Optus upgrade to double 4G speeds

Optus is doubling mobile download speeds - but customers will have to wait for compatible devices.

In an Australian first, the telco on Monday launched a technology that boosts speeds by bonding multiple radio frequencies.

So-called LTE-Advanced Carrier Aggregation effectively adds a lane to the network highway, allowing eligible phones to hit theoretical peak download speeds of 220 megabits-per-second (Mbps).

Current 4G services can reach about 150Mbps in perfect conditions, while the fixed-line National Broadband Network will deliver 25-100Mbps.

Yet no phone presently on the Australian market - including the newly-launched iPhone 6 - is compatible with the carrier aggregation technology.

Optus says it's switching on the upgrade in anticipation of at least four compatible devices that are set for release in the coming months.

"We are future proofing our network," said Optus's network chief Vic McClelland.

Optus hit speeds of 160Mbps in testing, and says customers who buy compatible devices will get speeds up to two times faster than present.

The technology has launched in Sydney, Melbourne, Adelaide and Brisbane, with Canberra coming within weeks.

Optus's main rival Telstra recently announced plans to double the peak speed of its 4G services to 300Mbps using carrier aggregation.