Japan's NTT may be one of the biggest telecoms operators in the world, but the company still considers itself something of an upstart on the global stage.

"We're still a challenger and there's still a lot to do," said Robert Steggles, senior marketing director, Europe, at NTT, speaking at day two of the Total Telecom Festival on Wednesday.

His comment came just hours after NTT was named Best Global Operator at the culmination of the 2014 World Communication Awards in London on Tuesday night.

NTT has expanded through network investment and significant M&A activity in recent years. In many ways, the telco is now a "bunch of disparate companies" working towards the same goals, Steggles said.

"Our next big challenge is to bring them all together."

NTT Communications picked up the most coveted WCA trophy this year because, according to an independent panel of judges, it is "the most assertive of the global telco challengers with a huge and ambitious investment programme, reflected in the IT acquisitions as well as the global cloud network management build."

And the move to the cloud is not as easy as much of the hype suggests, Steggles said. If it were, "everyone would have done it by now," he noted.

"For us, the next big thing on the horizon is…software-defined networking and network functions virtualisation," he added.

The way networks are bought and sold will change, he said. "What that allows people to do is a bit of an unknown."