Instructions
Read the following questions and choose the
most appropriate answer or fill in your answer on the question sheet. Mark all of your responses on the question
sheet.
You may carry out your working on the
question sheet.
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1 In
a mobile phone network, why are base station antennae angled down by a few
degrees?
a.
To keep rain off the antenna - rain degrades the signal
b.
To drop the power given off by unrequired lobes
c.
To get the best coverage possible in the area covered by the mast
d.
To help reduce co-channel interference
e.
To make the beam into a conical shape to increase coverage
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2 How
does a transmitting antenna provide gain to a wireless signal?
a.
Low loss coaxial feeder cable amplifies the radiated power
b.
The Fresnel zone focuses the beam in the required direction
c.
Its shape or design is able to focus the radiated power in a certain direction
d.
An amplifier is built into the antenna structure
e.
The wireless field is accelerated by a high electric field
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4 If
a wave has a frequency of 9.4 GHz, what is its wavelength in metres?
Give your answer to 3 decimal places.
The speed of light is 300 000 000 metres
per second.
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5 The
preferred backhaul technologies for European mobile base stations used in cellular
telephony is:
a.
Microwave
b.
Leased line
c.
Fibre optic
d.
Coaxial
e.
Public Internet
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6 Pick
two features of frequency hopping.
a.
It enables 2G, 2.5G and 3G operation
b.
It shares bad frequencies between several users so the bad frequency is not
noticed
c.
Allows the use of ASK
d.
Provides greater coverage
e.
Provides a form of protection from eavesdropping
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8 How
many dBW is 6.7 watts?
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11 The
main competitor to WiMAX is the local loop.
True False circle the correct response
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14 When
a Bluetooth device is a member of two or more piconets, what is the name for
the network type that it is involved in?
a.
Scramblenet
b.
Multi-Piconet
c.
Nibblenet
d.
Scatternet
e.
Splatternet
f.
Pico-tuple-net
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16 What
is abbreviation for the body that regulates the wireless spectrum and issues
licences in the
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17 Which
two of the following are true of Frequency Shift Keying?
a.
It is suitable for high quality audio
b.
The amplitude may be varied to convey signal depth information
c.
It can be used to enable full duplex operation over copper cabling
d.
It is the simplest form of modulation
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18 The
process by which a mobile phone switches its channels from one cell to another
is known as what?
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19 Select
the three correct responses
a.
IEEE 802.11g operates at 54 Mbps
b.
IEEE 802.11b operates at 2.4 GHz
c.
IEEE 802.11g operates at 5.8 GHz
d.
IEEE 802.11b operates at 11 Mbps
e.
IEEE 802.11b operates in a licensed band
f.
IEEE 802.11a is the successor to IEEE 802.11g
20 What
is the abbreviation for a wireless signal that has had its carrier signal
filtered out but retains both sidebands?
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22 In
the past, meshed wireless networks that used IEEE802.11x to distribute wireless
connectivity to a community have failed because:
a.
the power requirements were too high
b.
nobody wanted the new technology
c.
the frequency in use was injurious to health
d.
eagles nested on the transmitters
e.
the cost of installing many transmitting nodes was too high to recoup the
investment
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25 When
wireless signals bounce around between obstructions between transmitter and
receiver, signal impairment takes place. What is this known as?
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26 Which
two of the following are UNTRUE of wireless Ethernet?
a.
It operates in the licensed ISM band at 2.4 GHz
b.
No cabling needs to be installed
c.
It cannot transmit beyond line of sight
d.
It is a good choice for
e.
AM is used as the physical layer
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27 What
is the frequency (in MHz) of a radio station whose wavelength is 6.4 metres?
Speed of light is 3 x 108 ms-1
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29 Which
three are the properties of ASK ?
a.
It is the simplest form of modulation
b.
It is often used to modulate digital data onto optical fibres
c.
Binary one is represented by one frequency, binary 0 is represented by a
different frequency
d.
It is good for high quality audio
e.
It cannot transmit beyond line of sight
f.
It is susceptible to sudden gain changes
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30 UHF
waves are in the range 10 metres to 100 metres
True False circle the correct response
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32 A
salesman tells you that the gain of a certain antenna is 3.2 dBi.
You realise that he is attempting to
"big up" the antenna's characteristics.
How many dBd is this equivalent to?
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33 What
common substance causes severe attenuation of wireless signals in the 2.4GHz
band?
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35 Frequency
modulation produces how many sidebands?
a.
4
b.
2
c.
An infinite number, in theory
d.
1
e.
8
37 Bluetooth
provides a wide-band channel for voice and data transmission,
it being possible to operate up to three voice channels with 24 KB/s each
True False circle the correct response
What is the Maximum Permitted Power (in mW)
for Class 1 Bluetooth devices?
a.
15W
b.
100 mW
c.
1 mW
d.
12 Mbps
e.
100 MW
39 Bluetooth
devices use frequency-hopping spread spectrum (FHSS) at the network layer.
True False circle the correct response