Japan's Ministry of Internal Affairs and Communications (MIC) has enacted a regulatory revision affecting wireless power transmission (WPT) systems operating in the 920MHz band. Previously, these systems were restricted to indoor use; the new regulation removes this limitation, allowing for outdoor deployment under specific technical conditions. The revision was developed following a public consultation held from March 14 to April 13, 2026, with three opinions submitted, including input from an industry forum.

The updated regulation sets new antenna power limits for specified low power radio stations used for wireless power transmission. The standard limit is 0.25 watts, with an exception permitting up to 0.5 watts if the equipment is housed in a single enclosure that cannot be easily opened, provided the equivalent isotropic radiated power does not exceed 27 dB (with 1 mW as 0 dB).

This change aims to increase installation flexibility and expand the application range of WPT systems, particularly for powering sensor devices in factories and warehouses. The revision responds to industry demands for broader utilization and aligns with ongoing technological advancements, while maintaining compatibility with existing radio systems.

During the consultation, stakeholders raised concerns about coexistence with other systems in the 920MHz band, especially for maritime and coastal applications. Suggestions were made for future technical reviews to address specific operational conditions, such as transmission frequency, channel occupancy, and interference prevention measures.

Overall, the revision represents a significant step forward for Japan's regulation of wireless power transmission, fostering innovation and industrial expansion while emphasizing the need for balanced spectrum management.

This regulatory revision is classified as High Impact. Key reasons for high impact:

• Removal of indoor-only restriction for 920MHz WPT systems, enabling outdoor use.
• New antenna power limits directly affect product design, certification, and deployment.
• Broad applicability to industrial, warehouse, and factory environments.
• Stakeholder input led to technical adjustments in power limits, reflecting industry needs.

Who is affected?

Manufacturers of wireless power transmission systems, industrial automation companies, sensor device producers, operators of factory and warehouse equipment, and certification bodies.

Conclusion:

The change significantly alters the regulatory landscape for WPT systems in Japan, requiring immediate attention from affected stakeholders to ensure compliance and take advantage of expanded deployment opportunities.