SK Telecom (SKT), the largest mobile operator in South Korea, and Samsung completed what they said was the first 5G call using the 5G non-standalone new radio (NR) standard and commercial 5G equipment.

The 5G non-standalone call, made during a trial at the operator’s 5G testbed, used 100MHz of spectrum in the 3.5GHz band and commercial 5G equipment jointly developed by the two companies, SKT said in a statement.

3GPP’s Release 15 non-standalone and standalone standards were unveiled in December 2017 and June 2018 respectively.

In September Qualcomm and Ericsson completed a 3GPP Release 15-compliant 5G NR call on a “smartphone form factor mobile test device”, using mmWave spectrum in a non-standalone mode.

SKT last month selected Samsung, Ericsson and Nokia as its 5G network equipment suppliers, leaving China-based Huawei off the list.

The country’s three major mobile operators are working towards a joint commercial 5G launch in March 2019. Korea’s Ministry of Science and ICT has put pressure on the companies to collaborate on 5G technology to “avoid excessive competition” and ensure the country is the first to launch the next-generation technology.