South Korea-based operator KT identified lessons learned from its deployment of pre-standard 5G at the Pyeongchang Winter Olympics in February, as the operator prepares to use 3.5GHz spectrum as the dominant band for a commercial launch in 2019.

Speaking at the Brooklyn 5G Summit in New York today (26 April), KT’s 5G taskforce leader Lee Jong-sik noted the operator anticipates it will need around four times as many cell sites for outdoor 5G coverage compared with LTE.

During the Olympic trial, KT observed poor outdoor to indoor coverage penetration, particularly at 28GHz, he said, adding the operator will need to invest more in solutions including 5G repeaters and small cells to mitigate the problem.

Lee also revealed the operator will use Ethernet-based fronthaul for its 5G deployment.

The 5G taskforce leader said KT will use 28GHz to provide ultra-fast hotspot coverage in select areas and along highways, but noted 3.5GHz will be the primary band used to provide nationwide coverage.

South Korea’s 5G spectrum auction, which will divvy up the country’s 3.5GHz and 28GHz airwaves, is expected to kick off in June. Lee said KT is tentatively planning to use 100MHz of bandwidth at 3.5GHz and somewhere between several hundred MHz to 1GHz of bandwidth at 28GHz for its deployment.

The company is initially planning to launch 5G in a non-standalone format. However, Lee noted the operator plans to evolve to a standalone model in the future.

Lee also acknowledged a number of unknowns remain for KT. He said sorting out what the next killer application or device will be presents a “big headache” for the operator, adding KT is also still searching for a definitive answer to the question of how best to monetise its 5G service: a concern first raised at Mobile World Congress earlier this year.

The first step, Lee suggested, could be to offer a 5G smartphone with an extra large data plan. From there, he said the operator could move on to new applications including virtual reality and immersive media, vehicular networks, and other enterprise and industrial services.