About 30 of the superpressure balloons are being launched from New Zealand from where they will drift around the world on a controlled path.

Attached equipment will offer 3G-like speeds to 50 testers in the country.

Access will be intermittent, but in time the firm hopes to build a big enough fleet to offer reliable links to people living in remote areas.

It says that balloons could one day be diverted to disaster-hit areas to aid rescue efforts in situations where ground communication equipment has been damaged.

But one expert warns that trying to simultaneously navigate thousands of the high-altitude balloons around the globe's wind patterns will prove a difficult task to get right.