S?

1
S?µata

• ??a?????? - ??f?a??
• ?e???d??? (S?µata ?s????)
• ?pe???d??? (S?µata ?????e?a?)

2
??a?????? S?µata

• ???t??
• ?e???d??
• S????t?ta
• F?s?
• ?????s? st? ped?? t?? ??????
• ?????s? st? ped?? t?? s????t?ta?
• ?????s? Fourier ????? ????? F?sµa s????t?t??

3
?????s? Fourier
4
?? s??te?est??
5
??f?a?? S?µata

• Bit Interval (a?t? ??a pe???d?)
• Bit rate se bps ? b/s
• ?????s? se ?pe??? a???µ? ?µ?t???e?d??
  s??a?t?se??. ??µ?????? F?sµata

6
????? ????? ?????, p???a?e?

• ?p??e?a ??µ??????
• ?p??e?a ?????e?a?
• ?p??e?a ?????f???a?

7
??d???p??s? ?a? ??aµ??f?s?

• ?etat??p??
• ??f?a?? p??? ??f?a?? D/D
• ??a?????? p??? ??f?a?? A/D
• ??f?a?? p??? ??a?????? D/A
• ??a?????? p??? ??a?????? ?/?

8
??f?a?? p??? ??f?a?? D/D

• ??d???p???s? ???pe? ?a pa???e? ?a? s???????sµ?
• ?? s?s?e??? p?? p?a?µat?p????? ?????ta?
  ??d???p???t?? - ap?-. Coders-decoders.
• Unipolar. ?? p?? ap???, ???s?µ?p????? d?? st??µe?
  t? 0 ?a? t? 1.
• NRZ Non Return to Zero
• RZ Return to Zero
• Biphase Manchester Differential Manchester

9
??f?a?? p??? ??f?a?? D/D

• Bipolar ???s?µ?p??e? t?e?? st??µe? ?p?? ? RZ,
  ?et???, a???t??? ?a? µ?d??
• Alternative Mark Inversion AMI
• Bipolar 8 Zero Substitution B8ZS
• High Density Bipolar 3 HDB3

10
??a?????? p??? ??f?a?? ?/D

• S?s?e??? Codec. ??ad??as?e?
• Pulse Amplitude Modulation PAM
• Pulse Code Modulation PCM
• Sampling Rate ?e??µat?????a
• Te???µa t?? Nyquist ? s????t?ta de??µat?????a?
  p??pe? ?a e??a? t??????st?? d?p??s?a t?? µe??st??
  s????t?ta? t?? s?µat??

11
?a??de??µa

• ???ß??µa T????µe ?a ??f??p???s??µe t? s?µa t??
  a????p???? f????
• ? f??? pe????e? s????t?te? ap? 0 µ???? 4000 Hz
• ? de??µat?????a s?µf??a µe t? ?e???µa t?? Nyquist
  p??pe? ?a e??a? 2?4000 8000 samples/second
• ?? ???s?µ?p???s??µe ??a? ??t?µp?t? (8 bits)
  a?a?????? p??? ??f?a?? µetat??p?a d??ad? 8
  bits/sample, t?te t? bit rate p?? ?a ????µe
  e??a?
• Bit rate Sampling rate X Number of bits/sample
• 8000 X 8 64.000 bits/s 64Kbps

12
??f??p???s? ??a??????? S?µat??
13
??f?a?? p??? ??a?????? D/A

• D/A Modulators
• Bit rate (bits/second)
• Baud rate ???a? ? a???µ?? t?? sta?µ?? s?µat??
  a?? de?te???ept?. ?? Baud rate e??a? µ????te?? ?
  ?s? ap? t? bit rate.
• ?a??de??µa ?? bit rate e??? s?µat?? e??a? 3000.
  ???e st??µ? s?µat?? pe????e? 6 bits. ??s? e??a?
  t? Baud rate
• ?p??t?s? 3000 (bits/s)/6 bits 500 Bauds/s.

14
??aµ??f?s? t?? f????t?? (Carrier) ap? ??f?a?? s?µa

• Amplitude Shift Keying ASK
• Frequency Shift Keying FSK
• Phase Shift Keying PSK
• Quadrature Amplitude Modulation QAM ?????s?a
  ??aµ??f?s? ?????? (a combination
  of ASK and PSK)

15
??d???p???s? ?a? ??aµ??f?s? d?? ?a?a?t????
16
??a?????? p??? A?a?????? ?/? ??aµ??f?s?

