2.6.1 xDSL??

1
?????(? 5 ?)

• ? 2 ? ???

2
? 2 ? ???

• 2.1 ????????
• 2.2 ?????????
• 2.2.1 ?????????
• 2.2.2 ???????????
• 2.2.3 ???????
• 2.2.4 ???????????
• 2.3 ??????????
• 2.3.1 ??????
• 2.3.2 ???????

3
? 2 ? ???(?)

• 2.4 ??????
• 2.4.1 ????????????????
• 2.4.2 ????
• 2.4.3 ????
• 2.5 ??????
• 2.6 ??????
• 2.6.1 xDSL??
• 2.6.2 ???????(HFC ?)
• 2.6.3 FTTx ??

4
2.1 ????????

• ??????????????????????????,?
• ???? ??????????????????????????????????
• ???? ?????????????????????
• ???? ???????????????????????
• ???? ?????????????????????

5
2.2 ?????????2.2.1 ?????????
?????
?????
????
????
?? ??
?? ??
?????
?????
?????
PC ?
PC ?
6
????

• ??(data)????????
• ??(signal)?????????????
• ???(analogous)???????????????
• ???(digital)???????????????
• ??(code)??????(??????)??????????,??????????????

7
2.2.2 ???????????

• ????(????)????????????????????
• ??????(?????)????????????,?????????(??????????)?
  
• ??????(?????)?????????????????

8
??(baseband)?????(band pass)??

• ????(???????)???????????????????????????????????
  ????
• ????????????????,???????,?????????????????????????
  ??????????(modulation)?
• ????????????????,????????????????????????(??????
  ??????????)?

9
??????????

• ????????????????,???????,?????????????????????????
  ?????,????????????(modulation)?
• ????????????????
• ??(AM)????????????????
• ??(FM)????????????????
• ??(PM) ??????????????????

10
??????????????
0
1
0
0
1
1
1
0
0
????
??
??
??
11
?????? QAM(Quadrature Amplitude Modulation)
??
???????? 12 ?, ????????? 1 ? 2 ????????
(r, ?)
r
?
??4 bit ????16 ???? ??,??? 16 ?????? ??????? 4
bit ????
???????????????,??????? ??????????????????
12
2.2.3 ???????

• ?????????????,??????????????????????
• ?????????,??????????,??????????????????

13
???????????

• ???,????
• ???,????

????? (??????????????)
??????
??????
14
???????????

• 1924 ?,????(Nyquist)??????????????????????????,???
  ?????,????????????
• ??????,????????????,?????????????,??????????(???)?
  ?????
• ?????????,????????????????,???????????????????????
  ?

15
(2) ???

• ??(Shannon)???????????????????????????????????????
  ???
• ??????????? C ????
• C W log2(1S/N) b/s
• W ??????(? Hz ???)
• S ?????????????
• N ?????????????

16
??????

• ???????????????,??????????????
• ?????????????????????,?????????????????????
• ????? W ???? S/N ????(?????????????),????????????
  C ???????
• ???????????????????????????????

17
???

• ????????????,???????????,???????????????,?????????
  ?????????????????????????????????

18
2.3 ??????????
?????????????
100 102 104 106
108 1010 1012 1014
1016 1018 1020 1022 1024
?
???
??
???
X??
??
???
???
104 105 106 107
108 109 1010 1011
1012 1013 1014 1015 1016
???
??
??
????
????
?? ???
?? ???
?? ???
?? ???
??
??
LF
MF
HF
VHF
UHF
SHF
EHF
THF
19
2.3.1 ??????

• ???
• ????? STP (Shielded Twisted Pair)
• ?????? UTP (Unshielded Twisted Pair)
• ????
• 50 ? ????
• 75 ? ????
• ??

20
????
?????? UTP
????? STP
??
???
???
???? ??
???? ??
??
???
????
???
??????
??????
???
21
?????????
???
??
?? (???????)
??
?? (???????)
???
?? (???????)
22
???????
???? (??)
???? (??)
??????????????????
23
?????????
????
24
2.3.2 ???????

• ?????????????
• ??????????????,?????????????
• ?????????????
• ????????
• ????

25
2.4 ??????2.4.1 ????????????????

• ??(multiplexing)????????????

??
A1
A2
A1
A2
????
??
B1
B2
??
??
B1
B2
??
C1
C2
C1
C2
(a) ???????
(b) ??????
26
???? FDM(Frequency Division Multiplexing)

• ????????????,??????????????????
• ????????????????????????(???,???????????????????
  ?)?

27
????TDM(Time Division Multiplexing)

• ???????????????????????(TDM ?)??????????????? TDM
  ????????????
• ??????????????????(????? TDM ????)?
• TDM ???????(isochronous)???
• ??????????????????????????

