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MNA810S - MOBILE NETWORKS AND ARCHITECTURES - 1ST OPP - JUNE 2025 |
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nAmlBIA UnlVERSITY
OF SCIEnCE Ano TECHnOLOGY
Faculty of Computing and Informatics
Department of Computer Science
QUALIFICATION:BACHELOROF COMPUTER SCIENCEHONOURS
QUALIFICATIONCODE: 08BCHC
LEVEL: 8
COURSE:MOBILE NETWORl<SAND
ARCHITECTURES
DATE:JUNE 2025
COURSECODE: MNA810S
SESSION: 1
DURATION: 3 HOURS
MARKS: 100
FIRSTOPPORTUNITYEXAMINATION QUESTION PAPER
EXAMINER(S) PROFDHARM SINGH JAT
MODERATOR: DR LINOH MAGAGULA
THIS QUESTION PAPERCONSISTSOF THREEPAGES
(Excluding this front page)
INSTRUCTIONS
1. Write clearly and neatly.
2. Write all your answers in the answer booklet provided.
3. Number the answers clearly.
4. This paper consists of two sections; Section A and B.
5. Answer ALL questions in section A.
6. Answer any 3 questions in section B.
7. Begin each section on a new page.
8. Marks/scores per question are given in [ ].
9. Do not use or bring into the examination venue books, programmable calculators,
mobile devices and other material that may provide you with unfair advantage. Should
you be in possession of one right now, draw the attention of the examination officer
or invigilator.
10. NUST's examination rules and regulations apply.
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SECTIONA
{40Marl<s]
This section contains TWO questions.
Attempt ALLquestions.
Ql Choose the correct answer for each of the following multiple-choice questions.
[20 marks, 2 marks for each]
(i). In which multiplexing technique are multiple signals transmitted by sharing
the same frequency at different time intervals?
A. FDM
B. TDM
C. Wavelength Division Multiplexing
D. Code Division Multiplexing
(ii). Which multiplexing method is generally more efficient in systems where
users transmit in bursts?
A. TDM
B. FDM
C. Frequency Hopping
D. None of the above
(iii). What is the Normalised repeat distance when a cluster size in a cellular
topology is 13:
A. 6.5
B. 13.0
C. 3.6
D. 2.0
(iv). What is the bandwidth of a GSM channel?
A. 100 kHz
B. 150 kHz
C. 200 kHz
D. 250 kHz
(v). Which of the following is a component of a 3G network architecture?
A. User Equipment (UE)
B. Radio Access Network (RAN)
C. Core Network
D. All of the options
(vi). 3G W-CDMA is also known as
A. UMTS
B. DECT
C. DCS-1800
D. ETACS
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(vii).
(viii).
(ix).
Which multiple access technique is primarily used in 4G?
A. FDMA
B. TOMA
C. CDMA
D. OFDMA
Which of the following technologies is 6G expected to rely heavily on?
A. Circuit switching
B. Analog Modulation
C. Artificial Intelligence (Ai) and Machine Learning
D. Morse Code Signaling
Which multiple access technique is used by IEEE802.11 standard for wireless
LAN?
A. CDMA
B. CSMA/CA
C. ALOHA
D. None of the mentioned
(x). Which of the following is part of a BSS(Base Station Subsystem) in a GSM
network?
A. BTS- BaseTransceiver Station
B. BSC- Base Station Controller
C. BTSand BSC
D. None
Q2 (i). Write two functions of the Mobility Management (MM) protocol in UMTS. (4)
(ii)' Write two functions of the eNB in E-UTRANsystems.
(4)
(iii). Give two advantages and two disadvantages of wireless LANs.
(4]
(iv). Why is Temporary Mobile Subscriber Identity (TMSI) required when we (4]
have an International Mobile Subscriber Identity (IMSI)?
(v). Explain how CSMA/CA solves the Hidden and exposed terminals problems. (4)
SECTION B {60Marks]
This section contains FOUR questions
Attempt any THREEquestions.
Q3 a) A TDMA/FDD-based GSM cellular system has a band of 25 MHz for the
forward link, divided into radio channels of 200 kHz each. Suppose eight
speech channels (time slots) are supported on a single radio channel.
Calculate the maximum number of simultaneous subscribers that can be (4)
accommodated in the GSM system.
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b) The GSM System uses a frame structure where each frame consists of
eight-time slots and each time slot contains 156.25 bits, and data is
transmitted at 270.833 kbps in the channel, find:
a. Time duration of a bit
(4)
b. Time duration of a slot
(4)
c. Time duration of a frame and
(4)
d. How long must a user occupy a single slot and wait between two
(4]
simultaneous transmissions?
Q4 a)
b)
c)
With the help of an appropriate diagram, explain the basic steps
[8]
ofMobile originated call (MOC) in a GSM network.
With the help of an appropriate diagram discuss how Encryption is (6)
achieved in a GSM network.
What is the difference between LTEFDD and LTETDD?
[6]
Q5 a)
If a total of 33 MHz of bandwidth is allocated to a particular FDD cellular
telephone system, which uses two 25 kHz simplex channels to provide full
duplex voice and control channels, compute the number of channels
available per cell if a system uses:
(i). four-cell reuse
[3]
[3]
(ii). seven-cell reuse, and
[3]
(iii). 12-cell reuse.
b) What is 6G, and how does it differ from 5G technology? Provide four key (11]
differences.
Q6 a) Draw and explain the three main parts of 5G Network Architecture.
(10]
b) Draw and explain the 3GPPsecurity architecture for 5G.
[10]
GOOD LUCK!
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