M-Exam Flashcards
(130 cards)
Transmitted data both analog and digital are susceptible to many types of ____ and ______?
Noise and Errors
Unwanted electrical or electromagnetic energy that degrades the quality of signals and data.
Noise
Occurs in digital and analog systems, and can affects files and communications of all types including text, programs, images, audio, and telemetry.
Noise
a condition in which data on digital medium has been altered erroneously.
Error
are unavoidable, caused by noise on channel.
Error
complete link layer messages are called ______?
Frames
is a digital data transmission unit in computer networking and telecommunication.
Frames
it contains the source and the destination addresses of the frame.
Frame Header
it contains the messages to be delivered.
Payload Field
it contains the error detection and error correction bits.
Trailer
it marks the beginning and end of the frame.
Flag
these errors are occured in the communication media due to signal distortion or attenuation.
Transmission Errors
these errors occurs due to data storage where the memory tracks will corrupt during writing of by any power supply failures.
Storage Errors
Kinds of Transmission Error
- sent signal destroyed - doesn’t receive data
- sent signal changed - received wrong data
- spurious signal created - received random data
if two or more bits are different between sending and receiving data stream, then the error is called _____?
Multiple Bit Error
two or more bits changed in the transmitted data and the error is calculated from starting error bit to the ending error bit.
Burst Error
techniques that allow the destination to detect errors
Error Detection
to detect and correct errors, enough redundancy bits need to be sent with data.
Error Detection
are the extra bits sent by source to inform destination about the data sent.
Redundancy Bits
Types of Redundancy Check
- Parity Check
- Longitudinal Redundancy Check
- Cyclic Redundancy Check
one extra bit is sent along with the original bits to make number of 1s either even in case of even parity.
Parity Check
is an error detection method for determining the correctness of transmitted and stored data.
Longitudinal Redundancy Check
also known as Horizontal Redundancy Check.
Longitudinal Redundancy Check
is an error detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data.
Cyclic Redundancy Check