Satellite Communications Flashcards
7 cards from real Telecommunications practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Satellite Communications flashcards as text
What is a VSAT (Very Small Aperture Terminal)?
Answer: A small ground-based antenna system for two-way satellite communications
VSAT is a compact ground-based satellite terminal using dish antennas typically under 3 meters in diameter, enabling two-way satellite data, voice, and video communications.
Which multiple access technique allocates satellite bandwidth dynamically based on actual user demand rather than fixed pre-assigned slots?
Answer: DAMA (Demand Assigned Multiple Access)
DAMA assigns satellite capacity on demand in real time, improving efficiency by only allocating bandwidth when users actually need it rather than reserving fixed portions.
SpaceX's Starlink broadband internet service uses which type of satellite constellation?
Answer: LEO (Low Earth Orbit)
Starlink operates a LEO constellation at approximately 550 km altitude, enabling low-latency broadband internet coverage with thousands of satellites.
What is 'rain fade' in satellite communications?
Answer: Attenuation of satellite signals by precipitation in the atmosphere
Rain fade is the attenuation of satellite signals by rain, snow, or ice in the atmosphere, where water droplets absorb and scatter microwave energy, and it is most severe at Ku and Ka bands.
The 'footprint' of a communications satellite refers to:
Answer: The geographic area on Earth that the satellite's signal can cover
A satellite's footprint is the geographic region on Earth's surface within range of the satellite's antenna beams where ground stations can send and receive signals.
GPS (Global Positioning System) satellites orbit Earth in which orbit type?
Answer: MEO (Medium Earth Orbit) at ~20,200 km
GPS satellites operate in MEO at approximately 20,200 km altitude with a 12-hour orbital period, providing global coverage while remaining in range of ground receivers.
What is the primary purpose of the beacon signal continuously transmitted by a communications satellite?
Answer: To allow earth stations to locate, track, and align their antennas
A satellite beacon is a continuous carrier signal used by earth stations as a reference to find the satellite in the sky and maintain accurate antenna pointing alignment.