Multiplexing techniques allow multiple signals to be transmitted simultaneously over a single transmission medium by combining or dividing the signals in some manner. This document discusses various multiplexing techniques including FDM, TDM, WDM, and statistical TDM. It provides examples and diagrams to illustrate how each technique works. The document also covers topics like digital carrier systems, framing, interleaving, and different types of transmission media like twisted pair, coaxial cable, and optical fiber.

1. MULTIPLEXING DAN MEDIA TRANSMISI
Anhar, MT

2. OUTLINE
Pengantar
 FDM
 TDM
 WDM

Anhar : Komunikasi Data
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3. TIU

Dpt menjelaskan proses multiplexing analog dan
digital serta pengembangan teknologinya
Anhar : Komunikasi Data
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4. PENGANTAR

Mengapa multiplexing???
Keterbatasan bandwidth
 Melahirkan teknik efisiensi kanal

Anhar : Komunikasi Data

Apa multiplexing
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5. JENIS MULTIPLEXING
Anhar : Komunikasi Data
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6. FDM




Anhar : Komunikasi Data

Useful bandwidth of medium exceeds required bandwidth of
channel
Each signal is modulated to a different carrier frequency
Carrier frequencies separated so signals do not overlap (guard
bands)
e.g. broadcast radio
Channel allocated even if no data
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7. DIAGRAM FDM
Anhar : Komunikasi Data
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8. FDM PROSES
Anhar : Komunikasi Data
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9. FDM OF THREE VOICE BAND SIGNALS
Anhar : Komunikasi Data
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10. CONTOH 1
Asumsikan bhw sebuah channel suara menduduki bandwidth 4 KHz.
Kita perlu utk menggabungkan tiga channels suara kedlm sebuah
link dng bandwidth 12 KHz, dr 20 hingga 32 KHz. Tunjukkan
susunannya dng menggunakan FDM tanpa menggunakan guard
bands.

Modulasikan masing2 tiga channels suara utk bandwidth
yg berbeda-beda, spt pd slide berikut.
Anhar : Komunikasi Data

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11. PENYELESAIAN :
Anhar : Komunikasi Data
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12. SISTEM MULTIPLEXING ANALOG
AT&T (USA)
 Hierarchy of FDM schemes
 Group


Supergroup
Anhar : Komunikasi Data
12 voice channels (4kHz each) = 48kHz
 Range 60kHz to 108kHz

60 channel
 FDM of 5 group signals on carriers between 420kHz
and 612 kHz


Mastergroup

10 supergroups
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13. SISTEM MULTIPLEXING ANALOG
Anhar : Komunikasi Data
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14. SYNCRONOUS TDM
Data rate of medium exceeds data rate of digital
signal to be transmitted
 Multiple digital signals interleaved in time
 May be at bit level of blocks
 Time slots preassigned to sources and fixed
 Time slots allocated even if no data
 Time slots do not have to be evenly distributed
amongst sources

Anhar : Komunikasi Data
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15. Anhar : Komunikasi Data
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16. Time Slots dan Frames
Anhar : Komunikasi Data
Masing2 terminal/host memberikan “sebagian” dr time (time
slot)
Dlm TDM, sebuah frame terdiri dr satu siklus lengkap dr time
slots, dimana satu slot didedikasikan ke masing2 pengirim.
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17. SISTEM TDM
Anhar : Komunikasi Data
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18. TDM FRAMES

Pure TDM: mux-to-mux speed = penjumlahan terminal speeds

No loss of data (similar to voice call multiplexing)
28/11/2013
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19. TDM LINK CONTROL
No headers and tailers
 Data link control protocols not needed
 Flow control

Data rate of multiplexed line is fixed
 If one channel receiver can not receive data, the others
must carry on
 The corresponding source must be quenched
 This leaves empty slots


Error control

Errors are detected and handled by individual channel
systems

20. DATA LINK CONTROL ON TDM

21. FRAMING
No flag or SYNC characters bracketing TDM
frames
 Must provide synchronizing mechanism
 Added digit framing


One control bit added to each TDM frame

Looks like another channel - “control channel”
Identifiable bit pattern used on control channel
 e.g. alternating 01010101…unlikely on a data channel
 Can compare incoming bit patterns on each channel
with sync pattern


22. PULSE STUFFING
Problem - Synchronizing data sources
 Clocks in different sources drifting
 Data rates from different sources not related by
simple rational number
 Solution - Pulse Stuffing




