FIT3165/4165 Computer Networks: Physical Layer - Analogue and Digital Communications.

These flashcards cover key terms and definitions related to the physical layer in computer networks, focusing on analogue and digital communication methods.

Physical Layer (PHY)

The means via which data can be transferred from node to node in the network.

Modulation

The intentional manipulation of a signal or a carrier wave to encode or impose a message.

Amplitude Modulation (AM)

A modulation type where the amplitude of the radio carrier wave is deviated in proportion to the amplitude of the analogue message.

Frequency Modulation (FM)

A modulation type where the frequency of the radio carrier wave is deviated in proportion to the amplitude of the analogue message.

Phase Modulation (PM)

A modulation type where the phase angle of the radio carrier wave is deviated in proportion to the amplitude of the analogue message.

Data Transmission

Occurs between transmitter and receiver over a transmission medium.

Attenuation

The reduction in signal strength as it travels through a transmission medium.

Signal to Noise Ratio (SNR)

The measure of the level of desired signal to the level of background noise.

Transmission Medium

The physical materials through which signals travel, such as twisted pair cables or optical fibers.

Asynchronous Transmission

A transmission strategy where data is sent one character at a time, allowing for resynchronization.

Synchronous Transmission

A transmission method where a block of bits is sent in a steady stream without start and stop codes.

Orthogonal Frequency-Division Multiplexing (OFDM)

A modulation scheme used in modern digital broadcast technology, combining multiple subcarrier frequencies.

Digital Modulation

A process to encode binary data into signals for transmission over communication channels.

Bit Error Rate (BER)

The rate at which errors occur in a digital signal, indicating the number of bits received incorrectly.

Data Rate

The speed at which data can be transmitted over a communication channel, measured in bits per second (bps).