Optus has 4G coverage in Sydney, Melbourne, Newcastle, Perth, Brisbane and the Gold Coast. 

On 10 January, Optus said it had more than 100 4G sites live across Brisbane and the Gold Coast. 

The carrier has said it will add Adelaide in the first half of 2013. It turned on the first four sites there on 20 December. Optus expects to reach Canberra in March or April next year, however the network will use TD-LTE technology, which is currently compatible with fewer 4G devices.

The Optus 4G network currently runs on FD-LTE technology and operates in the 1800MHz spectrum band. However, Optus plans to roll out a Time-Division (TD) LTE 4G network in 2013 that it says is faster with higher throughput. "We are currently undertaking trials of the TD LTE network in Sydney, and our current 4G network will be integrated into our TD LTE rollout from 2013," the Optus spokesperson said.

Optus reportedly plans to spend $2 billion over two years on 4G services in an effort to take on Telstra. Optus just completed a $230 million acquisition of the Vividwireless Group from Seven Group Holdings. The deal gives Optus access to 98MHz of spectrum in the 2.3GHz band for its TD LTE network.

Optus spent $649 million at April\'s Digital Dividend auction, half of what Telstra paid. It took 2x10MHz of the 700MHz spectrum and 2x20MHz of the 2.5GHz spectrum.

Meanwhile, several other companies have rolled out 4G plans riding on the Optus network, including Virgin Mobile, Exetel and iiNet.

Amaysim and Boost Mobile have said 4G services are on the way, however Amaysim CEO Rolf Hansen has said he\'s not sure 4G is a commercial "slam dunk". It\'s not clear what Boost Mobile\'s recent move to Telstra means for its 4G plans.