News

2023.09.15

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 8th September 2024 or 3rd August 2025.

The subject models are designed to turn the clock back 19.6 years (23th January 2005), and will continue to work incorrectly under normal use, however there is no influence on positioning operation.
However, 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 objective equipment below started their week count from 23rd January 2005. It is on 8th September 2024 at 00:00 AM (UTC) that the week number counters rollover will occur.

1.Objective Equipment

1-1.Rollover date: 8th September 2024

Inmarsat Fleet Broadband FB500（JUE-500）
GPS navigator（JLR-7500/7600）
GPS receiver（JLR-4331W/4340）
GPS compass（JLR-20/30）

1-2.Rollover date: 3rd August 2025

AIS（JHS-182/183）
GPS navigator（JLR-7800/7900）
GPS receiver（JLR-4341）
GPS compass（JLR-21/31）

2.Notice and Countermeasures

2-1.The rollover day is on the 8th September 2024 at 00:00 AM (UTC).

Equipment	Models	Subject Serial No.	Notice	Countermeasures
Inmarsat Fleet Broadband FB250	JUE-500	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-500software version
GPS Navigator	JLR-7500	All	Note that time and date will go back to the starting date (January 23, 2005) 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-7500 Setting method of JLR-7600 Setting method of JLR-4331W Setting method of JLR-4340 Setting method of JLR-20/30
GPS Navigator	JLR-7600	All
GPS Receiver	JLR-4331W	After KE51719
GPS Receiver	JLR-4340	All
GPS Compass	JLR-20	All
GPS Compass	JLR-30	All

2-2.The rollover day is on the 3rd August 2025 at 00:00 AM (UTC).

Equipment	Models	Subject Serial No.	Notice	Countermeasures
AIS	JHS-182	JHS-182: after BB51401 NTE-182: after BB71401	Note that time and date will go back to the starting date (December 18 ,2005) when a master-reset or restarting of equipment is carried out after rollover day.	Upgrade the software^＊2 or JHS-183 replacement
AIS	JHS-183	NTE-183: up to BE04000 NCM-983: up to BB04206		Upgrade the software^＊2
GPS Navigator	JLR-7800	All	Note that time and date will go back to the starting date (December 18 ,2005) 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-7800 Setting method of JLR-7900 Setting method of JLR-4341 Setting method of JLR-21/31
GPS Navigator	JLR-7900	All
GPS Receiver	JLR-4341	All
GPS Compass	JLR-21	All
GPS Compass	JLR-31	All

*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