Cork Institute of Technology
Higher Certificate in Science in Computing (ACCS) – Award
(NFQ Level 6)
Summer 2006
Computer Organisation & Systems Software
(Time: 3 Hours)
Answer four questions, at least ONE from Examiners: Ms. D. Griffin
Section 1 and ONE from Section 2. Mr. J. Le Kernec
All questions carry equal marks Ms. M. Meagher
Ms. A. Brown
Section I
Q1. (a) Please distinguish between the terms Local Area Network (LAN), Metropolitan Area
Networks (MAN), and Wide Area Network (WAN). (4 marks)
(b) With the aid of a diagram please outline the OSI Reference Model. In your answer
state the functions of the various layers. (6 marks)
(c) What are transmission impairments? In your answer explain the most significant
transmission impairments?
With regards to noise, discuss the various forms of it. (7 marks)
(d) With reference to Data Encoding what does the term modulation mean?
Discuss in detail the encoding of Digital data to Analogue signals, and outline a
specific situation where this type of encoding is important. In your answer discuss in
detail two forms of encoding techniques. (8 marks)
