This memo is to advise customers to carry out LRIT software upgrading before conducting a Conformance Test on JRC Inmarsat C models JUE-75C and JUE-85.
Upgrading software for existing new GMDSS compliant JUE-75C’s and non LRIT capable JUE-85’s is required before carrying out a Conformance Test with LRIT application service providers (ASP), for example: Pole Star, Transas Limited, or Absolute Maritime Tracking Services INC, in order to meet the IMO LRIT requirements MSC 263(84). We believe that Inmarsat C equipment for LRIT should conform to Inmarsat’s new specification1
Without upgrading the equipment with LRIT software, most Conformance Tests may fail. Even if the Conformance Test is completed successfully, upgrading of the equipment with LRIT software is still required later on, in order to avoid troubles like no data transmission to the LRIT data center during the LRIT operation due to the following factors:
- Low success rate due to Inmarsat-C communication traffic congestion2
- Partial operational change in Inmarsat-C system to introduce LRIT system at LES
- Partial mismatch of operation between JRC models (JUE-75C/85) and LRIT ASP system
If you ask JRC for service because there is no data transmission from your JRC Inmarsat C terminals, without having upgraded the unit with LRIT software, we will advise you first to arrange to upgrade the JRC equipment with LRIT software before taking further action.
For further information, please contact our sales representatives.
- Inmarsat’s new specification (CN141 and CN142)
CN141: Enhanced Data Reporting with delivery confirmation and the retransmitting function
CN142: Multi-Ocean Region Polling (downloading function for DNID of all Ocean Region)
- A burst (data reporting) collision occurs essentially due to Inmarsat C communication traffic congestion, because Inmarsat C system adopts the slotted-ALOHA method. And it causes the decreased communication success rate.