Question T8D11
From subelement T8 - T8D
What is an ARQ transmission system?
Why is this correct?
ARQ (Automatic Repeat reQuest) is an error correction method where the receiving station detects transmission errors and automatically requests retransmission of corrupted data. Choice A is wrong because ARQ works with all digital modes, not just video. Choice B incorrectly describes encryption for satellites. Choice D fabricates a meaningless description using technical-sounding terms that don't relate to ARQ's actual function.
Memory tip
Look for 'Automatic Repeat' in the acronym expansion as your clue. ARQ systems follow a simple pattern: send data, check for errors, request repeats if needed. This error-detection-and-retry pattern appears in many digital protocols beyond amateur radio, making it a transferable concept.
Learn more
ARQ systems ensure error-free digital communications by implementing a feedback loop between stations. When operating digital modes like packet radio, your station's ARQ capability automatically handles data integrity without operator intervention. This reliability makes ARQ protocols essential for applications requiring accurate data transfer, such as APRS position reporting or emergency digital communications where message corruption could compromise safety or coordination efforts.
Think about it
Why do you think ARQ systems are particularly important for weak signal digital modes like those used in emergency communications or Earth-Moon-Earth contacts?