CHAPTER Copyright 2003 The McGraw-Hill Companies, Inc.Copyright 2003 The McGraw-Hill Companies, Inc. 1 Connectivity, the Wireless Revolution, and Communications 77 computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 2 Competencies Connectivity Wireless Revolution Communication systems Connection devices Transmissions and protocols Network architecture computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 3 Connectivity Computer networks that link people and resources Other computers Large storage devices Internet computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 4 Wireless Revolution Wireless and mobile telephones Most dramatic change in connectivity Connected all the time anywhere Originally voice communication Computer communications Bluetooth Device connections computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 5 Communication Systems Electronic systems that transmit and receive information Basic elements Sending/Receiving device Communication channel Connection devices Data transmission specifications computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 6 Communication Channels Essential element of communication system Two categories Physical connection Wireless connection computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 7 Wired Connections Telephone lines Twisted pair Old standard Coaxial cable – Single solid-copper core – 80 times faster Fiber-optic cable – Light through glass – 26,000 times faster computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 8 Wireless Connections Microwave High-frequency radio waves Line-of-sight communication Relayed Satellite Microwave relay stations Geostationary Large volume of data computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 9 Connection Devices Modulator-demodulator Converts analog signal to digital signal Speed in bits per second (bps) External Internal PC Card Wireless computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 10 Connection Types Dial-up service Most popular, but slow T1 – T4 lines Special high-speed lines Digital subscriber line (DSL) Uses existing phone lines, fast Cable Existing television cables Satellite/air connection services Slower than DSL, but faster than dial-up computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 11 Data Transmission Bandwidth How much information can be transmitted at one time Protocol Specific rules guiding the exchange of information computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 12 Bandwidth Measurement of capacity of the communication channel Categories Voiceband Standard phone line, dial-up Medium band Special leased lines Broadband High capacity transmissions DSL, cable, satellite computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 13 Data Transmission Direction Simplex One direction only Half-duplex One direction at a time Full-duplex Both direction simultaneously computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 14 Protocols Set of communication rules for exchange of information Transmission control protocol/Internet protocol (TCP/IP) Identification IP Address Domain name system (DNS) Reformatting Reassemble packets computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 15 Networks Two or more connected computers that share information and resources Node Device connected to a network Client Node that requests and uses resources available from other nodes Server Node that shares resources with other nodes computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 16 More Network Terms Network operating system (NOS) Software to control and coordinate activities between nodes on a network Distributed processing Computing power located and shared at different locations Host computer Large centralized computer, usually a mainframe computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 17 Network Architecture Arrangement of network communication channel Coordinates and shares resources Topology Star network Bus network Ring network Hierarchical computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 18 Star Network computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 19 Bus Network computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 20 Ring Network computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 21 Hierarchical Network computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 22 Strategies Ways to coordinate sharing of resources Most common Terminal network system Peer-to-peer network system Client/Server network system Enterprise computing computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 23 Network Types Networks differ in geographical size Types of networks Local Area Network (LAN) Metropolitan Area Network (MAN) Wide Area Network (WAN) computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 24 Local Area Networks Computers and devices linked in close proximity to each other Typically use a bus form of organization Network gateways Network bridge computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 25 Metropolitan Area Networks Link nodes and resources within the geographical bounds of a city Link between buildings Cellular phones can extend the reach of a MAN computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 26 Wide Area Networks Countrywide and worldwide network Use microwave relays and satellites Internet Widest of all WAN computing ESSENTIALS    

Copyright 2003 The McGraw-Hill Companies, Inc. 27 Look to Future Wireless robotic car Toyota and Sony collaboration Pod Connects wirelessly to portable terminal Download songs from Internet Use GPS to determine location Communicate with other cars computing ESSENTIALS    