Japan’s four main MNOs are preparing for interoperability testing of shared Open RAN radio equipment, laying the groundwork for power savings and the expansion of 5G services in dense urban settings. The tests conducted by KDDI, NTT DoCoMo, SoftBank, and Rakuten Mobile, will use shared units in sub-6 GHz mid bands developed by mobile infrastructure company JTower. This goes further than most existing systems by effectively extending the scope for 5G network sharing from antennas and repeaters, just relaying analog radio signals, to the RU functions – including modulation and demodulation, as well as transmission to baseband units (BUs). The latter, which in turn can be split into DUs (Distributed Units) and CUs (Centralized Unit), mediate connectivity to users over…