UNIVERSITY EXAMINATIONS: 2020/2021
EXAMINATION FOR THE DEGREES OF BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY/ BACHELOR OF SCIENCE IN APPLIED
COMPUTING/ BACHELOR OF BUSINESS INFORMATION TECHNOLOGY
BIT 4302/BAC 2107/BBIT 309: TELECOMMUNICATION
FULLTIME/ PART TIME/DISTANCE LEARNING
DATE: DECEMBER, 2021 TIME: 2 HOURS
INSTRUCTIONS: QUESTION ONE IS COMPULSORY, CHOOSE TWO OTHER
QUESTIONS
QUESTION ONE (20 marks) Compulsory
There is a global trend towards adopting digital communication as opposed to analogue
systems. Analogue data has therefore to be converted to digital data in a process known
as digitisation.
Required
a) Explain FOUR advantages of digitizing data. (4 Marks)
b) With the help of a diagram explain digital modulation. (4 Marks)
c) Draw a wave diagram for the data input 01001100011, showing how unipolar NRZ,
polar NRZ-L, NRZ-I and Bipolar line codings are used. (8 Marks)
d) Explain any FOUR factors that should be considered when selecting a line
encoding scheme. (4 Marks)
QUESTION TW0 (15 marks)
A digital stream 00110100010 needs to be passed through a modem for conversion
into an analogue signal.
Required
a) Briefly describe the following digital to analaog conversion techniques:
i. Amplitude Shift Keying. (2 Marks)
ii. Frequency Shift Keying. (2 Marks)
iii. Phase Shift Keying. (2
Marks)
iv. Quadrature Phase Shift Keying (2
Marks)
b) Illustrate the results of converting the following digital data (00110100010) to
analog signals using the encoding techniques ASK, FSK and PSK respectively.
(7 Marks)
QESTION THREE (15 marks)
Using a well labeled diagram, discuss the Internet model. Note: Your answer should
include the names of all the layers, the functions of each layer and at least TWO
protocols implemented at each layer. (15 Marks)
QUESTION FOUR (15 marks)
a) There are number of applications where satellite communication systems are
involved. Describe any FOUR of these areas. (8 Marks)
b) Satellite orbits are an essential characteristic of a satellite communication system.
They are characterized by the following properties:
i. Apogee
ii. Perigee
iii. Orbital period
iv. Inclination
c) Explain the meaning of the above terms. (4 Marks)
d) Describe THREE advantages of wireless communication (3 Marks)
