2. Telecommunications and Networks6
Chapter
Telecommunications and Networks
Business value of networks
The Internet
Network components

3. Learning Objectives Understand the concept of a network.
Apply Metcalfe’s law in understanding the value of a network.
Identify several major developments and trends in the industries, technologies, and business applications of telecommunications and Internet technologies.
Provide examples of the business value of Internet, intranet, and extranet applications.

4. Learning Objectives
Identify the basic components, functions, and types of telecommunications networks used in business.
Explain the functions of major components of telecommunications network hardware, software, media, and services.
Explain the concept of client/server networking.
Understand the two forms of peer-to-peer networking.
Explain the difference between digital and analog signals.

5. Learning Objectives
Identify the various transmission media and topologies used in telecommunications networks.
Understand the fundamentals of wireless network technologies.
Explain the concepts behind TCP/IP.
Understand the seven layers of the OSI network model.

6. Case 1: Wireless, Wireless Everywhere
Wireless sensor devices or motes
Package together a circuit board, software, sensors and wireless radio
Uses mesh networking software to transmit data from one mote to another

7. Case Study Questions
What are some of the business benefits associated with using wireless networks to collect and transmit data?
What are some of the challenges being faced in this use of wireless technologies? What solutions can you offer?
The use of wireless networking as described in the case is both innovative and useful. What other business uses can you envision for this approach?

8. Real World Internet Activity
The companies mentioned in this case, Intel, IBM, SAIC, and GE are all familiar names often associated with innovative approaches to technology. Using the Internet,
See if you can find examples of other companies that have found ways in which to apply mote wireless technology to business needs.

9. Real World Group Activity
One way of describing this use of wireless technologies is that it represents a marriage between RFID and wireless networking. This combination of enabling technologies results in an entirely new way of accomplishing an old task. In small groups,
Brainstorm other combinations of existing technologies to create new approaches to existing business activities.
We learned about RFID devices in Chapter 3.

10. Network Concepts Network
An interconnected chain, group or system
Number of possible connections on a network is N * (N-1)
Where N = number of nodes (points of connections on the network)
Example, if there are 10 computers on a network, there are 10 * 9 = 90 possible connections

11. Metcalfe’s Law
The usefulness of a network equals the square of the number of users
On a small network, a change in technology affects technology only
On a large network like the Internet, a change in technology affects social, political and economic systems
If there are only 2 users on the network, it’s not very useful; if there are 200 it’s much more useful.
So the Internet with millions of computers is incredibly useful.

12. Telecommunications Telecommunications
Exchange of information in any form (voice, data, text, images, audio, video) over networks

13. Trends in Telecommunications

14. Open Systems
Information systems that use common standards for hardware, software, applications and networks
Internet networking technologies are a common standard for open systems
Connectivity:
Ability of networked computers to easily access and communicate with each other and share information
Interoperability:
The ability of an open system to enable end user applications to be accomplished using different varieties of computer systems, software packages, and databases provided by a variety of interconnected networks
Open systems provide greater connectivity.
Open systems also provide high degree of interoperability.

15. Middleware
Any programming that serves to “glue together” two separate programs

16. Digital Network Technologies
Rapid change from analog to digital network technologies
Analog: voice-oriented transmission, sound waves
Digital: discrete pulse transmission
Digital allows:
Higher transmission speed
Larger amounts of information
Greater economy
Lower error rates
Multiple forms of communications on same circuit

17. Internet2 Next generation of the Internet High-performance network
In use at 200 universities, scientific institutions, communications corporations
Internet2 may never replace the Internet. May remain a scientific and government network.

18. Business Value of Telecommunication Networks

19. The Internet Over 46 million servers (2004)
710 – 945 million users (2004)
No central computer system
No governing body
No one owns it
With all these users, Metcalfe’s law suggests the possible connections are extraordinary

20. Internet Service Provider
ISP
A company that specializes in providing easy access to the Internet
For a monthly fee, you get software, user name, password and access
ISPs are connect to one another through network access points

21. Popular uses of the Internet

22. Using the Internet for business

23. Business value of the Internet

24. An Intranet A network inside an organization
That uses Internet technologies (such as Web browsers and servers, TCP/IP protocols, HTML, etc.)
To provide an Internet-like environment within the organization
For information sharing, communications, collaboration and support of business processes
Protected by security measures
Can be accessed by authorized users through the Internet

25. Enterprise Information Portal
Intranets provide an enterprise information portal.

26. Extranet Network links that use Internet technologies
To connect the Intranet of a business
With the Intranets of its customers, suppliers or other business partners

27. Extranet Uses

28. Case 2: Maryland and Colorado Serving their customers without using wires
Earth Alert Emergency Management System in Maryland provides
Devices to communicate warning to individuals before a disaster, and
Tools to collect timely information after a disaster
Aurora Colorado
Connects police and fire department vehicles via wire-less connections

29. Case Study Questions
What is the business value of advanced mobile technologies to Maryland’s emergency management services?
In what other government services could GPS serve to provide business value? Give some examples.
Are there disadvantages or risks associated with the deployment of GPS systems to monitor the location of people? Explain.

