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Japan MIC Certification FAQs

Recent Guidance for Japan MIC Certification FAQs

  1. Clarification of Reporting Required
    MIC has recently changed requirements for CBs and now require the test report, external photos and certificate exhibits be submitted to MIC. With this new requirement, MIC expects to see a summary table of Interference Prevention Function as well as other items necessary for Certification.
  2. Measurements required (screenshots of data collected):

    Occupied bandwidth at the rated voltage
    Unwanted emissions at the rated voltage
    Adjacent channel power
    Out of band power
  3. Test summary required (screenshots not required):

    Interference protection
    Carrier sense
  4. Interference Protection Guidance

    The interference prevention requirement is a requirement that client devices should send an identification code to the master device in order to identify itself as a valid/authorized client.

    In the case of the interference prevention function, it must be demonstrated with either a photograph or a screen capture that the device which needs to be certified transmits a MAC address (in the case of BT+EDR, BLE, Wi-Fi or ZigBee devices) consisting of 48 bits. Since a MAC address does consist of 48 bits it is not a problem of meeting the requirement. 

    An acceptable result is to take a screenshot to demonstrate that the MAC address is 48 bits, as shown here.

    The intent of this requirement is that client devices which do not have a valid identification code cannot connect to the master device (such unauthorized client devices therefore cannot “interfere” with authorized client devices because unauthorized client devices will not be allowed to connect to the master).

    This requirement applies to all 2.4 GHz devices (in fact, this requirement applies to most transmitters/transceivers when they are intended to be used in Japan). For 2.4 GHz devices, the identification code must consist of 48 bits.
    The majority of 2.4 GHz devices are still WLAN, Bluetooth or ZigBee devices. In such cases, one of the IEEE 802.xx protocols will be used. As it happens (and this is probably not a coincidence) the MAC address which is assigned to such devices consists of 48 bits.

    As a result of said changes in the Japanese Radio Law, the test laboratory (now) needs to verify the operation/existence of the interference prevention function and needs to report the result(s) of this test in the test report.

    A method of demonstrating this is to pair the device with a PC that has software to detect packets and determine the MAC address.

    Two such packages are (user must assess applicability):

  5. Labeling

    5.1 5.15 – 5.35 GHz operation

    Operation in the 5.15-5.25 and/or 5.25-5.35 GHz bands is restricted to indoor use only.

    LABEL: 電波法により5.2/5.3 GHz帯は屋内使用に限ります
    (Translation: “5.2/5.3 GHz band is restricted to indoor use due to the Radio Law.”)

    5.2 Module Integration

    If you are installing a Wi-Fi module which already has Japan certification then it is not necessary to certify your host device.

    There is some text which is recommended to place on your product, to show that it contains a certified radio module.


    (Translation: “This equipment contains specified radio equipment that has been certified to the Technical Regulation Conformity Certification under the Radio Law.”)

    5.3 Brand/Trade/Company name of the original certificate holder

    There is an issue when the brand/trade/company name of the original certificate holder is not noted on the label on the radio module. In the US the FCC ID is sufficient to indicate that the radio equipment has been certified, regardless of the brand/trade/company name on the radio module. The Grantee code holder is always the responsible party where it concerns non-compliances.
    However, in Japan (and in the EU also) the certification marking does not contain an element which could identify the responsible party, only the certification body which issued the certificate for the radio equipment in question can be identified. Because of the lack of an element in the certification marking to indicate the responsible party the identification of the responsible party is a combination of the brand/trade/company name (certificate holder) and model number as found on the certificate.
  6. Permissive Changes

    Japanese Radio Law is ambiguous where it concerns “permissive changes” on certified equipment and for which cases it would be allowed to continue to use the same certification number. In any case, each permissive change needs to be submitted to the certification body for review and if it is possible to keep using the same certification number the certification body will then issue a new certificate for the same certification number but with a revised date of issue.
    Please note that the certification number contains the identification number of the certification body which certified the device in question. Because of this, it is not possible to use any certification body for Japan in case permissive changes need to be reviewed. Permissive changes must always be filed at the certification body which issued the original certificate.

