Data Transmission, Transmission Media and Data EncodingSlide 2Analog vs DigitalFrequency, Period, and PhaseTime Domain vs Frequency DomainData Rate vs BandwidthData vs SignalAttenuation and Dispersion (Delay Distortion)DecibelsChannel CapacityShannon's TheoremTransmission MediaTwisted PairCoaxial CableOptical FiberCoding TerminologyCoding DesignSummaryHomeworkRaj JainThe Ohio State University3-1Data Transmission, Data Transmission, Transmission Media and Transmission Media and Data EncodingData EncodingRaj JainProfessor of CIS The Ohio State UniversityColumbus, OH [email protected]://www.cse.ohio-state.edu/~jain/CIS677-98/Raj JainThe Ohio State University3-2Time Domain and Frequency DomainDecibels Data vs SignalAttenuation, Delay Distortion, Noise, CapacityPhysical Media: Twisted pair, coaxial cable, optical fiberBit, Hertz, and BaudCoding Design: Terminology + ConsiderationsOverviewRaj JainThe Ohio State University3-3Analog vs DigitalAnalog vs DigitalFig 2.2Amplitude (volts)(a) ContinuousTimeAmplitude(b) DiscreteTimeRaj JainThe Ohio State University3-4Frequency, Period, and PhaseFrequency, Period, and PhaseA Sin(2 p ft+ )Fig 2.3a+2.4Raj JainThe Ohio State University3-5Time Domain vs Frequency DomainTime Domain vs Frequency DomainFig 2.5+2.6a1.00.50.0Ñ1.0Ñ0.51.00.50.0Ñ1.0Ñ0.51.00.50.0Ñ1.0Ñ0.52.0T0.0 0.5 1.0 1.5(a) sin (2p f1t )2.0T0.0 0.5 1.0 1.5(b) 1/3 sin (2p (3 f1) t )2.0T0.0 0.5 1.0 1.5(c) sin (2p f1t ) + 1/3 sin (2 p (3 f1) t )(f)1.41.21.00.80.60.40.20.0S4f13210(a) s(t) = sin (2pf1t) + 1/3 sin (3(2pf1t))Raj JainThe Ohio State University3-6Data Rate vs BandwidthData Rate vs Bandwidth1.00.50.0Ñ0.5Ñ1.00.0 0.5 1.0(a) sin (2p f1t ) + 1/3 sin (2 p (3 f1) t ) + 1/5 sin (2 p (5 f1) t )1.5 2.0 T1.00.50.0Ñ0.5Ñ1.00.0 0.5 1.0(b) sin (2p f1t ) + 1/3 sin (2 p (3 f1) t ) + 1/5 sin (2 p (5 f1) t ) + 1/7 sin (2 p (7 f1) t )1.5 2.0 T1.00.50.0Ñ0.5Ñ1.00.0 0.5 1.0(c) 1/k sin (2 p f1t )1.5 2.0 TFig 2.8Raj JainThe Ohio State University3-7Data vs SignalData vs SignalTelephoneModemCODECDigital TransmitterAnalogDigitalDataSignalAnalogDigitalAnalogAnalogDigitalDigitalData SignalMediumDataRaj JainThe Ohio State University3-8Attenuation Attenuation and Dispersion (Delay Distortion)and Dispersion (Delay Distortion)D i s t a n c eRaj JainThe Ohio State University3-9DecibelsDecibelsAttenuation = Log10 PinPoutExample 1: Pin = 10 mW, Pout=5 mWAttenuation = 10 log 10 (10/5) = 10 log 10 2 = 3 dBExample 2: Pin = 100mW, Pout=1 mWAttenuation = 10 log 10 (100/1) = 10 log 10 100 = 20 dBBelPinPoutdecibelAttenuation = 10 Log10 VinVoutdecibelAttenuation = 20 Log10Raj JainThe Ohio State University3-10Channel CapacityChannel CapacityCapacity = Maximum data rate for a channelNyquist Theorem: Bandwidth = WData rate < 2 WBilevel Encoding: Data rate = 2  Bandwidth05VMultilevel Encoding: Data rate = 2  Bandwidth  log 2 MExample: M=4, Capacity = 4  BandwidthRaj JainThe Ohio State University3-11Shannon's TheoremShannon's TheoremBandwidth = H HzSignal-to-noise ratio = S/N Maximum number of bits/sec = H log2 (1+S/N)Example: Phone wire bandwidth = 3100 HzS/N = 30 dB 10 Log 10 S/N = 30Log 10 S/N = 3S/N = 103 = 1000Capacity = 3100 log 2 (1+1000)= 30,894 bpsRaj JainThe Ohio State University3-12Transmission MediaTransmission MediaTwisted paircoaxial cableOptical FiberTerestrial MicrowaveSatellite MicrowaveRadioRaj JainThe Ohio State University3-13Twisted PairTwisted Pair Unshielded Twisted Pair (UTP)Voice Grade: Telephone wireData Grade: Better quality100 Mbps over 50 m possibleShielded Twisted Pair (STP)Raj JainThe Ohio State University3-14Coaxial CableCoaxial CableFig 2.20Raj JainThe Ohio State University3-15Optical FiberOptical FiberModesIndex=Index of referection=Speed in Vacuum/Speed in mediumMultimodeSingle ModeCladdingCoreCoreCoreCladdingCladdingRaj JainThe Ohio State University3-16Coding TerminologyCoding TerminologySignal element: PulseModulation Rate: 1/Duration of the smallest element=Baud rateData Rate: Bits per secondData Rate = Fn(Bandwidth, signal/noise ratio, encoding)PulseBit+5V0-5V+5V0-5VRaj JainThe Ohio State University3-17Coding DesignCoding DesignPulse width indeterminate: ClockingDC, Baseline wanderNo line state informationNo error detection/protectionNo control signalsHigh bandwidthPolarity mix-up  Differential (compare polarity)0 1 0 0 0 1 1 1 0 0 0 0 0ManchesterNRZIClockNRZBits+5V0-5VRaj JainThe Ohio State University3-18SummarySummaryTime domain vs frequency domainData rate vs BandwidthData vs Signal, Analog vs DigitalAttenuation, Dispersion (delay distortion)Media: Twisted pair, coaxial, fiberCoding: Higher data rate, error control, clock syncronization,NRZ, NRZI, Manchester, MultilevelRaj JainThe Ohio State University3-19HomeworkHomeworkRead Sections 2.3, 2B (appendix), 3.1, 4.1 of