South Korea ranks near the top among major countries in the share of 5G investment, but lags the United States and China in shifting to 5G standalone (SA) mode, data showed. The government and the country’s three mobile carriers are in the final stages of building and verification with a goal of nationwide SA service in December, putting the full implementation of 5G to the test.

According to the European Commission’s “Digital Decade 2026-5G Observatory Report,” the share of 5G investment in South Korea’s total mobile network investment was tallied at 67 percent in 2025. It was the second highest among major countries in the comparison, behind China at 72 percent. The United States stood at 62 percent, Japan at 58 percent and the average for the EU’s 27 member states was 50.6 percent.

But South Korea ranked somewhat lower in how fully it has converted network architecture to 5G. The share of 5G SA base stations among all mobile base stations was 26.2 percent in South Korea, below the United States at 36.2 percent and China at 34.8 percent. Japan was also at 26.3 percent, 0.1 percentage point higher than South Korea. The EU average was 20.9 percent. That suggests that while the share of investment going into 5G is high, the shift to SA, which fully enables key 5G functions, has been relatively slower.

5G investment share ranks second at 67 percent; SA shift is relatively slower

A significant part of South Korea’s 5G currently uses the non-standalone (NSA) approach. Under NSA, 5G is used on the wireless link between smartphones and base stations, but the core network, which serves as the network’s brain, also uses the existing LTE network. It was an efficient method in the early days of 5G commercialisation to rapidly build nationwide networks. That was because carriers could use the LTE core network and did not need to rebuild the entire network from scratch.

SA uses 5G not only for the radio access network but also for the core network. It reduces reliance on LTE and allows full use of 5G-specific functions such as network slicing, which divides a single physical network into multiple virtual networks depending on purpose.

In South Korea, KT first began commercial 5G SA service in July 2021. But the country’s overall mobile network did not quickly shift to an SA-centred structure. The Ministry of Science and ICT pointed out in December last year that domestic 5G remained centred on NSA as it confirmed its policy on reassignment of mobile spectrum frequencies, and it made the shift to SA mandatory. At the time, the ministry explained, “Domestic users are in a situation where they have no opportunity to properly use 5G’s various functions.”

The pace of the shift has quickened this year. The ministry, SK Telecom, KT and LG Uplus launched a public-private consultative body in August to promote investment in communications infrastructure in the AI era and plan to unveil nationwide SA service within the year. KT is expanding the scope of the SA commercial service it started earlier. SK Telecom and LG Uplus are conducting nationwide tests.

Standalone mode shift: user perception of latency and slicing, not speed, is key

Even if SA expands nationwide, smartphone download speeds will not all surge at once. That is because the speed users experience is also affected by radio network conditions such as spectrum used, base station density, user traffic and device performance.

That is increasing the emphasis on network slicing. Network slicing is a technology that separates a single physical communications network into purpose-specific virtual networks. For example, at a concert venue or festival where tens of thousands of people gather at once, it can logically separate the networks for general users and staff to guarantee the quality needed for specific services.

The ministry is also changing its quality evaluation method in line with nationwide SA. It plans a pilot measurement in December that adds SA connection and retention, latency and network slicing quality to the existing evaluation centred on download speed. It will ask manufacturers and operating system (OS) providers to expand devices that can use SA, and it will also revise its network neutrality guidelines.

South Korea touted the world’s first commercial 5G launch in 2019, but assessments of 5G since then repeatedly centred on controversy over speed, quality and insufficient investment. Whether nationwide SA service proceeds as planned in December and leads to services that users actually use, such as slicing and ultra-low latency, is expected to be a key test for the later stage of 5G.