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Book review of Blake's book on Electronics Communications
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BLAKE Summary
LISTS OF CONTENTS
CHAPTER 1: INTRODUCTION TO COMMUNICATION SYSTEMS
CHAPTER 2: RADIO FREQUENCY CIRCUITS
CHAPTER 3: AMPLITUDE MODULATION
CHAPTER 4: ANGLE MODULATION
ADDITIONAL NOTES: FM and PM
CHAPTER 5: TRANSMITTERS
CHAPTER 6: RECEIVERS
CHAPTER 7: DIGITAL COMMUNICATIONS
CHAPTER 8: THE TELEPHONE SYSTEM
CHAPTER 9: DATA TRANSMISSION
CHAPTER 10: LOCAL AREA NETWORKS
CHAPTER 11: WIDE AREA NETWORKS AND THE INTERNET
CHAPTER 12: DIGITAL MODULATION AND MODEMS
CHAPTER 13: MULTIPLEXING AND MULTIPLE-ACCESS TECHNIQUES
CHAPTER 14: TRANSMISSION LINES
CHAPTER 15: RADIO-WAVE PROPAGATION
CHAPTER 16: ANTENNAS
CHAPTER 17: MICROWAVE DEVICES
CHAPTER 18: TERRESTRIAL MICROWAVE COMMUNICATIONS SYSTEMS
CHAPTER 19: TELEVISION
CHAPTER 20: SATELITE COMMUNICATION
CHAPTER 21: CELLULAR RADIO
CHAPTER 22: PERSONAL COMMUNICATION SYSTEMS
CHAPTER 23: PAGING AND WIRELESS DATA NETWORKING
CHAPTER 24: FIBER OPTICS
CHAPTER 25: FIBER OPTIC SYSTEMS
ADDITIONAL NOTES: NAVIGATIONAL AIDS
CHAPTER 1: INTRODUCTION TO COMMUNICATION SYSTEMS
1. It moves information from a source to a destination Communication System
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BLAKE Summary
through a channel.
2. Elements of a communication system Source, Transmitter, Channel, Receiver, Destination
3. Three essential elements of any communication system
Transmitter, Receiver, Channel
4. Sources of information signals Analog and Digital
5. Sources are often described in terms of the ___________ ________ that they occupy
Frequency Range
6. The element of a communication system wherein the signal will be driven out of the source to the channel.
Transmitter
7. This element of communication system can be a pair of conductors or an optical fiber or the free space wherein the signal is traveling to the receiver
Channel
8. In a free space channel, ______ signal is required to avoid interference.
Carrier
9. When a carrier is used, the information signal can be also called as __________ ______.
Modulating Signal
10. Since the carrier frequency is generally much higher than that of the information signal, the frequency spectrum of the information signal is often referred to as _________.
Baseband
11. Modulation is done at the _______. Transmitter12. This process takes place at the receiver wherein the
signal has to be restored to its original baseband signal.Demodulation
13. It states that the amount of information that can be
transmitted in a given time is proportional to bandwidth
for a given modulating scheme..
Hartley’s Law
14. It refers to the combining of two or more information
signals.Multiplexing
15. Methods of multiplexing.
Frequency-Division
Multiplexing,
Time-Division Multiplexing16. When the available frequency is divided among the
signals, the process is known as ______________
_________.
Frequency-division
Multiplexing
17. In this process, the entire bandwidth is used for each
signal, but only for a small part of time.Time-Division Multiplexing
18. It is the available bandwidth of a communication
satellite divided among a number of transmitter-
receiver combinations.
Transponder
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BLAKE Summary
19. It is any undesirable change in an information signal. Distortion20. A representation of a signal’s power or amplitude as a
function of frequency.Frequency Domain
21. A way of representing the periodic functions as a series
of sinusoids.Fourier Series
22. Any undesired disturbance that is superimposed on a
signal and obscures its information contentNoise
23. Noise which originates within the communication
equipment.Internal Noise
24. Noise outside the communication equipment. External Noise25. Noise generated by equipment that produces sparks. Equipment Noise26. Noise that is originated from lightning. Atmospheric Noise27. Refer to no. 28: another name for this kind of noise Static28. Noise that comes from heavenly bodies that are
powerful sources of radiation.Space Noise
29. This noise is produced by the random motion of
electrons in a conductor due to heat.Thermal Noise
30. This is due to random variations in current flow in
active devices such as tubes, transistors, and
semiconductor diodes.
Shot Noise
31. Noise that occurs in the partition of the Negative and
Positive elements in a semiconductor such as BJT.Partition Noise
32. This noise is cause by variations in carrier density. Excess Noise33. Refer to no. 34: another name for it. Flicker Noise, Pink Noise34. Noise that many junction devices produce due to cut-off
frequency reaching.Transit-Time Noise
35. ratio of signal to noise power at a given point in a
system.Signal-to-Noise Ratio
36. Device for displaying signals in the frequency domain. Spectrum Analyzer37. It is a figure to merit, indicating how much a
component, stage, or series of stages degrades the
signal-to-noise ratio of a system.
Noise Figure
38. Refer to no. 39: Another name for that. Noise Factor39. It is the absolute temperature of a resistor that,
connected to the input of a noiseless amplifier of the
same gain, would produce the same noise at the
output.
Equivalent Noise
Temperature
40. Representation of a signal’s amplitude as a function of
time.Time Domain
CHAPTER 2: RADIO FREQUENCY CIRCUITS
1. A mixer in which the input frequencies are cancelled
and are therefore not present at the output.Balanced Mixer
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BLAKE Summary
2. Removal of an unwanted signal by providing a low-
impedance path to ground.Bypassing
3. The total frequency range over which a PLL can become
locked to a signal.Capture Range
4. A small stab of quartz with attached electrodes; used as
a resonant circuit.Crystal
5. It is to prevent the undesired passage of signals
between circuits.Decouple
6. A frequency multiplier whose output frequency is twice
that of the input signal.Doubler
7. The frequency at which a VCO operates when its control
voltage is zero.Free-running Frequency
8. A circuit whose output frequency is a small integer
multiple of the input signal frequency.Frequency Multiplier
9. A device that can produce a large number of output
frequencies from a smaller number of fixed-frequency
oscillators.
Frequency Synthesizer
10. Movement of a signal from one frequency to another
using a mixer-oscillator synthesizer.Frequency Translation
11. A small length of wire, connected at only one end as a
capacitance to ground.Gimmick
12. An artificial ground, often consisting of an area foil left
on one side of a circuit board.Ground Plane
13. Total range of frequencies over which a PLL, once
locked, can remain locked.Lock Range
14. This effect is in some amplifiers that the internal
capacitance of the active device can cause feedback
that produces the same effect on the circuit as much
larger capacitance across the amplifier input.
Miller Effect
15. A nonlinear circuit designed to generate sum and
difference frequencies when two or more frequencies
are present at its inputs.
Mixer
16. The number by which a digital divider chain divides.Modulus
17. A circuit whose output is proportional to the product of
the instantaneous amplitudes of two input signals.Multiplier
18. A means of avoiding instability in amplifiers by using
negative feedback.Neutralization
19. A device whose output voltage is a function of the
phase difference between two input signals.Phase Detector
20. A device that locks the frequency of a VCO exactly to
that of an input signal.Phase-locked Loop (PLL)
21. An effect that occurs in some materials, such as quartz
and some ceramics, whereby a voltage is produced
across the material when it is deformed.
Piezoelectric Effect
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BLAKE Summary
22. A divider that precedes the main programmable divider
in a frequency synthesizer.Prescaler
23. In a frequency synthesizer, it is the smallest amount by
which the output frequency can be changed.Resolution
24. The frequency at which a single component becomes a
resonant circuit, because the presence of stray
capacitance or inductance, or both.
Self-Resonant Frequency
25. A frequency multiplier whose output frequency is three
times that of the input signal.Tripler
26. A reverse-biased diode used as a voltage, variable
capacitor.Varactor
27. An oscillator whose frequency can be controlled by
changing external control voltage.
Voltage-Controlled Oscillator
(VCO)28. This oscillator type can be recognized by its use of a
tapped inductor, part of the resonant circuit, to provide
feedback.
Hartley Oscillator
29. It’s an oscillator that uses capacitive voltage divider
instead of a tapped inductor to provide feedback.Colpitts Oscillator
30. It is a variation of Colpitts circuit, designed to swamp
device capacitances for greater stability.Clapp Oscillator
31. This is typically tuned by moving a ferrite core into or
out of the coil.Slug Tuning
CHAPTER 3: AMPLITUDE MODULATION
1. A modulation scheme in which the amplitude of a high-
frequency signal is varied in accordance with the
instantaneous amplitude of an information signal.
Amplitude Modulation (AM)
2. The curve produced by joining the tips of the individual
RF cycles of a modulated waveEnvelope
3. Measure of the extent of the modulation of a signal. Modulation Index4. Modulation of a greater depth than allowed. Over modulation5. The power measured at modulation peaks in an AM or
single-sideband signal.Peak Envelope Power (PEP)
6. Transmission of two separate information signals using Quadrature AM
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BLAKE Summary
two amplitude-modulated carriers at the same
frequency but differing in phase by 90 degrees.7. A signal component in a modulated signal, at a
frequency different from that of a carrier.Side Frequency
8. All of the side frequencies to one side of the carrier
frequency.Sideband
9. Any AM scheme in which only one of the two sidebands
is transmitted.Single-sideband
10. An AM signal in which the carrier frequency component
is eliminated and only one or both sidebands are
transmitted.
Suppressed-carrier Signal
11. It is a colloquial term used to describe additional side
frequencies produced by over modulation or distortion
in an AM system.
Splatter
12. A signal consisting of two audio frequencies, not
harmonically related, used to test single-sideband
transmitters.
Two-tone Test Signal
13. The higher-frequency signal that is combined with an
information signal to produce the modulated waveform
is called ________.
Carrier
CHAPTER 4: ANGLE MODULATION
1. A general term that includes frequency and phase
modulation.Angle Modulation
2. It is the ability of an FM receiver to receive the stronger
of two signals, ignoring the weaker.Capture Effect
3. The frequency of a signal before modulation is applied
and the power transmitted at the carrier frequency
varies with modulation for an FM signal.
Carrier Frequency
4. It is the use of low-pass filter in a receiver to remove
the effect of pre-emphasis on the frequency response.De-emphasis
5. The amount by which the frequency of an FM signal
shifts to each side of the carrier frequency.Frequency Deviation
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BLAKE Summary
6. IN FM and PM, the peak amount in radians by which the
phase of a signal deviates from its resting value.Modulation Index
7. Fm with relatively low modulation index. Narrowband FM (NBFM)8. It is the use of a high pass filter in an FM transmitter to
improve the signal-to-noise ration; always used with de-
emphasis at the receiver.
Pre-emphasis
9. It is the frequency of the unmodulated carrier of an FM
signal.Rest Frequency
10. Refer to no. 9: Another name for it. Carrier Frequency11. A secondary carrier that can carry an additional
modulating signal and is itself modulated onto the main
carrier.
Subcarrier
12. It is the noise-reduction effect that occurs with strong
FM signals.Threshold Effect
13. FM with a relatively large modulation index. Wideband FM (WBFM)14. This represents normalized voltages for the various
frequency components of an FM or PM signal.Bessel Functions Table
ADDITIONAL NOTES: FM and PM
1. A type of angle modulation wherein the frequency is varied relative to the modulating frequency.
Frequency Modulation
2. It is the amount by which the frequency varies from its unmodulated value.
Frequency Deviation
3. The total Variation in frequency. Carrier Swing4. It is the ratio of the actual deviation to the
maximum deviation multiplied by 100%. Percentage of Modulation
5. In AM, P total is variable while in FM P total is _____. Constant6. It is the boosting of the higher modulating
frequencies at the transmitter, in accordance with pre-arranged curve to improve noise immunity at FM.
Pre-emphasis
7. The cutting of the higher modulating frequencies at the receiver.
De-emphasis
8. Forms of interference in FM. Image Frequency,
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BLAKE Summary
Co-channel interference,Adjacent channel
9. it is an effect of two stations being received simultaneously.
Image Frequency
10. It happens usually to mobile receivers when they travel from one transmitter to the other.
Co-channel Interference
11. It is the modulation wherein the phase of the carrier is made proportional to the instantaneous value of the modulating signal.
Phase Modulation
12. FM and Pm are indistinguishable for a single ______ ________. Modulating frequency
13. When modulating frequency is changed, PM modulation index ______ _______. Remains constant
14. It is the process by which the modulating signal is recovered from the modulated carrier, definitely found in receivers.
Demodulation
15. It has the function of selecting the desired signal from all the other unwanted signals, amplifying and demodulating it, and displaying it in the desired manner.
