Tokyo: KT Corporation (hereinafter KT) and Fujitsu Limited (hereinafter Fujitsu) have completed a verification facility at the KT Research and Development Center in Seoul, South Korea, at which the two companies leveraged Fujitsu’s Open RAN based 5G base station equipment to successfully test call connection during interoperability trials for open fronthaul (1). NTT DOCOMO, INC. (hereinafter NTT DOCOMO) has provided Fujitsu with technical support throughout the project. With the construction of this new test facility, KT will accelerate the introduction of Open RAN technology to Korea’s 5G network.

As a result of their successful collaboration, the three companies have concluded a Memorandum of Understanding (effective date January 6, 2022), centering on the introduction of software-defined virtualized RAN (hereinafter vRAN) and RAN Intelligent Controller (RIC) (2) in alignment with the “5G Open RAN Ecosystem” (3), an initiative whose participants include NTT DOCOMO and Fujitsu. In this Memorandum of Understanding, the three companies agree to cooperate towards further activities including the construction of an O-RAN test facility and multi-vendor interoperability testing in Korea.

In addition to these activities, the three companies will continue to create market-leading innovations and target the global expansion of Open RAN.

The multi-vendor RAN architecture enables optimum solutions for a variety of deployment scenarios, including small, space-saving base stations that can cover areas in city centers where communication is concentrated, or base stations that can cover wide areas and can thus contribute to efficient and flexible equipment procurement and cost reductions. Open specifications also make it possible to create safe and transparent RAN architecture.

5G mobile networks are becoming increasingly popular in Korea, and the demand for 5G is expected to grow even further in the future. KT is considering the introduction of multi-vendor Open RAN to reduce equipment procurement and construction costs and to achieve flexible network construction capabilities. To this end, KT and Fujitsu constructed an Open RAN verification facility and conducted testing for multi-vendor interoperability with O-RAN open fronthaul in October 2021. For the testing facility, KT has adopted Fujitsu’s 5G base stations, which were the world’s first O-RAN compliant (4) base stations adopted for commercial service by NTT DOCOMO. The tests involved verification of the interoperability between the base station controllers (CU: Central Unit/DU: Distributed Unit) of Fujitsu's 5G base station equipment and a Korean medium-sized vendor’s radio unit, as well as end-to-end communication tests. The companies successfully verified O-RAN compliant operation during the tests.
Fujitsu supplied KT with 5G base station equipment and provided support during the verification tests, while Fujitsu in turn received NTT DOCOMO's technical support for multi-vendor interoperability testing.

Moving forward, KT aims to further expand its verification facilities with an eye toward the future introduction of Open RAN based vRAN and RIC systems.

The three companies plan to further strengthen their collaboration as part of the “5G Open RAN Ecosystem” initiative.

• [1]
  Open fronthaul:
  O-RAN standardized interface that connects CU/DU and RU.
• [2]
  RAN Intelligent Controller (RIC):
  RAN Controller able to optimize the management of radio resources and automize operations.
• [3]
  5G Open RAN Ecosystem:
  Activity by NTT DOCOMO, Fujitsu and partner companies with the objective to globally accelerate open radio access networks (open RAN), and help enable flexible network deployment to serve diverse company and operator needs in the 5G era, including vRAN commercialization.
• [4]
  O-RAN compliant:
  Compliance with common specification developed by the O-RAN ALLIANCE (Open Radio Access Network ALLIANCE), an industry group that promotes standardization with the aim of realizing a next-generation radio access network that is open and extensible. KT, Fujitsu and NTT DOCOMO are members of the O-RAN ALLIANCE.