The 4G upgrades show that China will step up an existing technological advantage in the dispute to help tiny populations of citizens who live there, possibly as incentives to stay at their isolated posts, analysts say.

“I imagine that those living there would want such services and also that the government would want to ensure that individuals living in such a strategically significant location were well provided for,” said Jonathan Spangler, director of the South China Sea Think Tank in Taipei.

A stable resident population would in turn advance China’s hold over the sea in a range of fields, analysts believe.

The stronger network might eventually help Chinese-run schools, hospitals, and other facilities “where internet connectivity is standard in many countries,” Spangler said. Also possibly on the list: tourism cruise ships and oil exploration vessels.