Introduction to Chapter 7 :Telecommunications, the Internet and Wireless Technologies PDF

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Telecommunications, the Internet and Wireless Technologies Lecture Notes for Ch. 7...

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Introduction to Chapter 7 (Part I) Telecommunications, the Internet and Wireless Technologies (p. 230~240, p. 256~262) This week’s topic is networks and telecommunication. We discussed that an information system is composed of HW, SW, database and networks. We have already looked at HW, SW and database technology. So this is the last component of IS infrastructure technology. In the past decade, computer network has been growing exponentially. It is a very dynamic and also very confusing area. Chapter 7 will provide you with the foundation concepts of networks and telecommunications. This week, we’ll look at Chapter 7 (networking, telecommunications, Internet and WWW. Telecommunication Today’s businesses are dispersed both organizationally and geographically. Businesses are finding telecommunication essential for minimizing time and distance limitations. Communication is any process that permits information to pass from a sender to one or more receivers. There are many types of communications (e.g., communication by human speech, communication by fire signals, communications by electronic means, etc.) Especially, the communication by electronic means is called telecommunication. So telecommunication is a subset of communication. Telecommunications is a communication (or exchange) of information by electronic means (such as computer, phone, or fax) over some distance (short distance or long distance). Components of Telecommunications System A telecommunication system is composed of: - Sending/receiving units - Signals (analog or digital) - Transmission media (e.g., wire) - Communications processor (e.g., modem) - Communication protocol (e.g., TCP/IP) - Communications SW (e.g., network OS) In any communication, there are senders and receivers. In telecommunication, there are message sending computers and receiving computers. The sender has a message (or data) to send. To send the message, sending unit will need to encode the message. A signal is used to encode message (such as analog vs. digital signal). Then the signals with encoded messages are sent to receivers through transmission media. The media carry the signals (e.g., twisted wire, fiber optic cables, etc.). There may be some special communication devices needed (e.g., modem for signal conversion). A communication protocol defines the rules on how to communicate between senders and receivers (such as TCP/IP). Finally, network OS will manage and control the communication on the networks. We have already discussed popular network OS (such as Unix, Linux, and Windows Server).

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Signal and Modem Chapter 7 explains two types of signals: analog and digital. You’ll need to know what they are and why you need MODEM (Modulator/Demodulator) to translate one type of signal into another and vice versa. Transmission Media After data are converted into signals and then they are transmitted. We need something with which we can transport the signal. Various channels are used. Those are called transmission media. They are the physical paths that connect the sources and the receivers and are used to transmit the data. The medium can be wire based (such as twisted wire, copper, or fiber optics) or wireless (such as radio wave, microwave or satellite). You’ll need to know two popular measurements for transmission speed: BPS and Bandwidth. BPS (bits per second) is the most popular measure. It measures the number of bits that any telecommunication medium can transmit per second. Another popular measure is bandwidth. It is the measure of the differences between the highest and lowest frequencies that a medium can transmit. The larger the bandwidth a medium has, the faster it is. In general, if a channel is faster than 200 kbps, then we call it broadband. DSL and cable modem are examples of broadband technology. Key Digital Network Technologies Contemporary computer networks and the Internet are based on a few key technologies. The chapter introduces three key technologies: client/server computing, packet switching, and TCP/IP. These are the foundations of the contemporary networking technologies. You’ll need to know what they are and how they support today’s networking and telecommunications Networks Chapter 7 also introduces various networks. A network is a collection of the communications media, devices, and software needed to connect two or more computer systems and/or devices. They are connected by some type of transmission media, usually wires or cables. A network is a physical pathway on which telecommunication is made. Just as highways and streets provide foundation for automobile travel, networking media provide physical foundation of telecommunication. There are number of different ways of organizing networks. One major way is to use the geographical distance that a network covers. According to the distance, they can be classified into LAN (Local Area Network), MAN (Metropolitan Area Network) and WAN (Wide Area Network). Please understand what they are and how they are different. You should be able to distinguish different types of networks. Wireless Networks Finally, Chapter 7 introduces wireless networking (or mobile computing). Today’s mobile phones are not only for voice communication. They have become mobile platforms for delivering digital data. Many are able to navigate the Web, download music, games, and 2

video, and transmit photos, email, and short text messages. Some have embedded digital camera, and are able to record and transmit video clips. Mobile phones enable many millions of people to communicate and access the Internet in Africa and other countries where conventional telephone or Internet services is expensive and unavailable. In businesses, it means that firms can collaborate with suppliers and customers to create new products or make exciting products more efficiently. Millions of managers and employees rely heavily on the mobile digital platform to coordinate suppliers and shipments, satisfy customers, and organize work activities. A business day without these mobile devices or Internet access would be unthinkable. Note how the emerging mobile platform greatly enhances the accuracy, speed and richness of decision making. Chapter 7 introduces the major wireless technologies: cellular network, Bluetooth, Wi-Fi, Wi-Max, and RFID. You’ll need to know what they are and how they support contemporary networking and telecommunications.

End of Introduction.

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