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24 December 2021

Notice: GPS Week Number Rollover for equipment

Dear Customers,

We would like to announce that GPS week number rollover *1 for equipment is to occur on some of our GPS' on 15th May 2022.

The subject models are designed to turn the clock back 19.6 years (29th September 2002), and will continue to work incorrectly under normal use, however there is no influence on positioning operation.
As the results, the following abnormalities occur in some equipment.
- Some date information will be displayed erroneous.
- Communication function will not work properly.

For details, please see the 2. notice and countermeasures below.

*1 GPS week number rollover:
The week number counter in GPS resets once every 1023 weeks, which is approximately 19.6 years. The week number counters for the GPS in the discontinued models below started their week count from the 19 December 1999. It is on the 4th August 2019 at 00:00 AM (UTC) that the week number counters rollover will occur.

1.Objective Equipment

Inmarsat C(JUE-85)

Inmarsat mini-C(JUE-95SA/95LT/95VM)

Inmarsat Fleet Broadband FB250(JUE-250)

GPS navigator(JLR-7700MKⅡ)

GPS receiver(JLR-4330/4331)


2.Notice and Countermeasures

The rollover day is on the 15th May 2022 at 00:00 AM (UTC).

Equipment Models Subject Serial No. Notice Countermeasures
Inmarsat C JUE-85 GR10251 to GR23738 Scheduled transmission, LRIT and VMS
transmission functions is stopped.
The date in the transmitted data and the
log function returns to the starting date.
Upgrade the software*2
Inmarsat mini-C JUE-95SA GR10051 to GR23188 Upgrade the software*2
JUE-95LT GR11703 to GR23598 Upgrade the software*2
JUE-95VM GR10001 to GR23593 Upgrade the software*2
Inmarsat
Fleet Broadband FB250
JUE-250 All The registration process to the Inmarsat network fails and communication becomes impossible.
The date of the internal clock and log function of the device returns to the starting date.
Upgrade the software*2

Confirmation method of JUE-250
software version
GPS Navigator JLR-7700MKⅡ After KE47190 Note that time and date will go back to the starting date (September 29, 2002) when a master-reset of equipment or a battery replacement is carried out after rollover day. When the time and date go back to the staring date, the equipment will return to normal operation by the following settings.

Setting method of JLR-7700MkⅡ
Setting method of JLR-4330,JLR-4331
GPS Receiver JLR-4330 After KE54239
JLR-4331 After KE50479

*2 : For more information, and countermeasures, please contact our service agents or sales representatives.For the software update, the corresponding cost will be charged.

For further information : please contact

Japan Radio Co., Ltd.

Marine Business Department
TEL: +81-3-5534-1115