14/16 AHMADU BELLO WAY, VICTORIA ISLAND, LAGOS

SCHOOL OF SCIENCE AND TECHNOLOGY

MARCH/APRIL 2014 EXAMINATION

COURSE CODE: CIT 303

COURSE TITLE: PRINCIPLES OF COMMUNICATION TECHNOLOGY

TIME ALLOWED: 3HOURS

INSTRUCTION: ATTEMPT ANY FIVE (5) QUESTIONS

Question 1

a. Encrypt the word “IGNORANCE” with the following ciphers:

i. Shift cipher with key=1 (1 mark)

ii. Shift cipher with key= 26 (2 marks)

iii. Shift cipher with key=0 (2 marks)

iv. Transposition cipher where plain text: 1 2 3 4 5 6 7 8 9 and

cipher text: 4 3 1 5 2 6 7 9 8 (with no bogus character) (1.5 marks)

b. Decrypt the word “ANCEIGNOR” with the following ciphers:

i. Shift cipher with key=1 (1 mark)

ii. Shift cipher with key= 26 (2 marks)

iii. Shift cipher with key=0 (2 marks)

iv. Transposition cipher where plain text: 1 2 3 4 5 6 7 8 9 and

cipher text: 4 3 1 5 2 6 7 9 8 (with no bogus character) (1.5 marks)

c. The amplification in a cable is usually defined in decibels per kilometer (dB/km). If the signal at the beginning of a cable with 2 dB/km has a power of 2 mW, what is the power of the signal at 5 km? (3 marks)

d. Briefly explain the term attenuation (1.5 marks)

Question 2

.

a. Define the term “network topology”. (1 mark).

b. With the aid of diagrams, briefly explain the following network topologies:

i. Ring (3 marks)

ii. Mesh (3 marks)

iii. Tree (3 marks).

c. State and briefly explain 3 advantages and 3 disadvantages of using fiber optic cables in networking. (6 marks)

d. State 1 advantage and 2 disadvantages of STP cables in comparison to UTP cables. (1.5 marks)

Question 3

a. With the aid of a table ONLY, describe the five classes of IPv4 addresses under the following columns: (10 marks)

i. IP Address Class

ii. Format

iii. Purpose

iv. Number of network/ host bits

v. Max number of hosts

b. Briefly explain each of the following terms:

i. Linear filter (2 marks)

ii. Stable filter (1 mark)

iii. Unstable filter (1 mark)

iv. Time-invariant filter (1 mark)

v. Adaptive filter (1 mark)

vi. Linearity (in the context of linear-time invariant (LTI) (1.5 marks)

Question 4

i) Outline four (4) basic Network Topologies.

ii) List three guided Media.

iii) In one sentence, describe the OSI reference model (1 mark)

Question 5

a. Briefly explain the 3 modes of communication (with regards to the direction of communication). In each case, identify 2 examples of devices that utilize that mode of communication. (9 marks)

b. State the following:

i. 4 services/ functions provided by the OSI Physical Layer (2 marks)

ii. 4 services/ functions provided by the OSI Data Link Layer (2 marks)

iii. 4 services/ functions provided by the OSI Transport Layer (2 marks)

iv.3 services/ functions provided by the OSI Session Layer (2.5 marks)

Question 6

Contrast between:

i) Analog Signal Processing

ii) Digital Signal Processing

Question 7

a) What is Data Communications?

b) Define Protocols.

c) The effectiveness of a data communications system depends on four fundamental characteristics. List and define these characteristics.

For the 2015 – till date past questions for this course CLICK HERE

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NATIONAL OPEN UNIVERSITY OF NIGERIA

University Village, 91 Cadastral Zone, NnamdiAzikwe Expressway, Jabi, Abuja

FACULTY OF SCIENCES

April, 2019 Examinations

 
COURSE CODE: CIT303
COURSE TITLE: Principles of Communication Technology
CREDIT: 3 Units
TIME ALLOWED: 2½ Hours
INSTRUCTION: Answer Question 1 and any other FOUR (4) Questions
 
