MASTERING COMPUTER STUDIES VOLUME III , livre ebook
148
pages
English
Ebooks
2016
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148
pages
English
Ebooks
2016
Obtenez un accès à la bibliothèque pour le consulter en ligne En savoir plus
Publié par
Date de parution
01 janvier 2016
Nombre de lectures
2
Langue
English
Poids de l'ouvrage
5 Mo
Mastering Computer Studies Volume III is: • Easy to follow• User friendly and Practical• Enables you to focus and direct your studies towards acquiring skills at the beginner intermediate user level. D Excellent primer that uses a task-based approach with easy-to follow explanations.• Step-by-step approach that tells you how to do things in an intelligent and understandable manner.There is an in-depth Coverage of hardware and software basics.
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VOLUME III
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Agwe Lucas B. Mbarika Andrew Ngwa Mberewi ArreyNjok Tabe Takang
Copyright©
All rights reserved. No reproduction or transmission of this publication is allowed without written permission from the publisher and author. The author asserts his right to be identiîed as the author of this work in accordance with the copyright law.
Second edition 2016 © Nmi Education P.O. Box 31267 Yaounde - Cameroon
Email: frontdesk@nmieducation .org Website: www.nmieducation.org
Project Manager: Mela Fokam Gisele épouse NGADEHI Commissioning Editor : Makowo Momo Solange Typesetter and Cover designer: ABONGHEN Brigitte Illustration: Nmi Education
ISBN: 9956-773-57-3
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Computer Science and Information and Communication Technologies (ICT) are two new subjects that were introduced into the Cameroon National Curriculum in 2003. Students are expected to acquire basic concepts and skills that will provide the necessary impetus and aptitude to ît into a contemporary world ofInformation Technologyand enable them to become critical, effective and independent users ofICT. They should also be able beneît from the opportunities and advantages thatICTprovide to support learning in other can areas of the curriculum.
This second edition ofVolume III of Computer Studies for Secondary Schoolshas been written for Form three students who are studying Computer Science in the third year at the Secondary General, Commercial and Technical Education. The text is intended to provide a solid foundation in Networking (wired and wireless) and equip students with skills necessary to understand security issues in the transmission and storage of data and information. It is a veritable companion for anyone who is venturing in the îeld of Communication Technology as a beginner.
As Regional Coordinating and Pedagogic Inspectors, the authors have brought their professional expertise to bear on the content and presentation of material contained in this volume, that is the third of four volumes. The authors have used the competence-based approach, which suggests speciîc tasks that the users are expected to follow in order to meet the needs of a competitive and emergent information driven economy. The book is divided intoParts comprising Eleven Chapters. Two Part begins with general Each objectives followed by speciîc objectives for each Chapter. The exibility of treatment of the content in this volume, allows the learner to start with any part, chapter or topic and work at their pace till they achieve their desired goals. Once learners are through with one Part, chapter or topic, they can then embark on the next one after attempting the exercises found at the end of the Chapter. The last part of the book titledin The Computer Laboratory; gives users the opportunity to engage in hands-on practical sessions, useful for intermediate students who are embarking on a course of study in Computer Science leading up to the GCE Ordinary Level General, Commercial and Technical examinations.
The concepts and graphics included in the book have been carefully selected to reect the realities of Information and Communication Technologies.
Computer Studies for Secondary Schools (Volume III) is strongly recommended for Computer Science students who are pursuing a course in either General, Technical or Commercial Education, in computer science or ICT. Authors
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Part One - Networking .........................1 Chapter One - Communication ..................3 Chapter Two - Data Communication.......17 Chapter Three - Computer Networks........24 Chapter Four - Network Hardware and Topologies...........................31 Chapter Five - Network Protocols and Standards............................57 Chapter Six - Network Software............60 Chapter Seven - Network Security ............77 Chapter Eight - Wireless Networking Technology..........................88 Chapter Nine - The Internet.......................101
Part Two - In The Laboratory.....117 Chapter Ten - Spreadsheets.....................118 Chapter Eleven - The Web Browser.........131
DETAIL TABLE OF CONTENTS Part One......................................................1 Chapter One ...............................................2 1.1 Introduction................................................3 1.2 Importance of Communication...........5 1.3 Computers and Communication.........6 Basic Principles of Communicatio......9 1.5 Some Communication Concepts.....14 1.6 Exercise.......................................................16
Chapter Two.............................................17 2.1 Introduction..............................................18 2.2 Characteristics of Data ............................. Transmission.............................................18 2.3 Data Transmission Media....................21 2.4 Exercise.......................................................23
Chapter Three...........................................24 3.1 Introduction to Networking...............25 3.2 Beneîts And Limitations of Networ king…...........................................................25 3.3 Types of Networks.................................27 3.4 Exercise.......................................................30
Chapter Four.............................................31 4.1 Introduction..............................................32 4.2 Network Cabling.....................................32 4.3 Network Components..........................37 4.4 Network Topologies..............................42 4.5 Network Architecture …..………….….. 48 4.6 Exercise .....................................................55
Chapter Five..............................................57 5.1 Introduction..............................................58 5.2 Network Protocols..................................59 5.3 Standard Protocols.................................60 5.4 The Osi Reference Model....................60 5.5 The Ieee Speciîcations.........................64 5.6 Protocol Suites.........................................65 5.7 Exercise ……………………..........................67
Chapter Six................................................69 6.1 Introduction..............................................70 6.2 Network Operating Systems (Nos)..70 6.3 NOS Services................................... ........71 6.4 Domain and Workgroups....................72 6.5 Conîguring Networks: Server, Client, Workstation and Host.............73 6.6 Dedicated Servers and Peers.............74 6.7 Server-Based and Peer-to-Peer (P2p) Networking....................................75 6.8 Exercise ……………….……………..…..…... 76
