2.2 · Lesson 5 of 5
Automatic repeat query (ARQ)
Syllabus 2.2.5
What this lesson covers
- Describe automatic repeat query (ARQ)
Key vocabulary
- ARQ
- Automatic Repeat reQuest: uses acknowledgements and a timeout. Data is resent if no positive acknowledgement arrives in time.
- Acknowledgement
- A message sent back by the receiver to say the data arrived (positive) or had an error (negative).
- Positive acknowledgement
- Tells the sender the data arrived without errors, so the transmission is complete.
- Negative acknowledgement
- Tells the sender the data arrived with an error, so it must be sent again.
- Timeout
- The time the sender waits for an acknowledgement before sending the data again.
Check your learning
- Quick check: 4 questions
- Key vocabulary test: 5 terms
- Activity 1: What happens next? · 8 scenarios
- Activity 2: ARQ quiz · 8 questions
- Activity 3: ARQ step by step · drag and drop