 
Question 1
a. Discuss the characteristics of optical fibre cable as a transmission medium (3 marks)
b. Give the advantages and disadvantages of terrestrial microwave as a transmission medium in terms of cost, ease of installation and adaptability in providing a range of services to clients
(5 marks)
c. List in correct order the layer of the Open System Interconnect (OSI) model (3½ marks)
d. State the function of each OSI layer listed in (1c) above.(3½  marks)
e. Differentiate between the terms communication and telecommunication. (3 marks)
f. State the four fundamental characteristics upon which the effectiveness of a data communication depends. (4 marks)
 
(22 marks)
 
Question 2
a.    Give a list of possible data representation in data communication. (3 marks)
b.   Briefly describe each of the data representation identified in (2a) above and the form of their preparation for transmission. (6 marks)
c.    List the basic elements/components of Data Communications. (3 Marks)
(12 marks)
 
Question 3
a. Identify four main applications of Digital Signal Processing  (DSP) (2 marks)
b. Give four specific examples of DSP applications (2 marks)
c. Explain the way DSP is carried out (4 marks)
d. Discuss Signal sampling (4 marks)
(12 marks)
 
Question 4
a.Briefly explain the following terms:(4 x 2marks)
i.            Filter
ii.            Bandwidth
iii.            Impulse
iv.            Fourier transform
b. What do you understand by Signal-to-Noise Ratio (SNR) (2 marks)
c. What are the values of SNR and SNRdB if the power of a signal is 10 mW and the power of the noise is µW? (2 marks)
(12 marks)
 
Question 5
a. Write short notes with examples on:
Analog signal processing (3 marks)
Digital signal processing (3 marks)
b. Describe three characteristics of microwave propagation (3 Marks)
c. The loss in a cable is usually defined in decibels per kilometer (dB/km). If the signal at the beginning of a cable with -0.3 dB/km has a power of 2 mW, what is the power of the signal at 5 km? (3 marks)
(12 marks)
 
Question 6
a. Outline four services provided by Network security (2 marks)
b. Explain what is meant by cryptography (3 marks)
c. State the three types of keys in Cryptography and their uses  (3  marks)
d. Differentiate between Symmetric-Key and Asymmetric-Key Cryptography. (4 marks)
(12 marks)
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882

Exam summary sample below

National Open University of Nigeria

Plot 91, Cadastral Zone, Nnamdi Azikiwe Expressway, Jabi – Abuja

Faculty of Science

NOVEMBER, 2018 EXAMINATIONS

 
COURSE CODE: CIT 303
COURSE TITLE: PRINCIPLES OF COMMUNICATION TECHNOLOGY
CREDIT: 3 Units
TIME ALLOWED: 2½ Hours
INSTRUCTION: Answer Question ONE (1) and any other FOUR (4) Questions
 
QUESTIONS
1.
a)      Distinguish between Analog Signal processing and Digital Signal processing (4 marks)
b)      Explain Data Communication and outline and explain their features.           (3 marks)
c)      Describe an Encryption and Decryption?                                                       (3 marks)
d)     Outline and explain  three Network criteria                                                   (3 marks)
e)      Outline four (4) basic networking devices.                                                     (2 marks)
f)       Differentiate between Symmetric-Key Cryptography and symmetric-Key Cryptography
(4 marks)
g)     List three broad groups of wireless transmission: radio waves, microwaves, and infrared waves                                                                                             (3 marks)                (22 Marks)
 
 
2.
a)      Differentiate between guided media and unguided media with examples    (4 marks)
b)      Discuss the five services provided by Network security.                               (5 marks)
c)      Outline  three (3) examples of Network node  or  hardware equipment        (3 marks)
 
3.
a)      Describe with diagram the components of data communication                    (4 marks)
b)      What is a protocol and list its key elements                                                    (4 marks)
c)      List and explain different forms of information                                             (4 marks)
 
4.
a)      Describe the following with diagrams :
(i)                 Bus Topology
(ii)               Tree Topology
(iii)             Star Topology
(3 marks each)
b)      Outline the three (3) types of keys in cryptograph     (3 marks)
 