Outgoing data rate (excluding framing bits) higher than
sum of incoming rates
Stuff extra dummy bits or pulses into each incoming
signal until it matches local clock
Stuffed pulses inserted at fixed locations in frame and
removed at demultiplexer

23. TDM OF ANALOG AND DIGITAL SOURCES

24. DIGITAL CARRIER SYSTEMS
Hierarchy of TDM
 USA/Canada/Japan use one system
 ITU-T use a similar (but different) system
 US system based on DS-1 format
 Multiplexes 24 channels
 Each frame has 8 bits per channel plus one framing
bit
 193 bits per frame


25. DIGITAL CARRIER SYSTEMS (2)

For voice each channel contains one word of
digitized data (PCM, 8000 samples per sec)
Data rate 8000x193 = 1.544Mbps
 Five out of six frames have 8 bit PCM samples
 Sixth frame is 7 bit PCM word plus signaling bit
 Signaling bits form stream for each channel containing
control and routing info


Same format for digital data

23 channels of data


7 bits per frame plus indicator bit for data or systems control
24th channel is sync

26. DCS

Hirarki sinyal digital utk layanan telepon yg
menggunakan multiplexing digital..
Anhar : Komunikasi Data
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27. T LINES

DS : nama layanannya sementara T : nama saluran
yg dipakai utk layanan tsb
Anhar : Komunikasi Data
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28. T-1 FRAME
Anhar : Komunikasi Data
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29. E LINES
Anhar : Komunikasi Data
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30. contoh 1
Anhar, ST, MT.
Penyelesaian
28/11/2013
Empat koneksi 1-Kbps dimultiplexing bersama-sama.
Satu unitnya 1 bit. Tentukan (1) durasi 1 bit sebelum
dimultiplexing, (2) transmission rate dr link, (3) durasi dr
time slot, and (4) durasi dr frame?
Kita dpt menjawabnya :
1. durasi 1 bit adlh 1/1 Kbps, atau 0.001 s (1 ms).
2. rate link adlh 4 Kbps.
3. duratsi dr tiap time slot 1/4 ms atau 250 ms.
4. durasi dr sebuah frame 1 ms.
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31. PENYELESAIAN SECARA RINCI :
Anhar, ST, MT.
1bit
1bit

4000bps 4000bit / sec ond
 0.25ms / bit  250ms / bit
BitDurationlink 
28/11/2013
DataRatelink  4 1kbps  4kbps  4000bps
TimeSlotDurationlink  BitDuration  UnitSize
 250ms / bit 1bit / TimeSlot  250ms / TimeSlot
FrameDuration
 TimeSlotDuration  ChannelNumber
 250ms / TimeSlot * 4TimeSlot / Frame
 1ms / Frame
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32. INTERLEAVING


Multiplexer/Demultiplexer memproses terminal/host’s unit saling
berkebalikan
Character (byte) Interleaving


Multiplexing membentuk satu/lebih karakter(s) or byte(s) pd sebuah waktu
(one byte per unit)
Bit Interleaving

Multiplexing membentuk one bit pd satu waktu (one bit per unit)
28/11/2013
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33. Contoh 2
28/11/2013
Anhar, ST, MT.
Empat kanal dimultiplex menggunakan TDM. Bila
masing2 kanal mengirimkan100 bytes/s dan kita
memultiplex 1 byte per kanal, tunjukkan perambatan
frame pd link, ukuran dr frame, durasi dr
frame, kecepatan frame, dan bit rate dr link.
Penyelesaian
33

34. PENYELESAIAN RINCI
 4byte / frame  32bit / frame
 400  bytes / sec ond  3200bps
Anhar, ST, MT.
DataRatelink  4 100bytes / sec ond
28/11/2013
FrameSize  ChannelNumber  UnitSize
 4timeslot / frame1byte / timeslot
FrameRatelink  DataRate/ FrameSize
3200bit / sec ond
 100 frame / sec ond
32bit / frame
1
FrameDuration 
FrameRate
 10ms / frame

