Description : An FDM hierarchy which is formed by frequency – division multiplexing 10 super groups together for a combined capacity of 600 voice band message channels.
Last Answer : Mastergroup
Description : It is used to encode the minimum amount of speech information necessary to reproduce a perceptible message with a fewer bits that those needed by a conventional encoder/decoder
Last Answer : vocoders
Description : The characters making up the message in a synchronous transmission are collectively referred to as the data
Last Answer : block
Description : Packets which is self – contained and travels through the network independent of other packets of the same message by whatever means available
Last Answer : Datagram
Description : Message _______ means that the receiver is ensured that the message is coming from the intended sender, not an imposter
Last Answer : authentication
Description : n digital modulation, it is similar to standard amplitude modulation except there is only two amplitudes possible.
Last Answer : amplitude shift keying
Description : n T1, it is equal to the reciprocal of the sample rate
Last Answer : Frame time
Description : The fields surrounding the antenna do not collapse their energy back into the antenna but rather radiate it out in space
Last Answer : radiation field
Description : To permit the selection of 1 out of 16 equiprobable events, the number of bits required is
Last Answer : 4
Description : Data rate at which serial PCM bits are clocked out of the PCM encoder onto the transmission line.
Last Answer : line speed
Description : The magnetic field of an antenna is perpendicular to the earth. The antenna’s polarization ___
Last Answer : is horizontal
Description : It is the ratio of the power density radiated in a particular direction to the power density radiated to the same point by a reference antenna, assuming both antennas are radiating the same amount of power
Last Answer : directive gain
Description : The property of interchangeability for the transmitting and receiving operations is known as ____
Last Answer : reciprocity
Description : It is the ratio of the radiated to the reflected energy:
Last Answer : Radiation efficiency
Description : It is the resistance that, if it replaced the antenna, would dissipate exactly the same amount of power that the antenna radiates
Last Answer : . Radiation resistance
Description : Plots of field strength or power density with respect to the value at a reference point.
Last Answer : relative radiation pattern
Description : The radiation pattern plotted in terms of electric field strength or power density
Last Answer : absolute radiation pattern
Description : The line bisecting the major lobe, or pointing from the center of the antenna in the direction of maximum radiation is called _____
Last Answer : line of shoot
Description : A special type of transmission line that consist of conducting metallic tube through which high frequency electromagnetic energy is propagated
Last Answer : waveguide
Description : If energy is applied at the geometrical center of antenna, the antenna is said to be ___
Last Answer : center-fed
Description : The radiation pattern of collinear and a broadside antenna is __
Last Answer : bidirectional
Description : Hertz antenna are predominantly used with frequencies above
Last Answer : 2MHz
Description : The point on the antenna where the transmission line is connected is called _____
Last Answer : feedpoint
Description : The discone antenna is
Last Answer : useful as a UHF receiving antenna
Description : It is the same with directive gain except that the total power fed to the antenna is used and the antenna efficiency is taken into account.
Last Answer : power gain
Description : ____ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer.
Last Answer : UDP
Description : ______ are special-interest groups that quickly test, evaluate, and standardize new technologies
Last Answer : Forums
Description : _______ refers to the structure or format of the data, meaning the order in which they are presented.
Last Answer : Semantics
Description : ________ defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation.
Last Answer : syntax
Description : The effect of a large magnitude of the numerical aperture.
Last Answer : The amount of external light the fiber will accept is greater
Description : It is the figure of merit used to measure the magnitude of the acceptance angle.
Last Answer : numerical aperture
Description : It is a result of photons of light that are absorbed by the atoms of the glass core molecule
Last Answer : infrared absorption
Description : It is caused by valence electrons in the silica material from which the fiber are manufactured.
Last Answer : ultraviolet absorption
Description : It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light and covert it to heaT
Last Answer : absorption loss
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber.
Last Answer : Acceptance cone half-angle
Description : Laser light is very bright because it is:
Last Answer : coherent
Description : The process of moving from one energy level to another is called __
Last Answer : Absorption
Description : The process of decaying from one energy level to another energy level is called _______
Last Answer : Spontaneous emission
Description : Any energy above the ground state is called ________
Last Answer : excited state
Description : What phenomenon will result if the glass fiber is exposed to long periods of high humidity?
Last Answer : stress corrosion
Description : Developed an optical fiber with losses less that 2 dB/km
Last Answer : Kao and Bockham
Description : Optical power is sometimes called ____
Last Answer : Radiant flux
Description : The term single mode and multimode are best described as:
Last Answer : the number of wavelengths each fiber can support
Description : Photodiodes operate properly with:
Last Answer : reverse bias
Description : Range of wavelengths of ultraviolet
Last Answer : 10 nm to 390 nm
Description : Range of wavelength of visible light.
Last Answer : 390 nm to 770 nm
Description : Range of infrared.
Last Answer : 770 nm to 10^6 nm
Description : A popular light wavelength fiber-optic cable is
Last Answer : 1.3 micrometer
Description : Single-mode step-index cable has a core diameter in the range of
Last Answer : 2 to 15 micrometer
Description : It is caused by hydroxide ions in the material
Last Answer : ion resonance absorption