1 / 41

Chapter 3 Data Transmission

Chapter 3 Data Transmission. KONSEP DAN TERMINOLOGI. TERMINOLOGI TRANSMISI. Transmitter Receiver Medium Guided medium  kabel Contoh , kabel koaksial , twisted pair , serat optik Unguided medium  nirkabel Contoh , udara , ruang hampa udara dan air. Con’t. Direct link

gotzon
Download Presentation

Chapter 3 Data Transmission

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 3Data Transmission

  2. KONSEP DAN TERMINOLOGI

  3. TERMINOLOGI TRANSMISI • Transmitter • Receiver • Medium • Guided medium  kabel • Contoh, kabelkoaksial, twisted pair, seratoptik • Unguided medium  nirkabel • Contoh, udara, ruanghampaudaradan air

  4. Con’t • Direct link • Tidakadaalatperantara / langsung • Point-to-point • Direct link • Hanya 2 device yang berbagi link • Multi-point • Lebihdaridua device yang berbagi link

  5. Con’t • Simplex • Sinyalditransmisikansatuarah Televisi • Half duplex • Sinyalditransmisikanduaarah, tapihanyasatutransmisispadasatuwaktu, contoh police radio • Full duplex • Sinyalditransmisikanduaarah, dandapatdilakukanpadasatuwaktusecarabersamaan, contoh telephone

  6. Frequency, Spectrum and Bandwidth • Transmisi pengirimansinyal • Sinyal fungsiwaktu / frekwensi • Konsep domain waktu • Sinyal Analog • Tidakadasinyal yang terputus. • percakapan • Sinyal Digital • Mempertahankan level konstanpadabeberapawaktu, danberubahke level konstanlainnya. • Biner 1 dan 0 • SinyalPeriodik • Polasinyal yang samaberulangsepanjangwaktu • SinyalAperiodic • Polasinyaltidakberulangspeanjangwaktu

  7. Analogue & Digital Signals

  8. PeriodicSignals

  9. Gelombang Sinus Tiga Parameter • Peak Amplitude (A)  amplitudotertinggi • maximum strength of signal • volts • Frequency (f) • Rate of change of signal • Hertz (Hz) or cycles per second • Period = time for one repetition (T) • T = 1/f • Phase () • Relative position in time

  10. Varying Sine Wavess(t) = A sin(2ft +)

  11. Wavelength • Jaraksatusiklustunggal • Jarakantaraduatitikdarifase yang bersesuaiandariduaputaran yang berurutan. • Simbol  • Diasumsikan, sinyalbergerakdengankecepatanv, makahubunganpajanggelombangdenganperiodeadalah: •  = vT • f = v • Untukkasus v =c, makakecepatancahayadalamruangbebas= 3*108 ms-1

  12. Frequency Domain Concepts • Sinyaldibentukdaribanyakfrekuensi • Komponennyaadalahgelombang sinus

  13. Addition of FrequencyComponents(T=1/f) Gel. Sinus, frekuensi f Gel. Sinus, frekuensi 3f Gabungan a dan b

  14. Spectrum & Bandwidth • Spectrum • Rentangfrekuensidimanaspektrumberada • Absolute bandwidth • Lebar spectrum • Effective bandwidth • bandwidth • DC Component • Komponenfrekeunsinol = arud DC

  15. Signal with DC Component

  16. Analog and Digital Data Transmission • Data • Entitas yang menyampaikaninformasi • Signals • Representase data electric atau electromagnetic • Transmission • Komunikasi data melaluiperambatandanpemrosesansinyal

  17. Analog and Digital Data • Analog • Menerimanilai yang kontiyupadabeberapa interval • Contoh, suara, video, suhu, tekanan. • Digital • Menerimanilaidiskrit • Contohteks, bilanganbulat, dll

  18. Data analog • Contoh AUDIO

  19. Analog and Digital Signals • Dalamkomunikasi, data disebarkan • Analog • Gelombangelektromagnetik yang selalubervariasi • media • wire, fiber optic, space • Speech bandwidth 100Hz to 7kHz • Telephone bandwidth 300Hz to 3400Hz • Video bandwidth 4MHz • Digital • Use two DC components • Bit 0 & bit 1

  20. Advantages & Disadvantages of Digital • Lebihmurah • Tidakrentandengan noise • Memilikiatenuasilebihbesar • Kekurangandarikekuatansinyal atenuasi • Pulsamembulatdanmenjadilebihkecil • Menyebabkankehilanganinformasi

