Get premium membership and access revision papers, questions with answers as well as video lessons.
Comp 222: Telecommunications And Computers Day: Question Paper
Comp 222: Telecommunications And Computers Day:
Course:Bachelor Of Telecommunication And Information Engineering ()
Institution: Kabarak University question papers
Exam Year:2011
KABARAK UNIVERSITY
UNIVERSITY EXAMINATIONS
2011/2012 ACADEMIC YEAR
FOR THE DEGREE OF BACHELOR OF COMPUTER SCIENCE
COMP 222: TELECOMMUNICATIONS AND COMPUTERS
DAY: WEDNESDAY DATE: 21/03/2012
TIME: 9.00 – 11.00 A.M. STREAM: Y2S2
INSTRUCTIONS:
1. Answer ALL questions in PART ONE and any TWO questions in PART TWO
2. Any extra questions answered will not be marked
PART ONE
Question One (30 marks)
a. Describe simplex communication and full duplex communication, and give one type of
telecommunication network that uses each type of communication. (4 marks)
b. An analog signal has frequency components between 110Hz and 9800Hz. Determine the
frequency components of the filtered output signal if this analog signal is filtered using
i. A lowpass filter with a cutoff frequency of 7700Hz
ii. A bandpass filter with cutoff frequencies of 500Hz and 10000Hz (3 marks)
c. A transmission medium can transmit frequency components between 2200Hz and
19 KHz. The noise power at the output of the medium is 1.5milliwatts while the signal
power at the output of the medium is 2.9W. Calculate the capacity of the medium.
(4 marks)
d. Describe
i. Line coding. (2 marks)
ii. How synchronization is implemented in a line code. (2 marks)
e. Encode the data 10110010 using
i. Non return to zero level code. (2 marks)
ii. Manchester code. (2 marks)
f. Compare, giving reasons, the bandwidth and power requirements between digital signals
produced using Manchester code and return to zero code. (4 marks)
g. Describe synchronous serial transmission. (3 marks)
h. An analog signal with frequency components between 450Hz and 5600Hz is digitized
using pulse code modulation. The analog signal is sampled every 500 microseconds and
quantized using 202 quantization levels. Determine the bit rate of the resultant digital
signal. (4 marks)
PART TWO
Question Two (20 marks)
a. Describe
i. Phase modulation. (2 marks)
ii. Amplitude shift keying. (2 marks)
b. An analog signal with frequency components between 200Hz and 4400Hz is used to
amplitude modulate a carrier with a frequency of 15 KHz. Determine the maximum and
minimum frequency components of the modulated signal. (3 marks)
c. Describe one advantage and one disadvantage that amplitude modulation has compared
to frequency modulation. (4 marks)
d. A digital signal has a bit rate of 10Kbps. Calculate the bandwidth of the medium
required to transmit the signal when the following modulation techniques are used.
i. 32QAM. (3 marks)
ii. Frequency shift keying is used to modulate the digital data. Frequencies 5000Hz and
8200Hz are used to represent binary zero and one respectively. (3 marks)
e. Give two uses of modulation in telecommunication networks. (3 marks)
Question Three (20 marks)
a. Is frequency division multiplexing (FDM) an analog or digital process? Can FDM be
used to multiplex digital signals? Explain your answers. (3 marks)
b. Describe the time division multiplexing and demultiplexing processes. (3 marks)
c. How many analog signals each with frequency components between 300Hz and 3400Hz
can be frequency division multiplexed onto a medium with a bandwidth of 0.25MHz if a
guard band of 750Hz is used and the multiplexer uses amplitude modulation as the
modulation scheme. (4 marks)
d. Describe
i. The two technologies that are used to implement circuit switching. (3 marks)
ii. The two main disadvantages that a multistage crossbar switch has as compared to a single
stage (simple) crossbar switch. (3 marks)
e. A time slot interchanger (TSI) switch has 20 inputs and 20 outputs. Each of the inputs to
the switch has a bit rate of 800 bps. The duration of each time slot is 0.002 seconds.
i. Explain how the TSI switch implements the switching operation. (2 marks)
ii. Determine the minimum size of each memory location on the TSI switch. (2 marks)
Question Four (20 marks)
a. Describe
i. Frequency division multiple access. (2 marks)
ii. Polling access method. (3 marks)
b. You are the administrator of the local area network (LAN) at organization ABC. Most of
the users use laptops which they often carry home. Which access method between token
ring access method and carrier sense multiple access with collision detection
(CSMA/CD) would you use on the LAN? Explain your answer. (4 marks)
c. Which error correction methods between forward error correction and error correction
using retransmission is suitable for use with digital television broadcast? Give two
reasons for your answer. (4 marks)
d. Does the checksum error detection scheme correct odd or even errors? Explain your
answer. (4 marks)
e. Describe the stop and wait automatic repeat request error correction method. (3 marks)
More Question Papers
Popular Exams
Return to Question Papers