ch7 - wire and wireless communications

8/12/2019 Ch7 - Wire and Wireless Communications

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-wire and wireless communications-Typical speech powera. 10 to 1000 Wb. 100 to 1000 mWc. 10 to 1000 nWd. 100 to 1000 pWans: a

-The maximum intelligibility for voice frequency is located betweena. 250 and 500 Hzb. 1000 and 3000 Hzc. 500 and 1000 Hzd. 3000 and 5000 Hzans: b

-The maximum voice energy is located betweena. 250 and 500 Hzb. 1000 and 3000 Hzc. 500 and 1000 Hzd. 3000 and 5000 Hzans: a

-A device used to measure speech volume.

a. speech meterb. volume meterc. volume unit meterd. speedometerans: c

-By definition, for a sine wavea. 0 dBm = 0 V.U.b. 0 dBW = 0 V.U.c. 0 dBa = 0 V.U.d. 0 dBf = 0 V.U.ans: a

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Presently, this is the "standard" frequency bandwidth for voice transmissiona. 0 to 4000 Hzb. 100 to 3400 Hzc. 300 to 3400 Hzd. 300 to 3000 Hzans: c

-Which of the following is commonly used wire for subscriber loop design?a. AWG # 19b. AWG # 18c. AWG # 30d. AWG # 33ans: a

-The resistance limit for No. 2 Crossbar Exchange (US) isa. 1300 ohm(s)b. 2000 ohm(s)c. 1250 ohm(s)d. 1200 ohm(s)ans: a

-AWG # 26 has a typical loss ofa. 0.21 dB/1000 ft.


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b. 0.32 dB/1000 ft.c. 0.41 dB/1000 ft.d. 0.51 dB/1000 ft.ans:

-What is the standard voice channel spacing?a. 44 MHzb. 40 kHzc. 4 kHzd. 40 MHzans:

-Which tester is used to measure SWR?a. Multimeterb. Oscilloscopec. Spectrum analyzerd. Reflectometerans: d

-What is singing?a. The result of intermodulating two or more signals of different frequencies

to produce a tone having a frequency equal to the sum of the frequencies of thesignals intermodulated.b. The result of intermodulating two or more signals of different frequencies

to produce a tone having a frequency higher than that of the signal having the highest frequency.c. An undesired self-sustained oscillation in a system, generally caused by ex

cessive positive feedback.d. An art or a form of entertainment that can make one rich.ans: c

-Which stage increases the selectivity of the circuit in an AM receiver?a. Detectorb. IF stagec. Modulatord. Mixerans: b

- The __________ of radio receiver amplify weak signal and produce a desirable intelligence at the output speaker.a. sensitivityb. selectivityc. reliabilityd. fidelityans: a

-Full-duplex transmission meansa. one-way transmissionb. 24-hour transmissionc. broadcast transmission

d. two-way simultaneous transmissionans: d

-What is a multidrop line?a. A piece of wire with a thick insulating material that serves to protect the

conductive materials from damage in the event the wire is dropped.b. A line designed to withstand high pressure.c. A line or circuit interconnecting several stationsd. A bus line.ans: c


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-A passive _________ is an electronic device which reduce signal strength by a

specified amount in dB.a. splitterb. filterc. trimmerd. attenuatorans: d

-The signal quality of the calls is constantly monitored by the base station, w

hen the quality of the calls drops below a certain specified level, the base request the MTSO to try and find a better cell site.a. Hand-offb. Cell splittingc. Roamingd. Frequency reuseans: c

-A digital identification associated with a cellular system.a. SATb. SIDc. ESNd. MINans: d

- How many seconds does facsimile transmit a standard page?a. 5b. 10c. 20d. 25ans: d

