Telstra claims the move makes the Next G network the fastest and geographically biggest national wireless network in the world.

The announcement coincided with the release of new figures showing that the Next G network has already signed up more than 4000,000 customers in its first four months.

Telstra CEO, Sol Trujillo, said Next G had already created a paradigm shift in the way Telstra's customers work, live and play.

"The network has been super-charged as Telstra triples capacity and delivers peak network download speeds up to four times faster than originally available - the first national rollout of its kind globally," Trujillo said.

He said the switch on of the world's first 200 kilometer cell range in a commercial mobile broadband network increased Next G coverage to reach 98.8 per cent of Australians creating a network more than 100 times larger than Telstra's competitor 3G networks.