The mobile core network is a prime target for virtualization. In a Heavy Reading operator survey completed earlier this year 29% and 23% of respondents said they expected to start virtualizing IMS and EPC respectively by 2016.

Clearly, operators see an opportunity to optimize their networks and prepare for the next wave of growth and service through NFV and cloud technologies.

But why is this? And are the professed timelines realistic? Part of the enthusiasm is because virtual EPC and virtual IMS are serious enough applications to demonstrate that NFV can have a meaningful impact. This makes virtual mobile core a great NFV showcase and favorite of the trade show floor. But there are also more substantive reasons for operator interest. After detailed discussions with a large number of mobile operators, we have identified the following drivers:

So, when might operators put their NFV strategies into action in the mobile core?

It will take time -- many years -- for the entire industry to move to NFV at scale. However, we are already aware of operators preparing for commercial launch of virtual packet gateways for machine-to-machine (M2M) services and a good number using what could be termed "pre-NFV" virtualized Telephony Application Servers for upcoming VoLTE deployments. Some very progressive operators are also targeting 2016 for the introduction of virtual EPC into the main production network.

Mainstream, large-scale deployment of virtual mobile core is still some way off -- it will be perhaps three to four years before it's the default option -- because it involves a very challenging set of applications that are inherently risky to experiment with. Therefore, even for operators considering a core refresh in three years' time, now is the time start planning and trialing NFV-based products and architectures.

— Gabriel Brown, Senior Analyst, Heavy Reading