What is the primary difference between LOS and BLOS communications?

• A. LOS requires direct line-of-sight; BLOS uses satellite or relay
• B. BLOS relies on satellite or relay
• C. LOS uses fiber optic
• D. BLOS requires direct line-of-sight

Answer: (A)

The main idea is about whether the radio link between the controller and the drone needs a direct, unobstructed path. In line-of-sight (LOS) communications, there must be a clear line from transmitter to receiver; the signal can be blocked by terrain, buildings, or distance. Beyond-line-of-sight (BLOS) means you can’t rely on a direct path, so the system uses satellites or relay stations to carry the signal and maintain the link.

That’s why the best choice is the one stating that LOS requires direct line-of-sight, while BLOS uses satellite or relay. The other options aren’t accurate descriptions of how the typical drone control link works.