Discovering C omp omputers uters 20 2009 09
Chap apter ter 9 Communications and Network Networks s
Chap hapter ter 9 Obj Objec ecti tiv ves Discu Di scuss ss the com components re r equir ed for successful communications I de dentif ntify y various vari ous sending and receiving devices
Explain the purpose of communications software Describe various types of lines for comm com muni unicati cations ons over the telephone ne networ twork k
Descr Des criibe use uses of computer computer com comm muni unicati cations ons Descriibe commonl Descr only y used communications devices L ist advantage advantages of usi using a ne networ twork k Discu Di scuss ss differ differe ent ways to set up a home home networ network k Diffe Diff er enti ntiate ate among cl client/server, peer-to-peer, and P2P networks
I de dentif ntify y various vari ous phys physical ical and wire wir eless transmission media
Describe the various network communications standards
Next
Communications What are computer communications communications? ?
Process in which two or more computers or devices transfer data, ins nstr truc ucti tion ons s, and and iinfor nforma mati tio on
p. 460 – 461 Fig. 9-1
Next
Communications What is needed for successful communications? Sending device— device — initiates ins nstr truction uction to trans tr ansm mit data, ins nstr tructions uctions,, or information
Communications device — conne connects the sending device to the communications channel
Communications device — conne connects the communications channel to the recei ceiving ving device vice
p. 460 - 461
Communications channel — media on which data, ins nstr tructions uctions,, or inform nformation trav trave el
Receiving device — acce accepts trans tr ansm missi ssion of data, data, ins nstr tructions uctions,, or information
Next
Uses of Computer Com Communi nic cati ation ons s What are are some ome uses uses of of comm communicati unications ons technol technolog ogy? y? I nternet
Web
E-Mail
I nst nstan antt Mes essa sagi ging ng
Chat Rooms
Newsgroups
Blogs
Wikis
RSS
VoI P
FTP
Web Folders
Video Conferencing
Fax Machine or Com ompute puter Fax/Modem
p.462
Next
Uses of Computer Com Communi nic cati ation ons s
Vid Vi deo: Tril Trilllian
CLIICK TO ST CL START
Next
Uses of Computer Com Communi nic cati ation ons s What are are wir wir eless messag ssagiing se ser vice vices s? Text messagin ing g allows users to send and receive short text messages ssages on a phone or other mobile device
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click VideoMessagingbelow Chapter9 p. 463 - 464
Wireless instant messagi aging all allows wireless mobile devices to exchange messages Picture/video messag ssagiing allows user users to send send graphi aphics cs,, pictur picture es, video clips, sound files, and shor shortt text text messages
Next
Uses of Computer Com Communi nic cati ation ons s What hat are are wi wirr eless I nte nterr ne nett access points and cybercafés? cybercafés ?
Wireless Inter I nterne nett ac acce ces ss point allows wireless conne connecti ction on to Inte I nterrnet net in publ public loca locatio tion 4G 3G and 4G networks Cybercaféis Cybercafé is a coffee house that provides com computer puters with with Inte I nterrnet net access
p. 464-465 Fig. 9-4 9-4
Next
Uses of Computer Com Communi nic cati ation ons s What is a global positioning system (GPS)? (GPS)? Step 1. GPS sate satelllites orbit Earth. Every thousandth of a second, each satellite sends a signa signal that indicates its current position tion to theGPS receiver.
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click GPS GP S below Chapter 9 p. 466 Fig. 9-6
Step 2. A GPS receiver (such as in in a car, a wearable rable device, device, a smart phone, a handheld device, device, or a collar) determines its its location tion on Earth by analyzing nalyzi ng at least 3 separate satellite signals from the 24 satellites in orbit.
Next
Uses of Computer Com Communi nic cati ation ons s What are collaboration and groupware? groupware ?
Collaboration is working with other users connected to a ser ser ver ver
Web conference
Groupware is software Groupwareis that allows people work work tog toge ether ther and shar share e information
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click WebConferences below Chapter9 p. 467 Fig. 9-7
Next
Uses of Computer Com Communi nic cati ation ons s What are voice mail and web service vices? s?