5.
a)      Write short notes on the following:
(i) Simplex
(ii) Half- Duplex
(iii) Full – Duplex
(2 marks each)
b)      List and explain two (2) types of connection                         (3 marks)
c)      What is  OSI model                                                   (3 marks)
 
6.
a)      Outline five (5) types of topology                              (5 marks)
b)      Explain Cryptography algorithms, Use the shift cipher with key = 12 to encrypt the message “HELLO.”                                                              (4 marks)
c)      Write short notes on the following
(i) LAN
(ii) WAN
(ii) Wireless
(3 marks each)
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882

Exam summary sample below

National Open University of Nigeria, University Village Plot 91 Cadastral Zone,

Nnamdi Azikiwe Express Way, Jabi, Abuja

Faculty of Sciences

CIT 303: PRINCIPLES OF COMMUNICATION TECHNOLOGY  – (3 Credits)
Answer Question one (1) and four (4) other questions in 21/2 Hours.
Total of 70, Question 1 is 22 marks and others 12 marks each
 
 
1(a) Explain Data Communication and outline and explain their features. (5 marks)
1(b)  Describe an Encryption and Decryption? (3 marks)
1(c ) Outline and explain  three Network criteria (3 marks)
1(d) Outline four (4) basic networking devices. (4 marks)
1(e)  Differentiate between Symmetric-Key Cryptography and symmetric-Key Cryptography
4  marks)
1(f) List three broad groups of wireless transmission: radio
waves, microwaves, and infrared waves (3 marks)
 
 
2 (a). Describe with diagram the components of data communication (4 marks)
2(b) What is a protocol and list its key elements (4 marks)
2(b) List and explain different forms of information (4 marks)
 
3(a) Describe the following with diagrams :
 
(i)                 Bus Topology
(ii)               Tree Topology
(iii)             Star Topology
(3 marks each)
 
3(b) Outline the three (3) types of keys in cryptograph (3 marks)
 
4(a).Write short notes on the following:
(i) Simplex
(ii) Half- Duplex
(iii) Full – Duplex
(3 marks each)
4(b) 4(b)  List and explain two (2) types of connection ( 3 marks)
 
 
5.(a)  What is  OSI model ? (3 marks)
5(b) Outline five (5) types of topology (5 marks)
5 ( c) Explain Cryptography algorithms, Use the shift cipher with key = 12 to encrypt the message “HELLO.”  (4 marks)
.
6 (a) Distinguish between Analog Signal processing and Digital Signal processing (3 marks)
6 (b)  Write short notes on the following
(i) LAN
(ii) WAN
(ii) Wireless
(3 marks each)
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882

Exam summary sample below

NATIONAL OPEN UNIVERSITY

University Village, Plot 91, Cadastral Zone, Nnamdi Azikiwe Express Way, Jabi, Abuja

Faculty of Science and Technology

Course Title: PRINCIPLES OF COMMUNICATION TECHNOLOGY

3 Credit Unit
Course code: CIT303
Instruction: Answer Question 1 and any other four
 
1a.       With the aid of a suitably labelled sketch, LIST the FIVE(5) components that constitute a generic data communications system
(4marks)
b.        List and briefly explain the different forms of data
(2 marks)
c.        Explain briefly,  the following modes of data communication: simplex, semi-duplex, full
duplex
(2 marks)
 
d.        What are point-to-point and point-to- multipoint  connections in data communications?
(2 marks)
 
e.        Describe briefly, the FOUR(4) types of network topologies used  in data communications
networks
(2 marks)
 
f.         Why are standards necessary in data communications?
(2 marks)
 
g.        List and briefly explain the broad categories  of standards in data communications
(2 marks)
 
h.        Outline the layers that make up the OSI  model ?
(2 marks)
 
i.           LIST the methods  that enable the Media Access Control sub-layer to determine  where
one frame o data ends  and the next one starts
 
(2 marks)
j.          explain briefly, the main function of the IP component of the TCP/IP protocol and list its
main characteristics
(2 marks                       { Total  =  22 marks }
 
