5G Trial Services Demonstration: IFoF-Based Distributed Antenna System in 28 GHz Millimeter-Wave Supporting Gigabit Mobile Services

In this paper, we demonstrate fifth-generation (5G) trial services using intermediate frequency-over-fiber (IFoF) based distributed antenna system (DAS) implemented in a 28-GHz millimeter-wave (mmWave) during Pyeongchang winter olympics. To extend mmWave-based 5G wireless coverage, IFoF-based DAS with 2 × 2 multiple-input multiple-output configuration is presented. Error vector magnitude (EVM) measurements of the 5G signal on the IF and mmWave bands are performed for both downlink and uplink transmissions over 5-km single mode fiber. The experimental results confirm that the minimum requirement for 5G signals, defined by the technical specification of the 3G partnership project, are satisfied by EVMs less than 9%. In addition, the developed IFoF-based DAS that supports 5G mobile service using 28-GHz mmWave was deployed in the city of Pyeongchang, during winter olympics. An ultra-high speed 5G data service was offered to the general public for 5G trial demonstration. The reference signals received power and data throughput of the 5G handset are measured while moving in a DAS section and 5G connected car section. We confirm that the downlink throughput of ∼1 Gb/s and uplink throughput of ∼200 Mb/s are achieved for the 5G trial service area in which an IFoF-based DAS is deployed. We also successfully demonstrate the 5G connected car service, which is one of the 5G key services, through deployed IFoF-based DAS. At the intersection of baseband unit and DAS deployed sections, a seamless handover is performed to smoothly support 5G-based autonomous driving service.