Chapter Seven...........................................77 7.1 Introduction..............................................78 7.2 Reasons to Secure Data, Files And Networks....................................................78 7.3 Data and File Security...........................79 7.4 External (Network) Security................82 7.5 Network Security Management........84 7.6 Exercise…………..………….…………...…… 86
Chapter Eight............................................88 8.1 Wireless Networking.............................89 8.2 Wireless Hardware.................................90 8.3 Wireless Network Standards..............91 8.4 Other Wireless Technologies.............94 8.5 Conîguration of Wireless Net works…………………….............…..94 8.6 Wireless Security.....................95 v
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8.7 8.8 8.9
Beneîts and Limitations of WirelessNetwork......................................................96 The Future of Wireless Technology………………...........................98 Exercise …….………………..….................…99
Chapter Nine..........................................101 9.1 Introduction............................................102 9.2 Brief History of the Internet.............103 9.3 The Organisation and Functioning of the Internet........................................104 9.4 The Internet and the World Wide Web (Www)............................................106 9.5 Website Address..................................107 9.6 Uses of the Internet.............................108 9.7 Limitations and Misuse of the Internet………..…………………………......110 9.8 Internet Telephony ….…………….….. 111 9.9 Video Conferencing …..………….……113 9.10 Exercise ……………………………………….114
Part Two..................................................117 Chapter Ten............................................118 10.1 Spreadsheets.........................................119 10.2 Features of Spreadsheets.................119 10.3 Some Spreadsheets Environments To Open a Calc Spreadsheet From Windows..................................................119 The Calc Toolbars................................120 Main Menu Toolbar............................120 Function Toolbar..................................120 Formatting Toolbar.............................120 Formula Toolbar...................................121 10.4 Microsoft Excel 2013 …………......…...122 10.5 Exercise ………..……………………....……128
Chapter Eleven.......................................131 11.1 Introduction to the Web Browser..132 11.2 Mozilla Firefox.......................................132 11.3 Exercise …………….……..…………....…..138 Appendix - Acronyms ………….…... 139 Index ..………………………………..……… 141
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PART
1
NETWORKING
Sharing knowledge and information has helped mankind to be more intelligent and productive. It is the sharing of information, knowledge and resources that is at the background of any meaningful communication. This is the underlying principle of networked communication. This part of the book shows how the computer, together with the necessary cabling and peripheral devices, carries out this important duty of propagation of information and knowledge across networks. It concludes with a vivid description of the growth of a mammoth structure out of networking, the Internet which has reduced the great planet, earth, to the size of your desktop. You will not only be able to appreciate the role of this great facility but you will equally be shown its limits and above all, you will be able to uncover that it is still the human being who is at the anchor, calling the shots and not machines alone.
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CHAPTERONE
▶COMMUNICATION
In Volume I of this series, you were introduced to different means of communication and more especially, you were shown how communication has evolved over the years. You were equally shown at a later stage how the computer could be used as a communication tool. By the end of this chapter, you will be able to:
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•List some important aspects of communication.
•Consolidate your knowledge of the use of the computer as a communication tool.
•Identify some important methods of communication.
•Deîne some terms that are related to communication.
•Appreciate some concepts in thearea of communication.
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INTRODUCTION
The role of communication is to pass on data or information from one person or location (the sender or emitter) to another person or location (the recipient) and in a form that the recipient can understand. No matter how much we shout to a deaf person, he/she will not understand us; no matter what signs we make to a blind person, no information is received. Or imagine a situation where you speak to someone in a language he/she does not understand. In all these cases, we can say that no communication has taken place since information sent has not been received or understood.
One way to înd out if communication has taken place is to use feedback. This can be in the form of an expected or possible reaction on the part of the recipient in the form of an answer to a query or a statement or an indication.
Communicationhas therefore taken place if the following cycle is complete:
Sender
Medium
Feedback
Fig 1.1:Cycle to show communication
Recipient
The mediumrefers to the method used to convey the information from the here sender to the recipient. The feedback given must not necessarily have to use the same medium through which the information was sent. Equally, it may not be of the same form that the information was sent. Information could either take the verbal, written or pictorial form or any combination of these. The format information takes depend on
i. The distance between the sender and the recipient, ii.The type of information to be conveyed, iii.The availability of equipment to facilitate the transfer of information: Take a look at the following reports about the performance of a student in the îrst test, presented by a class master.
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Report A: English language = 13, French = 09, mathematics = 11, Biology = 15, Computer Science = 14, History = 08, Literature in English = 10, Physics = 09, Chemistry = 08, Geography = 12, Economics = 13.
▶B: Report English Subject language Mark13
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French
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Report C:
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Biology
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Computer science 14
History
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8
Literature in English 10
Physics
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9
Chemistry
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8
Geography
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Economics
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Clearly, it can be seen that report B looks more presentable than Report A. On the other hand, Report C will give a possibility of fast and easy analysis of the students’ marks than Report B. Consequently, the form in which information is transmitted must equally take into consideration the needs of the recipient. It is worth noting that communication, natural or man-made, comes in two basic forms: synchronous and asynchronous forms. Synchronous communication means that for each message, the sender expects to get a reply from the recipient, like in a telephone conversation. There is a two-way exchange of information and each person knows that the other is receiving the message. No response from one person indicates that communication has not taken place. On the other hand, asynchronous communication means that information is sent but the receiver is not expected to reply, like some radio or TV broadcast or reading 4 from a newspaper.
