Optus and its 4G network vendor Huawei have tested out combining four 20MHz spectrum bands in the 2.3GHz spectrum band using time-division duplex long-term evolution (TD-LTE) to achieve 520Mbps download speeds on Optus' 4G network.
Optus' managing director of networks Vic McClelland said the test of 4G carrier aggregation on the live TD-LTE network was the first in the world conducted on a fully operational commercial network.
FD-LTE, which most networks operate on in Australia in the 1800MHz band, has dedicated slots for uploads and downloads, while TD-LTE uses the entire spectrum allocated to it for both downloads and uploads, separated by time.
Optus has been using its TD-LTE network in Canberra to deliver 4G services in Australia's capital, but has recently been testing out using the TD-LTE network in combination with the FD-LTE network in other parts of Australia to increase capacity in high-density areas such as CBDs.
The company announced today that in the LTE-Advanced trial conducted in St Marys, Optus was able to achieve download speeds of 520Mbps by combining four 20MHz spectrum bands in the 2.3GHz band. In a Melbourne test combining two channels, Optus achieved peak download speeds of 160Mbps to a single user.
"In Melbourne, we've paired two channels in the same frequency band, on our 4G Plus network, which we expect to provide the consistent speed experience that customers want and expect from 4G networks of the future," McClelland said in a statement.
At the same time, Optus' biggest rival Telstra has been testing out LTE-Advanced, where the company has been able to achieve peak download speeds of 300Mbps using spectrum in the 1800MHz and 900MHz spectrum bands.
McClelland said that the company expects LTE-A compatible devices to likely enter the market in early 2014.
"This is about ensuring that Optus continues to build a mobile network that keeps pace with the ongoing evolution of 4G devices," McClelland said.
Optus' network partner Huawei said it expects to launch compatible devices in 2014, and the company already has approximately 80 TD-LTE compatible devices today.