Receiver
16. Two types of receivers. Tuned Radio Frequency,Superheterodyne Receiver
17. Characteristics of a tuned radio frequency receiver.
Simple logical receiver,Simplicity and high sensitivity,Align at broadcast frequencies 535-1640 kHz
18. It is the ability to amplify weak signals. Sensitivity19. It is the ability to reject unwanted signals. Selectivity20. It is the ratio of gain at desired frequency to the
gain of image frequency signal. Image Rejection Ratio
CHAPTER 5: TRANSMITTERS
1. A scheme for keeping a transmitter or receiver
tuned to the correct frequency.
Automatic Frequency Control
(AFC)2. A circuit for keeping the amplitude of a signal within
prescribed limits.
Automatic-level-control
Circuit3. An amplifier stage used to isolate two other stages
from each other.Buffer
4. Change of carrier amplitude with modulation in an
AM transmitter.Carrier Shift
5. It is the system that provides more gain for low- Compression
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BLAKE Summary
level than for higher-level signals.6. Any system that generates FM without using phase
modulation.Direct FM
7. A device that allows a signal moving along a
transmission line in one direction to be measured.Directional Coupler
8. An amplifier which supplies the required input signal
power for a power amplifier.Driver
9. A noninductive power resistor used to simulate an
antenna.Dummy Load
10. It is a ratio of time on to total time. Duty Cycle11. It is the ratio between largest and smallest signals
at a point in a system.Dynamic Range
12. The part of the transmitter that operates at low
power levels.Exciter
13. It is the ability of a transmitter to tune rapidly from
one operation frequency to another.Frequency Agility
14. Amplitude modulation of the output element of the
output stage of a transmitter.High-level Modulation
15. Any method that generates FM using a phase
modulator and an integrator.Indirect FM
16. Transmitter power amplifier stage immediately
before the output stage.Low-level Modulation
17. An oscillator whose frequency is controlled by a
binary number written to an internal register.
Numerically-controlled
Oscillator18. Ratio of the power output of a device to the total
power required from its power supply.Overall Efficiency
19. It is the absence of spurious signals in the output of
a transmitter.Spectral Purity
20. An emission from a transmitter other than the
carrier and sidebands required by the modulation
scheme in use.
Spurious Signal
21. Importance of transmitter efficiency.Maximum energy conversion,
reasonable cost efficiency
CHAPTER 6: RECEIVERS
1. The communications channel immediately above or
below the desired channel in frequency.Adjacent Channel
2. The next communications channel beyond the
adjacent channel.Alternate Channel
3. A combined mixer and local oscillator that uses one
transistor or tube for both.Autodyne Converter
4. A circuit to adjust the gain of a system in
accordance with the input signal strength.Automatic Gain Control (AGC)
5. Reduction of gain for a weak signal due to a strong
signal close to it in frequency.Blocking
6. A bandpass filter using piezoelectric ceramic Ceramic Filter
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BLAKE Summary
elements.7. A combination of a mixer and a local oscillator that
is used to move a signal from one frequency to
another.
Converter
8. a bandpass filter that uses piezoelectric quartz
element.Crystal Filter
9. Circuit to recover the baseband signal from a
modulated signal.Demodulator
10. It is a specialized microprocessor designed to
perform arithmetic operations on digitized
communication signals.
Digital Signal Processor
11. Any detector for FM or Pm signals. Discriminator12. An AM demodulator that works by rectifying the
signal and low-pass filtering the result.Envelop Detector
13. The first stage of a receiver. Front End14. It is the application to a mixer of a signal from a
local oscillator that operates at a frequency above
that of the incoming signal.
High-side Injection
15. In a frequency converter, it is a second input
frequency that produces the same output
frequency.
Image Frequency
16. A frequency to which a signal is shifted as an
intermediate step in reception or transmissionIntermediate Frequency (IF)
17. An oscillator used in conjunction with a mixer to
shift a signal to a different frequency.Local Oscillator
18. Application to a mixer of a signal from a local
oscillator that operates at a frequency below that of
the incoming signal.
Low-side Injection
19. A bandpass filter that uses mechanical resonators. Mechanical Filter20. Low-level carrier signal transmitted to facilitate
regeneration of the carrier at the receiver.Pilot Carrier
21. A detector for suppressed-carrier AM signals that
works by multiplying the signal with a regenerated
carrier.
Product Detector
22. The strength of an unmodulated carrier that
reduces the noise output of an AM receiver by a
specified amount.
Quieting Sensitivity
23. FM detector that is based on a 90-degree phase
shift network.Quadrature Detector
24. FM detector. Ratio Detector25. It is the ratio of signal-plus-noise and distortion to
noise-plus-distortion.SINAD
26. A meter on a receiver that indicates the strength of
the received signal.S-meter
27. The ability of a receiver to reject signals of
frequencies other than the frequency to which the
Selectivity
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BLAKE Summary
receiver is tuned.28. The ability of a receiver to receive weak signals with
a satisfactory signal-to-noise ratio.Sensitivity
29. For a bandpass filter, it is the ratio between the
bandwidths for two specified amounts of
attenuation.
Shape Factor
30. It is the reduction in effective cross-sectional area of
a conductor with increasing frequency.Skin Effect
31. It is the reception of signals at frequencies other
than that to which the receiver is tuned.Spurious Response
32. A system that disables the output of a receiver in
the absence of a suitable signal.Squelch
33. It is a receiver in which the signal is moved, using a
mixer, to an intermediate frequency before
demodulation.
Superheterodyne Receiver
34. The filter that uses acoustic waves on the surface of
a substrate to achieve the desired response.Surface-Acoustic Wave Filter
35. It is the adjustment of two or more tuned circuits so
that they can be tuned simultaneously with one
adjustment.
Tracking
36. It is a receiver in which the signal is amplified at its
original frequency before demodulation.
Tuned-radio-frequency (TRF)
Receiver37. The Fm signal strength with defined deviation,
required to produce a specified SINAD in the
receiver.
Usable Sensitivity
CHAPTER 7: DIGITAL COMMUNICATIONS
1. Distortion created by using too low a sampling rate
when coding an analog signal for digital
transmission.
Aliasing
2. A data code that uses both polarities of voltage and
current.Bipolar Code
3. Device that converts sampled analog signal to and
from its PCM or delta modulation equivalent.Coder-decoder (codec)
4. Conversion of sampled analog signal into a PCM or
delta modulation bitstream.Coding
5. Combination of compression at the transmitter and
expansion at the receiver of communication system.Companding
6. Amplification of a signal in such a way that there is
less gain for higher-level input signals than for
lower-level input signals.
Compression
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BLAKE Summary
7. Conversion of a PCM or delta modulation bitsream
to analog samples.Decoding
8. A coding scheme that records the change in signal
level since the previous sample.Delta Modulation
9. It is filtering of signals by converting them to digital
form.
Digital Signal Processing
(DSP)10. Sampling of an analog signal using a sample-and-
hold circuit.Flat-topped Sampling
11. Another name for aliasing. Foldover Distortion12. These are bits added to a digital signal to help the
receiver detect the beginning and end of data
frames.
Framing Bits
13. A system for translating logic ones and zeros into
voltage or current levels for transmission.Line Code
14. Sampling of an analog signal to know if it follows
the original signal for the duration of the sample.Natural Sampling
15. A logic system in which a low level represents logic
one and a high level represents logic zero.Negative Logic
16. A data line code in which the voltage or current
does not necessarily return to zero between bits.
Non-return-to-zero Code
(NRZ)17. A logic system in which a high level represents logic
one and low level represents logic zero.Positive Logic
18. A series of pulses in which the amplitude of each
pulse represents the amplitude of the information
signal at a given time.
Pulse-amplitude Modulation
(PAM)
19. A series of pulses in which the amplitude of the
information signal at a given time is coded as a
binary number.
Pulse-code Modulation (PCM)
20. A series of pulses in which the duration of each
pulse represents the amplitude of the information
signal at a given time.
Pulse-duration Modulation
(PDM)
21. A series of pulses in which the timing of each pulse
represents the amplitude of the information signal
at a given time.
Pulse-position Modulation
(PPM)
22. Another name for pulse-duration modulation.Pulse-width Modulation
(PWM)23. Representation of a continuously varying quantity
as one of a number of discrete values.Quantizing
24. Inaccuracies caused by the representation of
continuously varying quantity as one of a number of
discrete values.
Quantizing Errors
25. Refer to no. 24: Another name for it. Quantizing Noise26. A device that decodes and recodes a digital signal
as well as amplifying it.Regenerative Repeater
27. Method of data compression by encoding the length Run-length Encoding
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BLAKE Summary
of a string of ones and zeroes.28. A line code in which the voltage or current returns
to zero at the end of each bit period.Return-to-zero Code (RZ)
29. A device that detects the amplitude of an input
signal at a particular time.Sample-and-hold Circuit
30. It is an error condition that occurs when the analog
signal to be digitized varies too quickly for the
system to follow.
Slope Overload
31. A line code in which the polarity of the voltage
remains the same at all times.Unipolar Code
32. It is a circuit for digitizing voice at a low data rate. Vocoder33. Modern communication systems are often a mixture
of _______ and _________ sources and transmission
techniques.
Analog,
Digital
34. _________ _________ ______ have better performance
and use less bandwidth than equivalent analog
systems.
Modern Digital Systems
35. It requires that the amplitude of each sample of a
signal be converted to a binary number.PCM
36. It transmits only one bit per sample. Delta Modulation37. The S/N ratio for either PCM or delta modulation
signals can often be improved by using __________.Companding
38. It eliminates redundant data bits. Lossless Compression39. It compromises signal quality in order to reduce the
bit rate.Lossy Compression
40. It is a combination of modulation and demodulation. Modem41. He showed mathematically that it is impossible to
reconstruct a band-limited analog signal from
periodic samples.
Harry Nyquist
42. It provides strong timing information regardless of
the pattern of ones and zeros.Manchester Code
43. Manchester code is also a type of _________
_________.Biphase Code
44. In RZ coding, the system used in telephony is
_________.
Alternate Mark Inversion
(AMI)45. It states that the amount of information transmitted
is proportional to both bandwidth and time.Hartley’s Law
46. It is used mainly for digital communication. TDM
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BLAKE Summary
CHAPTER 8: THE TELEPHONE SYSTEM
1. An area consisting of several central offices and
handled by a local carrier.
Local Access and Transport Area
(LATA)2. The link from the central office to an individual
subscriber’s premises.Local Loop
3. It is the method of providing high-speed data
transmission on twisted-pair telephone loops by
using high-frequency carriers.
Asymmetrical Digital Subscriber
Line (ADSL)
4. In ISDN, these are channels that carry
subscriber communication.Bearer Channels
5. Described as the used of bits that normally
carry payload information for other purposes
such as controlling the communication system.
Bit Robbing
6. It is addition of bits to a bitstream to
compensate for timing variations.Bit Stuffing
7. It is the failure to connect a telephone call
because of lack of system capacity.Call Blocking
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BLAKE Summary
8. Switch in the telephone system that connects to
local subscriber lines.Central Office
9. It is a communication system in which a
dedicated channel is to set up between parties
for the duration of the communication.
Common-channel Signaling
10. A control system for telephone switching that
sets up one call and then goes on to set up
another call without being tied up for the
duration of the first call.
Common Control
11. A switching system that uses a matrix
arrangement of incoming and outgoing lines.Crosspoint Switch
12. Interference between two signals multiplexed
into the same channel.Crosstalk
13. In ISDN, it is the communication channel used
for setting up calls and not for user
communication.
Data Channel
14. It is a signaling using combinations of two audio
tones transmitted on the voice channel.
Dual-tone Multifrequency Dialing
(DTMF)15. Another name for central office. End Office16. It is the use of optical fiber for telephone
connections tom individual customers.Fiber-in-the-loop (FITF)
17. It is a switching network that relies on a
computer to find the most direct route between
two points.
Flat Network
18. A type of communication system that allows
communication in both directions
simultaneously.
Full Duplex
19. A frequency-division multiplexing scheme that
allows twelve voice signals to be transmitted in
one channel.
Group
20. It is a specialized transformer that allows
telephone voice signals to travel in both
directions simultaneously on a single twisted-
pair loop.
Hybrid Coil
21. Telephone system using digital local loops for
both voice and data, with the codec in the
telephone equipment.
Integrated Services Digital
Network (ISDN)
22. A frequency-division multiplexed signal
consisting of six mastergroups or 3600
voiceband channels.
Jumbogroup
23. Another name for bit stuffing. Justification24. Colloquial term for subscriber line interface
card.Line Card
25. Inductance added to a twisted-pair telephone Loading Coil
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BLAKE Summary
line to reduce its losses for voice frequencies.26. Small data network covering one or several
buildings.Local Area Network
27. A frequency-division multiplexed signal carrying
10 supergroups or 600 voice channels.Mastergroup
28. A system for setting up long-distance calls using
pairs of tones sent along voice channels.Multifrequency Signaling (MF)
29. A term used to describe a telephone instrument
that is ready for use, handset is lifted from its
cradle.
