South Korea’s 5G users increased by millions this year, but 5G network base stations are still being rolled out slowly, a local agency said Monday.

According to data compiled by the Korea Communications Agency, the number of 5G users increased by 1.99 million during the second quarter this year to reach 17 million, up 13.7 percent on-year.

As of June, 5G users accounted for 23.8 percent of the total mobile network users here. The number of 4G and 3G network users reached 50.5 million and 20.2 million, respectively.

However, the number of 5G network base stations in the country in the second quarter only went up by 9 percent on-year to reach 162,099, from 148,677 in the first quarter.

The 5G stations accounted for 11 percent of a total of 1.47 million mobile network stations in the country. There are currently 1 million and 300,000 base stations for 4G and 3G network services, respectively.

Amid the slow infrastructure rollout, user complaints of the quality of the 5G services increased, according to industry sources.

Earlier in July, a group of 5G subscribers filed a class action lawsuit against a local telecommunications firm over alleged poor service quality.

Industry officials say it is unfair to simply compare the number of stations in operation for the ultrafast wireless connection with those for 4G or 3G, as a 5G station contains more equipment.

Meanwhile, the Ministry of Science and ICT on Monday announced that it would shorten and simplify the review process for companies that apply for the 28-gigahertz and sub-6-gigahertz spectrum that the ministry promised to allocate in hopes it will lead to development of more 5G-based applications in a wide range of sectors.

The ministry said it will reduce the review process from three months to one month and cut the amount of required documents by half so companies can receive pieces of the 5G spectrum by the end of November.