30. Real World Internet Activity
The global positioning system (GPS) is a major technological achievement that has broad-reaching implications for business. Using the Internet,
See if you can find other innovative uses for GPS.
Good places to start familiarizing yourself with current accomplishments are
The GPSWorld site at
The GPS Overview at

31. Real World Group Activity
The first Real World Case in this chapter discussed the combination of two existing technologies, RFID and wireless networking, to create an innovative business solution. In small groups,
Brainstorm innovative applications of GPS and other existing technologies.

32. Telecommunications network
Any arrangement where a sender transmits a message to a receiver over a channel consisting of some type of medium

33. Telecommunications network components
Terminals: any input/output device that uses networks to transmit or receive data
Telecommunications Processors: devices that support data transmission and reception
Telecommunications Channels: media over which data are transmitted and received
Computers: all sizes and types
Telecommunications Control Software: programs that control telecommunications activities

34. Telecommunications network model

35. Wide Area Network (WAN)
Telecommunications network that covers a large geographic area
Source: Courtesy of Cisco Systems Inc.

36. Local Area Network (LAN)
Connect computers within a limited physical area such as an office, classroom, or building

37. Virtual Private Networks (VPN)
A secure network that uses the Internet as its backbone but relies on firewalls, encryption and other security
A pipe traveling through the Internet

38. VPN

39. Client/Server networks
Clients: End user personal computers or networked computers
Interconnected by LANs
Servers: manage networks
Processing shared between clients and servers
Two tiered client server includes just client and server
Maybe connected to optional super servers

40. Client/Server Network

41. Network Computing
Networks are the central computing resource of the organization
Thin clients: network computers and other clients provide a browser-based user interface
Thin client means that very little processing is done on the client. Most the processing is done on the server.
Three-tier model includes thin clients, application servers and database servers

42. Peer-to-peer networks
Networks that connect from one PC to another PC
Common use is the downloading and trading of files
With a central server architecture, P2P file-sharing software connects your PC to a central server that contains a directory of all the other users in the network. When you request a file, the server searches the directory for any other users who have that file and are online. You click on list and make the P2P connection.
Napster used this architecture.
Pure P2P has no central directory or server.

43. Peer-to-Peer Network

44. Telecommunications Media
Twisted-pair wire:
Ordinary telephone wire
Copper wire twisted into pairs
Twisted pair transmission speeds range from 2 million bits per second (unshielded) to 100 million bits (shielded)
Coaxial cable from 200 million bits to over 500 million bits per second
Fiber optic cable as high as trillions of bits per second. Uses light elements instead of electricity
Source: Phil Degginger/Getty Images.

45. Telecommunications Media
Coaxial cable:
Sturdy copper or aluminum wire wrapped with spacers to insulate and protect it
Twisted pair transmission speeds range from 2 million bits per second (unshielded) to 100 million bits (shielded)
Coaxial cable from 200 million bits to over 500 million bits per second
Fiber optic cable as high as trillions of bits per second. Uses light elements instead of electricity
Source: Ryan McVay/Getty Images.

46. Telecommunications Media
Fiber-optic cable:
One or more hair-thin filaments of glass fiber wrapped in a protective jacket
Twisted pair transmission speeds range from 2 million bits per second (unshielded) to 100 million bits (shielded)
Coaxial cable from 200 million bits to over 500 million bits per second
Fiber optic cable as high as trillions of bits per second. Uses light elements instead of electricity
Source: CMCD/Getty Images.

47. Problem of “The Last Mile”
Network providers use fiber optic to provide backbone
But houses are connected to the backbone via twisted-pair
Cannot get the benefit of the faster, better technology
Need to connect houses with a higher-speed technology. One solution is cable connection.
Another solution is to skip the wires and use satellite or wireless.

