I-3 to I-4 migration programme completion: all ocean regions successfully migrated

Following the successful completion of the fourth and final regional migration (IOR – Indian Ocean Region) of the Inmarsat legacy services (Classic Aero, Swift 64, Fleet 77 and Inmarsat C) from the I-3 satellites to the I-4 constellation on 12 December 2018, Inmarsat is pleased to announce that the overall migration programme has now been concluded.

We would like to take this opportunity to thank all our partners for their outstanding support and contribution towards the success of this migration. Also our thanks to all our customers for their patience and understanding during the period while the services were transitioned.

The transition of services from the I-3 fleet onto our I-4 constellation* started early in 2018. Our approach was to migrate all services, satellite by satellite, as per the schedule shown in the table below.

I-3 to I-4 migration Schedule
Atlantic Ocean Region West (AORW) I-3 to Americas (AMER) I-4 Classic Aero, Fleet 77 and Swift 64 services – migration successfully completed on 03 May 2018


Inmarsat C services (to include Aero C and Mini C) – migration successfully completed on 09 May 2018

Pacific Ocean Region (POR) I-3 to Asia/Pacific (APAC) I-4 Classic Aero, Fleet 77, Swift 64 and Inmarsat C services (to include Aero C and Mini C) – migration successfully completed on 29 August 2018
Atlantic Ocean Region East (AORE)* I-3 F2 moved to I-3 F5 Classic Aero, Fleet 77, Swift 64 and Inmarsat C services (to include Aero C and Mini C) – migration successfully completed on 30 October 2018
Indian Ocean Region (IOR) I-3 to Europe/Middle East/Africa (EMEA) I-4

Classic Aero, Fleet 77, Swift 64 and Inmarsat C services (to include Aero C and Mini C) –  migration successfully completed on 12 December 2018

* Note: AORE was part of the overall I-­3 to I­-4 migration programme but it did not move to the I­-4 constellation, it remained in the I-3 constellation.

Due to the move from the I-3 to the I-4 satellites*, the coverage areas changed and users needed to ensure that their devices were pointed to the relevant satellite. This process generally was managed automatically by the terminal without the need for user intervention. However, in some instances, users needed to manually repoint their devices to the appropriate satellite.

Under supervision of the International Mobile Satellite Organisation (IMSO), the Global Maritime Distress Safety System (GMDSS) and Maritime Safety Services were closely monitored during the migration, as was the Classic Aero Safety Service. These safety services were restored first with the highest priority.

Having concluded the migration programme, Inmarsat remains committed to supporting the legacy services on our network and will continue to monitor service availability as part of our routine operational task management.