• A/A Modulators
• ??aµ??f?s? ???t???, S????t?ta?, F?s??
• ??aµ??f?s? ???t??? Amplitude Modulation AM
• ?ad??f?????? sta?µ?? st?? µp??ta t?? 530-1700
  KHz. ???e sta?µ?? ???e? e???? ????? t??????st??
  d?p??s?? ap? t? e???? ????? t?? ?p? d?aµ??f?s?
  s?µat??. ?ts? ??a ?a µetad?se? f??? ?a? µ??s???
  e????? 5 kH, ??e???eta? ?a ??e? d?a??s?µ? e????
  ????? 10kH.

17
??a?????? p??? a?a?????? ?/? ??aµ??f?s?

• ??aµ??f?s? S????t?t?? Frequency Modulation FM
• ?? apa?t??µe?? e???? ????? ??a ta FM e??a?
  de?ap??s?? ap? t? e???? ????? t?? ?p? d?aµ??f?s?
  s?µat??. ?ts? ??a t?? µet?d?s? e??? s?µat??
  stereo 15 kH, ?a apa?t??e? e???? ????? 150 kH ?a?
  ??a asf??e?a 200 kH (0,2?H)
• ??aµ??f?s? F?s?? Phase Modulation PM
• ?pa?te?ta? ap???ste?? hardware ?a? ? a????s? t??
  d?aµ??f?µ???? s?µat?? d??e? ap?te??sµata pa??µ??a
  µe a?t? t?? d?aµ??f?s?? FM

18
??f?a?? ?p????????a. Interfaces Modems

• ?? ???a????? e?d?af????ta? ??a t? bit rate t??
  ?a?a????. T? 1944 ? Claude Shannon d?at?p?se ??a?
  t?p? p?? µa? d??e? t?? ?????te?? ta??t?ta e???
  ?a?a????
• C Blog2(1S/N)
• ?p?? ? e??a? t? e???? ?????, S/N ?
  s?µat?????ß???? ?????, ?a? C ? ????t???t?ta
  (Shannon capacity) se bps.
• ?a??de??µa ?a ?p?????s?e? ? µ???st? ta??t?ta t??
  t??ef?????? ??aµµ??.
• ?? e???? ????? t?? t??. ??aµµ?? e??a? 3000 Hz
  (300-3300Hz). ?? S/N s?????? 35 dB ? 3162.
  ?fa?µ????ta? t?? pa?ap??? t?p? ????µe
• C 3000 X log2(13162) 3000 X log2(3163) 3000
  X 11,62 34.860
• ??a ????µe C 34,86 kbps.

19
Interfaces MODEMS

• ?a??????? ep????????a (8 bits) st?????ta?
  ta?t?????a, ??a ??e?????ta? 8 a?e???t?te? ??aµµ??
  
• Se???a?? ep????????a (1 bit) ?a? ??e???eta? 1
  ??aµµ? s??des??.
• S??????? µet?d?s?
• ?s??????? µet?d?s?

20
Interfaces
Network
DTE
DTE
DCE
DCE
DTE Data Terminal Equipment. ?p??ad?p?te
?e?µat??? S?s?e?? DCE Data
Circuit-Terminating Equipment. ?a??d?a - Modems
21
DCE Data Circuit-Terminating Equipment

• EIA-232 Interface (p???? RS-232) µe 25 a???d??te?
  a?se????? ? ??????? t?p??. ?µß??e?a 15 m,
  ?a??t?ta 20 kbps
• ???-449
• DB-37 (37 a???d??te?)
• DB-9 (9 a???d??te?)
• RS-422, RS-423, EIA-530
• X.21 ?p??e? ?a p?e? µ???? 64kbps

22
MODEMS

• ?etat??pe? ??a ??f?a?? s?µa se ??a??????
  ???s?µ?p????ta? t?? te?????? d?aµ??f?s??
• ASK
• FSK
• PSK
• QAM

23
Modems

• ?a ????? Modems pe????????ta? ap? t? e???? ?????
  t?? t??ef?????? ??aµµ??. ?? t??ef?????? ??aµµ??
  ????? e???? ????? pe??p?? 4000 Hz. H
  de??µat?????a ???eta? µe ???µ? 8.000 de??µata/s
  ?a? ? d?aµ??f?s? (PCM) ???s?µ?p?e? 7 bits/sample.
• ?ts? te???? ????µe ta??t?te?
• 8.000 samples/s X 7 bits/sample 56 kbps