Off Hook
30. A term used to describe a telephone instrument
is ready to receive a ring signal.On Hook
31. A control or supervisory signal that is
transmitted on a voice channel, but at dc or at
such a frequency that it will not be heard.
Out-of-band Signal
32. A communication system that works using data
divided into relatively short transmissions called
packets.
Packet-switched Network
33. Place where one telephone network connects to
the other.Point of Presence (POP)
34. Dialing that works by interrupting the dc loop
current.Pulse Dialing
35. The earpiece of the telephone. Receiver36. The red wire in a telephone circuit that normally
has negative polarity.Ring
37. Signal sent by the network to the calling
telephone to indicate that the called telephone
is ringing.
Ringback Signal
38. A low-level voice signal sent to a telephone
receiver from the transmitter in the same
telephone.
Sidetone
39. System used in telephony which transmits all
call setup information on a packet-data network
that is separate from the voice channels used
for telephone conversations.
Signaling System Seven (SS7)
40. A switch that connects only to other switches
and not to individual customers.Tandem Office
41. The green wire in a telephone loop that
normally has positive polarity.Tip
42. A long-distance telephone switch. Toll Station43. The layout of a system such as a telephone
network.Topology
44. AT&T trademark for DTMF dialing. Touch-tone Dialing45. The microphone in a telephone. Transmitter46. A connection between telephone offices. Trunk Line47. The signal loss in decibels between the Via Net Loss (VNL)
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BLAKE Summary
transmitting and receiving ends of telephone
connection.48. The central office supply is the _______. Battery49. The circuit board that connects a local loop to
the central office.
Subscriber Line Interface Card
(SLIC)50. A frequency-division multiplexed signal
consisting of three jumbogroups or 10,800
voiceband channels.
Superjumbogroup
51. A switch that connects central offices together. Tandem Office52. The first automatic telephone switch is invented
byAlmon B. Strowger
53. The crossbar system used relays for _______. Memory54. The on-hook voltage. 48 V dc55. The off-hook voltage at phone. 5 to 10 V dc56. The off-hook current. 23 to 80 mA57. The dial tone frequencies. 350 and 440 Hz58. The ringing voltage at office. 100 V ac59. The ringing voltage at phone. 80 V ac60. The ringback voltage frequencies. 440 and 480 Hz61. The busy signal frequencies. 480 and 660 Hz62. The function of the line card can be
remembered by using the mnemonic ________.BORSCHT
CHAPTER 9: DATA TRANSMISSION
1. An error control system based on the repetition
of data blocks that contain errors.
Automatic Request for
Transmission (ARQ)2. Bits that do not carry the message. Bit Overhead3. Addition of extra bits to a data block to avoid
the accidental generation of a flag pattern.Bit Stuffing
4. A set of rules that translates alphanumeric
characters into binary numbers.Character Code
5. Refer to no. 4: Another name for it.Character Set,
Data Code6. An error-detecting method in which the binary
number corresponding to the group of bits to be
checked is divided by a predetermined binary
number.
Cyclic Redundancy Checking
(CRC)
7. A telephone connection via the public switched
telephone network.Dial-up Line
8. An error correcting system in which errors are
corrected at the receiver using redundant
transmitting data without using retransmission
requests.
Forward Error Correction (FEC)
9. A group of bits sent between framing signals in
a bit-oriented synchronous communication
Frame
17
BLAKE Summary
system.10. A data-compression scheme that uses fewer
bits to represent more frequently occurring
characters or bits patterns.
Huffman Coding
11. A line condition corresponding to a binary one. Mark12. Simultaneous transmission of multiple data bits
using several channels.Parallel Transmission
13. A data-compression scheme that replaces
repeated characters or bit patterns with a code
indicating the character and the number of
repetitions.
Run-length Encoding
14. A data transmission using only one channel. Serial Transmission15. A line condition corresponding to a binary zero. Space16. This bit alerts the receiver to the beginning of a
transmitted character by changing the line from
the mark to the space condition.
Start Bit
17. This bit marks the end of transmitted character. Stop Bit18. A device, generally an IC that converts from
parallel to serial format.
Universal Asynchronous
Receiver-Transmitter (UART)19. Data that consists of alphanumeric characters
must first be encoded using a ____________
___________.
Character Code
20. It actually involves synchronizing the
transmitting the receiver clocks at the start of
each character.
Asynchronous Communication
21. It must be converted from parallel to serial form
before being transmitted and back to parallel
form at the receiver.
Computer Data
22. Since noise is present in all communication
systems, ______ will occur.Errors
23. Errors can be detected and corrected by adding
_________ __________.Redundant Information
24. ____ data is important to ensure its privacy. Encryption25. It is originally used with electromechanical
teletype machines.Baudot Code
26. Refer to no. 25: It has been designated as
____________ by CCITT.
International Telegraph Alphabet
Number 2 (ITA2)27. The most common code for communication
between microcomputers.
American Standard Code for
Information Interchange (ASCII)28. Sometimes ASCII codes are expressed in
________ or ________ notation.
Decimal,
Hexadecimal29. The transmitter and receiver are synchronized
to the same clock frequency.Synchronous Communication
30. it involves the addition of one extra bit to the
bits that encode a character.Parity
31. It is a data-transfer protocol for microcomputers XMODEM
18
BLAKE Summary
that in its original and most basic form, uses
this method.32. They allow single errors in a block of data to be
corrected without any need for retransmission.Hamming Codes
CHAPTER 10:LOCAL AREA NETWORKS
1. The information signal on LAN. Baseband2. A system in which the baseband signal is used
to modulate a higher-frequency carrier signal.Broadband System
3. A system for controlling network traffic.
Carrier Sense Multiple Access
with Collision Detection
(CSMA/CD)4. a network in which a physical connection from
one end to the other of a data path is
maintained for the duration of a period of
communication.
Circuit-switched Network
5. The loss of data that occurs when two stations
transmit at the same time on a network.Collision
6. An Ethernet cable that has the transmit and
receive connections reversed at one end.Crossover Cable
7. A type of LAN that has a logical bus structure
using CSMA/CD.Ethernet
8. A network with one or more specialized nodes
that contain files and operating software for the
network.
Client-server Network
9. Refer to no. 8: another name for it. File Server10. Two-way communication in both directions at
the same time.Full Duplex
11. The central connecting point of a star network to
which all other nodes connect.Hub
12. A type of LAN that is a physical star and logical
token-ring.IBM Token-ring System
13. A small data network that typically operates
within one building or a localized group of
Local-area Network (LAN)
19
BLAKE Summary
buildings.14. The hub of an IBM token ring network. Multistation Access Unit (MAU)15. A term used to describe a computer operating
system that allows multiple programs to run
simultaneously without interfering with each
other.
Multitasking
16. A plug-in circuit board for a computer that
contains the necessary hardware and firmware
to connect the computer to the local area
network.
Network Interface Card
17. One station that is attached to a network. Node18. The smallest block of data transmitted over a
network.Packet
19. The network in which all nodes can contribute
network resources and also run local programs.Peer-to-peer Network
20. A network node dedicated to interfacing
between the network and one or more printers.Print Server
21. A modem that modulates data onto a very high
frequency carrier.Radio-frequency Modem (RF)
22. A network topology in which data circulates
from one computer to the next in sequence.Ring
23. A device that links two or more networks. Router24. A network topology in which all nodes are
connected individually to a central point.Star
25. In an Ethernet network, it is the device that can
send incoming packets to one of several
destinations.
Switch
26. A method of network control that involves a
short packet that circulates around the network.Token Passing
27. Refers to the messages to be transferred over a
network.Traffic
28. The ratio between the velocity of propagation of
electromagnetic energy through a medium or
along a transmission line and the speed of light
in vacuum.
Velocity Factor
29. A large network extending over an area greater
than that of a city.Wide-area Network (WAN)
30. Possible data network arrangements in a small
LAN.
Star,
Ring,
Bus31. The largest WAN. Internet32. Ethernet was originated by _______. Xerox33. The year that IEEE began to draft standards for
LANs.1980
34. It is used for the slowest 10 Mb/s version of
Ethernet.Coaxial Cable
20
BLAKE Summary
35. This is used by most 10 Mb/s and 100 Mb/s
Ethernet installations.
Unshielded Twisted Pair (UTP)
Cable36. It is a special cable that consists of two parallel
wires with a grounded shield around them.Twinax Cable
37. The effect of a switch is to greatly reduce
________.Contention
CHAPTER 11: WIDE AREA NETWORKS AND THE INTERNET
1. Any computer network that extends for more
than a short distance such as a building or
related groups of buildings.
Wide-area Network
2. A system that allows users to access documents
from widely separated sources on the Internet.World Wide Web (WWW)
3. A versatile data-transmission system using 53-
byte packets and designed o enable various
kinds of data.
Asynchronous Transfer Mode
(ATM)
4. A network-to-network connection that passes
only data addressed to a node in the other
network.
Bridge
5. A method of organizing a network in which a
physical path is dedicated to communication
between two node for the duration of
communication.
Circuit Switching
6. The second layer of the OSI model. Data Link Layer7. A data-communications protocol created by
Digital Equipment Company for its
minicomputer products.
DEC Network Architecture (DNA)
8. A method whereby messages can be left for
individual network users.Electronic Mail (e-mail)
9. A program in TCP/IP protocol that allows for the
transfer of both binary and text files between
computers with otherwise incompatible
operating systems.
File-transfer Protocol (FTP)
10. A software to prevent unauthorized access to
computers on a network by computers outside
the network.
Firewall
11. A bit or sequence of bits that indicates the Flag
21
BLAKE Summary
beginning or end of a packet.12. A packet-transport protocol, similar to X.25 but
with less error connectionFrame Relay
13. A computer system that provides modern
access to the public at no charge.Freenet
14. A device used to connect computers or networks
running incompatible operating systems.Gateway
15. A sequence of bits at the beginning of a packet,
containing information about the type of packet
and/or routing.
Header
16. A data-transfer that allows quick transitions by
simply clicking on a highlighted word or picture
with a mouse.
Hypertext Transport Protocol
(HTTP)
17. A worldwide public network of networks that
connects a very wide variety of computers,
applications, and users.
Internet
18. A suite of protocols that allows a wide variety of
computers to share the same network.
Transmission Control
Protocol/Internet Protocol
(TCP/IP)19. A network that encompasses a city and its
environs.
Metropolitan-area Network
(MAN)20. A private network that uses the same TCP/IP
protocol suite as the Internet.Intranet
21. The third layer of the OSI protocol model. Network Layer22. Electronic bulletin boards devoted to a wide
variety of subjects, accessible via the internet.Newsgroups
23. A system for organizing data-transmission
protocols developed by the ISO.
Open Systems Interconnection
(OSI) Model24. A way of organizing a network so that small
blocks of data are routed individually from
source to destination.
Packet Switching
25. The lowest level of the OSI protocol model. Physical26. A formal set of conventions governing the
format and the timing of messages.Protocol
27. A device used to extend a network or other
digital communication system by regenerating
bits and restoring voltage levels and timings to
their original values.
Repeaters
28. A device used to interconnect networks. Router29. The part of the TCP/IP suite that allows for email
over the Internet and similar networks by
specifying the control messages used in mail
transfer.
Simple Mail Transfer Protocol
(SMTP)
30. A network in which nodes receive a packet of
data from the source or a node closer to the
Store-and-forward Network
22
BLAKE Summary
source and then transmit it to the destination or
a node closer to the destination.31. An IBM system for transferring data between
IBM mainframes and between IBM mainframes
and other computers.
Systems Network Architecture
(SNA)
32. A system to allow users to log on to a distant
host by emulating a dumb terminal.Telnet
33. A link between computers in which each
recognizes a software connection to the other.Virtual Circuit
34. A very popular system for defining and
switching data packets on computer networks.X.25 Protocol
35. It is responsible for detecting and correcting
errors within frames of data and providing the
flags that indicate the beginning and end of
frames.
Data Link
36. It sets up the path to transmit data between
terminals and arranges data into packets.Network
37. It deals with the matters such as voltage and
current levels.Physical
38. ______ ______ are available with data rates from
56 kb/s up.Leased Lines
39. It was created by the United States military for
providing alternate route in their network in
case of trouble.
ARPANET
40. Meaning of ARPANET.Advanced Research Projects
Agency Network
CHAPTER 12: DIGITAL MODULATION AND MODEMS
1. Data transmission by varying the amplitude of the
transmitted signal.Amplitude Shift Keying (ASK)
2. The telephone local loop that combines analog
telephone service with data communications.
Asynchronous Digital Subscriber
Line3. Use of an audio tone of two or more different
frequencies to modulate a conventional analog
transmitter for data transmission.
Audio Frequency-shift Keying
(AFSK)
4. Speed at which symbols are transmitted in a digital
communication system.Baud Rate
5. Speed at which data is transmitted in a digital
communication system.Bit Rate
6. A device to allow data communication over cable-
television wiring.Cable Modem
7. Variant of QAM used with ADSL data
communication systems
Carrierless Amplitude Phase
(CAP) Modulation8. In digital communication, it is a pattern showing all Constellation Diagram
23
BLAKE Summary
the possible combinations of amplitude and phase
for a signal.
