The first service provided by the data-link layer is _____.

In a ____ protocol, frames are sent from one node to the next without any relationship between the frames; each frame is independent.

For a series-resonant circuit, if the circuit is resonant at a point above the generator frequency (the generator frequency is too low), then the circuit acts

When light waves, which travel in straight lines, encounter any substance, they are either:

The gain of a collinear antenna is greatest when the elements are spaced from ______ wavelength apart or when the number of elements is increased.

In circular waveguides, the second subscript indicates the number of _______.

The denser the medium, the higher the speed of sound. The denser the medium, the _____ the speed of light.

The color of light depends on its ______.

What refers to the bends, twists, and joints necessary to install waveguides. E bends, H bends, and twists must have a radius greater than two wavelengths?

What type of waveguide bend where the magnetic fields are distorted when a waveguide is bent in this manner?

In wave propagation, if either the source or the receiver or both move toward the other, the receiver will perceive a ______ frequency sound.

In a _____ code, if a codeword is cyclically shifted (rotated), the result is another codeword.

To guarantee the detection of up to s errors in all cases, the minimum Hamming distance in a block code must be ______.

In antennas, the exact value of radiation resistance depends on the ______.

A twisted-pair cable can pass a wide range of frequencies. Increasing frequency, the attenuation, measured in decibels per kilometer (dB/km), sharply increases with frequencies above ______.

In antennas, the points of minimum current and minimum voltage are known as current and voltage ____.

In wave propagation, as the angle of incidence increases, the amount of wave energy reflected _____.

In _____ propagation, radio waves travel through the lowest portion of the atmosphere, hugging the earth.

What is the most common UP connector, which is a keyed connector, meaning the connector can be inserted in only one way?

In wave propagation, the reflected energy is the greatest when the wave is ______ to the reflecting surface.

The frequency range of any system using waveguides is limited by the _____ of the waveguides.

In ____ TDM, the data rate of the link is n times faster, and the unit duration is n times shorter.

What signals can be used for short-range communication in a closed area using line-of-sight propagation?

The field associated with the energy stored in the antenna is the _____ field.

In what mode, each station can both transmit and receive, but not at the same time?

The narrowest dimension determines the maximum frequency ________ of the waveguide and is called the "b" dimension.

In a multipoint environment, the capacity of the channel is shared. If several devices can use the link temporally, it is a ____ connection.

What technique uses M different carrier frequencies that are modulated by the source signal? At one moment, the signal modulates one carrier frequency; at the next moment, the signal modulates another carrier frequency.

What deals with procedures for communication between two adjacent nodes-node-to-node communication-no matter whether the link is dedicated or broadcast?

Today, the prevalent coding system is called _____ which uses 32 bits to represent a symbol or character used in any language in the world.

In ______ propagation, higher frequency radio waves radiate upward into the ionosphere (the layer of atmosphere where particles exist as ions) where they are reflected back to earth.

The cutoff wavelength of a circular guide is_____ times the diameter of the waveguide.

For transmission over bodies of water, _______ polarization is much better for antennas at the lower heights.

What technique also expands the bandwidth of the original signal, but the process is different? In this technique, we replace each data bit with n bits using a spreading code.

Substances that transmit almost all the light waves that fall upon them are said to be _____.

At medium and low frequencies,______ polarization cannot be used at these frequencies because the electric lines of force are parallel to and touch the earth.

The effectiveness of a data communications system depends on what four fundamental characteristics?

Single-mode uses _____ fiber and a highly focused source of light that limits beams to a small range of angles, all close to the horizontal.

Graded index fiber optic cable is one with varying densities. Density is _____ at the center of the curve.

Changing the frequencies of a cavity is known as ______.

To connect coaxial cable to devices, we need coaxial connectors. The most common type of connector used today is the _____.

What is the process of adding one extra 0 whenever five consecutive 1s follow a 0 in the data, so that the receiver does not mistake the pattern 0111110 for a flag?

What is the process of adding one extra byte whenever there is a flag or escape character in the text?

On an open-ended resonant line, and at all even ¼-wavelength points, the voltage is _____, the current is ______ and the impedance is maximum.

In a circuit-switched network, a dedicated connection, called a _______, is always available between the two end systems; the switch can only make it active or inactive.

A parity-check code can detect an ____ number of errors.

In sound propagation, a denser material (such as lead) passes sound ______.

In the reflection of waves, if the reflecting surface is smooth and polished, the angle between the incident ray and the normal will be ____ the angle between the reflected ray and the normal.

In antenna radiation, a _____ is the area of a radiation pattern that has minimum radiation.

The diameter of an equivalent circular waveguide must be _____ times the "a" dimension of a rectangular waveguide.