    It is highly recommended to ask the certification for their opinion on a case-by-case basis in case of intended permissive changes. The certification body can then provide their recommendation of how to test (where required), how to submit the permissive change application and if the same certification number could still be used.
  7. Output Power Measurement for Bluetooth Hopping Devices

    The correct method of measuring RF output power for Bluetooth is to measure the RF output power with the device hopping:

    Antenna power(mW/MHz) = output power(mW) / Burst Ratio / Spreading Bandwidth (MHz)
  8. Compliance with the Telecommunications Business Law

    Devices that connect directly or indirectly to the public network (and this is carrier systems as well as the public internet) must comply with Article 9 of the Telecommunications Business Law. This is is a requirement that is designed to provide a minimum Quality of Service (QoS) for users of the public networks.

    It requires that a radio transmits an identification code in order to identify itself on the network (it’s like assigning a unique phone number to each transmitter).
  9. Duplicate Filing/Change of Certificate Holder 

    There is nothing formal or equivalent to an “FCC change of ID” process in Japan. However, we can issue a certificate in the name of a new certificate holder (although this implies that a new certification number must be placed on the radio module) based on the existing documentation. Please note additional exhibits may be required.
    (1) application form;
    (2) technical type specification form no. 3;
    (3) declaration that the radio module is identical to the radio module as it was previously certified;
    (4) copy of the product label and location;
    (5) ISO 9000 (or equivalent) certificate of the new certificate holder OR a quality procedure of the new certificate holder which details how the continued compliance of the radio module is ensured;
    (6) permission of the original certificate holder to use the existing documentation for the issue of a new certificate in the name of a specific certificate holder. Please note: such permission does not automatically imply that the new/specific certificate holder can have access to the existing documentation, the confidentiality status of the existing documentation will not change;
    (7) agent authorization letter of the new/specific certificate holder to apply for a new certificate.
    (8) Construction Protection Declaration
  10. RF Exposure Requirements 

    Japan has RF exposure regulations for head and body SAR. However, these regulations do not apply to 2.4/5 GHz (Wi-Fi, BT, BLE) transceivers when used in a stand-alone configuration.
    The Japanese body SAR regulation is only applicable when (1) a 2.4 GHz (Wi-Fi, BT, BLE) module is integrated into a host which also contains a cellular radio transceiver (e.g. 3G, 4G, 5G, satellite transceivers, etc.) AND (2) the host device may be used at a distance closer than 20 cm to the human body.
    If the host device only contains a 2.4/5 GHz (Wi-Fi, BT, BLE) transceiver then no action needs to be taken with respect to RF exposure, except that the host device should be labeled with the GITEKI mark and certification number as found on the label of the radio module.
  11. 401-406 MHz MEDS/MICS Interference Protection Requirements 

    The transmission of the ID code is not related to the LBT/CS function. The LBT/CS function basically means that the transmitter needs to check/listen if the operating channel is clear and not being used by other transmitters. It needs to do an LBT/CS check every time before it transmits. If the operating channel is clear the transmitter then starts to transmit its ID code after which data is transmitted. The receiving device receives the ID code + data. The receiver checks if the ID code is valid and then accepts the data if it is valid. If the ID code is not valid the receiver will ignore the data.
    Or, in an alternate configuration, the transmitter transmits its ID code, the receiver checks it and if the ID code is valid the receiver informs the transmitter to go ahead with transmitting the data.
    In a device which contains multiple transmitters, all individual transmitters must meet the interference protection function requirement. The 401-406 MHz transmitter must support it and the 2.4 GHz transmitter(s) must support it and both transmitters will need to be tested individually.
    The manufacturer of the device should provide how an ID code, used to identify the transmitter on the network or communications link has been implemented in the 401-406 MHz transmitter and of how many bits it exists.
    Note: for medical transmitters (e.g. operating in the 401-406 MHz band) the requirement is that the ID code consists of 24 bits minimum.
  12. Japan Quality Assurance Compliance

    MIC requires continuing compliance with the radio parameters. An ISO certificate is typically sufficient. If not available, what is required is a signed declaration of continuing quality control a copy of their quality system procedure(s) which describe(s) HOW they will ensure the continued compliance of the radio equipment with the requirements of the Japanese Radio Law.

    Such a procedure could describe incoming inspection procedures, possible sample testing, etc. However, the procedure must be focused on compliance with the Japanese Radio Law. The incoming inspection must include all radio and RF parameters.

    Such an example can be found at our document/resources pages: