Telecommunications, Networks, and Wireless Computing

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Madeline Reeves
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1 Objectives 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? Objectives Management Challenges 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

What telecommunications applications can be used for electronic business and electronic commerce? 5. What issues should be addressed in telecommunications planning? 1.

2 A corporate telecommunications system 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 Figure 8-1 Processing load balanced over many smaller machines Packet-switched networks and packet communications 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 Figure 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 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 8.12

8 Packet-switched networks and packet communications Packet Switching Messages broken into packets before transmission Packets include destination and error- checking information Packets travel

3 The Transmission Control Protocol/Internet Protocol (TCP/IP) reference model 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 Figure Functions of the modem 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 Figure 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 Frequency ranges for communication media and devices Figure

14 Functions of the modem 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

4 Amoco s satellite transmission system 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 Figure Transmission Speed Twisted wire Up to 100 Mbps Microwave Up to 200+ Mbps Satellite Up to 200+ Mbps Coaxial cable Up to 200 Mbps Fiber-optic cable Up to 6+ Tbps Low cost High cost Local Area Networks 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 A local area network (LAN) Network topologies 8.23 Figure Figure 8-8

20 Transmission Speed Twisted wire Up to 100 Mbps Microwave Up to 200+ Mbps Satellite Up to 200+ Mbps Coaxial cable Up to 200 Mbps Fiber-optic cable Up to 6+ Tbps Low cost High cost Local Area

5 Wireless Networks: Wi-Fi and Bluetooth Use radio waves to connect stations b: 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 An wireless LAN Figure Wireless Networks: Wi-Fi and Bluetooth Hot spot: Geographic location in which an access point provides public Wi- Finetwork service Bluetooth: Standard for wireless personal area networks that can transmit up to 722 Kbps within 10- meter area Wide Area Networks 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 WAN Value- Added Networks Private, third-party managed, data only networks Subscription basis Window on Organizations 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?

6 Broadband Network Services and Technologies Frame relay Asynchronous transfer mode (ATM) Integrated Services Digital Network (ISDN) Digital subscriber line (DSL) T1 line Network convergence Electronic Mail and Groupware 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 Window on Management 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. Voice Mail and Fax Voice mail Digitizes spoken message and transmits it over a network Fax Digitizes and transmits documents over telephone lines Teleconferencing, Dataconferencing, and Videoconferencing 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 Digital Information Services, Distance Learning, and E-Learning 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

work on shared documents and projects 8.31 8.32 Window on Management Monitoring Employees on Networks: Unethical or Good Business? Should managers monitor employee e- mail and Internet usage?

7 Electronic Data Interchange Electronic data interchange (EDI) 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 Figure Developing a Business-Driven Telecommunications Plan 1. Distance 2. Services 3. Points of access 4. Utilization 5. Cost 6. Security 7. Connectivity Implementation Issues: Seven Factors Chapter 8 Case Study Will New Systems Keep Delta Flying? 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? 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? 8.41

Services 3. Points of access 4. Utilization 5. Cost 6. Security 7. Connectivity Implementation Issues: Seven Factors Chapter 8 Case Study Will New Systems Keep Delta Flying? 1.

Chapter 9A. Network Definition. The Uses of a Network. Network Basics

Chapter 9A. Network Definition. The Uses of a Network. Network Basics Chapter 9A Network Basics 1 Network Definition Set of technologies that connects computers Allows communication and collaboration between users 2 The Uses of a Network Simultaneous access to data Data