You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
This lesson covers methods for detecting (and sometimes correcting) errors that occur during data transmission or storage. You need to understand parity bits, majority voting, checksums, check digits, and Hamming codes for the OCR H446 specification.
When data is transmitted over a network or stored on a medium, errors can be introduced by:
| Cause | Description |
|---|---|
| Electrical interference | Electromagnetic noise from nearby devices |
| Signal degradation | Signal weakening over long distances |
| Hardware faults | Faulty cables, connectors, or storage media |
| Cosmic rays | High-energy particles flipping bits (rare but real) |
| Crosstalk | Signals from adjacent wires interfering |
An error means one or more bits have been flipped (0 changed to 1 or vice versa).
A parity bit is an extra bit added to a group of data bits to make the total number of 1s either even or odd.
The parity bit is set so that the total number of 1s (including the parity bit) is even.
Subscribe to continue reading
Get full access to this lesson and all 10 lessons in this course.