Inmarsat C I-4 Migration

On 9th May 2018, at 14:00UTC, Inmarsat will migrate traffic from its Inmarsat C service I-3 to I-4. Some Pole Star services may be affected.

Important Information for Inmarsat Customers

As you may be aware, the Inmarsat-3 (I-3) constellation of satellites are reaching the end of their lifespan, which has made it necessary for Inmarsat to roll out the end of life process for several of their legacy services, and to migrate those that will continue onto Inmarsat-4 (I-4). One such service to be migrated is Inmarsat C.
On 9th May 2018, at 14:00 UTC, Inmarsat will migrate Inmarsat C traffic from AORW (I-3) to AMER (I-4).

This migration applies to all users of Inmarsat C, and is not initiated or controlled by Pole Star - however we realise this may affect some of our customers, particularly those who rely on our vital maritime safety and vessel tracking and positioning systems. Inmarsat are managing this essential process, and full details are available on their website.

Overall, the potential impact of this change is unknown at present; however it is considered to be minimal, and a smooth transition will go unnoticed by the vast majority of users.


Will I be affected?

If you're one of the customers who may be affected, you have probably already been in contact with your Service Provider regarding any required action on your part, as well as any potential impact. If you're unsure of your status, please contact your Service Provider and they will be able to help you.

Extremely old hardware may not be compatible; for example, in cases where the manufacturer is no longer operational.

Pole Star services which may be affected include:

  • DNID data reporting i.e. Inmarsat C position reporting
  • Inmarsat C SSAS messaging
  • Inmarsat C LRIT Conformance Testing

LRIT Conformance testing

We advise our customers to avoid scheduling LRIT Conformance tests between 8th - 10th May 2018, in case there is any unexpected impact on the system as a result of this change.


Please refrain from planning SSAS testing on this day and if possible put alternative measures in place

I'm an Inmarsat C terminal user - what do I need to know?

Before Migration

  1. If your terminal is located in the area between 30°W and 20°E and is logged into AORW, please log your terminal into Atlantic Ocean Region East (AORE) to ensure continuity of service.
  2. Check to see if the migration necessitates a switch of any on-board software to a different ocean region. (Contact your software provider if you need help with this.)

During Migration

  1. You don't need to take any action during this period.
  2. You may experience a short service interruption - don't be alarmed if this occurs.
  3. "To-mobile" messages will be accepted by the LES as usual and will be queued for delivery.
  4. "From-mobile" messages will also be queued; on the terminal.

After Migration

  1. Check your terminal is logged into the correct ocean region.
  2. If not, either manually log into a region, or reboot your terminal.
  3. There are thousands of poll commands expected to be sent following the migration, which will be queued and possibly delayed as a result


If you have any questions or concerns about your Inmarsat C service please contact your Inmarsat service provider, and they will be happy to answer any questions you may have.

As always, you are welcome to contact Pole Star Customer Support if you have any questions regarding your Pole Star account or services (Inmarsat C position reporting, SSAS, LRIT Testing).