9. A modem is also known as ____________.Data Communications Equipment
(DCE)10. A terminal or computer than communicates via a
modem.Data Terminal Equipment (DTE)
11. Digital modulation scheme that represents a bit
pattern by a change in phase from the previous
state.
Delta Phase-Shift Keying (DPSK)
12. Any digital modulation scheme that codes two bits
of information per transmitted symbol.Dibit System
13. It uses many carriers at different frequencies.Discrete Multi-tone (DMT)
Modulation14. A transmission speed that is less than the
maximum of which a modem is capable.Fallback
15. A device for the transmission and reception of
facsimile documents.Fax Modem
16. A means of ensuring that a transmitter sends data
only when the associated receiver is ready to
receive it.
Flow Control
17. digital modulation scheme using two or more
different output frequencies.Frequency Shift Keying (FSK)
18. Variant of FSK which uses the minimum possible
frequency shift for a given bit rate.
Gaussian Minimum-shift Keying
(GMSK)19. A series of commands transmitted to the modem
whenever a communications software program is
loaded.
Initialization String
20. A logic one. Mark21. acronym for modulation-demodulation. Modem22. A cable used to make a direct connection between
two devices using their serial ports.Null Modem
23. A means of transmitting data by shifting the phase
angle of the transmitted signal.Phase-shift Keying (PSK)
24. PSK that employs four different phases and allows
two bits of information to be transmitted
simultaneously.
Quadrature Phase-shift Keying
(QPSK)
25. A means of transmitting data by shifting both the
amplitude and the phase of the transmitted signal.
Quadrature Amplitude
Modulation (QAM)26. Binary zero. Space27. A transmitted signal that can have two or more
possible states.Symbol
28. A series of tones transmitted by a modem to allow
the automatic adjustment of line equalization.Training Sequence
29. Just as in analog transmission, digital transmission
uses the following variations.
Frequency,
Phase,
Amplitude
24
BLAKE Summary
30. the maximum data rate for a channel is a function
of the following.
Bandwidth,
Modulation Scheme,
Signal-to-noise Ratio31. The modem that places the call. Originate Modem32. The modem that receives the call. Answer Modem33. When the flow control is accomplished by changing
levels on the RS-232 lines it is called _____________.Hardware Flow Control
CHAPTER 13: MULTIPLEXING AND MULTIPLE-ACCESS TECHNIQUES
1. Extra bits used to spread the signal in a direct
sequence spread spectrum system.Chips
2. System to allow multiple users to use the same
frequency with separate PN codes and a
spread-spectrum modulation scheme.
Code-division Multiple Access
(CDMA)
3. Form of frequency spectrum communication in
which the RF carrier continually moves from
one frequency to another according to a
prearranged pseudo-random pattern.
Frequency Hopping
4. Sharing of a communication channel among
multiple users by assigning each a different
carrier frequency.
Frequency-division Multiple
Access (FDMA)
5. Combining of several signals into one
communication channel by assigning each a
different carrier frequency.
Frequency-division Multiplexing
(FDM)
6. Use of a single channel by more than one
transmitter.Multiple Access
7. Use of a single channel by more than one
transmitter.Multiplexing
8. Improvement in interference rejection due to
spreading in a spread-spectrum system.Processing Gain
9. A transmitted series of ones and zeros that
repeats after a set time, and which appears
random if the sequence is not known to the
receiver.
Pseudo-random Noise Sequence
(PN)
10. Variation of received signal strength due to
multipath fading.Rayleigh fading
11. A method of switching that provides a separate
physical path for each symbol.Space Switching
12. Improvement in interference rejection due to
spreading in a spread-spectrum system.Spreading Gain
13. system to allow several transmission to use
channel by assigning time slots to each.
Time-division Multiple Access
(TDMA)
25
BLAKE Summary
14. System to combine several data streams onto a
single channel by assigning time slots to each.Time-division multiplexing (TDM)
15. A method of switching that moves a signal from
one time slot to another on the same physical
path.
Time Switching
16. It is used extensively in telephony. TDM
CHAPTER 14: TRANSMISSION LINES
1. Any pair of conductors used to conduct electrical
energy.Transmission Line
2. A device for coupling balanced and unbalanced
lines.Balun
3. It is the ratio between voltage and current on an
infinitely long transmission line.Characteristic Impedance
4. A transmission line containing concentric
conductors.Coaxial Line
5. A transmission line containing parallel conductors
separated by spacers.Open-line Wire
6. It is the speed at which signals travel down a
transmission line.Propagation Velocity
7. A section of transmission line, electrically a quarter-
wavelength in length, that is used to change
impedances on a transmission line.
Quarter-wave Transformer
8. It is the ratio of reflected to incident voltage on a
transmission line.Reflection Coefficient
9. It is the graphical transmission line calculator. Smith Chart10. It is the ratio of maximum to minimum voltage on a
transmission line.Standing-wave Ratio
11. A short section of line, usually short-circuited at one
end, used for impedance matching.Stub
12. Another name for characteristic impedance. Surge Impedance13. It is the ratio of speed of propagation on a line to
that of light in free space.Velocity Factor
14. Two types of transmission line.Balanced and Unbalanced
Lines15. A coaxial cable is the best example for this kind of
transmission line because it lacks symmetry with
respect to ground.
Unbalanced Line
16. Parallel lines are usually operated as _________
_________ that is; the impedance to ground from
each of the two wires is equal.
Balanced Line.
17. This happens when frequency increases, the region
of high current density becomes thinner, reducing
Skin Effect
26
BLAKE Summary
the cross-sectional area and increasing the
resistance of the conductor.
18. What are present in the electrical model of a
transmission line?
Resistance,
Conductance,
Capacitance,
Inductance19. Such a line is called _______ since the inductive and
capacitive reactances store energy but do not
dissipate it.
Lossless
20. A transmission line that is terminated in its
characteristic impedance is called __________
________.
Matched Line
21. For a lossless line, resistance and conductance
values would be ______.Zero
22. A line that is terminated by an impedance other
than characteristic impedance is said to be ______.Mismatched
23. It is the expected signal that would simply move
down the line and disappear into the load because it
is a matched line.
Traveling Wave
24. The length of line that causes a delay of one period
is known as ________.Wavelength
25. It is the formation of which due to the interaction
between the incident and reflected waves that
causes what appears to the stationary pattern of
waves on the line.
Standing Waves
26. two kinds of traveling waves.Incident waves,
Reflected waves27. These are traveling waves that are coming from the
transmitter.Incident waves
28. These are traveling waves that are brought back to
the transmitter due to unmatched line.Reflected waves
29. Most desirable amount of SWR. 1 (one)30. Most desirable amount of reflection coefficient. 0 (zero)
31. Transmission line losses in mechanisms.
Conductor Loss,
Dielectric Loss,
Radiation Loss,32. Transmission line losses are usually given in
_________ per 100 meters or 100 feet.Decibels
33. The radius of the circle in the Smith Chart
represents _______.SWR
34. It is a specialized test equipment for transmission
line measurements in both the time and the
frequency domains.
Time-domain Reflectometry
35. It is a short section of air-dielectric coaxial line, with
a slot in the outer conductor through which a probe
Slotted Line
27
BLAKE Summary
is inserted.36. The length of a slotted line must be at least
___________.One-half wavelength
37. This device allows the measurement of power
moving along the line in each direction, that is, it is
possible to measure incident and reflected power
separately.
Directional Coupler
CHAPTER 15: RADIO-WAVE PROPAGATION
1. The process by which the waves travel through a
medium.Propagation
2. It is the reduction in signal strength due to
spreading of the waves at a distance from the
transmitter.
Attenuation of Free Space
3. The magnitude of the electric field required to cause
breakdown and arcing of the dielectric.Dielectric Strength
4. It is a means of propagation in which the waves are
confined within a refractive region of the
troposphere or between such a region and the
ground.
Ducting
5. A device that allows a transmitter and a receiver,
operating at different frequencies, to be connected
to the same antenna and operate simultaneously.
Duplex
6. The area from which a receiving antenna can be
considered to extract all the energy I an
electromagnetic wave.
Effective Area
7. It is the ratio of the electric force on a charge to the
charge, at a given point.Electric Field Strength
8. Refer to no. 7: another name for it. Electric Field Intensity9. A vacuum that allows radio waves to propagate
without any obstruction.Vacuum
10. A vertically-polarized electromagnetic wave that
propagates along the surface of the earth.Ground Wave
11. It is the ratio of the phase velocity of a wave in free
space to that in the medium under consideration.Index of Refraction
12. The ionized region of the earth’s atmosphere. Ionosphere13. A hypothetical antenna having zero physical size
and no loss and radiating equally in all directions.Isotropic Radiator
14. It is the highest frequency that will be returned by
the ionosphere at a given point.
Maximum Usable Frequency
(MUF)15. These are changes to the baseband signal caused Multipath Distortion
28
BLAKE Summary
by multipath reception.16. It is a situation in which a signal arrives at a
receiving antenna via two or more pathsMultipath Reception
17. A line drawn perpendicular to the interface between
two media.Normal
18. It is the ratio between the signal appearing at the
transmitting antenna terminals and that the
receiving antenna terminals.
Path Loss
19. It is the quantum of electromagnetic radiation. Photon20. It is the direction of the electric field vector of an
electromagnetic wave.Polarization
21. The power flowing through a unit cross-sectional
area normal to the direction of travel of an
electromagnetic wave.
Power Density
22. Characterized by a receiver capable of receiving
several versions of the same signal with different
arrival times, and combining the received versions
into a single signal with better quality.
Rake Receiver Sectorization
23. In cellular radio, it is the division of a cell into
sectors by the use of directional antennas at a
single cell site.
Sectorization
24. It is an electromagnetic wave that is returned to
earth by the ionosphere.Sky Wave
25. An electromagnetic wave that propagates directly
from the transmitting to the receiving antenna.Space Wave
26. It is a propagation along or near the surface of the
earth.Terrestrial Propagation
27. The region of atmosphere closest to earth. Troposphere28. Another name for vacuum. Free Space29. It involves the creation of electric and magnetic
fields in free space or in some physical medium.Electromagnetic Radiation
30. This means that the electric field, magnetic field,
and the direction of travel of wave are all mutually
perpendicular.
Transverse Electromagnetic
Waves (TEM)
31. The speed of propagation of an electromagnetic
wave in free space is the same as that of __________.Light
32. It is a surface on which all the waves have the same
phase, would be the surface of a sphere.Wavefront
33. The wave that rotate in all direction and if it rotates
in a clockwise direction as it recedes.Right-handed
34. Another name for attenuation of free space. Square-law Attenuation35. It is the intensity of the radiation of antenna in a
given direction.Antenna Gain
36. The comparison of the actual antenna’s radiated
power to an isotropic antenna.
Effective Isotropic Radiated
Power (EIRP)37. Three properties of radio waves when propagated Reflection,
29
BLAKE Summary
and reached its destinations that are also present in
the behavior of light.
Refraction,
Diffraction38. Ground wave propagation is used for propagating
signals with frequencies of up to approximately
____.
2 MHz
39. Ionization levels change with the amount of solar
activity which varies over an 11-year cycle called
____________.
Sunspot Cycle
40. Since there is a general instability of the
ionosphere, its is usually better to operate at lower
frequency, perhaps 85% of the MUF, also called as
____________________.
Optimum Working Frequency
(OWF)
41. These are regions that may be uncovered by the
signals propagated in the area due to its closeness
to the transmitter.
Skip Zones
42. Another name for tropospheric propagation.Line-of-Sight Propagation
(LOS)43. The transmitting antenna is aimed in the direction
of the receiver, but the receiver is over the horizon.Troposcatter
CHAPTER 16: ANTENNAS
1. A device used radiate or receive electromagnetic
radio at radio frequencies.Antenna
2. A receiving antenna with a built-in preamplifier. Active Antenna3. An enclosure lined with material that absorbs
electromagnetic radiation.Anechoic Chamber
4. Angle measured upward from the horizon. Angle of Elevation5. An antenna system composed of two or more
simpler antenna elements.Array
6. The angle between the points of the major lobe of
an antenna at which the radiated power density is
one-half its maximum value.
Beamwidth
7. The measure of antenna gain in decibels with
respect to a lossless half-wave dipole.dBd
8. A measure of antenna gain: decibels with respect to
an ideal isotropic radiator.dBi
9. Any antenna consisting of a single conductor with
zero current only at its two ends.Dipole
10. It is the ratio of the maximum to the average
radiation of intensity for an antenna.Directivity
11. For a receiving antenna, it is the ratio of the
available output power to the power density of the
Effective Area
30
BLAKE Summary
received wave.12. The product of the power supplied to a transmitting
antenna and the gain of the of the antenna with
respect to a lossless half-wave dipole.
