China Unicom is set to trial TD-LTE technology in the second half of 2013, as the country moves towards 4G licensing, although the world’s fifth-largest operator went to great lengths to state that the more popular FDD version of LTE will be an important part of its future.

“The size of this trial network will not be very big. We will mainly focus on the provincial capital cities as well as the coastal cities. But we will be well prepared for the FDD-LTE network construction, and we believe that the government and the regulators have very clear requirements for us,” said Chang Xiebing, its chairman and CEO.

Speaking at its results conference yesterday, the executive said that this reflects the expected 4G licensing regime in China, which (as with the 3G licensing of TD-SCDMA technology for China Mobile) will favour “indigenous” technologies ahead of international candidates. This will mean TD-LTE permits are issued later this year before the more globally popular FDD-LTE.

“We are going to work very seriously on our [3G] WCDMA construction work and actively promote the evolution of WCDMA to FDD-LTE. This is our long term strategy, and there won’t be any wavering on this issue,” Chang said.

Unicom, which recently passed the 100 million 3G subscriber mark, has benefitted from its adoption of the global 3G standard WCDMA and associated infrastructure and device availability.

“At the same time, due to the trend of the mobile internet evolution to support indigenous innovation, and at the same time taking into account the synergy of spectrum resources, starting from the second half China Unicom is planning to deploy and construct a pilot in TD-LTE networks in certain regions and areas,” Chang continued.

While TD-LTE is certainly an important technology for China, it has also seen significant traction internationally. Key supporters include SoftBank in Japan and Bharti Airtel in India. China Mobile remains the industry’s biggest backer of TD-LTE; it has deployed numerous trials across the country and is expected to move from 3G TD-SCDMA technology to TD-LTE as soon as 4G licenses are awarded.

The Global TD-LTE Initiative (GTI), the operator group supporting the technology, has put interoperability with FDD-LTE at the heart of its efforts, to enable the seamless coexistence of both options.

Of note, this week the Global mobile Suppliers Association (GSA) said that of the world’s 200 live LTE networks, 182 deployments use the frequency division duplex (FDD) version of LTE, with two channels of paired spectrum separated with a guard band for uploads and downloads. Nine networks use the time division duplex (TDD) version of LTE, which uses scheduling to allow data to be sent and received on a single channel. The other nine networks use a combination of FDD and TDD technology.

Certainly, any commercial deployment of TD-LTE technology by China Unicom – the world’s fifth-largest operator in terms of connections – would be a major boost to the success of this flavour of LTE.

The Unicom head would not be drawn on its 4G capital expenditure plans. At least in part that comes down to the timetable for 4G licensing, where “there isn’t a clear timeline, yet.”

“There has been lots of news regarding the issue of 4G licences, and the central government is going to actually give us the decision shortly. So for China Unicom, we are going to work with the central government and make our due contributions,” the executive observed.

Unicom said that moving forward, its 3G capex will be “relatively stable”, while noting that this is being done as a foundation to its 4G upgrade.

“We think a reasonable investment in our 3G network is not only necessary for our 3G service offering, but also four our long-term 4G development in the future,” Chang said.