Telecommunications, Networks, and Wireless Computing

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8.1

Telecommunications, Networks,

and Wireless Computing

8.2

Objectives

1. What are the features of a contemporary corporate telecommunications system? On what major technology developments are they based?

2. What telecommunications transmission media should our organization use?

3. What kind of networks and network services are appropriate for our organization?

8.3

Objectives

4. What telecommunications applications can be used for electronic business and electronic commerce?

5. What issues should be addressed in telecommunications planning?

8.4

Management Challenges

1. Selecting appropriate technologies for enterprise networking

2. Managing bandwidth

8.5

Telecommunications System

• Facilitation of electronic communication

• Telephone systems

• Broadcast and cable TV

• Radio, satellite, and local area networks

• Internet

• Analog or digital

The Corporate Telecommunications System

8.6

Three Major Developments Shaping

Contemporary Systems

1. Client/server computing

2. Packet switching

3. TCP/IP and other communications standards

The Corporate Telecommunications System Features of Contemporary Telecommunications Systems

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8.7

The Corporate Telecommunications System A corporate telecommunications system

Figure 8-1

8.8

Client/Server Computing

• Powerful personal computers connect to network with one or more server computers

• Has extended networking to parts of business that could not be served by centralized architecture

• Processing load balanced over many smaller machines

8.9

Packet Switching

• Messages broken into “packets” before transmission

• Packets include destination and error- checking information

• Packets travel independently using routers;

reassembled into original message at destination

8.10

The Corporate Telecommunications System Packet-switched networks and packet communications

Figure 8-2

8.11

TCP/IP

Transmission Control Protocol/Internet Protocol

• Open suite of protocols for connectivity developed in 1970s

• Provides standards for breaking messages into packets, routing them to destination addresses, and reassembling them at end

• Allows for communication regardless of hardware/software

8.12

TCP/IP: Four- Layer Reference Model 1. Application layer:Communication between applications

and other layers

2. Transport layer:Acknowledging and sequencing packets to/from application

3. Internet layer:Addressing, routing, packaging data packets

4. Network interface layer:Placing packets on and receiving them from network medium

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8.13

The Transmission Control Protocol/Internet Protocol (TCP/IP) reference model

Figure 8-3

8.14

• Twisted wire

• Copper wire twisted in pairs

• Older analog transmission medium

• Can be used for digital signals

• Modems used for translating analog to digital

• Coaxial cable:

• Insulated copper wire

• Faster, more interference-free than twisted pair

• Difficult to install; doesn’t support analog signals The Corporate Telecommunications System

Transmission Media

8.15

The Corporate Telecommunications System Functions of the modem

Figure 8-4

8.16

• Fiber optics

• Strands of clear glass fiber bound into cables

• Data sent as pulses of light

• Faster, lighter, more durable

• Difficult to install; more expensive

• Used in high-capacity optical networks

• Currently slowed by need to convert back and forth to electrical data

• Can use multiplexing; allows one channel to carry several transmissions

The Corporate Telecommunications System Transmission Media

8.17

• Wireless Transmission

• Use electromagnetic spectrum

• Microwave and infrared use high-frequency radio signals

• Paging systems, cellular telephones, PDAs, mobile data networks

• Wireless communication requires compatible standards

• Security/privacy issues

8.18

The Corporate Telecommunications System Frequency ranges for communication media and devices

Figure 8-5

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8.19

The Corporate Telecommunications System Amoco’s satellite transmission system

Figure 8-6

8.20

Transmission Speed

• Bps: Bits per second

• Baud rate:Rate of signal changes

• One signal change = cycle

• Transmission capacity is function of frequency

• Bandwidth:Range of frequencies accommodated on a particular channel

8.21

Transmission Speed

Transmission Media

High cost Up to 6+ Tbps

Fiber-optic cable

Up to 200 Mbps Coaxial cable

Up to 200+ Mbps Satellite

Up to 200+ Mbps Microwave

Low cost Up to 100 Mbps

Twisted wire

8.22

• Connects computers and other digital devices within 2000 ft radius

• Cabling or wireless technology links computers, network interface cards, and software

• Ethernet

• Network Operating System (NOS)

• Client/server or peer- to- peer architecture

• Star, bus, and ring topologies

Communications Networks Local Area Networks

8.23

Communications Networks A local area network (LAN)

