Description : A pulse modulation technique as the width of a constant amplitude pulse is varied proportional to the amplitude of the analog signal at the time the signal is sampled.
Last Answer : PWM, PLM, PDM
Description : It is proposed network designed by major telephone companies in conjunction with the ITU-T with the intent of providing worldwide telecommunications support for voice, data, video and facsimile information within the same networ
Last Answer : ISDN
Description : n digital modulation, it is similar to standard amplitude modulation except there is only two amplitudes possible.
Last Answer : amplitude shift keying
Description : In an AM transmitter with 100% modulation, the voltage of the final RF stage will be
Last Answer : approximately four times the DC supply voltage
Description : Pulse width modulation may be generated:
Last Answer : with a monostable multivibrator
Description : It is the ratio of the transmission bit rate to the minimum bandwidth required for a particular modulation scheme
Last Answer : Bandwidth efficiency, Information density, or Spectral efficiency
Description : Which is not purpose of modulation?
Last Answer : Increase in signal power
Description : Pulse – amplitude modulation signals are multiplexed by using
Last Answer : FET switches
Description : Rate of change of a signal on a transmission medium after encoding and modulation have occurred
Last Answer : baud rate
Description : The basic modulator and demodulator circuits in PSK are:
Last Answer : Balanced modulators
Description : It involves converting standard logic levels to a form more suitable to telephone transmission lines
Last Answer : igital line encoding
Description : It is logically equivalent to making telephone call through the DDD network except no direct end-to-end connection is made
Last Answer : Virtual call
Description : FDM telephone systems accommodate many channels by:
Last Answer : Using multiple levels of multiplexing
Description : Type of bend that occurs as a result of differences in thermal contraction rates between the core and the cladding material.
Last Answer : Microbending
Description : Sampling technique that when the tops of the sample pulses retain their natural shape during the sample interva
Last Answer : natural sampling
Description : It is the most prevalent encoding technique used for TDM signals:
Last Answer : PCM
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 : _______ refers to the structure or format of the data, meaning the order in which they are presented.
Last Answer : Semantics
Description : A ________ is a set of rules that governs data communication
Last Answer : protocol
Description : Sixteen different levels (symbols) are used to encode binary data. The channel bandwidth is 36 MHz. The maximum channel capacity is
Last Answer : 288 Mbps
Description : The characters making up the message in a synchronous transmission are collectively referred to as the data
Last Answer : block
Description : A transmission of binary data which involves the transmission of two non – zero voltage level
Last Answer : Bipolar
Description : It is how the primary designates the secondary as the designation of recipient of data
Last Answer : Selection
Description : Variation of biphase that is used for encoding SMPTE time code data and for recording on video tapes
Last Answer : Biphase – M
Description : Set rules implementing and governing an orderly exchange of data between layers of two devices, such as line control units and front – end processors.
Last Answer : Data Link Protocol
Description : Data rate at which serial PCM bits are clocked out of the PCM encoder onto the transmission line.
Last Answer : line speed
Description : Classification of protocol that interprets a frame of data as a group of successive bit combined into predetermined pattern of fixed length, usually 8 bits each.
Last Answer : Character and Byte-oriented protocols
Description : Dividing the data block by a constant produces a remainder that is used for error detection.
Last Answer : Cyclic redundancy check
Description : Category of data transmission if the binary pulse is maintained for the entire bit time?
Last Answer : Return to zero
Description : A _______ is a connecting device that operates in the physical and data link layers of the Internet model.
Last Answer : bridge
Description : IEEE has defined the specifications for a wireless LAN, called _______, which covers the physical and data link layers.
Last Answer : . IEEE 802.11
Description : In the ________ traffic model, the rate of the data flow changes in time, with the changes smooth instead of sudden and sharp.
Last Answer : variable bit rate
Description : In IPv4, what is the value of the total length field in bytes if the header is 28 bytes and the data field is 400 bytes?
Last Answer : 428
Description : The ________ is a function of three values: average data rate, peak data rate, and maximum burst size.
Last Answer : Effective bandwidth
Description : The main advantage of DM over PCM is:
Last Answer : simple circuit
Description : Inan HFC network, the upstream data are modulated using the _______ modulation technique. A) QAM B) QPSK C) PCM D) ASK
Last Answer : QPSK
Description : Inan HFC network, the downstream data are modulated using the _______ modulation technique. A) PSK B) QAM C) PCM D) ASK
Last Answer : QAM
Description : What is a Modem? What is the need of MODEM in data communication? Explain at least one modulation technique used for high speed modems.
Last Answer : Modems are essentially used to interface digital circuits to transmit information on analogue channels like telephone systems. Modem (from modulator-demodulator) is a device that modulates an analogue carrier ... caused by the lines makes the detection even harder than amplitude modulation.
Description : In amplitude modulation technique the unmodulated carrier is referred to as having ______. A. 100% modulation B. 0% modulation C. 50% modulated D. Over modulated
Last Answer : B. 0% modulation
Description : Which of the following statements is correct for the use of packet switching? A. the subdivision of information into individuallyaddressed packets in conjunction with alternativerouting arrangementenabled the transmission path ... capacity could be achieved. D. All of theabove E. None of the above
Last Answer : All of theabove
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 : 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 : 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