Read these instructions carefully and follow the guidance from your lecturer.

For multiple choice questions, mark the answer that you consider to be most appropriate by marking a vertical line through the letter that corresponds with your chosen response.

Some questions require you to fill in a word, others to carry out a calculation, others are true or false. Circle the correct response.

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.

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

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

3 Why are sectored aerials used in cellular telephony base stations?

a. To help reduce co-channel interference

b. To allow multiple calls to take place at once

c. To clutter up the landscape

d. To ensure even coverage of the cell

e. To reduce the cost of purchasing dipole antennae

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

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

7 IEEE 802.11a operates at 2.4 GHz

True False circle the correct response

8 How many dBW is 6.7 watts?

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9 If the Fresnel zone is obstructed, what two changes could be made to improve reception?

a. Lower transmission frequency

b. Raise the receiver

c. Make use of Fresnel harmonics

d. Raise the transmitter

10 What is the angular frequency of a signal having a frequency of 5 kHz?

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11 The main competitor to WiMAX is the local loop.

True False circle the correct response

12 A four-phase PSK system encodes four bits with each signal burst.

True False circle the correct response

13 What shape is the radio wave power from a 1/2 wave dipole?

a. Conical

b. Doughnut shaped or toroidal

c. Lobe

d. Concave

e. Convex

f. Spherical

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

15 A graph that displays Upper Side Band, Carrier and Lower Side Band of a signal is:

a. in the time domain

b. in the radio domain

c. in the wireless domain

d. in the frequency domain

16 What is abbreviation for the body that regulates the wireless spectrum and issues licences in the UK known as?

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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

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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21 Which two of the following are true of wireless Ethernet?

a. It has high security

b. It is suitable for installation in listed buildings

c. It can be used for WAN links

d. It is compatible with Bluetooth as they operate at the same frequency

e. No cabling needs to be installed

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

23 AM radio operates at a lower frequency than FM radio.

True False circle the correct response

24 What is the typical gain of a dipole antenna in dBd?

a. 3 to 12 dBd

b. 0 dBD

c. 5 to 30 dBd

d. 2.15 dBd

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 SOHO networks

e. AM is used as the physical layer

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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28 What is the maximum diameter of the first Fresnel zone if the transmitter and receiver are 2 km apart and the wavelength is 49 metres?

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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

30 UHF waves are in the range 10 metres to 100 metres

True False circle the correct response

31 A picocell transmitter is usually placed on a tall mast to avoid causing harm to people.

True False circle the correct response

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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34 Three 30° flat panel base station antennae are required to provide complete coverage around a base station.

True False circle the correct response

35 Frequency modulation produces how many sidebands?

a. 4

b. 2

c. An infinite number, in theory

d. 1

e. 8

36 What is the maximum data rate of Basic Rate Bluetooth 1.1?

a. 3 Mbps

b. 0.5 Mbps

c. 5 Mbps

d. 2 Mbps

e. 1 Mbps

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

40 Bluetooth technology has not gained approval for use in France.

True False circle the correct response