Effective Radiated Power
(ERP)
13. In an antenna array, it is an individual conductor or
group of conductors.Element
14. It is the distance far enough from an antenna that
local inductive and capacitive effects are
insignificant.
Far-Field Region
15. It is the ratio between the radiation intensity in an
antenna’s direction of the maximum radiation and
the intensity at an angle of 180° to this direction.
Front-to-back Ratio
16. An artificial ground consisting of a conductor
surface or an equivalent.Ground Plane
17. Also known as spiral. Helix18. It is a hypothetical antenna that would radiate all
the energy supplied to it, with equal intensity in all
directions.
Isotropic Antenna
19. It is the process of increasing the electrical length of
an antenna by an addition of inductance or
capacitance.
Loading
20. It is the portion of an antenna pattern between two
nulls.Lobe
21. An antenna with a current null at one end and a
maximum at the other, with no other nulls in
between.
Monopole
22. It is the region close to antenna, where local
inductive and capacitive effects predominate.Near Field Region
23. The lobe in the direction of maximum radiation. Major Lobe24. The lobe with less intensity than the main lobe. Minor Lobe25. It denotes the angle in the horizontal plane, from
the x axis toward the y axis. Phi (Φ)26. The direction of the electric field vector of an
electromagnetic wave. Polarization27. In a monopole antenna, it is the wire extending
along the surface of the ground or just below it,
away from the antenna is called _______.Radial
28. A set of it is used to improve the effective
conductivity of the ground in a monopole antenna.. Radial29. It is the equivalent resistance at the feedpoint
corresponding to the radiation of energy by an
antenna.Radiation Resistance
30. A minor lobe at an angle of approximately 90° to
the main lobe. Side Lobe31. It refers to the angle from the horizontal (x-y) plane
Theta (θ)
31
BLAKE Summary
toward the zenith, represented by the z-axis.32. It is the direction straight up from the horizontal
plane. Zenith
33. It refers to a dipole of infinitesimal length.Hertzian Dipole
34. Typically, the length of a half-wave dipole, assuming
that the conductor diameter is much less than the
length of the antenna, is _____ of one-half the
wavelength measured in free space.
95%
35. It refers to the wavelength.Lambda (λ)
36. It is the speed of light also constant to radio waves
in free space. 300 x 106 m/s37. It is the coordinate representation of the antenna’s
radiation. Radiation Pattern38. Fading is caused by _________ of antenna’s radiation
though it is very important at a considerable
distance..Reflection
39. Ground effects are important up through the ____
range. High Frequency (HF)40. It has the same length as a standard half-wave
dipole, but it is made with two parallel conductors,
joined at both ends and separated by a distance
that is short compared with the length of the
antenna.
Folded Dipole
41. The characteristic impedance of a balanced line
used mainly in TV and FM receiving installations. 300Ω42. This is used mainly for low and medium frequency
transmission that utilizes vertical polarization to
take advantage of ground wave propagation.Monopole Antenna
43. Refer to no. 42: another name for it.Marconi Antenna
44. This antenna is often used in vertically as either a
mobile or base antenna in VHF and UHF systems. 5/8 wavelength Antenna
45. This antenna is also known as air-wound coil.Loop Antenna
46. This antenna, its structure combination acts as a
transformer to match the feedline impedance to the
impedance of free space.Discone Antenna
47. How much is the impedance of free space?377Ω
48. Another name for helix or spiral antenna.Helical Antenna
49. Refer to no. 48: another popular name for it that is
used with many handheld transceivers. Rubber Ducky Antenna50. Classifications of arrays according to their direction
of maximum radiation.. Broadside,
32
BLAKE Summary
End-fire
51. Classification of antenna arrays according to how
the elements are connected.
Phased Array,
Driven Array,
Parasitic Array
52. Arrays that radiates through its length.Broadside
53. Arrays that radiates at its ends.End-fire
54. These arrays are connected to the feedline.Phase Array
55. Possible applications of phase arrays.
Phase-shifting,
Power Splitting,
Impedance Matching56. Arrays that each elements are supplying power for
transmission. Driven Array
57. refer to no. 56: Arrays that are dependent to it.Parasitic Array
58. Yagi antenna is more formally referred to as the
________. Yagi-Uda Array59. This antenna derives its name from the fact that the
feedpoint impedance is a periodic function of the
operating frequency.Log-periodic Antenna
60. This antenna is a combination of two dipoles
designed to give omnidirectional performance in the
horizontal plane, with horizontal polarization.Turnstile Antenna
61. This antenna has one type of broadside array using
half-wave dipoles. Collinear Arrays62. In an antenna, it acts as an ordinary mirror that
enhances the directivity of the antenna’s radiation. Reflector
63. Antenna often used for terrestrial microwave links.Hog-horn Antenna
CHAPTER 17: MICROWAVE DEVICES
1. It is conventionally the electromagnetic radiation in
the range above approximately 1GHz.Microwave
33
BLAKE Summary
2. In a klystron, it is a cavity that velocity modulates
the electron beam.Buncher
3. It is the velocity modulation of an electron beam. Bunching4. In a klystron, it is a cavity that removes some of the
energy from the electron beam and transfers it in
the form of microwave energy to the output.
Catcher
5. It is a space in which microwaves can resonate by
means of in-phase reflections from the walls.Cavity
6. A device with three or more ports that allows an
input to one port to emerge only at the next port in
order.
Circulator
7. It is the element in a klystron or TWT that receives
the electron beamController
8. refer to no. 7: another term for it. Anode9. It is a microwave tube in which the electric and
magnetic fields are at right angles.Crossed-field Tube
10. A device that launches or receives a wave in a
transmission line or waveguide in one direction
only.
Directional Coupler
11. It is the variation of velocity as a function of
frequency in a waveguide or medium.Dispersion
12. It is a concentration of charge. Domain13. It states that a change in frequency that occurs
when a wave reflects from a moving object.Doppler Effect
14. A lens that is stepped to reduce its size. Fresnel Lens15. It is the speed of transmission of a signal along a
waveguide.Group Velocity
16. It is a slab of N-type gallium arsenide that can
operate as an oscillator or amplifier by means of
domain formation.
Gunn Device
17. A combination of E-plane and H-plane tees. Hybrid Tee18. A junction device that can operate as an oscillator
or amplifier.IMPATT Diode
19. A waveguide device that has low loss in one
direction and high loss in the other.Isolator
20. a type of linear-beam microwave tube that uses
velocity modulation of the electron beam.Klystron
21. A microwave tube in which electrons travel in a
straight line down to the length of the tube.Linear-beam Tube
22. Another name for hybrid tee. Magic Tee23. A cross-field microwave-tube oscillator in which
electrons circle around the cathode under the
influence of a magnetic field.
Magnetron
24. A microwave transmission line constructed on a
printed-circuit board, consisting of a single
conductor on one side of the board and a ground
Microstrip
34
BLAKE Summary
plane on the other side.25. The speed of electron drift in a conductor or
semiconductor.Mobility
26. It is the specific configuration of electric and
magnetic fields that allows a wave to propagate.Mode
27. The apparent speed of propagation along a
waveguide based on the distance between
wavefronts along the walls of the guide.
Phase Velocity
28. A three-layer diode that can be used as a switch
and an attenuator at microwave frequencies.PIN Diode
29. The three layers of the PIN diode.
P-type,
Intrinsic Layer,
N-type30. It is the rotation of the axis or rotation of the
electrons.Precession
31. The equivalent size of a radar target, in terms of
perfectly conducting flat plate oriented toward the
receiver.
Radar Cross Section
32. It is any device that causes a wave to propagate at
less than the speed of light, so that the electron
beam and the wave move at approximately the
same speed.
Slow-wave Structure
33. A microwave transmission line that consists of a
conductor inside a circuit board, working against
two ground planes, one on top and one on the
bottom of the board.
Stripline
34. It is the object whose range, direction, and/or
velocity is to be measured.Target
35. Another name for Gunn Device.Transferred-electron Device
(TED)36. A variation of the IMPATT designed for high-power
operation.TRAPATT Diode
37. A metal object threaded into a waveguide to add
capacitance or inductance.Tuning Screw
38. A hollow structure that has no center conductor but
allows waves to propagate down to its length.Waveguide
39. A type of ferrite. Yttrium-iron-garnet (YIG)40. It means it is a more than one mode propagating at
a time.Multimode Propagation
41. It can be achieved by using only the mode with the
lowest cutoff frequency.Single-mode Propagation
42. Refer to no. 41: another name for it. Dominant Mode
43. Two kinds of modes.Transverse Electric (TE),
Transverse Magnetic (TM)44. The dominant mode depends on the shape of the Waveguide
35
BLAKE Summary
______.45. Like any transmission line, a waveguide has a
________ _____.Characteristic Impedance
46. The impedance of the free space is ________. 377Ω
47. Three ways to launch a wave down a guide.
By Probe,
By Loop,
By Hole48. It is used to transfer power from a waveguide to a
transmission line to which the line will accept only
energy traveling along the guide from right to left.
Directional Couplers
49. It is the amount by which a signal in the main guide
is attenuated.Insertion Loss
50. It gives the amount by which the signal in the main
guide is greater than that coupled to the secondary
waveguide.
Coupling
51. It refers to the ratio between the power coupled to
the secondary guide.Directivity
52. Striplines and microstrips, like waveguides, have
________ _________.Critical Frequency
53. Another name for H-plane tee. Shunt Tee54. Another name for E-plane tee. Series Tee55. Instead of using a continuous waveguide, waves can
also be launched in a short section that reflects
waves back and forth from one end to the other.
What is this short section?
Cavity Resonator
56. It is a type of frequency meter that consists of a
cavity with an adjustable plunger.Wavemeter
57. It allows separation of signals. Circulator58. The operation of both the isolator and the circulator
is based on the magnetic properties of __________.Ferrites
59. It is the interaction between an electromagnetic
wave and the ferriet results in a phase shift as the
wave propagates through the material.
Faraday Rotation
60. IMPATT meansImpact Avalanche and Transit
Time
61. Chronological layers of the IMPATT diode.
P-type,
N-type,
Intrinsic layer,
N-type62. The intrinsic layer of the IMPATT diode is commonly
made up of ______.Gallium Arsenide
63. TRAPATT meansTrapped Plasma Avalanche
Triggered Transit64. These device is often used as frequency multipliers. Varactor Diode65. Two variations of the varactor that can be also used
as multipliers.
Step-recovery,
Snap Diode
36
BLAKE Summary
66. This is essentially a resonant cavity that is made of
a solid slab of a dielectric material such as alumina.Dielectric Resonator
67. It is the oldest microwave tube design. Magnetron68. refer to no. 67: The year that it is invented. 192169. It is the preferred tube for high power, high stability
amplification of signals at frequencies from UHF to
about 30 GHz.
Klystron
70. It can be used as a moderate-power amplifier or as
an oscillator if modified.Traveling Wave Tube
71. This antenna can be viewed as impedance
transformers that match waveguide impedances to
that of free space.
Horn Antenna
72. It consist of thin metallic patch placed a small
fraction of a wavelength above conducting ground
plane.
Patch Antenna
CHAPTER 18: TERRESTRIAL MICROWAVE COMMUNICATIONS SYSTEMS
1. A single transmission path from transmitter to
receiver.Hop
2. The signal-to-noise ratio in a receiver at a point
before the detector.Carrier-to-noise Ratio
3. The deviation of a wave as it passes an obstacle or
passes through a small aperture.Diffraction
4. It is the use of more than one frequency or
transmission path to improve system reliability in
the presence of fading.
Diversity
5. It is the energy received in the time taken to
transmit one bit.Energy per Bit
6. Variation in received field strength over time due to
changes in propagation conditions.Fading
7. A region near an object in which diffraction effects
are significant.Fresnel Zone
8. It is the abrupt variations in the timing of a digital
signal.Jitter
9. It is a network using microwaves for two-way
transmission for telephony, television, and high-
speed data.
Local Multipoint Distribution
System (LMDS)
10. This is a terrestrial microwave system for the
distribution of television, Internet, and telephone
services to businesses and residences.
Multichannel Multipoint
Distribution System (MMDS)
11. A receiver-transmitter combination that amplifies
and transmits a signal.Repeater
12. A map showing surface features, including the
elevation of the terrain.Topographic Map
37
BLAKE Summary
13. Terrestrial microwave links generally use
______________ propagation.Line-of Sight (LOS)
14. Causes of fading.
Multipath Reception,
Attenuation due to rain,
Ducting,
Aging or partial failure15. Fading due to multipath reception can reduce the
received signal strength by ______ or more.20dB
16. This technique is done by slightly changing the
frequency so that the phase difference between the
direct and reflected signals is no longer 180°.
Frequency Diversity
17. To protect against fading on a moment-to-moment
basis, frequency diversity requires two transmitters
and two receivers, better known as a _____.
