ARIB STD-T66

ARIB STD-T66 defines the technical requirements for radio equipment operating in the 2.4 GHz ISM band in Japan. The standard covers → Signal Modulation methods, → Spurious Emission limits, and → Channel Bandwidth usage for short-range wireless communication systems. It serves as the regulatory basis for certifying Bluetooth and 2.4 GHz Wi-Fi devices under the Japanese Radio Law.

Scope and Application

The standard applies to low-power wireless systems using the 2.4 GHz band, including:

• Bluetooth and Bluetooth Low Energy (LE) devices

• Wi-Fi (IEEE 802.11b/g/n/ax/be) operating at 2.4 GHz

• Other short-range ISM-band applications (e.g. wireless game controllers, headsets)

Devices are categorized as Low-Power Data Communication Systems under Article 6 of the Radio Law Enforcement Regulations.

Frequency Range and Channelization

• Operating Band: 2,400 – 2,483.5 MHz

• Channel schemes depend on the protocol:

  • Bluetooth: 79 channels at 1 MHz spacing

  • Wi-Fi: Typically 13 channels at 20 MHz bandwidth

Power Limits

ARIB STD-T66 does not specify a single flat power limit. The applicable transmit-power and power-spectral-density requirements depend on the system type, modulation method and occupied bandwidth. They must be determined using ARIB STD-T66 Version 3.8 (March 1, 2024) and the current regulations of Japan’s Ministry of Internal Affairs and Communications (MIC).

Certification and Labeling

Devices must undergo conformity assessment by a Registered Certification Body (RCB). Certified devices must be labeled with the Giteki mark and assigned certification number.

No special usage limitations (e.g. indoor-only) are required for 2.4 GHz systems.

For support with testing and approval, see our → MIC Certification Services.

Note
A comprehensive overview of device categories, certification process, and Giteki marking can be found in the guide → MIC Requirements – Overview.