GMDSS Trainer
Subelement C: Satellite Systems— Topic :

Question 24C5

Element 9 (GMDSS Maintainer)

How many NCS’s operate in each Inmarsat ocean region per Inmarsat system?

Explanation
Each Inmarsat ocean region, for a given Inmarsat system (e.g., Inmarsat-C, Inmarsat-F77), operates with a single Network Coordination Station (NCS). The NCS serves as the central control point for managing satellite channels and network resources within its designated region and system. Its primary role is to assign frequencies, control access, manage call setup, and ensure efficient communication among all user terminals (Mobile Earth Stations) and Land Earth Stations (LES) through the satellite. Having only one NCS prevents conflicting instructions, avoids resource contention, and ensures orderly and efficient operation of the satellite network, which is critical for reliable maritime safety and distress communications. Multiple NCSs for the same system in the same region would lead to chaos and system failure.