Hot Standby
18. This technique is done by placing two antennas one
above and the other on the same tower.Space Diversity
19. Two systems of terrestrial microwave links.Analog,
Digital
20. Analog system is also called ______ or _______.AM System,
FM System21. Digital system is also called _______. QAM System22. Digital data can also be transmitted with FM
systems using ______ ______.External Modems
CHAPTER 19: TELEVISION
1. Ratio of the width to the height of a television
picture.Aspect Ratio
2. The portion of the horizontal blanking pulse after
the synch pulse.Bach Porch
3. The video level corresponding to zero luminance. Black Setup4. The period of time when the electron beam in a CRT
is cut-off.Blanking
5. A vacuum tube that uses a moving electron beam to
produce patterns or images on a photophorescent
screen.
Cathode-ray Tube (CRT)
6. The color signal. Chrominance (Chroma)7. These are several cycles of color subcarrier on the
back porch of the horizontal sync for color
synchronization.
Color Bursts
8. A filter that can pass or reject a fundamental Comb Filter
38
BLAKE Summary
frequency and its harmonics.9. A video system in which color and luminance are
sent separately, without frequency interleaving.Component Color
10. A video system in which luma, sync, and chroma
signals are combined.Composite Video
11. Alignment of the three electron beams in a color
CRT so that they land on the same triad of color
phosphor dots.
Convergence
12. the pulses in the vertical blanking interval of a video
signal that create interlaced scan.Equalizing Pulses
13. In an interlaced video system, it is one-half of a
frame consisting of alternate lines.Field
14. One complete image in a video system is called
________.Frame
15. The portion of horizontal blanking pulse before the
sync pulse.Front Porch
16. A television receiver design that uses mixing
between the picture and sound carriers to generate
the sound intermediate frequency.
Intercarrier Sound
17. A video scanning system that divides a frame into
two fields to reduce flicker.Interlace
18. The signal that provides brightness information in a
video system.Luminance (Luma)
19. A North American television standard. NTSC Video20. The video signal level representing maximum
luminance.Peak White
21. Picture element. Pixel22. A video system that does not use interlace. Progressive Scan23. In a color CRT, it is the adjustment of the three
electron beams so that each lands on phosphor dots
of the appropriate color.
Purity
24. The pattern of scanning lines in a video system. Raster25. The amount of detail produced by a video system. Resolution26. The return of the electron beam in a CRT from right
to left or from top to bottom.Retrace
27. A color video system in which the three primary
colors are transmitted separately.RGB Color
28. The main accelerating element in a CRT. Ultor29. The proportion of scanning lines in a video system
that can be used in determining vertical resolution.Utilization Factor
30. A specialized oscilloscope designed for the
observation of composite color signals.Vectorscope
31. The assembly that contains the deflection coils and
is mounted on the neck of a CRT.Yoke
32. The North American NTSC television system
transmits ___ frames per second.30
33. Each frame transmitted by NTSC consists of _______ 525
39
BLAKE Summary
lines.34. The NTSC uses a _______ interlace so that ______
fields are transmitted per second.
2:1,
6035. Composite color video uses two color signals
modulated on a subcarrier at 3.58 MHz using
_________ ________.
DSBSC QUAM
36. Terrestrial television broadcasting uses a channel
_______ wide.6 MHz
37. The picture in terrestrial television broadcasting is
transmitted using _______ with carrier.VSB AM
38. The sound in the terrestrial television broadcasting
uses ___ on separate carrier to the video.FM
39. Picture and sound travel together through the _____
and ___ ______ of a television receiver.
Tuner,
Picture IF Sections40. The sound is converted to a separate 4.5 MHz IF, in
a system known as __________ _________.Intercarrier Sound
41. Color receivers use _______ _________ to retrieve the
color signal.Synchronous Demodulation
42. The frequency and phase reference for the color
demodulators are provided by a ________ _______ on
the back porch of the horizontal synchronizing
signal.
Color Burst
43. The CRTs used in television receivers generate an
________ ______ that is intensity-modulated by the
video signal and deflected horizontally and
vertically by coils that surround the tube.
Electron Beam
44. Color CRTs use three electron beams striking three
different types of phosphors that glow ____, ____,
and ______.
Red,
Green,
Blue45. It reduce losses by moving UHF signals to the VHF
range.Cable-television System
46. It is a technique used for reducing flicker on frame
rates of 25 or 30 Hz..Interlaced Scan
47. Two time intervals.Horizontal Blanking Interval,
Vertical Blanking Interval
48. The three primary colors that are mixed to achieve
good color reproduction.
Red,
Green,
Blue
49. Two other standards of color television.
Phase Alteration By Line
(PAL),
Sequential Color and Memory
(SECAM)50. The television stereo sound system is called
___________ _____ _________.
Multichannel Television
Sound51. The first CRT. Monochrome CRT
40
BLAKE Summary
52. In order to reproduce the three primary colors of the
color television system, a color CRT must have
_______ electron beams.
Three (3)
CHAPTER 20: SATELITE COMMUNICATION
1. A structure that naturally orbits the earth. Natural Satellite2. Name of the natural satellite. Moon3. A structure that orbits the earth and was built by
humans.Artificial Satellite
4. The point farthest from earth in a satellite orbit. Apogee5. A satellite transponder design that receives signals
and retransmits them at higher power and at a
different frequency.
Bent-pipe Configuration
6. It is a group of satellites coordinated in such a way
as to provide continuous communication.Constellation
7. A radio or optical connection directly between
satellites, without going through an earth station.Crosslink
8. Transmission of signals from a satellite to an earth
station.Downlink
9. A satellite orbit that is entirely above the equator. Equatorial Orbit10. It is the change in the direction of polarization of
signals passing through the ionosphere.Faraday rotation
11. It is the ratio expressed in decibels of gain to noise
temperature.Figure of Merit
12. It is the depiction of the signal strength contours
from a satellite transmitter on the earth.Footprint
13. It is the satellite orbit in which the satellite appears
to remain stationary at a point above the equator.Geostationary Orbit
14. It is a satellite orbit in which the satellite’s period of
revolution is equal to the period of rotation of the
earth.
Geosynchronous Orbit
15. Antenna beam on a geostationary satellite that is
adjusted to cover the whole earth.Hemispheric Beam
16. It is an artificial satellite orbiting the earth at an
altitude less than about 1500 kilometers.
Low-Earth-Orbit (LEO)
Satellite17. A satellite in orbit at a distance above the earth’s
surface of approximately 8,000 to 20,000 km.
Medium-Earth-Orbit (MEO)
Satellite18. Any artificial satellite that is not geostationary. Orbital Satellite19. The point closest to Earth in a satellite orbit. Perigee20. A satellite orbit passing over the north and south
poles.Polar Orbit
21. It is the time taken for a signal to travel through
space from transmitter to receiver.Propagation Time
22. It is a focused beam of energy that covers a
relatively small area on the earth.Spot Beam
41
BLAKE Summary
23. It is the process of adjusting the orbit of a
geostationary satellite so that it appears to remain
stationary above a point on earth.
Station-keeping
24. It is the use of device to receive one or more data
packets, store them and restransmit them at a later
time.
Store-and-Forward Technique
25. It is adjusting the position of a directional antenna
on the ground.Tracking
26. A repeater located in the satellite. Transponder27. Transmission of signals from an earth station to a
satellite.Uplink
28. Geostationary satellites are far enough from earth
that on a satellite can cover about ___ of the earth’s
distance.
40%
29. Three geostationary satellites can provide
worldwide communication except for the ______
_______.
Polar Regions
30. All satellite orbit shapes are ____________. Elliptical31. All satellites are held in orbit by a balance between
the two.
Centrifugal Force,
Centripetal Force32. An antenna is aimed at a satellite by adjusting its
__________ and _______.
Azimuth,
Elevation33. It is a device incorporating a level that can measure
the angle of the antenna axis from the horizontal.Inclinometer
34. The amount by which the antenna axis is offset
from the earth’s axis is called ___________.Declination
35. It was established in 1979 and known as third
generation of satellites.
International Maritime
Satellite Organization
(INMARSAT)36. INMARSAT uses a total of __ GEO satellites. Nine (9)37. Range of Low-earth orbit satellites above the earth. 300 - 1500 km38. range of Medium-earth orbit satellites above the
earth.8000 – 20000 km
39. These radiation belts surrounds earth that can
damage satellites.Van Allen Belts
40. This system comprises 66 LEO satellites in a
complex constellation, such that at least one
satellite is visible from one everywhere on earth at
all times.
Iridium
41. This system began commercial operation in 1999,
and uses a constellation of 48 LEO satellites.Globalstar
42. This system is expected to use 288 satellites. Teledesic43. This system went into operation in 1998, uses 35
satellites.ORBCOMM
44. This system has a similar structure to ORBCOMM
and became operational in 2003.LEO One
42
BLAKE Summary
45. This system is considered a special case LEO
system, using only six satellites, orbiting an altitude
of 1260 km.
E-Sat
46. This MEO uses an interesting combination of
elliptical and circular orbits.Ellipso
47. This MEO is planned by Inmarsat that will launch ten
satellites providing global coverage.
Intermediate Circular Orbit
(ICO)
CHAPTER 21: CELLULAR RADIO
1. A cellular telephone system designed mainly for use
with portable telephones.
Personal Communication
System (PCS)2. North American first-generation cellular radio
standard using analog FM.
Advanced Mobile Phone
Service (AMPS)3. In wireless communication, it is the radio equipment
and the propagation path.Air Interface
4. It is the electronics that control base station
transmitters and receivers.Base Station Controller
5. It is interrupting the voice channel to send control
information.Blank-and-burst Signaling
6. Failure to connect a telephone call because of lack
of system capacity.Call Blocking
7. Method of transmitting data on AMPS cellular
telephone voice channels that are temporarily
unused.
Cellular Digital Packet Data
(CDPD)
8. Information sent by the base station in a cellular
radio system to set the power level of the mobile
transmitter.
Control Mobile Attenuation
Code (CMAC)
9. Signal transmitted by a cell site to identify that site
to the mobile user.Digital Color Code (DCC)
10. A telephone connection that is unintentionally
terminated while in progress.Dropped Call
11. Number assigned to a cell phone by the
manufacturer as a security feature.
Electronic Serial Number
(ESN)12. This is a control information that is transmitted by
“stealing” bits that are normally used for voice
information.
Fast Associated Control
Channel (FACCH)
13. Communication from a cell site or repeater to a
mobile unit.Forward Channel
14. Two-way communication in which both terminals
can transmit simultaneously.Full – Duplex
15. Two-way communication in which only one station
can transmit at a time.Half – Duplex
16. Transfer of a call in progress from one cell site to Handoff
43
BLAKE Summary
another.17. A mobile telephone service using trunked channels
but not cellular in nature.
Improved Mobile Telephone
Service (IMTS)18. A small cell designed to cover a high-traffic area. Microcell19. Number that identifies a mobile phone in a cellular
system.
Mobile Identification Number
(MIN)20. refer to no. 19: This is popularly known as Mobile telephone number21. Switching facility connecting cellular telephone base
stations to each other and to the public telephone
network.
Mobile Switching Center
(MSC)
22. A memory location that stores the telephone
numbers to be used on the system.
Number Assignment Module
(NAM)23. Very small cells in a cellular radio system. Picocells24. A company that acts as a carrier to the base station. Reverse Channel25. A cellular customer using a network other than the
subscriber’s local cellular network.Roamer
26. It is the control information that is transmitted along
with the voice.
Slow Associated Control
Channel (SACCH)27. Code which describes the maximum power output
of a cellular phone.Station Class Mark (SCM)
28. A sine wave above the voice frequency range,
transmitted on the voice channel used to detect the
loss of signal.
Supervisory Audio Tone
(SAT)
29. A number transmitted by the base station to identify
the system operator.
System Identification
Number (SID)30. Frequency of a signal tone during a call. 10 kHz31. Transmitters in adjacent cells are separated by
frequency by at least60 kHz
32. Two unique numbers of each mobile unit.
Mobile Identification Number
(MIN),
Number Assignment Module
(NAM)33. It is simply the 10-digit phone number for the
mobile phone.
Mobile Identification Number
(MIN)34. It is a unique 32-bit number assigned to the phone
at the factory.
Electronic Serial Number
(ESN)
35. The three station class marks.
Mobile (Class I),
Transportable (Class II),
Portable (Class III)36. ERP of Class I. +6 dBW (4 W)37. ERP of Class II. +2 dBW (1.6 W)38. ERP of Class III. -2 dBW (600 mW)39. Mobile transmitter power is controlled by the land
station in 4dB increments, with the lowest power
level being ___________ ERP.