-A kind of recording is used in facsimile.a. Electrolytic recordingb. Electrothermal recordingc. Electropercussive recordingd. Electrostatic recording

ans: a-A type of distortion a facsimile produces when it becomes out of synchronizati

on.a. Pincushionb. Barrelc. Skewingd. Fatteningans: c

-What is an acoustic coupler?a. A device that radiates audible signals via a transmitting antennab. A device that converts electric signal signals into audio signals, enabling

data to be transmitted over the public telephone network via a conventional telephone handsetc. A device that receives audible signals and retransmits them at VHF frequenc

iesd. A transducerans: b

-Cause a herringbone pattern in facsimile.a. Single-frequency interferenceb. Crosstalk


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c. Phase jitterd. Noiseans: b

-The _________ in an FM receiver causes a stronger signal to dominate over a we

aker signal on the same frequency.a. capture effectb. flywheel effectc. hall effectd. skin effectans: a

-A device that converts a 2-wire circuit to a 4-wire circuit.a. RS-232 interfaceb. Hybrid circuitc. Balund. Stubans: b

-__________ theory is deciding between a set of hypotheses when given a collection of imperfect measurements.a. Estimationb. Trafficc. Decision

d. Nyquistans: c-__________ of a data reduction says that when reducing a set of data into theform of an underlying mode, one should be maximally non-committal with respect to missing data.a. Jaynes maximum entropy principleb. Kullback principle of minimum discriminationc. Minimum discriminationd. Maximum entropyans: a

-__________ is selecting the best value of a parameter from a continuum of poss

ible values when given a collection of imperfect measurements.a. Estimationb. Trafficc. Decisiond. Nyquistans: a

-Combination of modulator, channel, and detector.a. Transceiverb. Transponderc. T/R channeld. Discrete channelans: d

-What is the frequency band of DECT?a. 1.88 - 1.90 GHzb. 1.68 - 1.70 GHzc. 1.48 - 1.50 GHzd. 1.28 - 1.30 GHzans: a

-How many simultaneous calls does each DECT system can support?a. 96


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b. 12c. 24d. 49ans: b

-How many simultaneous calls does a DECT radio transceiver can assess at any gi

ven time?a. 120b. 240c. 480d. 960ans: a

-The AGC voltage of a radio receiver is always ________.a. present before adjustments can me madeb. DC, but may have either polarityc. positive DCd. negativeans: b

-What is a concentrator?a. A system that improves the signal-to-noise ratio by compressing the volume

range of a signal.b. A device that varies the characteristics of a carrier signal in accordance

with the waveform of a modulating signal which contains useful information.c. A switching system that lets a large number of telephone or data processingsubscribers use a lesser number of transmission lines or a narrower bandwidth.d. An equipment in the central office.ans: c

-If you find that an SAW filter output is 6 dB down from the input of a receive

r during test, ______________a. this is normalb. the device is faultyc. the filter is improperly terminatedd. the filter is not resonatingans: a

- A triple conversion superheterodyne receiver, diode mixer stages area. operated in the linear regionb. operated in the nonlinear regionc. operated as Class-A amplifiersd. operated as Class-B amplifiersans: b

-What is a leased line?a. A piece of wire used in a local area network in one buildingb. A piece of wire connecting a telephone set to a PABXc. A temporary connection of one computer to a mainframe via a modem and a tel

ephone line

d. A permanent circuit for private use within a communication networkans: d

-If two FM signals of different strengths are received on the same frequencya. one steady heterodyne will appear in the AF outputb. both will appear in the AF outputc. only the stronger will appear in the AF outputd. neither signal will be intelligence unless the weaker signal is at least 10

timesans: c


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-Cellular mobile system was first operated ina. 1979b. 1981c. 1983d. 1985ans: c

-TACS is a cellular system with ____________ channels.a. 666b. 1000c. 832d. 200ans: b

-Supervisory Audio Tone (SAT) has _______ frequency.a. 5960 Hzb. 6000 Hzc. 6040 Hzd. 1004 Hzans: b

-What is the number of channels of a cellular system with an allocated spectrum

of 25 MHz and with a channel of 30 kHz bandwidth?

