Chapter 4: Telecommunications and Networks

1. Chapter 4: Telecommunications and Networks

2. Learning Objectives • Identify business applications of telecommunications and Internet technologies. • Provide examples of the business value of Internet, intranet, and extranet applications.

3. Learning Objectives (cont’d) • Identify the basic components, functions, and types of telecommunications networks used in business. • Explain the functions of major types of telecommunications network hardware, software, media, and services.

4. Real World Case 1 – FedEx versus UPS • Why does telecommunications play such a key role in the competition between FedEx and UPS? • Why does “information about the package” have such a strategic business value in the express delivery business?

5. Internet • Internet is the most influential development over the past two decades. • It is derived from the concept of Internetworking, linking hundreds of individual networks all over the world. • Frequently referred to as the “Net”. • The Internet is a global network of computer networks linked together so that its users can share data resources.

6. Internet • The Internet provides instant and local access to an amazing number of organizations, individuals, and information resources. • No one owns the Internet and it has no formal management organizations. • Originally the Internet was an initiative sponsored by the Department of Defense to link its labs with American universities. • The Internet does not have a central computer system. • The Internet does not have a governing body.

7. How can we connect to the Internet? • Even today individuals cannot connect directly to the Net. • Anyone with a computer, a modem and a willingness to pay a small monthly usage fee can access Internet through an Internet Service Provider (ISP). • ISPs will provide you a username, password and access phone number. • ISP is a commercial organization that offers Internet access (AT&T) or online service (MSN, AOL).

8. World Wide Web • Web is the Internet systems for hypertext linking, allowing users to move from one Internet site to another. • It is a system with universally accepted standards for storing, retrieving, formatting and displaying information. • Web pages are online documents that feature clickable hypertext links that transport you to documents, graphics or other Web pages. • Internet browser softwares such as Netscape Navigator or Internet Explorer enable end users to surf the Web. • Anyone using a Web browser can access any of millions of Websites. • To access a Web site the user must specify Uniform Resource Locator (URL) which is the address of a specific resource on the Internet. • The URL for our university is http://www.cwu.edu. • http stands for hypertext transport protocol, which is the communications standard to transfer pages on the Web. • Web sites are created by Web masters.

9. What are people doing on the Internet? • E-mail: You can use e-mail to communicate with your friends, to exchange messages. • Surf: You can browse websites and resources for information, entertainment and e-commerce. • Chatting: Allows two or more people who are simultaneously connected to the Internet to hold live, interactive conversations. (Ex: Yahoo! Messenger)

10. What are the people doing on the Internet? • Discussion: Participating in discussions on thousands of topics. • Download: Allows to transfer data files, software, articles, picture, music, video to your computer system. • Buy and sell: Buying and selling via e-commerce retailers, wholesalers (Ex: E-bay). • Search for information: Several companies have created directories of Web sites and their addresses, providing search tools for finding information. Another tools, called search engines can find Web sites. (Ex: Yahoo!, Google, Alta Vista). • Play games, watch TV, conduct free phone calls, listen to radio, etc.

11. Business use of the Internet The business value of the Internet • E-commerce is the major business use of the Internet. • For marketing, sales and customer relationship management applications, applications in engineering and human resources. • Enterprise communication and collaboration • Forming new business partnerships • Providing customer and vendor support

12. Internet connection • There are a number of ways that people can connect to the Internet. In addition to traditional connections through plain old telephones and modems, there are a number of high-speed alternatives. • Plain old telephone service: using phone line to connect the Internet. • Integrated Services Digital Network (ISDN): using existing twisted-pair phone wires to provide high speed service. • Digital Subscriber Line (DSL): provides high speed over regular copper telephone lines. • Cable Modems (TV lines): In some areas the company that provides cable TV service also provides Internet service. • Satellite connections: In many regions of the world people can now access the Internet via Satellite. • Cellular phones: There are Internet-enabled cellular phones from Sprint and others, and small palm-top computers from Palm and others, that give you Internet access nearly anywhere.

