Tomorrow’s Technology and You 8 th Edition

1. Tomorrow’s Technologyand You8th Edition

2. Tomorrow’s Technology and You 8/e Chapter 8 Networking and Digital Communication

3. Tomorrow’s Technology and You 8/eChapter 8Objectives Describe the basic types of technology that make telecommunication possible. Describe the nature and function of local area networks and wide area networks. Discuss the uses and implications of email, instant messaging, blogging, teleconferencing, and other forms of online communication.

4. Tomorrow’s Technology and You 8/e Chapter 8Objectives (continued) Explain how wireless network technology is transforming the ways people work and communicate. Describe current and future trends in telecommunications and networking.

5. Tomorrow’s Technology and You 8/eChapter 8 Arthur C. Clarke’s Magical Prophecy Clarke’s laws If an elderly but distinguished scientist says that something is possible, he is almost certainly right, but if he says that it is impossible he is very probably wrong. The only way to find the limits of the possible is to go beyond them into the impossible. Any sufficiently advanced technology is indistinguishable from magic.

6. Tomorrow’s Technology and You 8/e Chapter 8Arthur C. Clarke’s Magical Prophecy Arthur C. Clarke’s most famous work was the monumental 1968 film 2001: A Space Odyssey, in which he collaborated with movie director Stanley Kubrick. Clarke’s most visionary work may be a paper published in 1945 in which he predicted the use of geostationary communications satellites—satellites that match the Earth’s rotation so they can hang in a stationary position relative to the spinning planet below, relaying wireless transmissions between locations on the planet.

7. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy A computer network is any system of two or more computers that are linked together. How is networking important? People share computer hardware, thus reducing costs. People share data and software programs, thus increasing efficiency and production. People work together in ways that are otherwise difficult or impossible.

8. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Networks Near and Far In a local area network (LAN) computers are physically close to each other, usually in the same building. Computers are linked within a building or cluster of buildings. Each computer and peripheral is an individualnode on the network. Nodes are connected by cables, which may be either twisted pair (copper wires) or coaxial cable. In a wireless network each node has a tiny radio (or, less commonly, infrared) transmitter connected to its network port. Computers send and receive data through the air rather than through cables.

9. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy A metropolitan area network (MAN) links two or more LANs within a city. A wide area network (WAN) extends over a long distance. Each networked LAN site is a node on the WAN. Data transmitted over common pathways called a backbone.

10. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Communication frequently happens between LANs and WANs Routers: hardware devices or software programs that route messages as they travel between networks Mesh networks: an alternative to today’s networks; rely on centralized routers Used to set up small, temporary communication systems Example: emergency personnel use at fire scenes to coordinate actions “Pretty soon you’ll have no more idea of what computer you’re using than you have an idea of where your electricity comes from.” —Danny Hillis, computer designer

11. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Specialized Networks: From GPS to Financial Systems Global Positioning System (GPS) GPS is a specialized network developed by U.S. Department of Defense. It includes 24 satellites that circle the Earth. Each satellite contains a computer, an atomic clock, and a radio. On the ground, a GPS receiver can use signals broadcast by three or four visible satellites to determine its position.

12. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Networks that keep our global financial systems running: Automated Teller Machine (ATM): a specialized terminal linked to a bank’s main computer through a commercial banking network

13. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy The Network Interface A network interface card (NIC) permits direct network connection: Adds an additional serial port to the computer Controls the flow of data between the computer’s RAM and the network cable The most common types of networks today require some kind of Ethernet card or port in each computer. Ethernet is a popular networking architecture developed in 1976 at Xerox. Most newer PCs include an Ethernet port on the main circuit board, so they don’t require NICs to connect to Ethernet networks.

14. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Communication á la Modem • Modem: a hardware device that connects acomputer’s serial port to a telephone line (for remote access) • May be internal on the system board or external, sitting in a box linked to a serial port • Modem transmission speed measured in bits per second (bps) • Transmit at 28,000 bps to 56.6K bps

15. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Computers send digital signals. The modem (modulator/demodulator) converts the digital signals to analog so that the message can be transmitted through telephone lines and converts it back on the other end.

16. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Broadband connection—a connection with much greater bandwidth than modems have DSL uses standard phone lines and is provided by phone companies in many areas. Cable modems provide fast network connections through cable television networks in many areas. High-speed wireless connections can connect computers to networks using radio waves rather than wires. Satellite dishes can deliver fast computer network connections as well as television programs.

17. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Fiber Optic Connections • DSL and cable modems have nowhere near the bandwidth of the fiber optic cables that are replacing copper wires in the worldwide telephone network. • A fiber optic network can rapidly and reliably transmit masses of multimedia data at the same time that it’s handling voice messages.

18. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Wireless Network Technology • A lightning-fast network connection to your desktop is of little use if you’re away from your desk most of the time; when bandwidth is less important than mobility and portability, wireless technology can provide practical solutions. • The fastest growing wireless LAN technology is known as Wi-Fior802.11b.

19. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy • Bluetooth: another type of wireless technology • Named for a Danish king who overcame his country’s religious differences • Overcomes differences between mobile phones, handheld computers, and PCs, making it possible for all of these devices to communicate with each other regardless of operating system

20. Tomorrow’s Technology and You 8/eChapter 8 Basic Network Anatomy • With Bluetooth it’s possible to create apersonal area network (PAN)—a network that links a variety of personal electronic devices so they can communicate with each other. • Bluetooth technology is currently limited to simple device connectivity, but in the future it will open up all kinds of possibilities: • A pacemaker senses a heart attack and notifies the victim’smobile phone to dial 911. • A car radio communicates with parking-lot video camerasto find out where spaces are available.

21. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy • More examples of Bluetooth possibilities: • A pen scans business cards and sends the information to a PDA inside a briefcase. • A medical wristband transmits an accident victim’s vital information to a doctor’s handheld computer. • A cell phone tells you about specials on clothes that are available in your size as you walk past stores in a mall.

22. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Communication Software • Protocol is a set of rules for the exchange of data between a terminal and a computer or between two computers. • Communication software establishes a protocol that is followed by the computer’s hardware.

23. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy • Communication software takes many forms: • Network operating system (NOS) • System handles communications among many workstations. • Client/server model • One or more computers act as dedicated servers and all the remaining computers act as clients. • Peer-to-peer model • Every computer on the network is both client and server. • Many networks are hybrids, using features of theclient/server and peer-to-peer models.

24. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy The Network Advantage • Why do people use networks? • Networks enable people to share computer hardware resources, reducing costs and enabling people to take advantage of powerful computer equipment. • Networks enable people to share data and software programs, increasing efficiency and productivity. • Networks enable people to work together or collaborate in ways that are difficult or impossible without network technology.

25. Tomorrow’s Technology and You 8/e Chapter 8 Basic Network Anatomy Wireless access point DSL modem Wireless laptop Firewall/router A Home Computer Network USB cable Multiplayer games

26. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks The Many Faces of Email • Email systems enable you to send and receive messages to others on the network. • Web-based email systems and many older UNIX-based programs require that read and unread messages be stored in post office boxes or folders on the remote mail servers. • Many email messages are plain ASCII text.

27. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks • Even if their software can display HTML mail, not all email users want HTML emails: • HTML encoding can slow down an email program. • An HTML email message can also carry a Web bug. • Most email programs can send and receive formatted word processor documents, pictures, and other multimedia files as attachments to messages.

28. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks Mailing Lists • Mailing lists enable you to participate in email discussion groups on special-interest topics. • Subscribing to a busy list might mean receiving hundreds of messages each day. • To avoid being overwhelmed by incoming mail, many list members sign up to receive them in daily digest form. • Some lists are moderated to ensure that the quality of the discussion remains high.

29. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks Newsgroups • Newsgroup: a public discussion on a particular subject • Notes are written to a central Internet site. • Notes are redistributed through a worldwide newsgroup network called USENET. • Listserv mail messages are delivered automatically to your mailbox, but you have to seek out information in newsgroups. • Mailing list messages are sent to a specific group of people, whereas newsgroup messages are available for anyone to see. • Moderated newsgroups contain only messages that have been filtered by designated moderators.

30. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks Rules of Thumb: Online Survival Tips • Let your system do as much of the work as possible. • Store names and addresses in computer-accessible addressbook. • Don’t share your email address. • Don’t open suspicious attachments. • Protect your privacy. • Cross-check on-line information sources. • Be aware and awake. • Avoid information overload.

31. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks Instant Messaging and Teleconferencing:Real-Time Communication • Mailing lists and newsgroups are delayed or asynchronous communication. • The sender and the recipients don’t have to be logged in at the same time. • Instant messaging (IM) has been possible since the days of text-only Internet access. • Newer, easier to use messaging systems from AOL, Microsoft, Yahoo, Apple, and others have turned instant messaging into one of the most popular Internet activities.

32. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks • Online services also offer chat rooms—public or private virtual conference rooms where people with similar interests or motivations can type messages to each other and receive near instant responses. • Several IM programs make it possible to carry on two-way video teleconferences.

33. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks Computer Telephony • Voice mail is a messaging system with the ability to store, organize, and forward messages. • An example of a growing trend toward computer telephony integration (CTI) is the linking of computers and telephones to gain productivity. • It’s also possible to send voice signals through a LAN, a WAN, or the Internet, bypassing the phone companies (and their charges) altogether. • Handheld PDA computers use software to integrate the functions of a PDA, a phone, and an Internet terminal.

34. Tomorrow’s Technology and You 8/eChapter 8 Interpersonal Computing: From Email to Social Networks Computer Telephony • Internet Telephony has become a legitimate competitor to traditional phone companies. • Voice over IP (VoIP) requires a broadband connection to carry your call over the Internet. • You can place a calling using either a traditional phone with an adapter or an Internet-connected PC with a microphone headset and appropriate software.

35. Tomorrow’s Technology and You 8/eChapter 8 Interpersonal Computing: From Email to Social Networks Computer Telephony • Advantages of VoIP • Calls are less expensive if you already have a broadband connection. • Calls are routed to you no matter where you are connected. • VoIP phones integrate more easily with online address books, video conference services, and other Internet services.

36. Tomorrow’s Technology and You 8/eChapter 8 Interpersonal Computing: From Email to Social Networks Computer Telephony • Disadvantages of VoIP • Communication is impossible during a power outage (most networks are unusable). • There is no 911 or directory assistance service available. • Quality is suspect because there is no guarantee of packets being delivered in a timely manner.

37. Tomorrow’s Technology and You 8/eChapter 8Interpersonal Computing: From Email to Social Networks Social Networks and Information Sharing • Online communities such as MySpace and Facebook • Massively multiplayer role playing games (MMORPG) • Common information resources such as Flickr and Wikipedia

38. Tomorrow’s Technology and You 8/eChapter 8Online Risks Email Issues • Problems with Spam – more than 50% of e-mails are unsolicited. • Email and teleconferencing are vulnerable to machine failures, network glitches, human errors, and security breaches. • Email can be overwhelming. • Email can pose a threat to privacy.

39. Tomorrow’s Technology and You 8/eChapter 8Online Risks Don’t Get Hooked—Advice on Phishing • Examine the URL in the address bar. • Re-examine the URL in the address bar. • Look for the https prefix. • Look for the padlock icon. • Pay attention to pop-up warnings about fraudulent certificates. • Make your own Web connection.

40. Tomorrow’s Technology and You 8/eChapter 8Online Risks • Cookies – Can be used by snoopers to get information about you • Wireless issues of access, security, and privacy • Perils of posting too much information on blogs and websites • Internet Addiction – Some game players spend 40-80 hrs a week online • Virtual Sweatshops

41. Tomorrow’s Technology and You 8/eChapter 8Online Risks Digital Communication in Perspective • Many services we take for granted today—video rentals, cable TV, newspapers, and magazines, for example—will be transformed or replaced by digital high-bandwidth interactive delivery systems of the future. • At the same time, entirely new forms of communication are likely to emerge. • Telecommunications technology is rapidly changing our lives, and the changes will accelerate as the technology improves.

42. Tomorrow’s Technology and You 8/eChapter 8Lesson Summary Networking is one of the most important trends in computing today. LANs are made up of computers that are close enough to be directly connected with cables or wireless radio transmitters/receivers. Most LANs include shared printers and file servers. WANs are made up of computers separated by considerable distance. Many computer networks are connected together through the Internet so messages and data can pass back and forth among them. Some specialized networks, including global positioning systems and financial systems serve unique functions.

43. Tomorrow’s Technology and You 8/e Chapter 8Lesson Summary (continued) Most computer networks today use the Ethernet architecture; an Ethernet port is a standard feature on most modern PCs. Communication software takes care of the details of communication between machines—details like protocols that determine how signals will be sent and received. Email, instant messaging, and teleconferencing are the most common forms of communication between people on computer networks. It’s not clear how all of these emerging technologies will converge; what is clear is that the wireless revolution is far from over.