🔍 Key Concepts

• Inmarsat-C basic function in the GMDSS system • Difference between store-and-forward messaging vs real-time voice/data satellite services • What frequency band and channel type Inmarsat-C actually uses

💭 Think About

• Ask yourself: Does Inmarsat-C normally support live, continuous real-time conversations, or does it mainly handle short data messages and distress alerts? • Think about whether Inmarsat-C operates directly on HF radio bands, or if it uses a satellite link on a specific satellite band. • Consider what other GMDSS component is primarily responsible for Digital Selective Calling (DSC) watchkeeping and whether that is a core feature of Inmarsat-C.

✅ Before You Answer

• Verify which description mentions store-and-forward data messaging, which is central to Inmarsat-C. • Eliminate any option that says it works over HF bands if that doesn’t match what you know about Inmarsat-C frequencies. • Check whether Inmarsat-C is mainly for message/data and distress alerting rather than full-time real-time connectivity or global DSC coverage.