48. Wireless Technologies
Terrestrial microwave
Earthbound microwave systems that transmit high-speed radio signals in a line-of-sight path
Between relay systems spaced approximately 30-miles apart
Communications satellites
Satellite serves as relay stations for communications signals
Uses microwave radio signals

49. Wireless Technologies
Cellular and PCS telephone and pager systems
Divide the geographic area into small areas or cells
Each cell has transmitter or radio relay antenna to send message from one cell to another
Wireless LANs
Radio signals within an office or building
Connect PCs to networks
Bluetooth
Short-range wireless technology
To connect PC to peripherals such as printer

50. Wireless Web Connect portable communications devices to the Internet
Very thin client such as telephone, pager, PDA
WAP: wireless application protocol
WML: wireless markup language

51. Telecommunications Processors
Modems
Convert digital signals from a computer into
Analog frequencies that can be transmitted over ordinary telephone lines

52. Comparing modem and other technologies

53. Internetwork Processors
Switch – makes connections between telecommunications circuits in a network
Router – intelligent communications processor that interconnects networks based on different protocols
Hub – a port switching communications processor
Gateway – connects networks using different communications architectures

54. Communications Processors
Corporate LAN in upper left hand corner uses a hub to connect its multiple workstations to the network switch. The switch sends the signals to a series of switches and routers to get the data to its destination.

55. Telecommunications Processors
Multiplexer
Allows a single communications channel to carry simultaneous data transmissions from many terminals

56. Telecommunications Software
Used by servers and other computers to manage network performance
Network Operating Systems
Middleware

57. Network management functions
Traffic Management – manage network resources and traffic to avoid congestion and optimize service levels to users
Security – provide authentication, encryption, firewall, auditing and enforcement
Network Monitoring – troubleshoot and watch over the network, informing network administrators of potential problems before they occur
Capacity Planning – survey network resources and traffic patterns and users’ needs to determine how best to accommodate the needs of the network as it grows and changes

58. Network Topologies Topology: structure of a network
Star: ties end user computers to a central computer
Ring: ties local computer processors together in a ring on a relatively equal basis
Bus: local processors share the same communications channel

59. Network Topologies

60. Network Architectures & Protocols
Protocol: standard set of rules and procedures for the control of communications in a network
Network Architecture:
Master plan of standard protocols, hardware, software and interfaces between end users and computer systems
Goal of promoting an open, simple, flexible, and efficient telecommunications environment

61. OSI & TCP/IP Models Open Systems Interconnection (OSI) Model
A seven-layer model that serves as a standard model for network architectures
Model for how messages should be transmitted between two points in a network
Each layer adds functions
Transmission Control Protocol / Internet Protocol (TCP/IP)
A five layer telecommunications protocol used by the Internet

62. OSI & TCP/IP Models Two groups of layers.
Upper four layers are used whenever a message passes from or to a user.
Lower three layers are used when message passes through the host computer. If message is being sent to another host, it skips these layers.
TCP/IP analogous to postal system.
TCP: analogous to postal system and processes and protocols to use the mail.
IP: analogous to zip code and address.

63. Internet Telephony
Using an Internet connection to pass voice data using IP
Voice over IP (VoIP)
Skips standard long-distance phone charges

64. Bandwidth Bandwidth Transmission Rates:
Frequency range of a telecommunications channel
Determines transmission rate
Classified in bits per second (bps)
Transmission Rates:
Narrow-band – low-speed
Broadband – high-speed
Bandwidth is sometimes called baud rate.
Think of channel as a pipe with water in it. The wider the pipe, the more water that can flow through it.
Narrow-band – unshielded twisted-pair
Broadband – microwave, fiber optic or satellite

65. Transmission Speeds

66. Switching Alternatives
Circuit Switching
Switch opens a circuit to establish a link between a sender and receiver
it remains open until the communication session is completed
Packet Switching
Break messages into groups called packets
Transmit packets separately
Circuit switching: telephone service
Packet switching: Internet, x.25 protocols, ATM

67. Network Interoperability
Ensure that anyone anywhere on one network
Can communicate
With anyone anywhere on another network
Telecommunications as discussed in this chapter wouldn’t be possible without interoperability

68. Case 3: Voice Over IP is the Real Thing
VoIP works by
Digitizing a voice signal,
Chopping it into packets, and
Sending them over a company’s network or the Internet
Packets are reassembled at the destination
Minnesota Department of Labor has cut its monthly phone bill in half

69. Case Study Questions
What are the main benefits that can be gained by companies that switch to VoIP systems?
What are some of the major cost factors that may limit a positive rate of return from investments in VoIP projects?
Should more companies switch to VoIP systems? Visit the websites of Avaya and Cisco Systems to view their VoIP news, products, and services to help you answer.

70. Real World Internet Activity
VoIP is becoming a highly competitive marketplace for the delivery of services and the development of software to support the process. Using the Internet,
See if you can identify who the major players are in this market.
Where do you see the next significant development for VoIP?
Do you think the concept will eventually replace conventional telephone technologies? Why or why not?

71. Real World Group Activity
The original concept for the Internet never included many of the uses we have found for it and consider commonplace today. While Internet2 is on the horizon, we need to think about what uses we may want from the Internet in the future. In small groups,
Brainstorm how we might use the Internet in the future.
Do we run the risk of overloading the Internet or relying on it too much?