13. INTRANET • An Intranet is a private and internal network using Web technologies inside an organization. • It can be considered a private internal Web, which limits viewing access to authorized users within the organization. • It enables employees to communicate, share information and work together on common projects regardless of their physical location. • Employees access information on the Intranet through a Web browser. This information cannot be viewed by users outside the organization. Thus it is separated from the visible, publicly accessible Web. • It is protected by security measures such as passwords, firewalls.

14. INTRANET • Intranets require no special hardware. Intranet software technologies is the same as that of the Web. The Web browsers and Web server software for intranets are the same as those on the Web. • Ex: Hewlett Packard (HP) uses an intranet for many human resource functions. The company’s 88,000 employees in 150 countries can access HP’s intranet to fill out forms about beneficiaries, address changes, tax withholdings, etc. • Ex: Boeing offers over 200,000 employees training via the Center of Leadership and Training (CLT) intranet sites. It opens up the courses and training opportunities for employees worldwide. By using the CLT intranet, employees can choose from a wide range of course offerings.

15. EXTRANET • Extranets are private intranets extended to authorized users outside the company. • It is accessible to authorized outsiders. • Firms use such networks to coordinate their activities with business partners, suppliers, customers for making purchases, collaborating on design and other interorganizational work. • An extranet connects the intranets of two or more business partners. • Extranets are useful for linking organizations with suppliers, customers or business partners. • Extranets make customer and supplier access of intranet resources a lot easier and faster than previous business methods.

16. Characteristics of The Internet, Intranet, and Extranet

17. Telecommunications Networks • Communication is one of the most important of all human needs. • A business is a complex organization that relies on communication among its employees to organize its internal activities and communicate with its customers and suppliers to generate and sell its products and services. • Communication becomes even more important in a global environment. • Telecommunications is the communication of information by electronic means. • It requires the following five steps: • Sender initiates message communication • Device puts sender’s message onto a telecommunications medium. • Telecommunications medium transfers message to receiver’s location • Device takes message off the communication medium • Recipient receives the message

18. Telecommunications capacity • The capacity for information flow over a telecommunications channel is called bandwidth. • It is usually measured in bits/second. • Face-to-face bandwidth is simply limited by how fast we can talk. • Communication among computer devices usually occurs with much greater bandwidth.

19. Types of telecommunications networks • We distinguish among different network types based on the dimensions of communication: distance and organizational context. • On the organizational context dimension networks are called intranets if they serve a company’s employees, extranets if they serve employees and partner organizations.

20. Types of telecommunications networks • On the distance dimension; • Wide area networks (WAN) is a broad-band computer network that spans a large geographical area (they serve greater distance). • Used by multinational companies. • WANs transmit and receive information across cities and countries. • Some WANs are commercial, regulated networks while others are privately owned (Ex: AT&T or Sprint). Some others are public in terms of their management, resources and access. One such public WAN is the Internet.

21. Types of telecommunications networks • Local Area Networks (LANs)- A LAN connects two or more communicating devices within a short distance (One building or several buildings in close proximity). • It allows all computer users to connect with each other to share information and devices, such as printers. • In an office a LAN can give users fast and efficient access to a common collection of information while also allowing the office to pool resources, such as printers. • Metropolitan Area Networks (MANs)- They serve a large city.

22. Types of telecommunications networks • Virtual Private Networks (VPN): VPN is a private wide-area network that connects an organization's LAN and users to another through a public network, usually the Internet. • A VPN provides long-distance connections virtually free of direct charges. • A VPN handles the security and it uses the Internet as its main network, but relies on firewalls and other security features of its Internet and Intranet connections. • VNP is a means for allowing access to a private network’s e-mail, shared files or intranet via an Internet connection.

