Japanese mobile operators collaborate to expand 5G mmWave coverage

Japan’s four major mobile operators—SoftBank Corp, KDDI, NTT Docomo, and Rakuten Mobile—have signed a memorandum of understanding to jointly explore methods for expanding 28GHz mmWave 5G coverage. The initiative aims to address the technical limitations of the mmWave frequency band, which offers high connectivity over short distances but is susceptible to signal attenuation and physical obstructions. The companies will study compatible base stations, network architectures, and repeater equipment to improve reach, potentially involving shared access to assets to overcome deployment challenges.

In terms of recent network performance for the first half of 2026, SoftBank emerged as the leader in overall connectivity and 5G speed, recording the fastest median mobile download speed at 73.78 Mbps. NTT Docomo provided the widest 5G availability, while Rakuten Mobile led in network consistency. The competitive landscape shows operators focusing on diverse metrics including latency, reliability, and video streaming quality to meet increasing consumer demand for data-intensive services.