N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 2 - Data Communications Basics and Legacy Technologies                                                Slide 16 of 45 _________________                                                                                  __________

                             Building Blocks - Transmission Media Impairments

                                                Attenuation

                                                Noise

                                                Delay

                                                Non - Linearities

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The transmission medium impairments effect the transmitted signal which makes it difficult for the receiver to translate the signal. All media have different characteristics.

Attenuation - is the difference between transmitted and received power due to loss through lines and communications devices. All media loss signal.

Noise - The transmitted signal is distorted by noise near to the transmission line. Noise from mechanical devices, high voltage lines and lightening impact data transmission. Optical fiber is not susceptible to noise.

Delay - Signal delay is introduced by the line, equipment and the processing of the signal. Voice and video are susceptible to delays.

Non - Linearities - These are unwanted frequencies appearing at the receiver due to non-linearities in the communications channel.