  21. Attenuation of Digital Signals

  22. Components of Speech • Frequency range (of hearing) 20Hz-20kHz • Speech 100Hz-7kHz • Lebihmudahdikonversimenjadisinyal electromagnetic untuktransmisi • Frekuensisuaradenganberagam volume dikonversimenjadifrekuensi electromagnetic denganberagamteganganlistrik • Batas rata-rata frekuensiuntuk voice channel • 300-3400Hz

  23. Conversion of Voice Input into Analog Signal

  24. Video Components • USA - 483 lines scanned per frame at 30 frames per second • 525 lines but 42 lost during vertical retrace • So 525 lines x 30 scans = 15750 lines per second • 63.5s per line • 11s for retrace, so 52.5 s per video line • Max frequency if line alternates black and white • Horizontal resolution is about 450 lines giving 225 cycles of wave in 52.5 s • Max frequency of 4.2MHz

  25. Binary Digital Data • Dari terminal komputer, dll • Two dc components  bit 0 dan 1 • Bandwidth depends on data rate

  26. Conversion of PC Input to Digital Signal

  27. Data and Signals • Penggunaansinyal digital untuk data dgitaldansinyal analog untuk data adanalog • Menggunakansinyal analog untukmembawa data digital Modem • Menggunakansinyal digital untukmembawa data analogcompact disc audio

  28. Analog Signals Carrying Analog and Digital Data

  29. Digital Signals Carrying Analog and Digital Data

  30. Analog Transmission • Sinyal analog ditransmisikantanpamempedulikanisinya • Isi ==. Data analog atau data digital • Sinyal analog akanlemahpadajaraktertentu • Digunakan amplifiers untukmenaikkan signal • Dengan amplifier  noise meningkat

  31. Digital Transmission • Isi biner • TransmisiJarakterbatas • Jarakjauh Repeater • Repeater menerimasinyal digital, mempeerolehkembalipola 0 dan 1 danmentransmisikankembalisinyalbaru.

  32. Advantages of Digital Transmission • Digital technology • Low cost LSI (large scale integration)/VLSI technology • Data integrity • Transmisijarakjauh kualitaslebihrendah  repeater bukan amplifier • Capacity utilization • Lebihekonomis bandwith yang tinggi • High degree of multiplexing easier with digital techniques • Security & Privacy • Encryption • Integration • Can treat analog and digital data similarly

  33. Gangguantransmisi • Sinyalditerimaberbedadengansinyal yang dikirim • Analog  menurunkankualitassinyal • Digital - bit errors • Disebbkanoleh • Attenuation and attenuation distortion • Delay distortion • Noise

  34. Attenuation • Kekuatansinyalberkurang jarakjauh • Attenuation  pertimbanganuntuk transmission engineer. • Sinyal yang diterimaharuscukupkuatsehinggasirkuitelektronikdapatmendeteksisinyaltersebut • Sinyalharusdijagapada level yang cukuptinggidibandingkan noise sehinggadapatditerimatanpa error • Atenuasibervariasisesuaidenganfrekuensi • Solusi repeater  digital amplifier  analog

  35. Delay Distortion • attenuation bervariasisepertifungsidarifrekuensi • Sinyal yang diterimamengalamidistorsi /menyimpanh • Solusi • Menyamakan attenuation melintasi band frequencies. • Umum voice-grade telephone lines menggunakan coils yang menggantipropertielekrtikaldari line • amplifiers  frekuensilebihtinggidibandinkanfrekuensiterendah

  36. Noise (1) • Additional signals inserted between transmitter and receiver • Thermal • Pergelokanthermal dari electrons • Uniformly distributed • White noise • Intermodulation • Sinyal-sinyal yang bertambahdanberbedadarifrekuensiasli Signals that are the sum and difference of original frequencies sharing a medium

  37. Noise (2) • Crosstalk • A signal from one line is picked up by another • Impulse • Irregular pulses • e.g. External electromagnetic interference • Short duration • High amplitude

  38. Channel Capacity • Data rate • In bits per second • Rate at which data can be communicated • Bandwidth • In cycles per second of Hertz • Constrained by transmitter and medium

  39. Nyquist Bandwidth • If rate of signal transmission is 2B then signal with frequencies no greater than B is sufficient to carry signal rate • Given bandwidth B, highest signal rate is 2B • Given binary signal, data rate supported by B Hz is 2B bps • Can be increased by using M signal levels • C= 2B log2M

  40. Shannon Capacity Formula • Consider data rate,noise and error rate • Faster data rate shortens each bit so burst of noise affects more bits • At given noise level, high data rate means higher error rate • Signal to noise ration (in decibels) • SNRdb=10 log10 (signal/noise) • Capacity C=B log2(1+SNR) • This is error free capacity

  41. Required Reading • Stallings chapter 3

More Related