Lecture 10 - Introduction to computer networks and data communications. After studying this chapter you will be able to understand: Introduction to telecommunications, basic components of communications, telecommunications media, rate of data transfer, define the basic terminology of computer networks,...
Lecture 10 Introduction to Computer Networks and Data Communications Summary of Previous In the previous lecture we have learnt, Managing business data MS Access 2007 Purpose and Data Organization Creating a Database Table Form Query Report Summary of Previous Data Presentation Purpose and Types of presentations Microsoft Power Point A New presentation Design Templates Animation Slide Master Adding Pictures Working With Text Graphs and Charts Today’s Topics Introduction to Telecommunications Basic Components of Communications Telecommunications Media Rate of data transfer Define the basic terminology of computer networks Network Topology Classification of Computer Networks Network Devices Recognize the individual components of the big picture of computer networks Today’s Topics Computer Network Layouts Microcomputer-to-local area network Microcomputer-to-Internet Local area network-to-local area network Personal area network-to-workstation Local area network-to-metropolitan area network Local area network-to-wide area network Today’s Topics Sensor-to-local area network Satellite and microwave Cell phones Computer terminal / microcomputer-tomainframe Summary Introduction Everyone is using a computer network today Mass transit, interstate highways, 24-hour bankers, grocery stores, cable television, cell phones, businesses and schools, and retail outlets support some form of computer network What is Telecommunication? Transmission of different forms of data such as text, audio, video, images, graphics It occurs between one set of electronic devices over media to another set of geographically separated electronic devices Basic Components of Communications Sender: Person or device sending the message Receiver: Person or device receiving the message Medium: What carries the message from sender to receiver Face-to-face Communication Message Voice Channel/Medium Sender Person A short distance of air Receiver Person Local Area Network-to-Metropolitan Area Network Layout Used to interconnect companies (usually their local area networks) to networks that encompass a city High-speed networks Typically, this interconnection uses only fiber- optic links 54 Local Area Network-to-Metropolitan Area Network Layout (continued) 55 Local Area Network-to-Wide Area Network Layout One of the most common ways to interconnect a user on a LAN workstation to the Internet (a wide area network) A router is the typical device that performs LAN to WAN connections Routers are more complex devices than switches 56 Local Area Network-to-Wide Area Network Layout (continued) Data Communications and Computer Networks: A Business User's Approach, Sixth Edition 57 Wide Area Network-to-Wide Area Network Layout High-speed routers and switches are used to connect one wide area network to another Thousands of wide area networks across Pakistan, many interconnected via these routers and switches 58 Sensor-to-Local Area Network Layout Not all local area networks deal with microcomputer workstations Often found in industrial and laboratory environments Assembly lines and robotic controls depend heavily on sensor-based local area networks 59 Sensor-to-Local Area Network Layout (continued) 60 Satellite and Microwave Layout Typically long distance wireless connections Many types of applications including long distance telephone, television, radio, long-haul data transfers, and wireless data services Typically expensive services but many companies offer competitive services and rates Newer shorter-distance services such as Wi-Max 61 Satellite and Microwave Layout (continued) 62 Cell Phone Layout Expanding market across the world specially Pakistan Third generation services available in many areas and under many types of plans with fourth generation services starting to appear Latest generation includes higher speed data transfers (100s to 1000s of kilobits per second) 63 Cell Phone Layout (continued) 64 Terminal/Microcomputer-to-Mainframe Computer Layout Predominant form in the 1960s and 1970s Still used in many types of businesses for data entry and data retrieval Few dumb terminals left today, e.g Telnet 65 Terminal/Microcomputer-to-Mainframe Computer Layout (continued) 66 One More Layout An Additional Basic layout – telephone-tonetwork Telephone systems are ubiquitous and now carry more data than voice Voice over IP – telephone-to-LAN via gateway or telephone to gateway via DSL/cable 67 Summary We have been discussed about Telecommunication Computer essentials Networks Definition Topology Classification Layouts We have understood that using network we can perform day to day business functions Depending upon the types and nature of business we want to set up our computer network ... Layouts Microcomputer-to-local area network Microcomputer-to-Internet Local area network-to-local area network Personal area network-to-workstation Local area network-to-metropolitan area... network Local area network-to-wide area network Today’s Topics Sensor-to-local area network Satellite and microwave Cell phones Computer terminal / microcomputer-tomainframe Summary Introduction... Telecommunications Media Communications media - the paths, or physical channels, in a network over which information travels Wired communications media - transmit information over a closed, connected