Telecommunications and Networking

1. Telecommunications and Networking MIS 503 - Management Information Systems MBA Program

2. A Significant Underestimation “This ‘telephone’ has too many shortcomings to be seriously considered as a means of communication. the device is inherently of no value to us.” Western Union internal memo, 1876.

3. Telecommunications: The Technology

4. AN OVERVIEW OF TELECOMMUNICATIONS AND NETWORKING Networking – the electronic linking of geographically dispersed devices Telecommunications – communications (voice and data) at a distance Page 97-98

5. What is communication? • The Romans used the Latin word communicare when they meant "to make common, to share, or to impart.” • Communication is the sharing of information or messages between two or more entities.

6. Elements of a Communication System • Source - the originator of the message, whether it is a person or machine. • Transmitter - the equipment that modifies the message (either data or voice) into the form required for transmission. • Communications channel - the means of carrying the signal from the source to the destination.

7. Elements of a Communication System • Transmission media - may be physical, like a copper wire or fiber optic cable, or atmospheric, like radio waves. • Receiver - is the device that captures the message from the communications channel and converts it into a form that the person or machine at the destination can understand. • Destination - the person or machine to whom the message is directed

8. Elements of a Communication System

9. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Analog and Digital Signals Figure 4.1 Use of Modem in Analog Network Page 99

10. Types of Signals • Analog signal- a continuous fluctuation over time between high and low voltage. • Digital signal- discrete voltage state - either high or low.

11. Transmission Modes • Data can flow between telecommunication devices in three ways: • Simplex - the data can flow only in one direction. • Half-Duplex - the data can flow in both directions, but it can only flow in one direction at any point in time. • Full-Duplex - data can flow in both directions at the same time.

12. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Transmission Media Typical Speeds Table 4.2 Telecommunications Transmission Speeds

13. Data Transmission • Asynchronous transmission - the data is sent in packages of characters, one character at a time. • Each character set includes a parity bit surrounded by start and stop bits. The parity bit is used for error checking. • Synchronous transmission - data is sent in packages of more than one character at a time with each block sandwiched between a header byte and a trailer byte, called flags.

14. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Topology of Networks Figure 4.5 Network Topologies

15. More Complex Networks Figure 4.6 vBNS+ Network Map

16. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Local Area Networks • LAN Topologies and Standards • Contention bus design … IEEE 802.3 • Token bus design … IEEE 802.4 • Token ring design … IEEE 802.5 • Wireless design … IEEE 802.11

17. Mesh Topologies

18. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Types of Networks • Backbone network terminology: • Bridge – connects two LANs using same protocol • Router (gateway) – connects two or more LANs that may use different protocols • Switch – connects more than two LANs using the same protocols

19. Figure 4.11 Sample Backbone Network

20. Microwave and Satellite Transmission • A communications satelliteis a microwave station placed in outer space. • Satellites don’t “bounce” the microwave signal; rather, the signal is received and then rebroadcast at a different frequency. • Satellites can broadcast over long distances.

21. A Classic Case of MiscalculationIridium • Iridium communications • Launched November 1, 1998 • Went into Chapter 11 bankruptcy on August 13, 1999 • Why? • Miscalculated competition from cellular • Development costs were high • Prices were too high • Technology was awkward and limited • The project was mismanaged • Visit http://en.wikipedia.org/wiki/Iridium_%28satellite%29#Quotes for more informaiton

22. Other Transmission Options • Cellular transmission– Well, you know about this one…

23. Mobile Phone Infrastructure

24. Mobile Phone Generations • 1G: The first generation of wireless technology • used analog communication • designed for voice communication • 2G: The second generation of digital wireless technology • Uses digital circuit switched transmission protocols • Capable of providing voice/data/fax transfers, albeit at low data rates • SMS was introduced in 1994 and became a popular tool associated with GSM (Global System for Mobile communications)

25. Mobile Phone Generations (cont.) • 2.5G: Interim wireless technology that has greater bandwidth • CDMA2000 1x (Code Division Multiple Access) and GPRS (general packet radio service) • Uses packet switching, which offers high data transfer rates (e.g., up to 307 kbit/s) compared to the circuit switching of GSM and other 2G networks

26. Mobile Phone Generations (cont.) • 3G: The third generation of digital wireless technology • For example, UMTS and CDMA2000 1xEV-DO • High data transfer rates (2.4Mbit/s) • It has the potential to support rich media such as video and graphics

27. Mobile Phone Generations (cont.) • 4G: The next generation of wireless technology • Very high data transfer rates (20 Mbps) • In the context of mobile phones, it is expected to be available by 2010 • 4G also refers to the integration of mobile phones, Wi/Fi networks, and other components of a pervasive network

28. WLAN Architecture

29. Wireless Networking Standards • 802.11 - IEEE’s Radio Frequency Wireless networking standard committee. • 802.11b - uses direct sequence spread spectrum (DSSS) signaling. Also used the 2.4 - 2.4835 GHz frequency range and separates it into 14 overlapping 22-MHz channels. • 802.11g - designed to be just as affordable as 802.11b while increasing its maximum capacity from 11 Mbps through different encoding techniques. • 802.11a - uses multiple frequency bands in the 5 GHZ range. Like 802.11g, 802.11a provides a maximum throughput of 54 Mbps.

