Technicians ride wave of modern communications

Vast distances, loneliness, wind and tide, are no obstacles to technicians answering the call, so that others can, well, answer their calls. China's largest cellular network provider is boosting and ensuring fourth generation signal access in the South China Sea.

Their work has connected many isolated remote islands to the outside world. Even Vietnamese fisher-men, who sometimes illegally fish nearby, have bought the China Mobile SIM cards for signals, local islanders said.

But the scale of the operation, including shipping, installing, maintaining and upgrading transceivers and cellular radio towers, is huge, especially as it takes 10 to 15 hours to cover more than 300 km from Hainan Island to Yongxing Island.