24
Modems

• ?e?a??te?e? ta??t?te? d????? ta cable modems p??
  pa?????? ?a? t?? ?a??d?a?? t??e??as?. ?a
  ?µ?a?????? a?t? ?a??d?a d????? 750 MHz e????
  ????? e?? d?at??e?ta? ?a????a t?? 6 MHz. ?e????
  p????pt??? ?e???t??? µ???sta
• Downloading 6 MHz X 6 36 Mbps µe ap?d?aµ??f?s?
  64-QAM (6 bits t? f???). St? p???? 3 10 ?bps
• Uploading 6 MHz X 2 12 Mbps µe d?aµ??f?s? QPSK
  (2 bits t? f???). St? p???? 0,5 - 1 Mbps

25
S??des? st? ???t??

• ?????ste? p???p???se??
• ?pa??? e??? MODEM
• ???ef????? ??aµµ? (Dial Up). ??e???eta?
  e?d??µes?? ?p?????st?? ??a t? s??des? µe t?
  d??t??
• SLIP/PPP ?e? ??e???eta? e?d??µes?? ?p?????st??. ?
  s??d??µ?t?? s??d?eta? ??te??e?a? st? d??t??
• ?f?e??µ??? S??des? (Leased Line, Dedicated Line
  connection). ? ?a??te??? t??p?? s??des??. ?
  ?p?????st?? t?? ???st? e??a? µ???µa s??dedeµ????
  µe t? d??t??.

26
?a?e??µe?e? ?p??es?e? ???t???

• PSTN Public Switched Telephone Networks
  ??a?????? ?et?d?s?
• ISDN Integrated Services Digital Network
  ??f?a?? ?et?d?s? µ?s?
• Telecommunications Operating Company (TELCO)
• Internet Service Provider (ISP) Networks

27
?a?e??µe?e? ?p??es?e? ???t???

• ???a?????? ???t?a (Video-on-demand, broadcast TV,
  Interactive d?ad?ast??? TV). ??p??? bit rates
  e??a? ??a VCR Quality Video, MPEG-1, ta 1,5
  Mbps, e?? ??a Broadcast-quality video µe ???,
  MPEG-2, ta 4/6/8 Mbps.
• - ???t?a ?a??d?a??? ???e??as?? CATV
• - ???t?a ????f?????? ???e??as?? (???ß???e?? ??a
  ??f?a?? ???e??as? ?a? ??ad?ast???? ?p??es?e?
  Interactive Services)

28
S??????e? ?e???????e? ??as??des??

• ???s?µ?p????µe t?? ?d?a Customer Line or
  Subscriber Line
• Broadband Modems
• Private Branch Exchange PBX µe1,5 Mbps or 2Mbps
  (24-30 ???µe?a)

29
S??????e? ?e???????e? ??as??des??

• ??f?a?? ?et?d?s? ?e???????e?
• Plesiochronous Digital Hierarchy (PDH)
• Synchronous Digital Hierarchy (SDH) ???st? ?a? µe
  t? ???µa Synchronous Optical Networks SONET
• ??a ???s?µ?p????? t? UTP ?a??d?? ?a? µ?a s?s?e??
  t?? Line Termination Unit (LTU).

30
S??????e? ?e???????e? ??as??des??

• ISDN (Integrated Services Digital Network)
• S?????s? f???? ?a? ded?µ???? ape??e?a? st?
  t??ef????? d??t?? µe t?? ?p?????se? ??aµµ??
• S??e????eta? µe ???e? te???????e? ?p?? ???, Fame
  Relay.
• ?a??t?te? µ???? ?a? 2,048 Mbps.
• DSL Digital Subscriber Line

31
Digital Subscriber Line DSL

• To DSL e??a? s??d?asµ?? p???p?e??a?,
  ap?p???p?e??a? ?a? d?aµ??f?s??, ???s?µ?p??e? ta
  ?f?st?µe?a d??t?a t??ep?????????? ?a? t???
  s??d??µ?t????? ß?????? ??a t?? pa???? ded?µ????,
  f???? ?a? p???µ?s??. St? ?at?????a a?t? a??????
  ?? te???????e? ADSL (AsymmetricDSL), RADSL (Rate
  Adaptive ADSL), HDSL (High bit rate DSL), SDSL
  (Symmetric DSL) ?a? VDSL (Very High bit rate DSL)

32
DSL

• ?a???e?
• Basic Rate Interface BRI µe 2 a?e???t?ta 64 kbps
  duplex ?a????a
• Primary Rate Interface PRI µe 23 ? 30 a?e???t?ta
  duplex ?a????a t?? 64 kbps ?a?
• Primary Rate Interface PRI µe 1 duplex ?a???? ap?
  p64 kbps ?p?? p e??a? 1-23 ? 1-30
• ?? f??-?a? µp???a e??a? t? RJ45