a. 833b. 240c. 1000d. 666ans: a

-GSM uses what digital modulation technique?a. QAMb. GFSKc. BPSKd. GMSKans: d

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What is the power output of Personal Communications System (PCS)?a. 10 mWb. 75 mWc. 150 mWd. 10 Wans: a

-RG-58 cable has a loss of about ___________ dB at cellular frequencies up to 1

5 feet length.a. 2b. 1c. 4d. 3

ans: d-The signals designed to keep the receivers and transmitters aligned.a. Carrier frequenciesb. Pilot carrier signalsc. Synchronizing signalsd. Reference signalsans: b

-If the spacing of a two-wire open air transmission line is 12 inches and the c


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onductor diameter is 0.25 inch, the characteristic impedance isa. 547 ohm(s)b. 357 ohm(s)c. 273 ohm(s)d. 300 ohm(s)ans: a

-The impedance of the quarterwave transformer used to match a 600 ohm(s) line t

o a 300 ohm(s) load isa. 382 ohm(s)b. 424 ohm(s)c. 565 ohm(s)d. 712 ohm(s)ans: b

-When a line and a load are match the reflection coefficient isa. unityb. zeroc. positive infinityd. negative infinityans: b

-When line is terminated in an open circuit load, the reflection coefficient is

a. unityb. zeroc. infinityd. negative unityans: a

-A 300 ohms line is terminated in a resistive load of 200 ohms, the VSWR isa. 0.66b. 1.5c. unityd. zeroans: b

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If the reflection coefficient is 0.5, the standing wave ratio isa. 0.33b. unityc. 3d. zeroans: c

-To test the fault of a given line, a signal is fed to the line, 30 s later the

signal returned. What is the distance of the fault?a. 9000 mb. 300 mc. 100 md. 4500 m

ans: d-The telephone set is powered by the central office on the ring side ata. 42 to 52 Vdcb. -42 to -52 Vdcc. 24 to 64 Vdcd. -24 to -64 Vdcans: b

-The telephone voice band frequency is from


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a. 300 to 4 kHzb. 400 to 3400 Hzc. 300 to 3400 Hzd. 400 to 4 kHzans: c

-Which of the following wire is used to transmit the signal?a. Blackb. Yellowc. Redd. Greenans: d

-The corresponding frequencies for digit 7 in the touch tone telephone isa. 770 and 1477 Hzb. 852 and 1209 Hzc. 852 and 1336 Hzd. 770 and 1336 Hzans: b

-The physical connection between the telephone set and the switching equipment

is called thea. trunk lineb. link

c. subscriber loopd. leased lineans: c

-What is the local loop of a telephone system?a. It is a two-wire or four-wire communication circuit between the customer's

premise and the central office.b. It is a group of wires connecting a telephone set to a modem.c. It is a four-wire circuit connecting a facsimile machine to a computer.d. It is a single piece of wire connecting the subscriber's telephone set to a

nother set in an adjacent room.ans: d

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Which of the following equipment is used in long loop design?a. Dial long linesb. Voice repeaterc. Loop range extenderd. All of the aboveans: d

-What is a two-wire circuit?a. A circuit usually in the subscriber loop, between the telephone set and the

local central office.b. A circuit having only two terminals, both terminals having the same instant

aneous voltage.c. A circuit with one input terminal, one output terminal, and a common ground

.d. A circuit consisting of two transmission lines.ans: a

-1 mW is equal toa. 90 dBrnb. 0 dBrnc. -30 dBrnd. 120 dBrnans: a


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-Which of the following responds to the request of a subscriber by sending a di

al tone?a. Line finderb. First selectorc. Connectord. Line equipmentans: b

-The other name of Class 2 office in the North American Switching Plan.a. Primary centerb. Sectionc. Regional centerd. Toll pointsans: b

-A cell in the cellular telephone system meansa. a power sourceb. small areac. large aread. service areaans: b

-What is the linking point between cell phone and regular telephone?

