Optus reached 4G download speeds of 480 Mbps in a test using carrier aggregation methods on four channels of spectrum.
Optus reached that speed on a single user device by aggregating four separate 4G channels, each of which were 20 MHz wide, and using a Category 8 4G user device at an indoor live network site at Optus’s headquarters in Macquarie Park, NSW.
Optus also tested the technology outdoors at a site in Newcastle and reached a peak speed of 478 Mbps, with typical speeds ranging from 250 to 450 Mbps at various places around the base station.
Carrier aggregation allows greater data download speeds by combining spectrum across multiple, separate spectrum bands.
For the test, Optus combined three 20 MHz time-division duplexing (TDD) channels on its 2.3 GHz spectrum and one 20 MHz paired frequency-division duplexing (FDD) channel on its 2.6 GHz spectrum.
“Carrier aggregation is typically achieved by combining FDD and FDD, or TDD and TDD channels; but we have successfully tested 4 carrier aggregation using 3 LTE TDD channels and 1 LTE FDD channel, achieving an incredible data speed of 480 Mbps in our live network,” said SingTel Group CTO Tay Soo Meng.
“With this new technology of combining 4 channels of LTE FDD and TDD together, we can make better use of our spectrum resources to deliver even higher data speeds to our customers in the future.”
Separately, Optus tested carrier aggregation with 4x4 Multiple input multiple output (MIMO) equipment, and achieved a peak download speed of 415 Mbps indoors at its headquarters. In the test, two TDD 2.3 GHz channels, 20 MHz each, were aggregated.
Outside in Newcastle, Optus reached a peak speed of 350 Mbps, with speeds averaging 320Mbps close to the base station.
Most 4G technology today uses 2x2 MIMO, but 4x4 MIMO almost doubles the peak speed and capacity of a single 4G channel.
Optus partnered with Huawei for all of the tests.
Earlier today, Telstra announced it had reached 450Mbps in its own carrier aggregation test by combining three 20 MHz channels and using a Category 9 4G device.
While the speeds achieved by the telcos are impressive, actual speeds are likely to be less when there are more people on the network at the same time. Actual speed also will depend on distance from the base station and other factors.