AUSTRALIANS won't be able to get speeds of 100 megabits per second under the National Broadband Network's fixed wireless product.

NBN chief executive Bill Morrow made the revelation to a Senate hearing on Thursday, despite a committee being told earlier this year 50 per cent of premises could have access to such speeds by the end of the rollout.

"We killed it," he told senators in Canberra.

Mr Morrow said the cost of adding more bandwidth to a fixed wireless network is exponential.

Outgoing National Broadband Network  CEO Bill Morrow at the  Senate Estimates hearing.
Outgoing National Broadband Network CEO Bill Morrow at the Senate Estimates hearing.

"If you stay at a certain level it's not a problem but the cost of that incremental capacity starts to double, even quadruple."

"The ideal of offering a 100 mbps services means driving even more capacity into the network and the economics of that break apart to a point where it doesn't make any sense," he added.

NBN Co has so far spent $2 billion on the fixed wireless portion of the network, which will deliver no economic return.

According to NBN Co, over 600,000 homes will be covered by fixed-wireless technology.

NBN works in Sydney’s Mona Vale.
NBN works in Sydney’s Mona Vale.

Half-yearly figures released by the Telecommunications Industry Ombudsman last month show more than a quarter of the 84,914 complaints by residential and business customers were about services delivered over the NBN.

In total, a staggering 22,827 official complaints about NBN-related connections were made in the six months prior to December 31 - twice the number from the same period the year earlier.

Majority of complaints were related to service quality, with customers unsatisfied by provider responses, while other issues were around connection delays.