Press Releases May 25, 2026 Successful Demonstration of Stable, High-Capacity mmWave Communications for Multiple High-Speed Vehicles for the 6G Era — A major step toward real-world deployment, including mmWave-enabled autonomous driving and enhanced in-vehicle experiences — NTT DOCOMO, INC. NEC Corporation TOKYO, JAPAN, May 25, 2026 --- NTT DOCOMO, INC. (“DOCOMO”) and NEC Corporation (“NEC”), in collaboration with NTT, Inc. (“NTT”), have developed a technology (the “Technology”) that enables multiple vehicles traveling at high speed to simultaneously maintain stable communications using high-capacity millimeter-wave (mmWave) communications in the 40 GHz band, which is expected to be leveraged in the 6G era. The Technology combines distributed MIMO*1, in which multiple antennas are distributed and deployed from a base station, with a technique that pre-compensates the transmit frequency and transmit timing of signals. In a demonstration trial conducted in March 2026 at a full-scale tunnel test facility installed at Japan's National Institute for Land and Infrastructure Management (NILIM), Ministry of Land, Infrastructure, Transport and Tourism, multiple vehicles equipped with mobile terminals traveling at high speed in opposite lanes maintained stable, high throughput, achieving approximately a 1.3x improvement in average throughput compared to the conventional method. This result represents a major step toward social implementation of 6G-related technologies—including implementation in new base stations—such as autonomous driving utilizing mmWave and improved in-vehicle user experiences. Video of the demonstration: https://www.nec.com/en/global/onlinetv/en/mmwave_b5g_en.html Background When communicating in high-frequency bands such as mmWave in high-mobility environments (e.g., automobiles and trains traveling at high speed), frequent base station switching occurs, causing abrupt changes in Doppler frequency*2 and propagation delay, which degrades communication quality. DOCOMO, NEC, and NTT have been working to address this challenge, and in March 2025 successfully demonstrated*3 a technology that stabilizes communication quality for a single vehicle traveling at high speed by compensating the transmit frequency and transmit