30. WIMAX • WiMAX is an acronym for Worldwide Interoperability for Microwave Access • IEEE 802.16d • WIMAX improves upon the limitations of Wi-Fi by providing increased bandwidth and range and stronger encryption • Applications • An alternative to cable and DSL for last mile • Connecting Wi-Fi hotspots • high-speed mobile data services

31. Bluetooth • A mobile wireless networking standard that uses direct sequence spread spectrum (DSS) signaling in the 2.4 GHz band to achieve a maximum throughput of less than 1 Mbps. • Designed to be used on small networks composed of personal communications devices, also known as personal area networks.

32. Significant Quotes “No sensible man would transact his affairs by a means of communication such as Bell’s telephone.” Western Union Board of Directors letter to shareholders - - October 1876. The Americans have need of the telephone, but we do not. We have plenty of messenger boys. Sir William Preece, chief engineer of the British Post Office, 1876

33. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING • The Internet • Network of networks that use the TCP/IP protocol • Contain gateways to computers that do not use TCP/IP • Provides four basic functions: • Electronic mail • Remote login • Discussion groups • Sharing of data resources Types of Networks Page 117-118

34. Page 118 Table 4.4 Internet Applications

35. KEY ELEMENTS OF TELECOMMUNICATIONS AND NETWORKING • Internet access services: • Digital subscriber line (DSL) – service offered by telephone companies using copper wire already installed in homes … moving data over wires without disturbing voice traffic • Cable modem – connection obtained from cable TV company using existing home coaxial cable • Satellite – most expensive, but may be only option for customers in rural areas DSL, Cable Modem, and Satellite

36. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Intranets • Intranet– • a network operating within an organization that uses the TCP/IP protocol

37. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING • Internet2– • not-for-profit consortium of over 200 universities, working with over 60 technology companies and the U.S. government, to develop and deploy advanced network applications and technologies

38. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING • Primary goals of Internet2: • Create a leading-edge network capability for the national research community • Enable revolutionary Internet applications based on a much higher-performance Internet that we have today • Ensure the rapid transfer of new network services and applications to the broader Internet community

39. KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Network Protocols • Protocol– • agreed-upon set of rules governing communication among layers or levels of a network

40. Major Telecommunications Laws • Graham Act, 1921 • Exempted telephone companies from antitrust laws • Communications Act of 1934 • legislation which created the Federal Communications Commission • AT&T Consent Decree of 1956 • AT&T and the US Justice department agree on a consent decree to end an antitrust suit against AT&T in 1949 • Carterfone Decision of 1968 • allowed other businesses to attach telephones, equipment and business switchboards to the Bell network • MCI Decision • FCC decree in 1969 that granted MCI Communications Inc., as well as any other company, the right to offer long distance service to customers and to connect to AT&T's network • Modified Final Judgment and Divestiture, 1984 • Split up the Bell Network • The Telecommunications Act of 1996

41. The Telecommunications Act of 1996 • The Telecommunications Act of 1996 was the first major overhaul of United States telecom policy in nearly 62 years. The focus of the Act was to enhance competition • The legislation regulates: • Broadcasting by over-the-air television and radio stations; • cable television operators; • satellite broadcasters; • Wireline telephone companies (local and long distance), wireless telephone companies, and others.

42. Data Voice Video Services Technology Convergence

43. Voice Over IP (VoIP) • The use of packet-switched networks and the TCP/IP protocol suite to transmit voice conversations. • Reasons for implementing VoIP may include: • To improve business efficiency and competitiveness • To supply new or enhanced features and applications • To centralize voice and data network management • To improve employee productivity • To save money

44. VoIP and IP Telephones • Popular features unique to IP telephones include: • Screens on IP telephones can act as Web browsers, allowing a user to open HTTP-encoded pages and, for example, click a telephone number link to complete a call to that number. • IP telephones may connect to a user’s personal digital assistant (PDA) through an infrared port, enabling the user to, for example, view his phone directory and touch a number on the IP telephone’s LCD screen to call that number. • If a line is busy, an IP telephone can offer the caller the option to leave an instant message on the called party’s IP telephone screen.

45. VoIP and Softphones

46. Virtual Organizations

47. Communication Technology Audio Communication Video Conferencing Synchronous Chat Project Management E-mail Personal Information Management Group Support Systems Data Warehouses Internet Search Engines Spreadsheet Analysis Tools OLAP Decision Support Technology Information Access Technology Technologies for Virtual Teams

48. Collaboration-Enabling Tools:Groupware • Groupware: Software products that support collaboration, over networks, among groups of people who share a common task or goal • Provide a way for groups to share resources and opinions

49. Collaboration-Enabling Tools: Group Decision Support Systems (GDSS) • Virtual meetings:Online meetings whose members are in different locations, frequently in different countries • Group decision support system (GDSS): An interactive computer-based system that facilitates the solution of semistructured and unstructured problems by a group of decision makers

50. Collaboration-Enabling Tools: GDSS (cont.) • Major characteristics of a GDSS • Its goal is to support the process of group decision makers by providing automation of subprocesses using information technology tools • It is a specially designed information system • It encourages generation of ideas, resolution of conflicts, and freedom of expression