33
ADSL

• ?? ADSL e??a? as?µµet?? µe t?? ?????a ?t? ??e?
  µe???e? ta??t?te? (bit rate) st? downloading ap?
  t? ???t?? st?? s??d??µ?t? ?a? µ????te?e?
  a?t???t?? (uploading).
• ???s?µ?p?e? te??????
• CAP Carrierless ?mplitude/Phase ??t? pe??p?? sa?
  t?? d?aµ??f?s? QAM a??? p?? s???et?.
• DMT Discrete Multitone Technique p?? e??a?
  s??d?asµ?? QAM ?a? FDM

34
ADSL

• ??a??e? t? e???? ????? t?? s??est?aµµ???? ?e?????
  ?a??d??? p?? pa???e? t?? t??ef?????? s??d?se?? (1
  MHz) se t?e?? ???e?
• 0-25 kHz ??a f??? 4 kHz, ta ?p????pa ??a ??e???
  ?a? d?a????sµ? ded?µ????
• 25-500 kHz ADSL-Lite ? G-Lite p?? pa???e? 1,5
  mbps downstream ep????????a ?a? 384kbps ??a
  upstream
• 25 kHz - 1,1 MHz
• ?????? e??p??s? pa???sµ??? st?? ?s?a ?ap???a, N.
  ????a (Asian Pacific), ?µe????, ????p?,
  ??t??a?at????? ?s?a, ??s? ??at???, ?f???? ?.a.
• ?a??t?te? p??? ap? 1,5 Mbps, µe a???t??? t?s?

35
??sa ?et?d?s?? MAC (Medium Access Control)

• ??s??µata ? ?p??e?a ? ?d????µe?a (Terrestrial -
  Guided)
• S??est?aµµ??? ?e???? ?a??d???
• ?µ?a?????? ?a??d??
• ?a??d?? ?pt???? ??a?
• ?s??µata ? ?? ?d????µe?a (Aerial-Unguided)
• ?ad??f????? ??µata
• ???????µata
• ????f?????? t??ep????????e?
• ????t? t??ef???a

36
??s??µata ? ?p??e?a (Terrestrial)?d????µe?a
(Guided)

• S??est?aµµ??? ?e???? ?a??d??? µ? ?e??µ???
  (Unshielded Twisted Pair UTP).
• 100 ?z -5 MHz
• ?p??e? ?a ft?se? µ???? 100 Mbps
• ?????t??e? RJ45
• S??est?aµµ??? ?e???? ?a??d??? ?e??µ??? (Shielded
  Twisted Pair STP).
• ?p?? ?a? t? p??????µe?? µe pe?????sµ? t??
  pa?eµß???? crosstalk

37
??s??µata ? ?p??e?a (Terrestrial)?d????µe?a
(Guided)

• ?µ?a?????? ?a??d?? (Coaxial cable ? ap??? Coax).
• 100 KHz 500 MHz
• RG-8 Used for Thick Ethernet (Radio Government
  ratings)
• RG-9 Used for Thick Ethernet
• RG-11 Thick Ethernet
• RG-58 Used for Thin Ethernet
• RG-59 Use for TV

38
??s??µata ? ?p??e?a (Terrestrial)?d????µe?a
(Guided)

• ?µ?a?????? ?a??d??
• ?? s??d?se?? ?????ta? e????a µe BNC connectors
  (Bayonet Network Connector)
• ????? t?p?? e??a? ?-connectors
• St?? te?µat?sµ? ??e?????ta? Terminators, ?ste ?a
  pe????????ta? ?? a?a???se?? ?a? ? pa?eµß???? µe
  t? µetad?d?µe?? s?µa

39
??s??µata ? ?p??e?a (Terrestrial)?d????µe?a
(Guided)

• ?pt??? ??a (Fiber Optic), ?p?? t? µ?s?? e??a?
  ??a?? ?a? t? s?µa ap? ??e?t???? ??e? d?aµ??f??e?
  se f?te??? d?sµ?.
• ????t??p? (multimode), µe d?ad?????? a?a???se??
• ????t??p? (single-mode), ????? a?a???se??,
  ????te?? e?as????s?, ?ept?te?? ?a? a???ß?te??

40
?pt???? ??e?. ???et?? ??at?µ?
41
?pt???? ??e? ??aµ???? ??at?µ?
42
?pt???? ??e?

• ??e??e?t?µata
• ?e? ?p?????? ??e?t??µa???t???? pa?eµß????
• ????? st? ????ß?
• ????? e?as????s?
• ???? µe???? e???? ?????
• ?e???e?t?µata
• ????ß?? e??p??sµ??
• ?e???? ??st?? e??at?stas?? s??t???s?? ap?
  e?e?d??e?µ??? p??s?p???. ??s????a st?? epe?t?se??
• ????a?ste? ??e?????ta? p??s???.

