Enterprise manage information systems 6th by laudon ch08

What are the features of a contemporary corporate telecommunications system?. Telecommunications System• Facilitation of electronic communication • Telephone systems • Broadcast and cabl

Telecommunications, Networks,

and Wireless Computing

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?

4 What telecommunications applications can be

used for electronic business and electronic

commerce?

5 What issues should be addressed in

telecommunications planning?

1 Selecting appropriate technologies for enterprise

networking

2 Managing bandwidth

Telecommunications System

• Facilitation of electronic communication

• Telephone systems

• Broadcast and cable TV

• Radio, satellite, and local area networks

• Internet

• Analog or digital

Three Major Developments Shaping

Contemporary Systems

1 Client/server computing

2 Packet switching

3 TCP/IP and other communications standards

Features of Contemporary Telecommunications Systems

A corporate telecommunications system

Figure 8-1

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

Features of Contemporary Telecommunications Systems

• Packets travel independently using routers;

reassembled into original message at destination

Features of Contemporary Telecommunications Systems

Packet-switched networks and packet communications

Figure 8-2

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

TCP/IP: Four-Layer Reference Model

and other layers

to/from application

them from network medium

Features of Contemporary Telecommunications Systems

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

Figure 8-3

• 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

Transmission Media

Functions of the modem

Figure 8-4

• 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

Transmission Media

• 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

Transmission Media

Frequency ranges for communication media and devices

Figure 8-5

Amoco’s satellite transmission system

Figure 8-6

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

Transmission Media

• 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

Local Area Networks

A local area network (LAN)

Figure 8-7

Network topologies

Figure 8-8

• 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

Wireless Networks: Wi-Fi and Bluetooth

An 802.11 wireless LAN

Figure 8-9

• 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

Wireless Networks: Wi-Fi and Bluetooth

• Span broad geographic distances

• Can consist of combination of:

• Switched lines

• Dedicated lines

• Microwave

• Satellite communications

• Private WANs expensive to support

Wide Area Networks

• Metropolitan Area Network (MAN)

• Scope between LAN and WAN

• Limited distance; faster and less expensive than

Is the World Falling for Wi-Fi?

• What management, organization, and

technology factors account for different patterns

of Wi-Fi adoption in various countries?

• What value can Wi-Fi service provide to

businesses?

Window on Organizations

• Frame relay

• Asynchronous transfer mode (ATM)

• Integrated Services Digital Network (ISDN)

• Digital subscriber line (DSL)

• T1 line

• Network convergence

Broadband Network Services and Technologies

• E-mail

telephone charges

• Groupware

participate in discussion forums and work on shared documents and projects

Electronic Mail and Groupware

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.

Window on Management

• Digital Information Services :

• Online services providing general and business

information, such as LexisNexis, AOL, Dow Jones News

• Distance learning

individuals in one or more locations

• 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 Data Interchange

Electronic data interchange (EDI)

Figure 8-10

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?

Will New Systems Keep Delta Flying?

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?

Will New Systems Keep Delta Flying?