Japan's Big Four Carriers Sign MoU on Shared 5G mmWave Coverage
Tokyo – October 12, 2026 -- KDDI, NTT DOCOMO, SoftBank and Rakuten Mobile signed a memorandum of understanding on September 11, 2026, to jointly study how 5G millimeter-wave base stations can serve customers across operator boundaries. The four carriers announced the agreement on September 16.
Four carriers will test technical feasibility of cross-operator mmWave use
The study will assess whether the usage coverage of 5G millimeter-wave base stations can be expanded among mobile network operators. The companies will also evaluate efficient operational frameworks for implementing such an arrangement.
The work will focus on technologies and approaches related to 5G millimeter-wave base stations, repeaters and other related assets. The operators plan concrete studies on how to make effective use of facilities that have already been deployed.