Voice mail is voice message converted to digital form Web ser vice vices s des descri cribe standardized software that enable nables prog pr ogrramm ammer s to create applications that communicate with other remote com compu puter ters s over the the I nter nter net net or on an inter inter nal nal business network
p. 468 Fig. 9-8
Next
Networks What is a network network? ?
Collection of comput compute er s and devices connected via communications devices and transmission media
p. 469 Fig. 9-9
Next
Networks What is a local area ne netwo tworrk (L A N) and a metro tropol politan tan are area netwo networrk (MA (M A N)?
A L A N is a ne networ twor k in in lim limited ted ge geogr ogr aphical phical area such as home or office building
Wire Wir ele les ss L A N (WL A N)
M etro tropol politan tan ar area netwo networrk (MA (M A N) con conne nec cts L A Ns in city or town
p. 471 – 472 Fig. 9-10
Next
Networks What is a wide area netw two ork (W (WA A N) N)? ?
Network that covers large geographic area using many types of media I nter nternet net is is wor wor ld’s largest WAN
p.472Fig.9-12
Next
Networks What is a client/server network? network ?
One or more computers act as ser ve verr and other other computers, or clients clients,, access ser ser ver
p.472Fig.9-13
Next
Networks What is a peer-to-peer network?
Simple network that connects fewer than 10 computers E ach ach compute computer, r, or peer, has equal capabilities
p.473Fig.9-14
Next
Networks What is Inte I nterrnet net pee peer-to-pee to-peer (P2P)?
Sometimes called a file sharing network Enables users to connect connect to to each each other other ’s hard disks and exchange files directly
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click BitTorrentbelowChapter9 p. 473 - 474Fig. 9-15
Next
Networks What is a bus network?
A ll com computer puter s and and devi device ces s connect connect to central ntr al cable or bus E xam xampl ple e of network topology (layout of devices in network)
p.474Fig.9-16
Popular topologies are bus, ring, and star
Next
Networks What hat is is a ri ring netwo networrk?
Cable forms closed loop (ring), with all compu computer ters s and de device vices s arranged along ring Data travels from device to device around enti entirre r ing, ng, in in one direction
p.474Fig.9-17
Next
Networks What is a star network?
A ll devi device ces conne connect ct to a central device (hub or switch) A ll data data tra trans nsfferred from one computer to another passes through hub or switch
p.475Fig.9-18
Next
Networks What is an intranet? I nte nternal rnal ne network twork tha thatt uses uses Inte I nternet rnet technol chnologi ogie es
M akes inf inform orma ati tion on acces accessi sibl ble e to empl ploye oyee es
Ty T ypic ica ally in inc clu lud des connectio ion n to In Intternet Extranet all allows customers or sup suppl pliiers to access access part pa rt of com compa pany’ ny’s s intrane intranett
p.475
Next
Net etw work Com Commun uniicat atiion ons s Standard Standards s What are Ethernet and token ring? ring? Ethernet technology allows computers to contend for access to network
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click Ethernetbelow belowChapter9 p.476
I f two computers send dataat same tim time, a coll collision sion occurs and com compute puters must send send aga again
Token ring Tok ringtechnology technology controls access to network by requiring devices to pass a special signal, called toke token
Next
Net etw work Com Commun uniicat atiions St Standard andards s What are T are TCP/I CP/IP P and 802.11 (Wi-Fi Wi-Fi))?
TC P/II P ( Transmission TCP/ Transmission Control Protocol/I rotocol/I nternet Protocol) technology transmits data by breaking it up into small pieces, or packets
Commo ommonl nly y used for for I nter nter net net trans tr ansmiss missiions
802.11 (Wi-Fi Wi-Fi)) is a family of standards for wireless LANs
p. 477 - 478Fig. 9-20
Next
Net etw work Com Commun uniicat atiion ons s Standard Standards s What is Bluetooth Bluetooth? ?
