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29 Jun 2016
Given everyone in the telecoms industry is now fully aware
of the potential financial, operational and customer benefits
of VoLTE, the continual delays in deployment have come as a
surprise. By the end of 2015, there had been 40 commercial
deployments of VoLTE across the globe, many of which remain as
limited location trials. With so many operators still
maintaining that they are planning to launch a VoLTE service,
why are we still not seeing the progress we’d
expected by this point?
It’s the little things
According to existing tests, the majority of VoLTE calls
have excellent audio quality, however if something else goes
wrong, it has a detrimental impact across the board. Even the
most minimal temporary packet loss in a VoLTE call can cause an
intolerable experience for the user.
And call audio quality isn’t the only issue -
research has shown that VoLTE call set up times are not as fast
as expected. Moreover, switching the device between 2G, 3G and
LTE networks can also lead to an unacceptable window of time in
which a device cannot be reached. And since LTE is not
yet ubiquitous in most regions, this is bound to happen quite
The technical challenges of a sporadic LTE
Operators currently investing in, and providing VoLTE
services each have different capabilities and varying levels of
LTE network infrastructure on which to provide a VoLTE service.
Many of them have had to make modifications to their
infrastructure in order to pass the certification process.
Once this is achieved, operators will inevitably still need
to connect to multiple older networks, enterprise networks and
other service providers. This complexity makes interoperability
another huge challenge, implying a need for intermediary
Introducing mediating signalling has the potential to
resolve the concerns on voice quality and quality of experience
(QoE) through advanced audio processing. To manage this
complexity, many operators are putting in place OSS management
tools that can provide a complete VoLTE network end-to-end view
(across all solution components), monitoring the service
performance with an end goal of improving the QoE over
Certainly, sporadic or geographically patchy LTE coverage
(concentrated on specific urban markets with a fall-back
solution) is one reason why we haven’t seen a
quicker drive to VoLTE. As more digital spectrum becomes
available, the coverage issue will eventually be resolved.
However, while limited LTE network rollout may be one
explanation for the delay, it cannot explain it entirely.
Is there any money left in voice?
Another major issue is defending the case for more
investment in voice technology in the current landscape.
Overall voice revenues are on the decline due to the popularity
of services such as Skype, and the effects of competition and
regulatory intervention on termination rates (e.g. roaming in
Carriers will have a difficult time actually charging for
VoLTE services, and introducing expensive video calling plans
is not a viable option when subscribers have been used to
getting this for free with OTT players.
Another major financial challenge operators face is the
deployment of IP Multimedia Subsystems (IMS) required to
support VoLTE. The adoption of IMS has been somewhat slow and
disappointing, and while there are many IMS deployments today,
it didn’t quite deliver on its initial
expectations (allowing OTTs to gain influence). Network
operators have had to wait for the technology to become stable,
and the standard fully ratified, diminishing the prospects of
launching advanced new services.
Despite all these challenges, VoLTE is still making
progress, albeit quite slowly. 2015 saw VoLTE deployment go
from 16 to 40, proving that VoLTE is still a technology jump
that remains on the cards. As the many pieces of the VoLTE
jigsaw come together, the delay in deployments should see a
U-turn going into 2016 and beyond.