For a remote batch-processing setup where data is only sent from the remote site to the central computer (input only), which transmission mode is most appropriate?
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ATelegraph line
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BSimplex lines
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CMixedband channel
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DAll the above
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ENone of the above
Answer
Correct Answer: Simplex lines
Explanation
Introduction / Context:Transmission modes determine the directionality of data flow between endpoints. In remote batch processing with input-only traffic, understanding simplex versus half-duplex and full-duplex is essential to select a cost-effective and technically suitable link type.
Given Data / Assumptions:
- Workload: remote site sends data to a central computer.
- No return traffic is required other than possible acknowledgments that can be handled out of band or are not required by the problem statement.
- Goal: choose a mode that matches one-way communication.
Concept / Approach:
Simplex communication supports one-way transmission only. Half-duplex alternates directions, and full-duplex supports simultaneous two-way communication. For pure input to the central host, simplex lines align directly with the requirement, often reducing complexity and potentially cost compared to bidirectional modes.
Step-by-Step Solution:
Step 1: Identify traffic direction: remote → central only.Step 2: Match to transmission mode: simplex provides one-way flow.Step 3: Eliminate modes needing reverse direction: half-duplex/full-duplex are unnecessary.Step 4: Select simplex lines as the most appropriate answer.Verification / Alternative check:
Historically, many batch data collection systems used one-way feeds (e.g., telemetry, forms scanning) where simplex links sufficed, validating the choice.
Why Other Options Are Wrong:
Telegraph line: A historical medium, not a transmission mode; it does not specifically denote one-way suitability.
Mixedband channel: Nonstandard term in this context; does not directly address directionality.
All the above: Incorrect because only simplex directly meets the requirement.
None of the above: Incorrect because simplex is appropriate.
Common Pitfalls:
Assuming acknowledgments require reverse data flow. The question constrains the scenario to input only, making simplex the intended match.
Final Answer:
Simplex lines