a. Base stationb. Control officec. C.O.d. MTSOans: d

-What is the typical power output of a cellular phone?a. 5 Wb. 10 Wc. 1 Wd. 3 Wans: d

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When a single cell is subdivided into smaller cells the process is calleda. cell splittingb. cell divisionc. reused. cell sharingans: a

-The first cell shape is aa. squareb. circlec. rectangled. triangleans: b

-In order to provide 100% coverage without overlap, cellular telephone system c

an usea. hexagon cell shapeb. trianglec. rectangulard. all of the aboveans: d

-What is the beamwidth of the reflector of the receiving antenna in the base st


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ation?a. 20 degreesb. 30 degreesc. 50 degreesd. 60 degreesans: d

-A cellular phone operates ona. half duplexb. full duplexc. echoplexd. lincomplexans: b

-Cellular phones transmit in the band froma. 825 to 845 MHzb. 835 to 855 MHzc. 825 to 855 MHzd. 825 to 865 MHzans: a

-Cell phone receives in the band froma. 860 to 880 MHzb. 870 to 890 MHz

c. 870 to 880 MHzd. 860 to 890 MHzans: b

-What is the frequency separation between the transmit and the receive channels

?a. 30 MHzb. 45 MHzc. 55 MHzd. 40 MHzans: b

-For channel 1, transmit/receive frequency is

a. 825.030/870.030 MHzb. 835.03/880.03 MHzc. 825.015/870.015 MHzd. 825.15/870.15 MHzans: c

-The number of transmit/receive channels in the cellular system isa. 625b. 645c. 655d. 666ans: d

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The transmission range of cellular telephony is generally abouta. 80 kmb. 65 kmc. 160 kmd. 16 kmans: a

-When the message is transferred from one cell site transmitter to another cell

site transmitter as the caller crosses a boundary _________ process takes place.


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a. shiftingb. hand offc. give offd. turn overans: b

-What is the sensitivity of a cellular receiver?a. 20 dBb. 40 dBc. 50 dBd. 60 dBans: c

-What is the frequency deviation of the cellular telephone system?a. 15 kHzb. 30 kHzc. 12 kHzd. 75 kHzans: c

-Hailing channel is otherwise known asa. conversation channelb. calling channelc. signaling channel

d. remote channelans: b-What is an Erlang?a. It is a unit of magnetic field intensity measured around a conductorb. It is the number of erroneous bits received per unit of timec. It is a unit of electrical energy radiated in spaced. It is equal to the number of simultaneous calls originated during a specifi

c hourly periodans: d

-All of the cell base stations are linked together by ______ which serves as th

e central office and management node for the group.

a. MTSb. IMTSc. MSTOd. MTSOans: d

-Provides interface between the mobile telephone switching office and the mobil

e units.a. Databaseb. Cell sitec. Terrestrial linkd. Radio transmitterans: b

-A phone call over the cellular network requiresa. simplex channelsb. half duplex channelsc. full duplex channelsd. full/full duplexans: c

-A method of expressing the amplitudes of complex non-periodic signals such as

speech.


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a. Volumeb. Pitchc. Frequencyd. Wavelengthans: a

-_________ is a signal returned to the talker after making one or more round trips between the talker and the listener.a. Singingb. Echoc. Jitterd. Crosstalkans: b

-_________ is a voice operated device that insert a high loss in the opposite direction of transmission of the talking party.a. Hybridb. 2-wire circuitc. Echo suppressord. VNLans: c

-_________ is picking up of the same station at two nearby points on the receiver dial.

a. Double spottingb. Hot shotc. Image frequencyd. Bail shotans: a

-When one channel picks up the signal carried by another channel.a. Echob. Crosstalkc. Party lined. Crosslinkans: b

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What type of connector arrangement wherein a customer may move to another location and still retain the same telephone number.a. TPLb. Bridgec. TPSd. Party lineans: c

