1. Management Information Systems MANAGING THE DIGITAL FIRM, 12 TH EDITION TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY Chapter 7

2. Management Information Systems Problem: Shipbuilding space is too large (4.2 sq mi) and complex to track inventory in real-time, limiting efficiency Solution: High-speed wireless network built by KT Corp, using radio sensors, notebooks, mobiles, Web cams Illustrates: – Powerful capabilities and solutions offered by contemporary networking technology – Use of radio sensor technologies to track inventory Hyundai Heavy Industries Creates A Wireless Shipyard CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 20112

3. Management Information Systems Networking and communication Trends – History 2 types of networks: – Telephone Networks (Voice Communication) built by Telephone companies – Computer Networks (Data Communications) built by Computer companies – Convergence Telephone networks and computer networks converging into single digital network using Internet standards – E.g. cable companies providing voice service, Mobile companies providing internet Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 20113

4. Management Information Systems Both voice & data communication networks have also become more powerful (faster) and more portable (mobile) and less expensive – Dial-up Connection » Used with phone lines and Modem – Broadband: » More than 60% U.S. Internet users have broadband access – Broadband wireless: » Voice and data communication as well as Internet access are increasingly taking place over broadband wireless platforms » E.g., Fixed Wireless broadband, 2.5G, 3G, 3G+, LTE (4G) etc. © Prentice Hall 20114

5. Management Information Systems What is a computer network? – Two or more connected computers Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 20115 Illustrated here is a very simple computer network, consisting of computers, a network operating system residing on a dedicated server computer, cable (wiring) connecting the devices, network interface cards (NICs), switches, and a router.

6. Management Information Systems – Major components in simple network 1.Client computer 2.Server computer 3.Network interface Card (NICs) with a unique MAC (Media Access Control) address – Can be built-in to the mother board 4.Connection medium – A telephone wire or a Coaxial cable, or radio signal in the case of cell phone and Wi-Fi 5.Network operating system – Routes and manages communications on the network and coordinates network resources Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 20116

7. Management Information Systems 6.Hub or switch Hubs are very simple devices that connect network components, sending a packet of data to all other connected devices – Broadcast to all ports, cannot distinguish destination A Switch has more intelligence than a hub and can be a filter and forward data to a specified destination on the network – Keeps record of the MAC address of the devices connected to it © Prentice Hall 20117

8. Management Information Systems 7.Routers Device used to route packets of data through different networks (at least two LANS) – Packets have data as well as destination address Ensuring that data sent gets to the correct address Routers are gateways to a network © Prentice Hall 20118

9. Management Information Systems Components of networks in large companies – Hundreds of local area networks (LANs) linked to firmwide corporate network – Various powerful servers Web site Corporate intranet, extranet Backend systems – Mobile wireless LANs (Wi-Fi networks) – Videoconferencing system – Telephone network – Wireless cell phones Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 20119

10. Management Information Systems Telecommunications and Networking in Today’s Business World CORPORATE NETWORK INFRASTRUCTURE Today’s corporate network infrastructure is a collection of many different networks from the public switched telephone network, to the Internet, to corporate local area networks linking workgroups, departments, or office floors. FIGURE 7-2 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201110

11. Management Information Systems Key networking technologies (cont.) – Packet switching Method of slicing digital messages into parcels (packets), sending packets along different communication paths as they become available, and then reassembling packets at destination Previous circuit-switched networks (leased telephone line connection) required assembly of complete point-to-point circuit Packet switching more efficient use of network’s communications capacity circuit switching is characterized by a fee per time unit of connection time, even when no data is transferred (e.g., Dial-up Connection), while packet switching is characterized by a fee per unit of information (e.g., Broadband per MB usage) Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201111

12. Management Information Systems Key networking technologies (cont.) In circuit-switched networks, such as telephone system, a complete point-to-point circuit is assembled, and then communication can proceed – These dedicated techniques were expensive and wasted available communication capacity (phone gets engaged) – The circuit was maintained regardless of data being sent or not In packet-switched networks, data/messages are first broken down into small fixed bundles of data called packets – Packets include info. about the destination + data – Packets get re-assembles at the destination Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201112

13. Management Information Systems Telecommunications and Networking in Today’s Business World PACKED-SWITCHED NETWORKS AND PACKET COMMUNICATIONS Data are grouped into small packets, which are transmitted independently over various communications channels and reassembled at their final destination. FIGURE 7-3 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201113

14. Management Information Systems Key networking technologies (cont.) – TCP/IP and connectivity Diverse H/W and S/W components need to work together to transmit information Connectivity between diverse computers enabled by adhering to a common set of rules called protocols Protocols: Rules that govern transmission of information between two points Transmission Control Protocol/Internet Protocol (TCP/IP) – Common worldwide standard that is basis for Internet Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201114