34

35. Contoh 3
28/11/2013
Sebuah multiplexer menggabungkan empat 100-Kbps
kannels menggunakan sebuah time slot dr 2 bits.
Tunjukkan output dng empat input sembarang. Berapakah
frame ratenya? Berapakah durasi frame? Berapa bit rate?
Berapa bit duration?
Anhar, ST, MT.
Solution
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36. PENYELE
RINCI
 4timeslot / frame 2bit / timeslot  8bit / frame
DataRatelink  4 100kbps  400kbps
1
1

sec ond / bit
BitRate 400k
FrameRatelink  DataRate/ FrameSize
Anhar, ST, MT.
BitDurationlink 
28/11/2013
SAIAN
FrameSize  ChannelNumber  UnitSize
400kbit / sec ond
 50kframe/ sec ond
8bit / frame
 50,000 frame / sec ond

FrameDuration 

1
FrameRate
1
 20ms / frame
50,000 frame / sec ond
36

37. SINKRONISASI


Satu /lebih Framing bit (s) ditambahkan ke masing2 frame utk
singkronisasi antara multiplexer dan demultiplxer
Bila framing bit per frame, framing bits berubah-ubah antara 0 dan 1
28/11/2013
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38. Contoh 4
28/11/2013
Anhar, ST, MT.
Kita memiliki 4 sumber, masing2 membangkitkan 250
karakter per second. Bila interleaved unit adlh sebuah
karakter dan 1 singkronisasi bit is ditambahkan ke
masing2 frame, tentukan (1) data rate dr masing2 sumber,
(2) durasi dr masing2 karakter dlm masing2 sumber, (3)
frame rate, (4) durasi dr masing2 frame, (5) jumlah bits
pd masing2 frame, dan (6) data rate dr link.
Penyelesaian
Lihat slide berikutnya
38

39. Penyelesaian
28/11/2013
Kita dpt menjawab pertanyaan tsb sbb berikut :
Anhar, ST, MT.
1. Data rate dr masing2 sumber adlh 2000 bps = 2 Kbps.
2. Durasi dr sebuah karakter adlh 1/250 s, or 4 ms.
3. Link diperlukan utk mengirim 250 frames per second.
4. Durasi dr masing2 frame adlh 1/250 s, or 4 ms.
5. Masing2 frame adlh 4 x 8 + 1 = 33 bits.
6. Data rate dr link adlh 250 x 33, or 8250 bps.
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40.  4timeslot / frame1character / timeslot  1bit / frame
 33bits / frame
FrameRate  250 frame / sec ond
Anhar, ST, MT.
SAIAN
FrameSize  ChannelNumber  UnitSize  Fra min gBits
28/11/2013
PENYELE
DataRate  FrameRate FrameSize
 250 frame / sec ond  33bits / frame
 8250bit / sec ond
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41. Contoh 5
Anhar, ST, MT.
Penyelesaian
28/11/2013
Dua kannels, satu dng bit rate 100 Kbps dan yg lain dng
bit rate 200 Kbps, dimultiplex. Bagaimana hal ini dpt
dilakukan? Berapakah frame rate? Berapa frame
duration? Berapa bit rate dr link?
Kita dpt mengalokasikan satu slot utk channel pertama
dan dua slot utk channel kedua. Masing2 frame
membawa 3 bits. Frame ratenya adlh 100,000 frames per
second krn ia membawa 1 bit dr channel pertama. Frame
duration nya adlh 1/100,000 s, atau 10 us. Bit rate adlh
41
100,000 frames/s x 3 bits/frame, atau 300 Kbps.

42. PENYELESAIAN
RINCI
DataRatelink  100kbps  200kbps  300kbps
 3bit / frame
300kbit / sec ond
 100kframe/ sec ond
3bit / frame
 100,000 frame / sec ond

FrameDuration 

Anhar, ST, MT.
FrameRatelink  DataRate / FrameSize
28/11/2013
FrameSize  UnitSize1  UnitSize2
1
FrameRate
1
 10ms / frame
100,000 frame / sec ond
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43. WDM
WDM dirancang utk membawa data dng kec
tinggi...
 Secara prinsip sama dng FDM...
 Hanya menggunakan perbedaan panjang gel..