-It is an advantage of sidetone.a. Transmission efficiency is increasedb. Speaker increase his voice resulting in a strengthened signalc. No dissipation of energy in the balancing networkd. Assures the customer that the telephone is working

ans: d-Radio communications between points using a single share frequency.a. Simplexb. Full duplexc. Half-duplexd. Full/full duplexans: c

-The transmission of information from multiple sources occurring on the same fa


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b. FSKc. Vestigial sideband AMd. FMans: a

-Most fax printers are of which type?a. Impactb. Thermalc. Electrosensitived. Laser xerographicans: b

-Facsimile standards are set by thea. FCCb. DODc. CCITTd. IEEEans: c

-What type of graphics are commonly transmitted by radio fax?a. Newspaper textb. Architectural drawingsc. Cable moviesd. Satellite weather photos

ans: d-What is the transmission speed of group 4 fax?a. 4800 baudb. 9600 baudc. 56 kbits/sd. 192 kbits/sans: c

-What is the cause of insertion loss?a. Thermal noise that intermodulate with signal traveling on the same medium.b. A momentary disruption of signal due to power interruptionc. A low level high frequency signal inserted into the original signal caused

by thermal noised. none of theseans: d

-__________ is the master control center for cellular telephone system.a. Cell siteb. Mobile telephone switching officec. Central officed. Branch officeans: b

-Each cell site contains aa. repeater

b. control computerc. direct link to a branch exchanged. touch-tone processorans: a

-What is a trunk?a. The base of a communications tower.b. A telephone line connecting two central offices.c. A line connecting one telephone set to a PABX.d. Refers to the body of a tree.


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ans: b-Cellular telephones use which type of operation?a. Simplexb. Half-duplexc. Full-duplexd. Triplexans: c

-What is the maximum frequency deviation of an FM cellular transmitter?a. 6 kHzb. 12 kHzc. 30 kHzd. 45 kHzans: b

-Receive channel 22 is 870.66 MHz. Receive channel 23 isa. 870.36 MHzb. 870.63 MHzc. 870.96 MHzd. 870.69 MHzans: d

-A transmit channel has a frequency of 837.6 MHz. The received channel frequenc

y isa. 729.6 MHzb. 837.6 MHzc. 867.6 MHzd. 882.6 MHzans: d

-A receive channel frequency is 872.4 MHz. To develop an 82.2 MHz IF, the frequ

ency synthesizer must supply an LO signal ofa. 790.2 MHzb. 827.4 MHzc. 954.6 MHzd. 967.44 MHz

ans: c-The output power of a cellular radio is controlled by thea. user or callerb. cell sitec. called partyd. MTSOans: d

-When the signal from a mobile cellular unit drops below a certain level, what

action occurs?a. The unit is "handed off" to a closer cellb. The call is terminated

c. The MTSO increases power leveld. The cell site switches antennaans: a

-In a cellular radio, the duplexer is aa. ferrite isolatorb. waveguide assemblyc. part of TR/ATR tubesd. pair of sharp bandpass filtersans: d


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-On a telephone system, the loop is open duringa. on-hook conditionb. off-hook conditionc. both A and Bd. none of theseans: a

-For every button pressed on a touch-tone telephone, how many signals are trans

mitted to the C.O.?a. Two VHF signalsb. One VHF signal and one audio-frequency tonec. Two audio-frequency tonesd. Three audible tonesans: c

-What is the traffic model about blocked calls clear condition specified blocki

ng probability?a. Erlang Bb. Erlang Cc. Erlang Dd. Poissonans: a

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A touch-tone telephone generates how many different tones.a. 10 audio-frequency tonesb. 8 audible tone frequenciesc. 4 VHF signalsd. 16 audio-frequency tonesans: b

-The base-to-mobile frequency assignment of a GSM system.a. 890 - 915 MHzb. 825 - 845 MHzc. 870 - 890 MHzd. 935 - 960 MHzans: d

