TRANSMISSION MEDIA AND BANDWIDTH UTILIZATION

______ can be achieved by using multiplexing; ______ can be achieved by using spreading.

Efficiency; privacy and antijamming

Can be applied when the bandwidth of a link (in hertz) is greater than the combined bandwidths of the signals to be transmitted.

Frequency Division Multiplexing (FDM)

A multiplexing technique that involves signals composed of light beams?

Wavelength-division multiplexing

In a multiplexed system, ____line(s) share the bandwidth of __ link(s).

n; 1

In synchronous TDM, for n signal sources of the same data rate, each frame contains _______ slots.

0 to n

The sharing of a medium and its link by two or more devices

multiplexing

This technique can be classified into: synchronous or statistical.

Time Division Multiplexing (TDM).

This technique does not transmit analog signals?

none of the above

This technique expands the bandwidth of a signal by replacing each data bit with n bits.

Direct sequence spread spectrum (DSSS)

This technique is designed to be used in wireless applications in which stations must be able to share the medium without interception by an eavesdropper and without being subject to jamming from a malicious intruder.

Spreading

This technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, the signal modulates/hops to another carrier frequency.

Frequency hopping spread spectrum (FHSS)

A parabolic dish antenna is a(n).

unidirectional

Fiber optic cable uses this kind of wave to transmit data:

light

In a fiber-optic cable, the signal is propagated along the inner core by?

reflection

Signals with a frequency below 2 MHz use : propagation.

ground

These cables are composed of a glass or plastic inner core surrounded by cladding, all encased in an outside jacket.

fiber-optic

These media transport electromagnetic waves without the use of a physical conductor?

free space

This cable consists of an inner copper core and a second conducting outer sheath.

Coaxial

This cable consists of two insulated copper wires twisted together.  

Unshielded Twisted Pair

Transmission media are usually categorized as?

guided or unguided

Transmission media lie below the this layer.

physical

When the angle of incidence is?

more than

Occurs when a wave impinges upon an object with, causing the reflected energy to spread out in many directions.

Scattering

Involves the bending of waves around obstacles and openings

Diffraction

Involves a change in direction of waves when they bounce off a barrier.

Reflection

Involves a change in the direction of waves as they pass from one medium to another.

Refraction

Involves the transmission of radio signal in a direct path from the source to the receiver.

Line-of-sight propagation

Involves the transmission of radio signal in a direct path from the source to the receiver.

Ground wave propagation

Involves either the reflection or refraction of radio signal back to the earth from the ionosphere which is an electrically charged layer of the upper atmosphere.

Skywave propagation