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• 60
~~,~
UNIVERSITY
OF
GHANA
(All rights reserved)
B.SC
COMPUTER
SCIENCEIINFORMATION
TECHNOLOGY,
SECOND
SEMESTER
EXAMINATIONS: 2015/2016
CSIT
302:
DATA
COMMUNICATION
(3
CREDITS)
INSTRUCTION:
ANSWER
ALL
Questions in Section A
Answer Question
Bl
and
Any
Other
Two
(2)
TIME
ALLOWED:
TWO
AND
A HALF
(2~)
HOURS
Al.
A2.
a)
b)
SECTION
A (40 Marks)
hj7he
Explffifi tho-eofieept
o:f
Channel Capacity.
[2
Marks
1
Given a channel with an intended capacity
of
20Mbps, the bandwidth is 3MHz.
Assuming White normal noise, what signal-
to
-noise ratio (in decibels) is required to
achieve this?
[4
Marks]
c)
List and explain the three most significant impairments to signal transmission.
a)
Explain the following concepts
i.
Circuit Switching
ii. Packet Switching
[6
Marks]
[6
Marks]
b)
What
is
the channel capacity for a teleprinter channel with a 300Hz bandwidth and
asignal-to-noise ratio
of
3 dB, where the noise
is
white thermal noise?
[4
Marks]
Page 1
of
3
EXAMINER: DR F-A. KASTRIKU