15. Management Information Systems Key networking technologies (cont.) TCP handles the movement of data b/w computers – Established a connection b/w computers – Sequences the transfer of packets – Acknowledges the packages sent IP is responsible for – Delivery of packets – Disassembling and assembling of packets Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201115

16. Management Information Systems Department of Defense reference model for TCP/IP – Application Layer Application layer enables client application program to access the other layer & defines protocols that application uses to exchange data (e.g., HTTP for transferring web pages) – Transport Layer Responsible for providing the application layer with communication & packet services (TCP protocol) – Internet Layer Responsible for addressing, routing and packaging data packets called IP Datagrams. IP protocol – Network Interface Layer Responsible for placing packets and receiving them from the network medium Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201116

17. Management Information Systems Telecommunications and Networking in Today’s Business World THE TRANSMISSION CONTROL PROTOCOL/ INTERNET PROTOCOL (TCP/IP) REFERENCE MODEL This figure illustrates the four layers of the TCP/IP reference model for communications FIGURE 7-4 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201117

18. Management Information Systems Signals: (Analog Vs Digital) – When data (e.g., Sound) is transmitted or stored it may need to change form, hopefully without being destroyed – Consider music: Sound is simply pressure waves in air, caused by drums, guitar strings or vocal cords Converted to electrical signals by a microphone Converted to magnetism when it's put on a master tape and edited Converted to spots on a CD when the CD is manufactured Converted to laser light, then electricity when played by a CD player Converted back to sound by a speaker Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201118

19. Management Information Systems Signals: (Degradation) – Any time signals are transmitted, there will be some degrading of quality: 1.signals may fade with time and distance 2.signals may get combined with interference from other sources (static) 3.signals may be chopped up or lost Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201119

20. Management Information Systems © Prentice Hall 201120 When we continue to transmit and transform signals, the effect is compounded. Think about photocopies of photocopies of photocopies...

21. Management Information Systems Signals: (Analog Vs Digital) – With a digital signal, we are using an analog signal to transmit numbers, which we convert into bits and then transmit the bits. Suppose we want to transmit the number 6. In binary, that number is 110. We first decide that, say, "high" means a 1 and "low" means a 0. Thus, 6 might look like: Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201121

22. Management Information Systems Degradation of Digital Signal – The signals used to transmit bits degrade, too, because any physical process degrades – the degraded signal can be "cleaned up," because we know that each bit is either 0 or 1 : the computer files are perfect copies of the original file whereas photocopies are not CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201122

23. Management Information Systems Telecommunications and Networking in Today’s Business World FUNCTIONS OF THE MODEM A modem is a device that translates digital signals into analog form (and vice versa) so that computers can transmit data over analog networks such as telephone and cable networks. FIGURE 7-5 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201123 Modem: Translates digital signals (computer) into analog form (telephone)

24. Management Information Systems Types of networks – Local-area networks (LANs) Physical Standard: Ethernet (100 Mbps to 1 Gbps) Peer-to-peer (P2P) e.g., Torrent Downloading – Treats all processors equally and is used primarily in small networks with 10 or fewer users – Computers can share peripheral devices without going through a server Topologies: – STAR: All devices connect to a central hub – BUS: one station transmits signals, which travels in both directions to the entire network – RING: connect networks components in closed loop. Messages pass in only direction » One station may transmit at one time Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201124

25. Management Information Systems Telecommunications and Networking in Today’s Business World NETWORK TOPOLOGIES The three basic network topologies are the star, bus, and ring. FIGURE 7-6 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201125

26. Management Information Systems Types of networks – Metropolitan and wide-area networks Wide-area networks (WANs) – Span broad geographical distances, entire region, states or continents – Most powerful WAN is the Internet Metropolitan-area networks (MANs) – Network that spans a metropolitan area Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201126

27. Management Information Systems Physical transmission media – Twisted wire (modems) Stranded copper wire twisted in pairs Older type of transmission Telephone systems in buildings used to have these – Coaxial cable Similar to that used of cable television Thickly insulated copper wire Was used in older LANs Speed up to 1 Gbps Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201127

28. Management Information Systems Physical transmission media – Fiber optics and optical networks Bound strands of clear glass fiber, each thickness of a human hair Data are transformed into pulses of light Up to several Trillion bits per second Expensive than other physical media – harder to install Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201128

29. Management Information Systems Physical transmission media – Wireless transmission media and devices Microwave – Point-to-point communication – High-volume, long distance communication Satellites – Communication in geographically dispersed orgs. (e.g., BP) Cellular telephones – Radio waves to communicated with BTS – Transmission speed (hertz, bandwidth) – Measured in bit per second (bps) – Number of cycles per second that can be sent is in hertz – Bandwidth is the difference b/w highest and lowest frequencies Telecommunications and Networking in Today’s Business World CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201129

