China Mobile, the world’s largest mobile operator with 850 million subscribers, outlined its 5G deployment schedule at a meeting of the IMT-2020 5G Promotion Group, with an initial focus on the sub-6GHz band.

The operator next year will select four to five cities where it will set up facilities for system verification and development of pre-commercial prototypes, according to C114.net. It will turn its focus to high-frequency bands (above 6GHz) after about 18 months.

China Mobile aims to build about 20 sites in each of several cities in 2018 for large-scale tests and develop end-to-end commercial products and a pre-commercial network, C114.net reported. The next year it will expand the scale of the 5G trial network and in 2020 targets deploying 10,000 5G base stations, which will allow it to launch commercial 5G service.

The country’s IMT-2020 (5G) Promotion Group last week announced technical specifications for the second phase of 5G tests. According to the Ministry of Industry and Information Technology (MIIT), China will accomplish 5G technology R&D tests in 2016-2018 and carry out product R&D tests in 2018-2020.

The general industry consensus is to bring 5G to the market in 2020, with Phase 1 standardisation of 5G set for completion sometime in 2018.

But operators in South Korea aim to bring the next-generation of mobile networks to the market in time for the 2018 Winter Olympics in Pyeongchang. And a month ago Mobile World Live reported that South Korea’s second largest operator KT plans to be the first to commercialise 5G in 2019, a year earlier than its previously stated target, and believes the standards used for the 2018 Winter Olympics will become the de facto 5G standards.