South Korean operator SK Telecom has deployed 5G-PON (Passive Optical Network) for distribution networks, which can deliver both LTE and 5G communications services. SK Telecom will roll out 5G-PON service in 85 areas nationwide including Seoul, Busan, Daegu, Daejeon and Gwangju, and later expand the deployment.
Source: https://www.telecompaper.com/news/sk-telecom-deploys-5g-pon-for-ran-radio-access-network--1221196