Optus has today announced its planned launch of its 4G time-division duplex long-term evolution (TD-LTE) network in Australia's capital in June, two months later than originally planned.
As part of its acquisition of Vividwireless last year, Optus picked up 98MHz of spectrum in the 2.3GHz spectrum band. Optus will use this spectrum to deploy a time-division duplex LTE network to complement its frequency-division duplex network running in the 1800MHz spectrum band.
Optus has chosen Canberra to launch the service, because Optus lacks spectrum in the 1800MHz band in Australia's capital. In June, the company will offer a mobile broadband dongle and a wi-fi hotspot that can use the 2.3GHz network, as well as the 1800MHz network and the company's existing 3G network when people are outside of Canberra.
While FD-LTE has dedicated slots for uploads and downloads, TD-LTE uses the entire spectrum allocated to it for both downloads and uploads, separated by time. Because the network still needs to account for Vividwireless, a portion of the band has been left to Vividwireless, and the download speed on TD-LTE has been set at 70Mbps, but the company's managing director of networks Günther Ottendorfer said that the network has achieved speeds as high as 61Mbps.
The ratio of download speed to upload speed on the TD-LTE network has been estimated at 3:1.
While there are only two devices now, Ottendorfer said that Optus has been working closely with Japanese telco Softbank on TD-LTE devices, and he showed off three handsets designed by Huawei and Motorola that work on TD-LTE, albeit in a different spectrum band.
"Our friends at Softbank have rolled out several devices in TD-LTE," he said. "These are TD-LTE smartphones that are available on the market in Japan already."
Optus will start with 12 base stations in Canberra, and then will expand over the next few months, Optus' vice president of mobile engineering Andrew Smith said.
"[It is] another 20 [base stations] in the next few months, and then it expands from there. The rollout expands in the third and fourth quarter," he said.
The company will then roll out the TD-LTE network with its 1800MHz LTE network and the upgrades in preparation of the 700MHz network that will be made available in 2015.
Optus will continue to expand its 3G network, at the same time, with the so-called 3G plus — DC-HSPA+ — upgrades to reach another 1,000 sites over the next 24 months to reach 95 percent of the population, including into Wollongong, Adelaide, the Central Coast, and Canberra.
Smith highlighted the recent launch of French electronic duo Daft Punk's album Random Access Memories in Wee Waa over the weekend as one event where the telco had to improve mobile coverage in an unexpected place.
"There are more and more festivals we need to provide 4G and 3G coverage," he said.
Ottendorfer said Optus' 3G network now reaches 98 percent of the population, and that Optus is now the first multiband 4G network operator in Australia. Smith boasted that in metropolitan Australia, Optus now holds more spectrum — 245MHz worth — than any other telco.
Rolling out 4G in four spectrum bands — 700MHz, 1800MHz, 2.3GHz, and 2.5GHz — would offer the company significant capacity on its network, Smith said.
"We have an unrivalled capacity stack," he said. "We consider this like a layer cake in the network. Coverage is great, but coverage without capacity doesn't help anyone."
Optus could not say which companies would be brought on to roll out the new 4G networks, but said that an announcement would be coming in the very near future.
Despite picking up significantly less spectrum at the digital dividend auction than rival Telstra, Smith said that Optus is pleased with the amount of spectrum it has.
"We're very happy with what we got at the auction."
He said that the push is to now get devices that work in the 700MHz Asia-Pacific spectrum band.
"Now having firmly acquired the spectrum [and] we are actually installing antennas that are 700[MHz] capable, once that spectrum is available to work, we will be very quickly into the market."