2a.       Explain briefly, the concept of convolution
(4 marks)
 
b.        State, in a mathematical form, the condition necessary for systems or signals to be
transformed by Fourier transform
(4 marks)
c.        LIST ANY TWO(2) applications of Digital Signal Processing(DSP)
(4marks)
3a        Describe briefly the following network types:
·                     Local Area Network(LAN)
·                     Meropolitan Area Netwok(MAN)
·                     Wide Area Network(WAN)
(4 marks)
b.        What are the most common wireless  LANs? Explain briefly, their areas of application as
well as their advantages and disadvantages
(4 marks)
 
c.        List  the  basic networking devices .
(4 marks)
 
4a.       Distinguish between guided and unguided transmission media
(4 marks)
b.        Describe the aid of a suitable sketch, the performance of optical fiber in terms of attenuation as a function of frequency
(4 marks)
c.        Explain, using a suitable illustration, the performance of coaxial cable in terms of
attenuation as a function of frequency
(4 marks)
4a.       Define cryptography in the context of network security
(2 marks)
b.        Describe the following cryptographic techniques:
i.          Symmetric-key cryptography
ii.         Asymmetric-key cryptography
(2 marks)
c.        Use the shift cipher with the key = 15 to encode the message; “HELLO”
(2 marks)
5a.       LIST and, briefly describe the main transmission impairments
(8 marks)
b.        What is the performance metric used in evaluating the performance of transmission systems?
(4  marks)
6a.       Define a network operating system(NOS) and state its function(s)
(4 marks)
b.        Compare a computer with NOS and one without NOS
(4 marks)
c.        Distinguish between peer-peer and client-server network configurations
(4 marks)
7a.       Write short but pertinent notes on the following switching techniques:
·                     Circuit switching
·                     Packet switching
(4 marks)
b.        Describe, briefly, the time-division switching technique
(4 marks)
c.        Design a three-stage, 200 x 200 switch(N =200) with k = 4,  n = 20. Use the CLOS
criterion
(4 marks)
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882

Exam summary sample below

NATIONAL OPEN UNIVERSITY OF NIGERIA

University Village, Plot 91, Cadastral Zone, NnamdiAzikiwe Express Way, Jabi, Abuja

Faculty of Sciences

July 2017

Course Code: CIT 303                                                                                    Course Unit: 3
Course Title: Principles of Communication Technology
Instruction: Answer Question One and Any Four Other Questions
Time allowed:  2 1/2 hrs
 
1a.          Define the term ‘Data Communication’                                                                                                 2 marks
b.            Outline and discuss four components of data communication.                                                    6 marks
c.             Mention 4 different forms in which data is represented today                                                    4 marks
d.            Define the following terms
i. Cipher               ii. Key                                                                                                                                    4 marks
e.            list and explain three causes of transmission impairment.                                                             6 marks
 
2a.          Enumeratethree major criteria that a networkmust be able to meet                                       3 marks
b.            With the aid of a well labeled diagram write a short note on the following possible connection types
i. Point-to-Point
ii. Multipoint                                                                                                                                                      4 marks
c.             Explain what is meant by the physical topology of a network                                                       3 marks
d.            List the key elements of a protocol.                                                                                                         2 marks
 
3a.          Describe the OSI model                                                                                                                                                4 marks
b.            State the role of the Session Layer of the OSI model                                                                       3 marks
c.             Enumerate the five layers of the TCP/IP model                                                                                  5 marks
 
4a.          Explain why the TCP/IP is the most widely used protocol in the world.                                    3 marks
b.            Define the following terms
i. LAN
ii. WAN
iii. Router
iv. Hub
v. Firewall
vi. Modem                                                                                                                                                          6 marks
c.             Write a short note on the technical barriers in VOIP                                                                         3 marks
 
5a.          Give two major disadvantage of the bus topology                                                                            3 marks
b.            Distinguish between guided media and unguided media.                                                                              3 marks
c.             Explain four characteristics that determine the effectiveness of a data communications system                                                                                                                                                                                                 6 marks
6a.          Differentiate between the following
i.                     A computer with a NOS and one without an NOS
ii.                   Peer-to-Peer and Client/Server networks
4 marks
b.            Define the following modes of data communication between two devices
i. Simplex             ii. Half-Duplex          iii. Duplex                                                                                      3 marks
c.             Use the Caesar cipher with the key = 9 to encrypt the message “NOUN”                                               2 marks
d.            Enumerate the five services provided by Network Security                                                          3 marks
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882