- A voice-grade channel is suitable for transmission ofa. VHF signalsb. UHF signalsc. VHF and UHF signalsd. signals with a frequency ranging from 300 to 3400 Hzans: d

-What is the bandwidth of cellular CDMA system?a. 1.23 MHzb. 1.23 GHzc. 1.23 kHzd. 1.23 THz

ans: a-What is a communication link?a. It is a piece of wire that is connected to ground terminals of all communic

ations equipment in one establishment.b. It is a channel or circuit intended to connect other channels or circuits.c. It is a cable connecting a transmitter to the antennad. It refers to a radio link.ans: b

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Block calls held condition specified the held probability at a time period equal to an average holding time.a. Erlang Bb. Erlang Cc. Erlang Dd. Poissonans: d

-What is an echo?a. A signal of the same amplitude but 180 degrees out of phase from the origin

al signal and mixed with the original signal at the transmitter to produce a more intelligible output signal.b. A wave which has been reflected or otherwise returned with sufficient magni

tude and delay for it to be perceptible in some manner as a wave distinct from that directly transmitted.c. The signal having a higher frequency than the original and transmitted back

to earth by a passive satellite.d. A reflected signal.ans: b

-What is the system used by Personal Communication Network (PCN)a. TACSb. Modified GSMc. AMPS

d. CDMAans: b-Termination refers toa. cutting both ends of a conductorb. disconnecting a line from a transmitterc. looking back impedance of a line with no loadd. load connected to the output end of a transmission lineans: d

-The multiple access used by Digital European Cordless Telephone (DECT).a. CDMAb. FDMA

c. TDMAd. CDMA/FDMAans: c

-Blocked calls delay condition specified delay probability.a. Erlang Bb. Erlang Cc. Erlang Dd. Poissonans: b

-Status information provided by telephone signaling.a. Busy tone, dial tone and ringing

b. Congestion and call charge datac. All of the aboved. none of the aboveans: c

-The modulation technique used by DECT.a. GFSKb. ASKc. QAMd. PSK


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ans: a-What is a four-wire circuit?a. is used between serving central offices for long-distance connections, with

one pair being used for each direction of transmission.b. Is a circuit with three output terminals and one input terminalc. Is an oscillator that produces four different frequencies simultaneouslyd. A circuit consisting of four transmission lines.ans: a

-Cellular CDMA system uses what modulation method?a. GFSKb. ASKc. QAMd. BPSKans: d

-PABX meansa. Private All-purpose Broadcasting Exchangeb. Private Automatic Branch Exchangec. Public Access Bi-directional Exchanged. Public Automatic Branch Exchangeans: b

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What is the voted cellular digital standard at TIA?a. Digital AMPSb. GSMc. CDMAd. TACSans: a

-What is the number of channels for Band A and for Band B in Digital AMPS?a. 832b. 416c. 666d. 888ans: b

- The mobile-to-base frequency assignment for GSM system isa. 890 - 915 MHzb. 935 - 960 MHzc. 870 - 890 MHzd. 825 - 845 MHzans: a

-The range (in miles) of a cellular CDMA system.a. 13b. 30c. 45d. 20

ans: a-In a cellular system, ____________ is used to measure the spectrum efficiency.

a. radio efficiencyb. diversityc. frequency reused. radio capacityans: d

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Which of the following echo is completely out of control?a. Worst echob. Reverberationc. Singingd. Feedbackans: c

-Which of the following devices increase the battery voltage on a loop and exte

nds its signaling range?a. Loop extenderb. VF repeaterc. VF amplifierd. All of theseans: a

-Under ordinary circumstances, the CCITT recommends that the number of circuits

in tandem must not exceeda. 9b. 10c. 11d. 12ans: d

-What is the system capacity of AMPS?

a. 30,000b. 60,000c. 100,000d. 120,000ans: c

-NAM meansa. Non Alternable Memoryb. Number Allocation Modulec. Numeric Assignment Moduled. Numeric Access Moduleans: c

ch7 - wire and wireless communications

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