Short-range radio waves transmit data between Bluetooth devices
p.478
Next
Net etw work Com Commun uniicat atiion ons s Standard Standards s What areUWB, are UWB, I rDA rDA,, RFID RFID,, WiMAX WiMAX,, and Wireless A pp ppllication tions s Proto toc col (WA (WAP P)? UWB
IrDA
specification allows data data to be transferred transferred wirelessly via short-range radio waves
specification allows data data to be transferred transferred wirelessly via infrared light waves
Radio Frequency I dentifi ntific cation (R (RF F I D) uses radio radio signa signals to communi unicate cate with wi th a tag tag pl placed in an obje object ClicktoviewWeb Click Link, clickChapter9, ClickWebLinkfromleft navigation, then click WiMAX belowChapter 9 p. 478 - 480
Worldw Worl dwiide I nte nterrope perr ab abiility for M icrow crowa aveA cc cce ess (WiM (Wi M A X or 802.16) standa sta ndard that that speci ciffies how wirel wirele ess devi de vices ces communi unicate cate over the air in a wi wide de area
Wireless Appli Applica cati tio ons Proto toc col (W (WA A P) allow wireless mobile devices to access access Interne Internett Next
Commun uniicati ation ons s Softw Software are What is communications software? software? Programs that help users establish stablish connecti connection on to I nter nternet, net, other networ network, or another another computer
Programs that help users manage transmission of data, data, instructions, instructions, and information Progr ograms that prov proviide an interface for users to comm communicate uni cate with with one another
p.480
Next
Communicati ations ons Ov Over the the Teleph Telephone one Network What is the public switched tel telephone networ network k (P (PSTN ST N)?
Worldwide telephone system that handles voice-oriented telephone calls
p.481Fig.9-23
Next
Communicati ations ons Over Over the Teleph Telephone one Network What is a dia diall-up up line?
Temporary rary connection ion usin ing g telep lephone line line for for communications
p.481
Costs no no more than than making aking regul regular ar call call Computers at any two locati locations ons can establ stabliish a connection connection using using modem odems and tele telephone netw networ ork k
Next
Communicati ations ons Ov Over the the Teleph Telephone one Network What is a dedicated line? line? A lwaysways-on conne connecti ction on between two communications devices
Five type types are ISDN SDN line, DSL, DSL, FT FTTP, TTcarrier line, and ATM
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click FTTH FT TH below Chapter 9 p.482Fig.9-24
Next
Commun uniicati ation ons s Dev eviices What are examples of communications devices? devices? Com ommo mon n type types s ar are e di dialal-up up mode modems ms,, I SDN and DSL modems ms,, cable cable mode modems ms,, wi wireless modems ms,, networ ne twork k cards, cards, wire wir eless acc acce ess poi point nts, s, routers, and hubs
I SD SDN N and DSL mode odem ms se send and receive da data ta fr from I SDN and DSL DSL line nes s
p.484
Next
Commun uniicati ation ons s Dev eviices What is a dial-up modem modem? ?
A dial-up modem converts digital signals to analog signals and vice versa Usually in the form of an adapter card
Next
p.485
Commun uniicati ation ons s Dev eviices What are ISDN and DS DSL L mode odem ms? Communications devices that send and receive di dig gita tall I SDN and DSL signa nalls Usually external devices in which one end connects to a telephone line and the other end connects to a port on the system unit
p.485
Next
Commun uniicati ation ons s Dev eviices What is a cable modem? modem?
Sends Sends and recei ceives ves data over cable tel televis vision network twor k M uch uch ffa aster ter than than dial-up modem or ISDN Sometimes called a broadband modem
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click Cable Cabl e Modems below belo wChapter 9 p. 484 - 486Fig. 9-28
Next
Commun uniicati ation ons s Dev eviices What is a wi wirreless mode odem m?
A llows acce access to the the Web wirelessly from a notebook comput compute er, a sm smart ar t phone, or other mobile device Typ Typica ically use the same waves waves used by by cellular telephones
p.486Fig.9-29
Next
Commun uniicati ation ons s Dev eviices What is a network card? card?
Adapter card, PC Card, ExpressCard modul odule, USB U SB network adapter, or flash card that enables computer or device to access network Sometimes called network interface card (NIC (NI C )
p. 486 - 487Fig. 9-30
Next
Commun uniicati ation ons s Dev eviices What is a wireless access point?