-22 dBW (6.3 mW)
40. It occurs when two or more mobiles try to use the
control channel at the same time.Collision
44
BLAKE Summary
41. Three possible frequencies of a supervisory audio
tone.5970 Hz, 6000 Hz, 6030 Hz
42. Most portable cell phones use this kind of antenna. Quarter-wave Monopole43. Refer to no. 42: At 800 MHz, the length of this
antenna is ____.9.5 cm
44. Phone traffic is defined in ________. Erlangs (E)
45. Refer to no. 44: One unit of it is equivalent toOne (1)continuous phone
conversation46. The most obvious way to avoid call blocking and call
dropping is to __________.Provide more channels
47. The reduction of cell size to increase traffic. Cell-splitting48. The bit rate in the RF channel for CDPD. 19.2kb/s49. The common digital system developed by the
European Community.Global System for Mobile
50. The digital system would seem to be able to carry
___ times as much traffic as the analog system.Three (3)
51. It provides essentially the same information as SAT
in AMPS.
Coded Digital Verification
Color Code (CDVCC)
52. The two TDMA control channels.
Analog Control Channel
(ACCH),
Digital Control Channel
(DCCH)
CHAPTER 22: PERSONAL COMMUNICATION SYSTEMS
1. Signal path from a base station or satellite to a
mobile station or a ground station.Downlink
2. Changing the time order or digital information
before transmission to reduce the effect of burst
errors in the channel.
Interleaving
3. It is the telephone number that is unique to a given
user worldwide.
International Mobile
Subscriber Identification
(IMSI)4. It is the tendency for stronger signals to interfere
with the reception of weaker signals.Near-Far Effect
5. A radio receiver that is capable of combining
several received signals with different time delays
into one composite signal.
Rake Receiver
6. Transmission of brief text messages, such as page
or email, by cellular radio or PCS.
Short Messaging
Service (SMS)7. A card with an embedded integrated circuit that can
be used for functions such as storing subscriber
information for a PCS system.
Smart Card
8. It is connecting a mobile to two or more base Soft Handoff
45
BLAKE Summary
stations simultaneously.9. It contains all user information which is inserted into
the phone before use.Subscriber ID Module (SIM)
10. Transmission of data in two directions on a channel
by using different time slots for each direction.
Time-division Duplexing
(TDD)11. Transmission channel to a satellite or base station. Uplink12. Class of orthogonal spreading codes used in CDMA
communications.Walsh Code
13. The eventual goal of personal communication
systems.
To allow each individual to
have personal phone and
phone number which will
take the place of home,
office, care, and portable
phones.14. Current PCS resemble cellular radio systems except
that they operate at
Higher frequency and are
completely digital15. The PCS frequency range is divided in such a way
that there can be up to _______ service providers in
a given region.
Six
16. They allow roaming on the analog cellular system
when the correct type of PCS service is unavailable.Dual mode, dual band phones
17. This features higher maximum data rates, greater
capacity of voice calls, and the ability to work with a
wide range of cell sizes and types.
Third Generation
18. These systems appear likely to be part of the third
generation specifications.
CDMA,
TDMA19. Voice channels are called ___________ _______ in
GSM.Traffic Channels
20. This is used by the mobile to contact the base, for
registration, authentication, and call setup.
Random Access Channel
(RACH)21. It is used for control messages to individual
telephones and for short paging-type messages to
be displayed on the phone.
Short Message Service,
Paging and Access Channel
(SPACH)22. It is the system used in Europe and most of Asia for
both cellular and PCS bands.GSM
23. This allows the mobile receiver to lock on the
beginning of the transmission.Synchronizing (SYNCH)
24. They provide acknowledgement of messages from
mobiules and inform the mobiles of the status of the
reverse control channel.
Shared Channel Feedback
(SCF)
25. Time slots per superframe of fast broadcast
channel.3 to 10
26. Time slots per superframe for extended broadcast
channel.1 to 8
27. Functions of short message service channel. Short message service,
46
BLAKE Summary
Remote phone programming28. Function of paging channel. Paging
29. Function of access response channel.Control messages to
individual phones30. Bandwidth of GSM channels. 200 kHz31. Total bit rate for an RF channel in GSM. 270.833 kb/s32. Time slots in the structure of an RF channel is also
called as ______ in GSM.Burst
33. Each voice transmission in GSM is coded at ______. 13 kb/s
34. Two codes in use at a CDMA base station.Short code,
Long code35. This code in CDMA base station is for synchronizing. Short code36. This code in CDMA base station in used for
encryption of voice and control system data.Long code
37. CDMA uses this for voice coding. Variable rate vocoder
38. The four possible bit rates used in voice coding of
CDMA.
9600 b/s,
4800 b/s,
2400 b/s,
1200 b/s
39. The packet-switched data in GSM system is calledGeneral Packet Radio Service
(GPRS)40. The de facto standard created by wireless
manufacturers for displaying web content on
wireless devices.
Wireless Application Protocol
(WAP)
41. Requirements for the third generation PCS.
Improved Data
Communication;
Greater Capacity;
Adaptability to mobile,
pedestrian, and fixed
operation
CHAPTER 23: PAGING AND WIRELESS DATA NETWORKING
1. A device to connect two segments of a network. Bridge2. Unique address for a pager. Capcode3. Method of reducing contention in a network by
involving each station checking for interference
before transmitting.
Carrier-Sense Multiple-
Access With Collision
Avoidance (CSMA/CA)4. Method of reducing contention to the network by
involving each station by checking continuously for
interference before and during transmissions.
Carrier-sense Multiple-access
with Collision Detection
(CSMA/CD)5. Attempt by two transmitters to use the same
channel simultaneously.Collision
6. Form of local-area network using CSMA/CD and a Ethernet
47
BLAKE Summary
logical bus structure.7. Communication channel from mobile to base
station.Inbound Channel
8. A radio channel used for communication from a
base station to mobile stations.Outbound Channel
9. Transmission of data in two directions on a channel
by using different time slots for each direction.
Time-division Duplexing
(TDD)
10. Options for wireless data communication.
Paging system,
Cellular and PCS radio,
Wireless LAN and Modems,
Packet Data Network
11. Types of paging systems.
One-way beeper,
One-way numeric,
One-way alphanumeric,
Two-way alphanumeric,
Voice pagers12. It transmit all pages throughout the whole system to
avoid having to locate the recipient.One-way paging system
13. Most current wireless LAN equipment follows the
___________ standard.IEEE 802.11
14. This resembles the standard in no. 13. Bluetooth15. It is common for very short-range connections and
is occasionally used for wireless LANs.Infrared Light
16. Uses of public packet data networks.
Email,
Keeping contact with
employees in the field,
Limited web browsing,
Low-data-rate applications
17. Most common protocol for one-way paging system.
Post Office Code
Standardization Advisory
Group (POCSAG)18. It is the de facto standard for two-way alphanumeric
pagers.Motorola ReFLEXTM
19. Standards that have been established in IEEE
802.11.
1. A set of wireless nodes
is called Basic Service Set
(BSS).
2. A network can consist
of only of wireless node
communicating with each of
wireless nodes in BSS
3. There can be multiple
access points for extended
coverage.
48
BLAKE Summary
4. A network with
multiple access points is
called an Extended Service
Set (ESS)
5. Wireless units can
roam within the ESS.20. It is a wireless networking scheme that competes
with both 802.11 and Bluetooth schemes.HomeRF™
21. The Bluetooth specification is a joint venture
involving these several companies.
Ericsson,
IBM,
Intel,
Nokia,
Toshiba22. The simplest Bluetooth network Piconet23. A conglomeration of two or more piconets. Scatternet24. It is a short range infrared system that has been
used for some time to allow two devices
communicate with each other.
Infrared Data Association
(IRDA)
25. This standard for wireless packet-switched data was
created by the Swedish telephone company for use
by its field personnel.
Mobitex
26. Mobitex can best be called ________. Near real time27. This system is created by IBM as a joint venture
with Motorola for its own use.
Advanced Radio Data
Information Services (ARDIS)
CHAPTER 24: FIBER OPTICS
1. The maximum angle between the axis of an optical
fiber and a ray of light entering the fiber.Angle of Acceptance
2. The angle an incident ray makes with the normal to
a reflecting or refracting surface.Angle of Incidence
3. The angle a reflected ray makes with the reflected
to a reflecting surface.Angle of Reflection
4. The angle a refracted ray makes with the normal to
a refracting surface.Angle of Refraction
5. In optical fiber, it is the material of lower refractive
index that surrounds the core.Cladding
6. It is the central part of the fiber where the light
propagates.Core
7. The maximum angle of incidence for which
refraction takes place.Critical Angle
8. Interference between signals on separate cables in
close proximity.Crosstalk
9. In a photodetector, it is the current that flows in the Dark Current
49
BLAKE Summary
absence of light.10. A measure of how well a coupler or similar device
rejects power passing through it in the reverse
direction.
Directivity
11. Variation of propagation velocity with wavelength. Dispersion12. the energy given to or absorbed by an electron that
moves through a potential difference of one volt.Electron-volt
13. The proportion of the power entering a coupler that
is lost inside the coupler.Excess Loss
14. An optical fiber in which the index of refraction of
the core decreases gradually with decreasing
distance from the center.
Graded-index Fiber
15. A PN junction in which the two sides of the junction
are made of different materials.Heterojunction
16. The ratio between the velocity of light in free space
and that in a given medium.Index of Refraction
17. Acronym for light amplification by stimulated
emission of radiation.LASER
18. A low-power laser resembling an LED in its
construction.Laser Diode (LD)
19. A fiber that allows light to travel along it in more
than one waveguide mode.Multimode Fiber
20. A line perpendicular to a reflecting or refracting
light surface.Normal
21. The sine of the aperture of acceptance in optical
fiber.Numerical Aperture
22. A quantum of electromagnetic radiation. Photon23. The smallest amount in which energy can exist. Quantum24. The relationship between output current and input
light power for a photodetector.Responsivity
25. An optical fiber whose core is sufficiently narrow
that only one waveguide mode can propagate.Single-mode Fiber
26. An optical finer that has one index of refraction for
the core and a second.Step-index Fiber
27. reflection at the boundary between two media when
the angle of incidence is greater than the critical
angle.
Total Internal reflection
28. Detectors in fiber optics systems are usually
_________ or _____________.
PIN Diodes,
Avalanche Photodiode29. A well-made splice can have as much loss as ______
of fiber.1km
30. Advantages of fiber optics over copper cable. Larger bandwidth,
Greater distance between
repeaters,
Lower weight,
Smaller size,
50
BLAKE Summary
Immunity from electrical
interference,
Lower cost31. Optical fibers are waveguides for _____. Light
32. An infrared LED is also called as _______.Infrared-emitting Diode
(IRED)33. The light is emitted from the flat surface of the
junction.Surface-emitting
CHAPTER 25: FIBER OPTIC SYSTEMS
1. Synchronization of digital signals by adding extra
bits to one signal.Bit Stuffing
2. A 100 Mb/s LAN signaling standard intended for use
with fiber optics but also used with coax.
Fiber Distributed Data
Interface (FDDI)3. Use of fiber –optic cable for telephone subscriber
connections.Fiber in the Loop (FITP)
4. Use of fiber for all of a telephone system except for
the subscriber loop.Fiber to the Curb (FTTC)
5. Calculation of received power in a system in order
to compare it with the power required for
satisfactory performance.
Loss Budget
6. A laser used as an energy source to excite electrons
into a higher energy state.Pump Laser
7. The time required for the voltage level at the
beginning of a pulse to increase from 10 to 90
percent of its maximum value.
Rise Time
8. Single pulses that can travel through a medium with
no dispersion.Solitons
9. The European Standard for synchronous
transmission over a fiber-optic network.
Synchronous Optical Network
(SONET)10. The use of two or more light sources at different
wavelengths separately modulated with the same
fiber.
Wavelength-division
Multiplexing (WDM)
11. The maximum distance that can be used with a
fiber link can be limited by either ________ or ______.
Losses,
Dispersion12. Limitations due to losses are expressed in a ___
__________.Loss Budget
13. Dispersion is expressed in terms of either
_____________ or _____________.
Bandwidth-distance,
Rise Time14. These can be used in digital systems to extend the
communication distance indefinitely.Regenerative Repeaters
15. Optical amplifiers can amplify an optical signal
without converting it to _____________ ______.Electrical Form
16. To increase the amount of data that can be carried
on a fiber, wavelength-division multiplexing can be
Time-division Multiplexing
51
BLAKE Summary
used in conjunction with ___________ ___________.17. fiber optics has greatly increased both the capacity
and the reliability of __________ ___________.Submarine Cables
ADDITIONAL NOTES: NAVIGATIONAL AIDS
1. It is the art of detecting the movements of a craft from
one point to another along a desired path.Navigation
2. Methods of navigation.
Navigational by Pilotage,
Celestial Navigation,
Navigation by Dead
Reckoning,
Radio Navigations3. A method of navigation wherein the navigator fixes his
position on a map by observing known visible
landmarks.
Navigational by Pilotage
4. It is accomplished by measuring the angular position of
celestial bodies.Celestial Navigation.
5. It is the most common and widely used method of
navigation wherein the position of crafts at any instant
of time is calculated from previously determined
position, speed of its motion with respect to the earth
with the direction and the time elapsed.