Exam summary sample below

NATIONAL OPEN UNIVERSITY OF NIGERIA

14/16 AHMADU BELLO WAY, VICTORIA ISLAND, LAGOS

SCHOOL OF SCIENCE AND TECHNOLOGY

MARCH/APRIL 2014 EXAMINATION

 
COURSE CODE: CIT 303
COURSE TITLE: PRINCIPLES OF COMMUNICATION TECHNOLOGY
TIME ALLOWED: 3HOURS
INSTRUCTION: ATTEMPT ANY FIVE (5) QUESTIONS
 
Question 1
a.       Encrypt the word “IGNORANCE” with the following ciphers:
i.      Shift cipher  with key=1                                     (1 mark)
ii.      Shift cipher with key= 26                      (2 marks)
iii.      Shift cipher with key=0                         (2 marks)
iv.      Transposition cipher where plain text: 1 2 3 4 5 6 7 8 9   and
cipher text: 4 3 1 5 2 6 7 9 8 (with no bogus character)                         (1.5 marks)
 
b.       Decrypt the word “ANCEIGNOR” with the following ciphers:
i.          Shift cipher  with key=1                                 (1 mark)
ii. Shift cipher with key= 26                      (2 marks)
iii.                   Shift cipher with key=0                             (2 marks)
iv. Transposition cipher where plain text: 1 2 3 4 5 6 7 8 9   and
cipher text: 4 3 1 5 2 6 7 9 8 (with no bogus character)                         (1.5 marks)
 
c.        The   amplification   in   a   cable   is   usually   defined   in   decibels  per kilometer (dB/km). If the signal at the beginning of a cable with 2 dB/km has a power of 2 mW, what is the power of the signal at 5 km? (3 marks)
 
d.       Briefly explain the term attenuation (1.5 marks)
 
Question 2
 
.
a.       Define the term “network topology”. (1 mark).
b.      With the aid of diagrams, briefly explain the following network topologies:
i.  Ring (3 marks)
ii.      Mesh (3 marks)
iii.    Tree (3 marks).
c.       State and briefly explain 3 advantages and 3 disadvantages of using fiber optic cables in networking. (6 marks)
d.      State 1 advantage and 2 disadvantages of STP cables in comparison to UTP cables. (1.5 marks)
 
Question 3
 
a.       With the aid of a table ONLY, describe the five classes of IPv4 addresses under the following columns:            (10 marks)
i. IP Address Class
ii. Format
iii. Purpose
iv. Number of network/ host bits
v.      Max number of hosts
 
b.       Briefly explain each of the following terms:
i.      Linear filter       (2 marks)
ii.      Stable filter       (1 mark)
iii.      Unstable filter   (1 mark)
iv.      Time-invariant filter (1 mark)
v.      Adaptive filter              (1 mark)
vi.      Linearity (in the context of linear-time invariant (LTI) (1.5 marks)
Question 4
i)                    Outline four (4) basic Network Topologies.
ii)                   List three guided Media.
iii)                 In one sentence, describe the OSI reference model (1 mark)
 
 
Question 5
a.       Briefly explain the 3 modes of communication (with regards to the direction of communication). In each case, identify 2 examples of devices that utilize that mode of communication. (9 marks)
b.       State  the following:
i.  4 services/ functions provided by the  OSI Physical Layer         (2 marks)
ii. 4 services/ functions provided by the  OSI Data Link Layer (2 marks)
iii. 4 services/ functions provided by the  OSI Transport Layer (2 marks)
iv.3 services/ functions provided by the  OSI Session Layer           (2.5  marks)
 
Question 6
Contrast between:
i)             Analog Signal Processing
ii)            Digital Signal Processing
 
 
Question 7
 
a)      What is Data Communications?
 
b)      Define Protocols.
 
c)       The effectiveness of a data communications system depends on four fundamental characteristics. List and define these characteristics.
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882

Exam summary sample below