The AIS data transmission is designed to exchange information automatically over which medium?

The AIS data transmission is designed to exchange information automatically over which medium?

• A. Satellite-based data
• B. Line-of-sight VHF-FM
• C. Microwave line-of-sight
• D. Undersea cable

Answer: (B)

The main idea here is how AIS broadcasts are carried. AIS uses marine VHF radio, transmitting data on dedicated VHF channels with FM modulation. These signals travel across the sea by line-of-sight, meaning ships must be within each other’s radio horizon to hear the broadcasts. That makes line-of-sight VHF-FM the designed medium for AIS data exchange. While there are satellite AIS services and other communication methods, the standard, everyday AIS traffic relies on short-range, line-of-sight VHF transmissions between ships and shore stations. The other options aren’t the typical medium because they involve either satellite relays, fixed cables, or higher-frequency point-to-point links that aren’t how AIS originally broadcasts its automatic information.

The main idea here is how AIS broadcasts are carried. AIS uses marine VHF radio, transmitting data on dedicated VHF channels with FM modulation. These signals travel across the sea by line-of-sight, meaning ships must be within each other’s radio horizon to hear the broadcasts. That makes line-of-sight VHF-FM the designed medium for AIS data exchange. While there are satellite AIS services and other communication methods, the standard, everyday AIS traffic relies on short-range, line-of-sight VHF transmissions between ships and shore stations. The other options aren’t the typical medium because they involve either satellite relays, fixed cables, or higher-frequency point-to-point links that aren’t how AIS originally broadcasts its automatic information.