23. Essential components of Telecommunications Networks • Computers • Terminals or any input/output devices • Telecommunications network software • Telecommunications processors • Telecommunications channels/media

24. Computers • Telecommunications networks interconnect computers of all sizes and types. They include • Host computers (mainframes) • Front-end Processors (minicomputers) • Microcomputers

25. Terminals • Terminals are any input/output devices that use telecommunications networks to transmit or receive data. They include: • Telephones • Personal computers • Network computers • Office equipment • Video terminals

26. Telecommunications network software • Consists of programs that control telecommunications activities and manage the functions of telecommunications networks. They include network operating systems, Web browsers, and programs. • Ex: Many operating systems such as Windows 2000/Server provide a number of key network services. Allows network managers to add or delete users and to specify their permission to access to files, devices and services. • Ex: HP’s OpenView is a network management software. A network analyst can perform many network management functions.

27. Telecommunications processors • Support data transmission and reception between terminals and computers. • They include modems and switches. • A modem provides an interface between a computer (or network) and the phone line, cable line (or cellular connection).

28. Types of Signals: Analog and Digital • Information travels through a telecommunications system in the form of electromagnetic signals. • Signals are represented in two ways: analog and digital signals. • An analog signal is a continuous waveform that passes through a communications medium; used for voice communications. • A digital signal is a discrete rather than continuous, waveform. • Most computers communicate with digital signals. • All digital signals must be translated into analog signals before they can be transmitted in an analog system. The device that performs this translation is called a modem (Modem is an abbreviation for MOdulation/DEModulation). • A modem translates a computer’s digital signals into analog form for transmission over ordinary telephone lines, or it translates analog signals back into digital form for reception by a computer.

29. Telecommunications channels • Telecommunications channels connect the message source with the message receiver. • A channel can use different kinds of telecommunications transmission media. • Telecommunications media physically link the devices in a network. • They include twisted wire, coaxial cable, fiber optics, terrestrial microwave, satellite and other wireless transmission.

30. Telecommunications media • Twisted pair • Consists of copper wire twisted in pairs. • It connects a telephone to its telephone jack in most homes. • It is an older transmission medium. • Used to transmit analog phone conversations but can be used for digital communication as well. • Relatively slow for transmitting data. • Inexpensive. • Widely available.

31. Telecommunications media • Coaxial cable • Consists of thickly insulated copper wire. • Used by cable TV companies, brings television signals into the home. • Can transmit large volumes of data quickly. • Hard to wire in many buildings. • Cannot support analog phone conversations. • More expensive. • Less common in buildings than twisted-pair wire.

32. SIGNAL LASER CABLE PHOTO DETECTOR SIGNAL Telecommunications media • Fiber optics cable • Has the greatest capacity of the telecommunications media. • A fast, light and durable transmission medium. • Can transfer large volume of data. • More expensive, harder to install. • Many long-distance companies use it. • Can carry digital signals as well as analog signals.

33. Telecommunications media (cont’d)

34. Telecommunications media (cont’d) • Wireless transmission sends signals through air or space without being tied to a physical line. Common technologies for wireless data transmission include; • Microwave: • Used for long-distance transmission. • uses the atmosphere as the medium through which to transmit signals. • Can carry high-volume data. • Expensive. • Requires no cabling.

35. Telecommunications media (cont’d) • Communication satellites: • The transmission of data using orbiting satellites. • Cost effective for transmitting large quantities of data over very long distances. • Typically used for communications in large, geographically dispersed organizations that would be difficult to tie together through cabling media. • Very expensive. • Signals weaken over long distances. • It is useful for only 7-10 years.

36. ORBITING SATELLITES MICROWAVE TRANSMISSION UPLINK DOWNLINK

37. Telecommunications media (cont’d) • 3. Cellular phones: Work by using radio waves to communicate with radio antennas placed within adjacent geographic area called cells. It transmits voice or data. It is for mobile voice and data communications. • 4. Pagers: A wireless transmission technology in which the pager beeps when the user receives a message. Used to transmit short alphanumeric messages.

38. The characteristics of telecommunications media

39. Telecommunications Technology • Organizations use diverse network technologies that may or may not be compatible with the technologies of other organizations. • So many different networks are interconnected nowadays, they must have a common language or protocol to communicate. • The protocol of the Internet is called Transmission Control Protocol/Internet Protocol (TCP/IP). • Two computers using TCP/IP would be able to communicate even if they were based on different hardware and software platforms.