43
?s??µata ? ?? ?d????µe?a (Aerial-Unguided)

• ?ad?o??µata ap? 3kHz µ???? 3GHz
• ???d?s?
• ?p?fa?e?a??
• ???p?sfa?????
• ????sfa?????
• ?pt???? ?paf??
• ??s? ??ast?µat?? (µ???? 31 GHz)

44
?s??µata ? ?? ?d????µe?a (Aerial-Unguided)

• ???????µata 30GHz µ???? 300GHz
• ?f?sta?ta? µe???? ap????f?s? ?a? ??a?t?
  ??e?????ta? epa?a??pte? t?? s?µat?? ??a µe???e?
  ap?st?se??.
• ?? ?e?a?e? e??a?
• ?a?aß??????
• ???t??
• Horn p?? µ???e? µe ???t??a ? s?ss???a

45
????f?????? ?e??e??

• ????f????? ?e??? (satellite link) ?p?? t? µ?s??
  e??a? ?a? ed? ??e?t??µa???t??? ??µata, ?p??
  p??????µ????.
• ?? ?e?stat???? d???f???? p?? fa????ta? a????t??
  se ???? 36.000 km, pe??f????ta? st? ep?ped? t??
  ?s?µe?????. ?d? pa?at??e?ta? ?a??st???s? t??
  d??d?s??, pe??p?? 270 milliseconds, ???? t??
  ap?stas?? t?? 80.000 km p?? ??e???eta? t? s?µa
  ??a ?a p?e? ?a? ?a ep?st???e?. ???? t??
  pe?????sµ???? a???µ?? t??? (pe??p?? 90 e? ???),
  ???s?µ?p?????ta? ?a? d???f???? se ?at?te?a ??? µe
  d?ad??as?e? µeta????? ?ta? a?at?????? ?a? d????.

46
????t? ???ef???a

• ?a???e? ep????????a se ???ste? p?? de? ?????
  sta?e?? ??s?. O??a?????ta? se ??????e? (cells),
  ?p?? ???e µ?a ??e? t??? d????? t?? p?µp?d??te?
  ?a? ?e?a?e?, e?? e??????ta? ap? ??a ?e?t????
  s?µe?? p?? ???eta? Base Station Controller (BSC)
  ? Mobile Telephone Switching Office (MTSO).

47
????t? ???ef???a

• ?p?te?e?ta? ap?
• Mobile Station (t? ????t? t???f??? µe t? PIN,
  International Mobile Equipment Identity (IME),
  Authentication key (ki), Location area
  Identification (LAI).
• Base Transceiver Subsystems (BTS) µe t?? ?e?a?e?
  ?a? p?µp?d??te?, µe data rates 9,6 kbps ?a? 14,4
  kbps.
• Base Station Controller ? Radio Network
  Controllers, p?? ?ata??µe? t?? s????t?te? sta
  BTS, ?a? f???t??e? ??a t?? µeta?????

48
?ad??d?a????
49
????f????? ?p????????a
50
S?????s? µ?s?? µet?d?s??

• ??st??
• ?a??t?ta
• ??as????s?
• ??e?t??µa???t???? ?a?eµß????
• ?sf??e?a

51
?et?d?s? ?as???? ?????

• ????p?e??a ?ata??µ?? ?????? (Time Division
  Multiplexing, TDM)
• S???????
• ?s???????

52
S??????? TDM µe t? d???es? ?s?? ?????d?ast?µ?t??
53
?s??????? TDM µe t? d???es? µetaß??t??
?????d?ast?µ?t??
54
????p?e??a ???te??? ?????
55
? ???s? ????p?e?t?? MUX ??a d?as??des? d?af????
te?µat???? µ?s??
56
??p?????e? ???t???
57
Buss Topology (??t???a?)
58
Ring (?a?t?????)
59
???t?????a ?a? p??t?pa ep????????a?

• ?eta???? ?????µat?? (Circuit switching)
• t??ef???a, N-ISDN
• ?eta???? pa??t?? (Packet switching)
• FDDI, Frame Relay, Internet
• ?e s??des? (connection oriented)
• N-ISDN, X.25, TCP, ST-2
• ????? s??des? (Connectionless)
• Ethernet, Token Ring, Internet (IP)

60
?? p??t?p? t?? p??t??????? OSI
61
?? s?s?e??? d??t??s??
62
???f??a p??t?pa d??t??? Ethernet