UNIVERSITY EXAMINATIONS: 2011/2012
YEAR III EXAMINATION FOR THE BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY
BIT 4302 TELECOMMUNICATIONS
DATE: APRIL 2012 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One and Any other Two Questions
QUESTION ONE
a) State, with appropriate equations, Nyquist and Shannon’s Theorems. (6 Marks)
b) Distinguish between “piconet” and “scatternet” as used in Bluetooth technology. (4 Marks)
c) i. Define the term convergence as used in Computer networks (1 Mark)
ii. Converged networks have existed for a while now, but were only feasible in large enterprise
organizations. Why? (4 Marks)
iii. Why is it difficult for some organizations to make a decision to move towards converged
networks? (2 Marks)
d) State five major differences between WLANs and wired Ethernet. (5 Marks)
e) Teleworkers require a connection to an ISP to access the Internet. ISPs offer various connection
options. Describe the following main connection methods used by home and small business users:
i. DSL (2 Marks)
ii. Cable modem (2 Marks)
iii. Satellite (2 Marks)
f) State any two major characteristics of WANs. (2 Marks)
QUESTION TWO
a) Describe the two levels of ISDN services (BRI and PRI). (7 Marks)
b) Explain briefly four major criteria that a data communication network must meet. (4 Marks)
c) Discuss briefly the importance of error detection and correction, flow control and recovery in data
communications. (5 Marks)
d) Differentiate between a packet and a frame. (2 Marks)
QUESTION THREE
a) With the aid of relevant diagrams, describe Very Small Aperture Terminals (and satellite)
communications. (9 Marks)
b) WANs use numerous types of devices that are specific to WAN environments. Describe any five
of these devices (5 Marks)
c) With any communications medium, the received signal will differ from the transmitted signal due
to various transmission impairments. Discuss any three of these impairments. (6 Marks)
QUESTION FOUR
a) With the aid of a relevant diagram, describe the GSM Architecture (9 Marks)
b) A routing protocol is a set of processes, algorithms, and messages that are used to exchange
routing information and populate the routing table with the routing protocol’s choice of best paths.
State the three purposes of a routing protocol. (3 Marks)
c) Given the bit stream below, encode it using: 10011010
i. Non-Return to Zero-Inverted (2 Marks)
ii.Manchester (3 Marks)
iii.Differential Machester (3 Marks)
QUESTION FIVE
a) With the aid of relevant diagrams, describe the principal components of a digital communication
system. (9 Marks)
b) Explain the following terminologies as used in the TCP three-way handshake:
i. Positive acknowledgment and retransmission (PAR) (2 Marks)
ii. Windowing. (2 Marks)
iii. Sequencing (2 Marks)
c) There are three key factors that influence network uptime/availability. State these three factors and
illustrate how they affect availability. (5 Marks)