Figure 8-7

8.24

Communications Networks Network topologies

Figure 8-8

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8.25

• Use radio waves to connect stations

• 802.11b:Current standard; 54 Mbps in 2.4 GHz range

• Infrastructure mode:Wireless devices communicate with wired LAN via access points

• Ad- hoc mode:Peer- to- peer mode; wireless devices communicate with each other directly

Communications Networks Wireless Networks: Wi-Fi and Bluetooth

8.26

Communications Networks An 802.11 wireless LAN

Figure 8-9

8.27

• Hot spot:Geographic location in which an access point provides public Wi- Fi network service

• Bluetooth: Standard for wireless personal area networks that can transmit up to 722 Kbps within 10- meter area

Communications Networks Wireless Networks: Wi-Fi and Bluetooth

8.28

• Span broad geographic distances

• Can consist of combination of:

• Switched lines

• Dedicated lines

• Microwave

• Satellite communications

• Private WANs expensive to support

Communications Networks Wide Area Networks

8.29

• Metropolitan Area Network (MAN)

• Scope between LAN and WAN

• Limited distance; faster and less expensive than WAN

• Value- Added Networks

• Private, third-party managed, data only networks

• Subscription basis

Communications Networks Wide Area Networks

8.30

Is the World Falling for Wi-Fi?

• What management, organization, and

technology factors account for different patterns of Wi- Fiadoption in various countries?

• What value can Wi- Fiservice provide to businesses?

Communications Networks Window on Organizations

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8.31

• Frame relay

• Asynchronous transfer mode (ATM)

• Integrated Services Digital Network (ISDN)

• Digital subscriber line (DSL)

• T1 line

• Network convergence

Communications Networks Broadband Network Services and Technologies

8.32

• E- mail

• Eliminates telephone tag and costly long-distance telephone charges

• Groupware

• Enables work groups at different locations to participate in discussion forums and work on shared documents and projects

Electronic Business and Electronic Commerce Technologies Electronic Mail and Groupware

8.33

Monitoring Employees on Networks:

Unethical or Good Business?

• Should managers monitor employee e- mail and Internet usage? Why or why not?

• Describe an effective e- mail and Web use policy for a company.

Electronic Business and Electronic Commerce Technologies Window on Management

8.34

• Voice mail

• Digitizes spoken message and transmits it over a network

• Fax

• Digitizes and transmits documents over telephone lines

Electronic Business and Electronic Commerce Technologies Voice Mail and Fax

8.35

• Teleconferencing

• Ability to confer with a group of people simultaneously

• Data conferencing

• Two or more users can edit and modify data files simultaneously

• Videoconferencing

• Participants are able to see each other over video screens

Electronic Business and Electronic Commerce Technologies Teleconferencing, Dataconferencing, and Videoconferencing

8.36

• Digital Information Services:

• Online services providing general and business information, such as LexisNexis, AOL, Dow Jones News

• Distance learning

• Education or training delivered over a distance to individuals in one or more locations

• E- learning

• Instruction delivered online using the Internet or private networks

Electronic Business and Electronic Commerce Technologies Digital Information Services, Distance Learning, and E-Learning

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8.37

• Computer- to- computer exchange between two organizations of standard transaction documents, such as invoices, purchase orders

• Minimizes paper- handling and data input;

lowers transaction costs

• Transmits structured data with fields, unlike e- mail

Electronic Business and Electronic Commerce Technologies Electronic Data Interchange

8.38

Electronic Business and Electronic Commerce Technologies Electronic data interchange (EDI)

Figure 8-10

8.39

1. Distance 2. Services 3. Points of access 4. Utilization 5. Cost 6. Security 7. Connectivity

Developing a Business-Driven Telecommunications Plan Implementation Issues: Seven Factors

8.40

1. Analyze Delta using the competitive forces and value chain models.

2. What is Delta’s business strategy? What is the role of information systems and

telecommunications technology in this strategy?

Chapter 8 Case Study Will New Systems Keep Delta Flying?

8.41

3. Assess Delta’s Digital Nervous System (DNS) effort. What value does it provide the company?

How does it support Delta’s business strategy?

4. What problems at Delta can be solved with information systems? What problems cannot be solved with systems?

Chapter 8 Case Study Will New Systems Keep Delta Flying?