Navigational by Dead
Reckoning
6. Refer to no. 6: Another name for it. Deduced Calculations7. It uses electromagnetic waves to attain a fix. Radio Navigation8. It is basically a means of gathering information about
distant objects or targets by sending electromagnetic
waves at them and analyzing the echoes.
Radio Detection and Ranging
(RADAR)
9. A one radar mile can be traveled by a signal within
______.6.16 microsec
10. A round trip of a transmitted signal in a radar will
consume a time of __________.12.36 microsec
11. After the radar pulses has been transmitted, a
__________ _______ _______ must be allowed for the echo
to return so as not to interfere with the next transmit
pulse.
Sufficient Rest Time
12. It determines the maximum distance to the target to be
measured.Pulse Repetition Time
13. It is the range beyond which objects appear as second
return echoes.
Maximum Unambiguous
Range14. It is the transmitted pulse that maybe reflected by the
target for one complete round trip.Double Range Echoes
15. The effective areas considered in a radar cross section
of the target.
Rayleigh Region,
Resonance Region,
Optical Region,
52
BLAKE Summary
16. The radar cross section target depends on…
Polarization of the
independent wave,
Degree of surface roughness,
Use of special coatings on
the target,
Aspect of the target
17. Pulse characteristics is…Flat-topped rectangular
pulses18. Leading edge must be _____ to ensure that the leading
edge of the received pulse is also close to it.Vertical
19. It is required for the voltage pulse applied to the
magnetron anode.Flat Top
20. It is needed for the transmitted pulse so that the
duplexer can switch the receiver over to the antenna as
soon as the body of the pulse has passed.
Steep Trailing Edge
21. Antennas that can be used for radar.
Dipole,
Horn Fed Paraboloid
Reflector,
Reflectros of basically
paraboloid shape
22. Antenna tracking and scanning techniques in radar.
Lobe switching technique,
Conical Scanning,
Monopulse Tracking23. It is a sequential lobing and the direction of the antenna
beam is rapidly switched between two positions.Lobe Switching Technique
24. It is the logical extension of lobe switching. Conical Scanning25. It is a system using four horn antennas displaced about
the central focus of the reflector.Monopulse Tracking
26. Disadvantages of conical scanning.
More complex motion of the
antenna,
Additional servomechanisms
are required,
More than one returned
pulse is required.
27. Methods of radar display.
A scope,
Plan Position Indicator,
Automatic Target Detection28. It is the deflection modulation of the CRT screen. A scope29. It is the intensity modulation of the CRT and it shows a
map of the largest area.Plan Position Indicator
30. It is a method of radar display where direct feeding is
toward a computer.Automatic Target Detection
31. General tasks of radar systems. Search for targets,
Track them once they have
53
BLAKE Summary
been acquired
32. Types of tracking radar systems.Tracking in angle,
Tracking in range33. It is a system that gives the angular position of a target
accurately.Tracking in Angle
34. It is a type of tracking radar system wherein the range
information is continuously obtained.Tracking In Range
35. It is the transmitting and receiving antennas that are
located at the same point.Monostatic Radar
36. In this radar, the transmitter and receiver are separated
by quite large distances.Bistatic Radar
37. It is the effect that the apparent frequency of the
electromagnetic or sound waves depends on the
relative radial motion of the source and the observer.
Doppler Effect
38. These are small radar sets consisting of a receiver, a
separate transmitter and an antenna which is often
omni directional.
Radar Beacons
39. Applications of radar beacons.
Identification Friend or Foe
(IFF),
Calculation of position, similar
to lighthouses40. This provides a sloping glide path for instrument
landing approach of an aircraft.
Instrument Landing Services
(ILS)
41. Components of an ILS.
Localizer,
Glide Slope Equipment,
ILS Marker Beacons,
Runway Lights42. It provides lateral guidance. Localizer
43. Parts of a localizerVHF Radio Transmitter,
Antenna System
44. A localizer uses same general range as ____
Very High Frequency
Omnidirectional Range (VOR)
Transmitters45. It provides vertical guidance. Glide Slope Equipment46. A glide slope equipment is produced by a ________ and
_______.
Ground-base UHF Transmitter,
Antenna System47. The UHF transmitter of the glide slope equipment is
operating at the range of _____.329.30 MHz to 335 MHz
48. It provides information on distance from the runway by
identifying predetermined points along the approach
track.
ILS Marker beacons
49. These ILS beacons are low power transmitters that
operates at a frequency of _______.75 MHz
50. The power rated output of ILS beacons. Less than 3 Watts51. Kinds of runway lights. Approach Lights,
54
BLAKE Summary
Sequence Lights,
Runway Edge Lights,
Threshold Lights,
Runway End Lights,
Precision Approach Path
Indicator (PAPI) Lights52. The color of approach lights. White53. The color of runway edge lights. Yellow54. The color of threshold lights. Green55. The color runway end lights. Red56. It provide guidance to the pilot on an approaching
aircraft to the runway.Approach Lights
57. It is a part of approach light that flashes twice in second
in sequence that distinguishes aeronautical ground
lights in an aero dome to the other lights in the area.
Sequence Lights
58. It provides sufficient guidance to the pilot during
landing and takeoff especially at night or zero visibility.Runway Edge Lights
59. it signifies the end of runway and is placed on a lines at
right angle to the runway access.Runway End Lights
60. It provides a positive indicating on the aircraft position
relative to the optimal slope during final approach to
the runway.
PAPI Lights
61. This is an instrument approach system consisting of
extremely high precision microwave radar equipment
that gives the position of an aircraft in range, azimuth,
and elevation.
Ground-Controlled Approach
(GCA)
62. The ground equipment of the airport consists of two
microwave radar sets, these are _______ and _______.
Search System,
Precision System63. It locates all aircraft within 30 miles or so of the airport
and it provides a radar map of the vicinity.Search System
64. It is the medium range radar accomplished in the initial
phase of the GCA.Plan Position Indicator
65. It provides continuous information regarding the
position of the incoming aircraft with respect to the
runway.
Precision System
66. The final approach of the GCA operator uses short-
range precision radar that indicates the proper glide
path for descent.
Precision Approach Radar
(PAR)
67. These are low-frequency transmitters operating into an
omni directional vertically polarized antenna.
Non-Directional Beacons
(NDB)68. Frequency range of NDB. 200 kHz to 415 kHz69. the reception range of the radio beacon of NDB 15 Nautical Miles70. It is an equipment that provides information of the
distance between an aircraft and the VOR Station.
Distance Measuring
Equipment (DME)71. Components of DME. Transceiver,
55
BLAKE Summary
Internal Computer,
Antenna,
DME Controls72. It sends out signals to ground station. Transceiver73. It is built within the transceivers that measures the time
intervals that elapsed until the response.Internal Computer
74. It is used for both transmission and reception, mounted
on the underside of the aircraft.Antenna
75. It incorporates digital readouts of frequency, DME and
ground speed information.DME Controls
76. DME displays information in the form of _______,
________, and __________.
Distance to the station,
Aircraft’s Ground Speed,
Time to station77. It is a radio facility providing bearing information to and
from such facility at all azimuth within its service area.
Very High Frequency Omni
Range (VOR)
78. Components of the VOR.
VOR Receiver,
Navigation Indicator,
Track Arrow,
Reference Line79. This receives the VOR signals. VOR Receiver80. It gives the pilot aircraft position information. VOR Navigation Indicator
81. The three components of the VOR navigation indicator.
Track Selector,
TO-FROM/OFF Flag,
Track Deviation Bar82. It is used to rotate the azimuth ring which displays the
VOR track.Track Selector
83. Refer to no. 87: Another name for it. Omni Bearing Selector (OBS)84. It indicates whether the track will take the pilot to or
from the station.TO-FROM/OFF Flag
85. It shows the pilot the position relative to the track
selected and indicates whether the radial is to the right
or left when the aircraft heading agrees generally with
the track selector.
Track Deviation Bar (TB)
86. It is a needle that you could think of as a line that runs
through the station and points in the direction of the
selected track that divides the area around the VOR
station into halves.
Track Arrow
87. It is a line perpendicular to the track arrow and
intersecting it at the station.Reference Line
88. It is a microwave pulse system that provides highly
accurate bearing and range information from a
shipboard or ground radio beacon.
Tactical Air Navigation
(TACAN)
89. TACAN operates completely in the UHF band from
______ to ____.962 to 1213 megacycles
90. The TACAN system has a total of ______ channels in the 126
56
BLAKE Summary
UHF band.91. TACAN provides ______ _______ with less than one
degree error end.Compass Direction
92. TACAN can use a very small ground station antenna
which permits its installation on _________ and _________.
Air Force Mobile Units,
Navy Carriers
93. Components of TACAN.
Airborne Interrogator-
Responsor,
Ground or Shipboard Surface
Beacon94. It could be tuned to 126 channels and has a special
range and azimuth circuit.
Airborne Interrogator-
Responsor95. This is a beacon that could be triggered by distance
interrogation pulses coming from an airborne radio set.
Ground or Shipboard Surface
Beacon96. It is the combination of VOR and TACAN. VORTAC97. These are range stations that provides four aircraft
course legs.
Low Frequency Radio (LFR)
Range98. The LFR depends on the superposition of the figure-8
directional antenna patterns that provide __________.ON-COURSE Signals
99. Radio range stations operate on frequency between
_______ and _______.200 kHz and 400 kHz
100. An existing area where practically no signal is heard
in a radio range station.Cone of Silence
101. The station references in long distance navigation
system.
Ground Referenced,
Satellite Referenced102. Navigational aids installed in the ground. Ground Referenced103. It uses the interferometic techniques in the satellite. Satellite Referenced104. Produces hyperbolic lines of position through the
measurement of the difference in times of transmission
of radio signals from two or more synchronized
transmitters at fixed points.
Hyperbolic System
105. It is an electronic method of determining ship
position by the reception of signals from transmitting
stations of known locations.
Long Range Navigation
(LORAN)
106. It has a peak power of 100 kW and can be received
over sea at a distance of 500 to 700 nautical miles.LORAN A System
107. Its transmitters operate at a lower frequencies of
100 kHz and this frequency, ground waves of a 300 kW
transmitter can be received up to 1200 nautical miles.
LORAN C System
108. the ground stations are transportable and therefore
be quickly deployed.LORAN D System
109. A continuous wave hyperbolic system operating in
the 70 to 130 kHz band.DECCA
110. It is a hyperbolic system which works in the very low
frequency region and has a very long base line of the
order of 7000 km.
OMEGA
111. Refer to no. 115: The developers of this system. US Navy
57
BLAKE Summary
112. Refer to no. 115: The year it was developed. 1957
113. It operates from 20 to 85 MHz.Ground Electronics
Engineering (GEE)114. It is the contraction of the phrase “Sound Navigation
and Ranging”.SONAR
115. A system used aboard navy ships for sonic and ultra
sonic underwater detection, ranging, sounding and
communications.
SONAR
116. It alerts the flight crew of potential conflicts with
other airplanes in the same area.
Traffic alert and Collision
Avoidance System (TCAS)
117. TCAS tracks other airplanes or intruders if it is
equipped with ______________ or _____________.
Air Traffic Control Radar
Beacon System (ATCRBS),
Mode S ATC Transponder118. Two types of collision avoidance alerts provided by
TCAS.
Traffic Advisory (TA),
Resolution Advisory (RA)119. It shows the relative position of any intruder
airplane.TA
120. It shows a vertical maneuver to avoid a possible
airplane collision.RA
121. It is a worldwide navigation radio aid which uses
satellite signals to provide accurate navigation
information.
Navigation Systems Time and
Ranging Global Positioning
System (NAVSTAR GPS)
122. The three segments of NAVSTAR.
Space Segment,
Control Segment,
User Segment123. It is composed of a constellation of 24 satellites
arranged in six separate orbital planes of four satellites
each on a circular orbit.
Space Segment
124. It is composed of four monitor stations and one
master control station which track the satellite,
compute the ephemeris, clock corrections and control
the navigation parameters and transmit them to the
GPS users.
Control Segment
125. The civil and military users of the GPS. User Segment
126. Characteristics of the space segment.
55° inclination to the Equator,
An altitude of approximately
20200 km with an orbit period
of 12 sideral hours
127. What do these satellites in the space segment
provide?
Satellite Position,
Constellation Data,
Atmospheric Corrections128. The four monitor stations of the GPS are located
in…
Kwajalein,
Hawaii,
Ascencion Island,
58
BLAKE Summary
Diego Garcia129. The master control station of the GPS is located in
…Colorado Springs
130. Who funded and controlled GPS?US Department of Defense
(DOD)
131. Advantages of GPS.
Anytime, anywhere and in any
weather,
Highly accurate
measurements,
GPS has almost endless
applications
132. Disadvantage of GPS.
GPS measurements becomes
less accurate when SA and AS
is effected.
-end-
(ELECTRONIC COMMUNICATION SYSTEMS, 2nd edition by BLAKE)
59
