Question 23C1

Shipboard Inmarsat-C terminals operate within specific L-band frequencies allocated for Mobile Satellite Service (MSS). Satellite communication systems typically use a frequency separation between uplink (terminal to satellite) and downlink (satellite to terminal) to prevent interference and optimize system performance. For Inmarsat-C: * **Reception (shipboard terminal receives from satellite):** This is the satellite's downlink. These frequencies are 1530.0 - 1545.0 MHz. * **Transmission (shipboard terminal transmits to satellite):** This is the satellite's uplink. These frequencies are 1626.5 - 1645.5 MHz. Option C correctly identifies these specific frequency ranges. The other options provide broader MSS L-band allocations or incorrectly swap the reception and transmission bands for the shipboard terminal. The lower L-band frequencies are used for reception (satellite downlink), and the higher L-band frequencies are used for transmission (satellite uplink) by the ship.