TRANSMISION MODES (MIDTERMS)

simplex transmission

In a ______, data can only flow in one direction, which is usually from the source to the sink.

half-duplex transmission (HDX)

In a ________, data can flow in both directions, but never simultaneously. It first flows in one direction, and then in the other direction.

full-duplex transmission (FDX)

In a ________, data can flow in both directions simultaneously. It can be viewed as a pair of simplex lines between the source and sink with one line going from the source to the sink and the other going from the sink to the source.

Serial data transmission

when data is sent or received, the data bits are organized in a specific order since they can only be sent one after another.

Asynchronous transmission

is used when data is transmitted as individual characters.

In this method, each character is preceded by one start bit and one or two stop bits that are used by the receiver for synchronization purposes.

Synchronous transmission

is used to transmit large blocks of data at a time.

In this scheme, data is usually organized in frames and each frame is preceded by a flag that consists of a few bits and terminated by another flag.

Parallel data transmission

multiple data bits are transmitted over multiple channels at the same time.

Antennas

It is the metal rod or dish that catches radio waves and turns them into electrical signals feeding into something like a radio or television or a telephone system.

Log Periodic Antennas

It is a directional antenna that is made of a series of dipoles placed along its axis at different space intervals of time followed by a logarithmic function of frequency.

Wire Antennas

These antennas use a length of wire for transmitting and receiving wavelengths of signals.

Traveling Wave Antennas

It is a directional aperiodic antenna that uses a travelling wave as its guiding structure

traveling wave

A _______ is a temporary wave that creates a disturbance and moves along the transmission line at a constant speed.

Microwave Antennas

This type of antenna uses microwave transmission to broadcast signals between two or more locations.

Microwave

_____ is a form of electromagnetic radiation that is used mostly in point-topoint communications and radar

Wave Propagation

These waves are basically defined as superimposed oscillations of an electric and a magnetic field in space with their direction of propagation perpendicular to both.