30. Management Information Systems Telecommunications and Networking in Today’s Business World BP’S SATELLITE TRANSMISSION SYSTEM Communication satellites help BP transfer seismic data between oil exploration ships and research centers in the United States. FIGURE 7-7 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201130

31. Management Information Systems Telecommunications and Networking in Today’s Business World CELLULAR COMMUNICATION CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201131

32. Management Information Systems What is the Internet? – A public communication system – Internet Service Provider (ISP): A permanent connection with intranet and provider of service Internet Addressing and Architecture – IP Addressing – 32 Bit addressing (IPv4) e.g., 207.46.250.119 is Microsoft’s address = Total possibilities = 4294967296 (2 32 ) addresses. The Global Internet CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201132

33. Management Information Systems – The Future Internet: IPv6 and Internet 2 Internet was not originally designed to handle the transmission of massive quantities of data and billions of users – The world will run out of available IP addresses (IPv4) using the existing convention IPv6 contains 128-bit addresses (2 128 ) Internet 2 or NGI (Next generation Internet) – Consortia of 200 US universities and firms » Advanced labs, research but not public yet (100 Gbps) – The Domain Name System (DNS) Hierarchical structure Top-level domains (.com,.edu,.pk etc.) Second-level domain (amazon.ca) CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201133

34. Management Information Systems The Global Internet THE DOMAIN NAME SYSTEM Domain Name System is a hierarchical system with a root domain, top-level domains, second-level domains, and host computers at the third level. FIGURE 7-8 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201134

35. Management Information Systems The Global Internet INTERNET NETWORK ARCHITECTURE The Internet backbone connects to regional networks, which in turn provide access to Internet service providers, large firms, and government institutions. Network access points (NAPs) and metropolitan area exchanges (MAEs) are hubs where the backbone intersects regional and local networks and where backbone owners connect with one another. FIGURE 7-9 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201135

36. Management Information Systems Internet services – E-mail (most emails work through internet Gmail etc) – Chatting and instant messaging (etc. IRC, Gtalk, ICQ) – Newsgroups – Telnet (Remote access) – File Transfer Protocol (FTP) – World Wide Web – VoIP (Voice over IP e.g., Skype, Viber, and IP Phones) – Virtual private network (VPN) The Global Internet CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201136

37. Management Information Systems The Global Internet HOW VOICE OVER IP WORKS An VoIP phone call digitizes and breaks up a voice message into data packets that may travel along different routes before being reassembled at the final destination. A processor nearest the call’s destination, called a gateway, arranges the packets in the proper order and directs them to the telephone number of the receiver or the IP address of the receiving computer. FIGURE 7-11 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201137

38. Management Information Systems The Global Internet A VIRTUAL PRIVATE NETWORK USING THE INTERNET This VPN is a private network of computers linked using a secure “tunnel” connection over the Internet. It protects data transmitted over the public Internet by encoding the data and “wrapping” them within the Internet Protocol (IP). By adding a wrapper around a network message to hide its content, organizations can create a private connection that travels through the public Internet. FIGURE 7-12 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201138

39. Management Information Systems The World Wide Web – HTML (Hypertext Markup Language): Formats documents and links for display on Web – Hypertext Transfer Protocol (HTTP): Communications standard used for transferring Web pages (every web address starts with HTTP followed by a domain name) – Uniform resource locators (URLs): Addresses of Web pages (HTTP + Domain Name) – E.g. http://www.megacorp.com/content/features/082602.html – Web servers Software for locating and managing Web pages (Apache HTTP server dominates the market) CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201139

40. Management Information Systems The World Wide Web (cont.) http://www.worldwidewebsize.com/ ( updated Number of webpages) http://www.worldwidewebsize.com/ – Indexed pages, deep web pages (additional pages) – Link: Infographics on state of WebInfographics – Search engines (e.g., Google, Yahoo, Bing etc.) Started in early 1990s as relatively simple software programs using keyword indexes Today, major source of Internet advertising revenue via search engine marketing, using complex algorithms and page ranking techniques to locate results The Global Internet CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201140

41. Management Information Systems How do search engines search through billions of pages? – In 1994, Stanford University CS students made “Yet Another Hierarchical Officious Oracle” (Yahoo!) Edited selection of Web sites organized by categories – In 1998 Larry Page and Sergey Brin, Stanford CS students released 1 st version of Google Indexing + relevance of page (Page Rank Algorithm) Page Rank Algorithm calculates the relevance or popularity of a web page by calculating the no. of sites that link to the page as well as the number of pages that link to it CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201141