Anhar : Komunikasi Data
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44. STATISTICAL TDM
Anhar : Komunikasi Data
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45. MEDIA TRANSMISI - OVERVIEW
Guided - wire
 Unguided - wireless
 Characteristics and quality determined by medium
and signal
 For guided, the medium is more important
 For unguided, the bandwidth produced by the
antenna is more important
 Key concerns are data rate and distance


46. DESIGN FACTORS

Bandwidth


Higher bandwidth gives higher data rate
Transmission impairments

Attenuation
Interference
 Number of receivers

In guided media
 More receivers (multi-point) introduce more attenuation


47. ELECTROMAGNETIC SPECTRUM

48. GUIDED TRANSMISSION MEDIA
Twisted Pair
 Coaxial cable
 Optical fiber


49. TWISTED PAIR

50. TWISTED PAIR - APPLICATIONS
Most common medium
 Telephone network



Within buildings


Between house and local exchange (subscriber loop)
To private branch exchange (PBX)
For local area networks (LAN)

10Mbps or 100Mbps

51. TWISTED PAIR - PROS AND CONS
Cheap
 Easy to work with
 Low data rate
 Short range


52. TWISTED PAIR - TRANSMISSION
CHARACTERISTICS

Analog


Amplifiers every 5km to 6km
Digital
Use either analog or digital signals
 repeater every 2km or 3km

Limited distance
 Limited bandwidth (1MHz)
 Limited data rate (100MHz)
 Susceptible to interference and noise


53. UNSHIELDED AND SHIELDED TP

Unshielded Twisted Pair (UTP)
Ordinary telephone wire
 Cheapest
 Easiest to install
 Suffers from external EM interference


Shielded Twisted Pair (STP)
Metal braid or sheathing that reduces interference
 More expensive
 Harder to handle (thick, heavy)


54. UTP CATEGORIES

Cat 3
up to 16MHz
 Voice grade found in most offices
 Twist length of 7.5 cm to 10 cm


Cat 4


up to 20 MHz
Cat 5
up to 100MHz
 Commonly pre-installed in new office buildings
 Twist length 0.6 cm to 0.85 cm


55. NEAR END CROSSTALK
Coupling of signal from one pair to another
 Coupling takes place when transmit signal entering
the link couples back to receiving pair
 i.e. near transmitted signal is picked up by near
receiving pair


56. COAXIAL CABLE

57. COAXIAL CABLE APPLICATIONS
Most versatile medium
 Television distribution

Ariel to TV
 Cable TV


Long distance telephone transmission


Can carry 10,000 voice calls simultaneously
Being replaced by fiber optic
Short distance computer systems links
 Local area networks


58. COAXIAL CABLE - TRANSMISSION
CHARACTERISTICS

Analog
Amplifiers every few km
 Closer if higher frequency
 Up to 500MHz


Digital
Repeater every 1km
 Closer for higher data rates


59. OPTICAL FIBER

60. OPTICAL FIBER - BENEFITS

Greater capacity

Data rates of hundreds of Gbps
Smaller size & weight
 Lower attenuation
 Electromagnetic isolation
 Greater repeater spacing


10s of km at least

61. OPTICAL FIBER - APPLICATIONS
Long-haul trunks
 Metropolitan trunks
 Rural exchange trunks
 Subscriber loops
 LANs


62. OPTICAL FIBER - TRANSMISSION
CHARACTERISTICS

Act as wave guide for 1014 to 1015 Hz


Portions of infrared and visible spectrum
Light Emitting Diode (LED)
Cheaper
 Wider operating temp range
 Last longer


Injection Laser Diode (ILD)
More efficient
 Greater data rate


Wavelength Division Multiplexing

63. OPTICAL FIBER TRANSMISSION MODES

64. WIRELESS TRANSMISSION
Unguided media
 Transmission and reception via antenna
 Directional

Focused beam
 Careful alignment required


Omnidirectional
Signal spreads in all directions
 Can be received by many antennae


65. FREQUENCIES

2GHz to 40GHz
Microwave
 Highly directional
 Point to point
 Satellite


30MHz to 1GHz
Omnidirectional
 Broadcast radio


3 x 1011 to 2 x 1014


Infrared
Local

66. TERRESTRIAL MICROWAVE
Parabolic dish
 Focused beam
 Line of sight
 Long haul telecommunications
 Higher frequencies give higher data rates


67. SATELLITE MICROWAVE
Satellite is relay station
 Satellite receives on one frequency, amplifies or
repeats signal and transmits on another frequency
 Requires geo-stationary orbit


Height of 35,784km
Television
 Long distance telephone
 Private business networks


68. BROADCAST RADIO
Omnidirectional
 FM radio
 UHF and VHF television
 Line of sight
 Suffers from multipath interference


Reflections

69. INFRARED
Modulate noncoherent infrared light
 Line of sight (or reflection)
 Blocked by walls
 e.g. TV remote control, IRD port


70. REQUIRED READING
Stallings Chapter 4
 Komunikasi data by Dony
