New Technology for Computer Network

NewTechnologyforComputerNet[e-mail]1420723126Teachersbackground•1980Physicsdegree-WashingtonStateUniv.•1984Master’sdegree-WashingtonStateUniv.–ElectricalEngineering/Computernetworks•1991-PhDClemsonUniversity–Electricalengineering/ComputerNetworksWorkExperience•1982-1983-GTETelenet–1stcommercialcomputernetwork•1984-1998-IBMengineer–Systemsperformancemodeling•1998-now–TeachinginQingdao•海洋大学，青岛科技大，青岛理工大学，1sttermat–山东科技大学Classoverview•NewTechnologiesforcomputernetworks–Giveintroductionfornewtechnologiesforcomputernetworks–Encourageclassdiscussion/questions–15%totalgradeforclassattendanceinlast3weeksofclass•CheckattendancewithstudentphotoAreastobecovered•Networkhistory•Networkapplications–Onlinemessaging–Multiplayergames–Peertopeernetworking–Cloudcomputing–Smartpowergrid–Socialnetworking–Web2.0–NetworkandcomputersecurityAreastobecovered•Newnetworktechnologies–Sensornetworks–AdHoc/Meshnetworks–Wireless•Wifi-802.11•Bluetooth•Extendedwifi-802.16Networktechnologies•Networkinfrastructure–Virtualprivatenetworks–MPLSother•Issueofnetneutrality•RFID•Softwareandcognitiveradio•SOA•Browsers•Search•E-commerceHistoryofNetworks•Telegraph1837invention-–2006(westernunioncancelledtelegramservice)–Adigitalmedia–Permittedworldwide•Communications•newsreporting–19thcenturyinternetHistoryofNetworks•Telephone–Inventedbybell1876•Voice•Analognotdigital–Originallyusedhumanoperator–Telephoneswitchinventedby»Undertaker(承办单位)•Progressoftelephonetechnology–Transistorinventedforelectronictelephoneswitching–Digitaltransmission(t1)1960s–Cellphone1980s–IPphone/skype(1990s-present)HistoryofNetworks•Computersprogressfrom1940s–Vacuumtubeeniac–Transistor–Integratedcircuits-IBM360–VLSI–PCHistoryofNetworks•Computercommunication–1stcomputernetworkinSAGE(developedforMilitarybyIBMforairdefense)–Arpanet–militaryresearchproject•1stwideareapacketswitchednetworkHistoryofnetworks•Differencebetweendataandvoice–Dataisbursty,voiceisconstant•Packetswitchingisbetterfordata•Circuitswitchingisdesignedforvoice–Aloha/multipleaccessradio•Ethernet,developedbyxerox•AlohaappliedtocableHistoryofNetworks•1970’s•IBMSNA•Telenet1stcommercialcomputernetwork–Foundedbyarpanetmanager/lossesmoney•1978ISO/OSI7layermodel1980s•IBMlookstonetworking•AT&Tlookstocomputer–Bothfailinotherbusiness•AT&TwithNCR,IBMwithROLM,SBS•WithPCriseinLocalAreaNetworks–Ethernet–IBMtokenring•TCP/IPsuccessful/OSIfails•InternetopentocommercialtrafficHistoryofNetworks•1990s–Onlineservices•IBMProdigy/AOL–With–Browserwars-NetscapevsIE•MicrosoftantitrustdamagesagainstNetscape–Dotcomboom•AOL/TimeWarnermerge•Followedbydotcomcrash–HowtomakemoneyfromnetHistoryofNetworks–Aftercrash,newwinners•Google•Yahoo•Facebook•Ebay–RiseofnetTV/filesharing•Strainonnetwork•Netneutralitycontroversy–TelephonecompaniesemphasizewirelessHistoryofNetworksNewWirelesscommunication•Wirelessmodem–Slow30kb/sec,widerange(GPRS2.5Gm)•Wi-Fi–IEEE802.11–Access100mbps,upto100Mb/s,54MB/s•Bluetooth–DevelopedbyErikson–Pointtopoint,3mbps10M–Lowpower•Satellite–Expensive,worldwide,NewwirelesscommunicationsBluetooth-developedbyEriksonreplacementforwire2.45GHzlicenseexemptbandspreadspectrumhoppingover79bandslowpower/shortrangeprotocolonemasteruptosevenslavesBluetoothconfiguration•Problemswithbluetoothsecurity–Bluespamming–Eavesdropping–Bluetracking–Spamming–Bluesniper-listen2km•SolutionismakedeviceundiscoverableNewwirelesscommunications•Wi-fiIEEE802.11–2.4GHzsharedspectrum–5GHzsharedspectrum–802.11a,802.11b,802.11g•Upt054Mb/s•100m•MorepowerthanBluetooth•Basedonbasestation–Spreadspectrum–MultipleaccesscollisionavoidanceMultiplexingtechniques•Timedivisionmultiplexing–Usedbygsm(2Gcellphone)•CDMA(spreadspectrum)–Originallyformilitarycommunications–Varyfrequencyusingacode•Frequencyhopping•DirectsequenceNewwirelesscommunications•ALOHA-Multipleaccess–Sendanytimehavedata–17%maximumutilization•EthernetCSMA/CD–CarriersenseMultipleaccess/collisiondetect•WI-FIMultipleaccesscollisionavoidance–Requesttosend(RTS)–CleartoSend(CTS)–Hearctscannottransmittooclose–Hearrtsbutnotctsoktosend/far–Receiversendsack,otherstationswaitforacknowledgement–Iftwortscollide,transmittersrealizebecausenoctsComputerinternetaccess•TelephoneModem–Limitedbandwidth–Shannon’stheoremisphysicallimit–ISDN•DSL/ADSL•Cablemodem•Wi-max-wirelesswidearea•Fiber-fast–expensivetoinstalltohome•PowerlinemodemComputerinternetaccess•Modem–Digital/Analog,Analog/Digital–Earlymodemssimple•300bits/sec,2frequencies(FSK)•Complexsignaling,errorcorrecting,compressionincreasedspeedto33kbit/sec,56kbitsfromdigitaloffice–Closetophysicallimitofshannon’stheorem•C=B*log2(1+S/N),fortelephone•B=3000,S/N=1000ISDN•Integratedservicesdigitalnetwork–Designedtointegratevoiceanddata–Basicrate2B+D–Maxdatarateis128bit/sec–Fasterthanmodem–Initiallysomepopularity–NownotaspopularasasdlADSL•Asymmetricdigitalsubscriberline–Usesnonvoicefrequencies–Asymmetricbecausesendrateislowerratethanreceiverate–Usuallyupto4kmfromtelephoneoffice–Telephonelineismeasuredtose