42. Management Information Systems – Search Engine Marketing Sponsored links and unsponsored “organic” search – Search Engine Optimization (SEO) Achieving a higher ranking on a search engine The Global Internet CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201142

43. Management Information Systems The Global Internet HOW GOOGLE WORKS The Google search engine is continuously crawling the Web, indexing the content of each page, calculating its popularity, and storing the pages so that it can respond quickly to user requests to see a page. The entire process takes about one- half second. FIGURE 7-13 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201143

44. Management Information Systems The Global Internet TOP U.S. WEB SEARCH ENGINES Google is the most popular search engine on the Web, handling 72 percent of all Web searches.FIGURE 7-14 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201144

45. Management Information Systems Web 2.0 Web 3.0 − the Semantic Web – Effort of W3C to add meaning to existing Web – Make searching more relevant to user – Machine based learning – Intelligent computing – Geographical searching – Video “How Google Search Works?”How Google Search Works The Global Internet CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201145

46. Management Information Systems Cellular systems – Competing standards for cellular service CDMA: United States GSM: Rest of world, plus AT&T and T-Mobile – Third-generation (3G) networks Suitable for broadband Internet access 144 Kbps – 2Mbps – 4G networks Entirely packet-switched 100 Mbps – 1Gbps The Wireless Revolution CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201146

47. Management Information Systems Wireless computer networks and Internet access – Bluetooth (802.15) Links up to 8 devices in 10-m area Useful for personal networking (PANs) and in business to transmit data from handheld devices to other transmitters – Wi-Fi (802.11) Set of standards: 802.11a, 802.11b, 802.11g, 802.11n Used for wireless LAN and wireless Internet access Use access points: Device with radio receiver/transmitter for connecting wireless devices to a wired LAN The Wireless Revolution CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201147

48. Management Information Systems The Wireless Revolution A BLUETOOTH NETWORK (PAN) Bluetooth enables a variety of devices, including cell phones, PDAs, wireless keyboards and mice, PCs, and printers, to interact wirelessly with each other within a small 30-foot (10-meter) area. In addition to the links shown, Bluetooth can be used to network similar devices to send data from one PC to another, for example. FIGURE 7-15 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201148

49. Management Information Systems The Wireless Revolution AN 802.11 WIRELESS LAN Mobile laptop computers equipped with network interface cards link to the wired LAN by communicating with the access point. The access point uses radio waves to transmit network signals from the wired network to the client adapters, which convert them into data that the mobile device can understand. The client adapter then transmits the data from the mobile device back to the access point, which forwards the data to the wired network. FIGURE 7-16 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201149

50. Management Information Systems Wireless computer networks and Internet access – Wi-Fi (cont.) Hotspots: Access points in public place to provide maximum wireless coverage for a specific area Weak security features – WiMax (802.16) Wireless access range of 31 miles Require WiMax antennas Sprint Nextel building WiMax network as foundation for 4G networks The Wireless Revolution CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201150

51. Management Information Systems Radio frequency identification (RFID) – Use tiny tags with embedded microchips containing data about an item and location, and antenna – Tags transmit radio signals over short distances to special RFID readers, which send data over network to computer for processing – Active RFID: Tags have batteries, data can be rewritten, range is hundreds of feet, more expensive – Passive RFID: Range is shorter, also smaller, less expensive, powered by radio frequency energy The Wireless Revolution CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201151

52. Management Information Systems Radio frequency identification (RFID) (cont.) – Common uses: Automated toll-collection Tracking goods in a supply chain – Requires companies to have special hardware and software – Reduction in cost of tags making RFID viable for many firms The Wireless Revolution CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201152

53. Management Information Systems The Wireless Revolution HOW RFID WORKS RFID uses low-powered radio transmitters to read data stored in a tag at distances ranging from 1 inch to 100 feet. The reader captures the data from the tag and sends them over a network to a host computer for processing. FIGURE 7-17 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201153

54. Management Information Systems Wireless sensor networks (WSNs) – Networks of hundreds or thousands of interconnected wireless devices embedded into physical environment to provide measurements of many points over large spaces Devices have built-in processing, storage, and radio frequency sensors and antennas Require low-power, long-lasting batteries and ability to endure in the field without maintenance – Used to monitor building security, detect hazardous substances in air, monitor environmental changes, traffic, or military activity The Wireless Revolution CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201154

55. Management Information Systems The Wireless Revolution A WIRELESS SENSOR NETWORK The small circles represent lower-level nodes and the larger circles represent high- end nodes. Lower level nodes forward data to each other or to higher-level nodes, which transmit data more rapidly and speed up network performance. FIGURE 7-18 CHAPTER 7: TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY © Prentice Hall 201155