Central communications device that allows comput compute er s and devices to transfer data wir wi relessly among among themselves or wirelessly to a wired network
p.487Fig.9-31
Next
Commun uniicati ation ons s Dev eviices What is a router?
Connects onnects comput compute er s and transmits data to correct destination on network Routers forward data on I nter nter net net using using fastes fastest avai available able path Some routers have a built-in hardware firewall
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click Wireless Routers belowChapter9 p.488Fig.9-32
Next
Commun uniicati ation ons s Dev eviices What is a hub or switch?
Device that provides central point for cables in network
p. 488 - 489Fig. 9-33
Next
HomeNetw Network orks s What is a hom home e ne netw twor ork k?
M ul ulti tipl ple e computer puters connected in home Seve Severr al types ypes of of home home networks
E ther ther net net — con connect computers computers via via cable cable
Powe ower line cab cablle — use electrical lines in house Phoneline — use telephone lines
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click HomeNetworks Networks below Chapter 9 p. 489 - 490Fig. 9-34
Next
Commun uniicati ation ons s Chann Channel el What is a communications channel?
Tran Transmis iss sion ion media on which ich data trav ravels in communications system Transmis Tran iss sio ion n media are materials or substances capable of carrying one or more signals
p.491
Bandwidth is amount of data that can travel over a communications channel
Next
Commun uniicati ation ons s Chann Channel el How is is a re reques quest sent sent over the the I nter nternet net using using a com comm munica unicati tions ons channel?
p.491Fig.9-35
Next
Physi sic cal Tran ransm smissi ssion onMed Mediia What is physical transmission media?
Wire, cable, and other tangible materials used to send communications signals
p.492Fig.9-36
Next
Physi sic cal Tran ransm smissi ssion onMed Mediia What are twi twis ste ted-pair d-pair cabl ble e and coaxial cable? cable?
Twis Tw iste ted-p -pa air ca cable is used for for tele telephone sy syste stems ms and and networ network cabli cabl ing
Coaxial cableis cable is often used for cable television wiring
p. 493 Fig. 9-37—9-38
Next
Physi sic cal Tran ransm smissi ssion onMed Mediia What is fiber-optic cable? cable?
Capabl pable e of carr carrying ying significantly more data at faster speeds than wire cables L ess susce uscepti ptibl ble e to interference (nois (noise) and, the therefore ore, more secure Smaller size (thinner and li lighter hter)
p.493Fig.9-39
Next
Wirel reless ess Transm Transmissi ssion onMedi Media a What is wireless transmission media?
Used when inconvenient, impractical, or impossible to ins nstall tall cabl cable es I ncl ncludes Bluetoo uetooth th and and Ir I rDA
p.494Fig.9-40
Next
Wirel reless ess Transm Transmissi ssion onMedi Media a What are broadcast radio and cellular radio? radio?
Broadc dcas astt rad r adiio distributes radio signals over long and short distances Cell llula ularr radio is form of broa broadc dcas astt r adi adio used for mobile communications
ClicktoviewWeb Click Link, click click Chapter 9, Click WebLi Link nk fromleft navigation, then click 4G Networks below Chapter 9 p. 494 and495 Fig. 9-41 9-41
Next
Wirel reless ess Transm Transmissi ssion onMedi Media a What is a microwave microwavestation? station?
Earth-based reflective dish used for microwave communications M us ustt tra trans nsm mit in in straight line with no obstructions
p. 496Fi Fig. g. 9-42
Next
Wirel reless ess Transm Transmissi ssion onMedi Media a What is a communications satellite? satellite?
Space station that receives microwave signals from earth-based station, amplifies signals, and broadcasts signals back to any number of earthbase based stati tations
p.496Fig.9-43
Next
Summ Sum mary of Com Commun uniicat atiions and Networks Networks
Communications terminology and appli applications cations
How to join join co com mpute puterrs into into a networ twork k
Chapter 9 Complete
Various communications devices, media, and procedures
