KDDI to launch au Hikari Plus hybrid 5G and fiber service

KDDI has announced the launch of ‘au Hikari Plus’, a new hybrid internet service that combines fiber-optic lines with au 5G mobile networks. Scheduled to begin on September 17, the service utilizes a specialized hybrid home router to allow users to access the internet and telephone services via 5G immediately upon receiving the device, even before fiber-optic installation is complete.

Once the fiber-optic installation is finalized, the service automatically switches to the high-speed line—reaching speeds of up to 10Gbps—without requiring any manual configuration or procedures from the user. This seamless transition mechanism is a patented technology and represents a first in the Japanese domestic market.

The service also provides a backup function; if the fiber-optic line experiences an outage, the system can switch to the 5G network to maintain connectivity. While initial manual switching via web settings or router restarts will be required during outages, KDDI plans to implement automatic failure detection and switching via firmware updates by fiscal year 2026.

The hybrid home router supports Wi-Fi 7 and Multi-Link Operation (MLO) to optimize performance for high-bandwidth activities like online gaming and teleworking. Initial service rollout will include providers BIGLOBE, So-net, and @nifty.