Siemens Networks’ Fast Track Voice over LTE – essentially an MSC upgrade to support access-agnostic VoIP.

Even operators that choose to launch data-only services over LTE need to think about how they will deliver SMS. This is because SMS is widely used as a way to provision datacards and communicate between the device and the network. In addition, the EU has mandated that operators should interact with users while roaming via SMS – to prevent bill shock, for example.

The technological route that operators take will be influenced by the following factors:

Timescale. Operators that want to launch LTE with voice services in the next two to three years will have to choose between CSFB, VoLGA and NSN’s Fast Track VoLTE.