🔍 Key Concepts

• Digital Selective Calling (DSC) is a digital, not voice, alerting system • Difference between voice/telex modes and digital decoding • Role of the DSC controller vs. the radio transceiver in handling DSC calls

💭 Think About

• Ask yourself: Is a DSC distress or routine call listened to by ear like normal voice traffic, or is it decoded by equipment first? • Which device in a GMDSS installation is specifically designed to handle DSC formats and MMSI numbers: the transceiver itself, or a dedicated controller? • Look at the modes listed (J3E, H3E, F1B, J2B): which are traditionally associated with voice/telex, and which with digital/data signals?

✅ Before You Answer

• Verify that DSC = digital signaling, not standard voice or telex traffic • Check which option clearly states that the signal is digitally decoded instead of being received as ordinary audio • Confirm which component (controller vs. transceiver mode) is primarily responsible for interpreting DSC messages in GMDSS equipment