Over the past few weeks we interviewed the Chief Technology Officers of several high profile operators to find out what keeps them awake at night. With many carriers juggling several generations of network technologies, as well as a hefty portfolio of spectrum frequencies, there are plenty of challenges to consider, but some of the common ones our executives discuss are: the OTT threat; network optimisation; spectrum fragmentation; network capacity; data revenues; offload; outsourcing; and regulation.

Hugh Bradlow, CTO of Australian operator Telstra

Andrei Ushatskiy, Vice President and Chief Technology Officer for MTS

Yves Bellego, Director of Technology Strategy for Orange Group

Ed Candy, Group CTO, 3

CTO of Orange Spain, Eduardo Duato

Mock Pak Lum, chief technology officer, StarHub

Stephen Bye, CTO and VP technology development, Sprint Nextel