A remote batch-processing operation in which data is solely input to a central…

Concept

A data transmission line is classified by the direction in which data may flow. A simplex line carries data in one direction only; a half-duplex line carries data in both directions but only one direction at a time; a full-duplex line carries data in both directions at the same time.

Application

In remote batch processing the terminal collects a batch of records and sends them to the central computer, where they are processed later. When the data is solely input to the central computer, information travels in a single direction only — from the remote terminal to the computer — with no return stream needed during the transfer.

A line that transmits in exactly one direction is, by definition, a simplex line. So this one-way, input-only operation requires simplex lines.

Why not the others

• A telegraph line names a physical medium, not a direction of flow; it does not describe the one-way characteristic the operation calls for.

• A "mixed band channel" is not a recognised transmission-mode category, so it cannot be the requirement.

• "All of the above" cannot hold once the individual non-directional choices are ruled out.