28
????
??
A ? TDM ?? ?????
B
C
D
B
C
D
B
C
D
B
C
D

??
29
????
??
B ? TDM ?? ?????
C
D
C
D
C
D
A
A
A
A
C
D

??
30
????
??
C ? TDM ?? ?????
B
D
B
D
B
D
A
A
A
A
B
D

??
31
????
??
D ? TDM ?? ?????
B
C
B
C
B
C
A
A
A
A
B
C

??
32
????????????????
????????????????, ????????????,??? ???????????????
???
??
????
a
a
A
t
?
B
b
t
b
?
t
a
b
b
c
a
c
d
?
c
c
C
t
1
2
3
4
?
d
D
t
4 ??????
33
?????? STDM(Statistic TDM)
??
??????
A
a
a
t
?
B
b
b
?
t
t
a
b
b
c
a
c
d
?
C
c
c
t
3
2
1
?
D
d
t
3 ? STDM ?
34
2.4.2 ???? WDM(Wavelength Division
Multiplexing)

• ?????????????

8 ? 2.5 Gb/s 1310 nm
????
????
1550 nm 0 1551 nm 1 1552
nm 2 1553 nm 3 1554 nm
4 1555 nm 5 1556 nm 6
1557 nm 7
0 1550 nm 1 1551 nm 2
1552 nm 3 1553 nm 4
1554 nm 5 1555 nm 6 1556 nm
7 1557 nm
20 Gb/s
EDFA
? ? ?
? ? ?
120 km
35
2.4.3 ???? CDM(Code Division Multiplexing)

• ?????????? CDMA
• (Code Division Multiple Access)?
• ????????????????,???????????
• ??????????????????,?????????,????????
• ?????????? m ?????,????(chip)?

36
????(chip sequence)

• ??????????? m bit ?????
• ????? 1,?????? m bit ?????
• ????? 0,???????????????
• ??,S ?? 8 bit ????? 00011011?
• ???? 1 ?,????? 00011011,
• ???? 0 ?,????? 11100100?
• S ??????(1 1 1 1 1 1 1 1)

37
CDMA ?????

• ??????????????????,?????????(orthogonal)?
• ?????????????????

38
?????????

• ??? S ??? S ?????,? T ?????????????
• ????????????,???? S ?T ??????(inner product)?? 0

(2-3)
39
???????????

• ??? S ?(1 1 1 1 1 1 1 1),?? T ?(1 1 1
  1 1 1 1 1)?
• ??? S ? T ???????(2-3)?????????????????

40
????????????

• ????????????????????????1 ?
• ??????????????????????? 1?

41
CDMA ?????
1
1
0
??????
t
m ???
t
S ?????? S
? ? ?
S ?????? Sx
t
T ?????? Tx
t
t
?????? Sx Tx
? ? ?
t
????? S ? Sx
t
????? S ? Tx
42
2.5 ??????1. ???? PCM ??

• ???? PCM ??????????????????????????
• ????????,PCM ????????????,???? 24 ? PCM(???
  T1)???? 30 ? PCM(??? E1)?????????? E1 ???
• E1 ???? 2.048 Mb/s,? T1 ???? 1.544 Mb/s?
• ???????????,?????????

43
2. ????? SONET ??????? SDH

• ?????????????????????????????
• ????????
• ???????????????????,?????????????????
• ???????
• ?????????,??????,?????????????????

44
????? SONET

• ????? SONET (Synchronous Optical Network)
  ???????????????????
• ? 1 ??????? STS-1 (Synchronous Transport
  Signal)?????? 51.84 Mb/s?
• ??????? 1 ???? OC-1,OC ??Optical Carrier?

45
?????? SDH

• ITU-T ????? SONET ???,????????????? SDH
  (Synchronous Digital Hierarchy)?
• ????? SDH ? SONET ?????
• SDH ?????? 155.52 Mb/s,??? 1 ??????? (Synchronous
  Transfer Module),? STM-1,??? SONET ???? OC-3 ???
  

46
SONET ? OC ?/STS ?? SDH ? STM ??????
???? (Mb/s) SONET ?? ITU-T ?? ?????? ??????
51.840 OC-1/STS-1 ?
155.520 OC-3/STS-3 STM-1 155 Mb/s
466.560 OC-9/STS-9 STM-3
622.080 OC-12/STS-12 STM-4 622 Mb/s
933.120 OC-18/STS-18 STM-6
1244.160 OC-24/STS-24 STM-8
2488.320 OC-48/STS-48 STM-16 2.5 Gb/s
4976.640 OC-96/STS-96 STM-32
9953.280 OC-192/STS-192 STM-64 10 Gb/s
39813.120 OC-768/STS-768 STM-256 40 Gb/s
47
SONET ?????
SDH ??
SDH ??
??? ? ???
??? ? ???
???
???
?
?
?
(section)
(section)
(section)
?? (line)
?? (path)
???
???
???
???
???
???
??
??
??
??
??
??
???
???
???
???
???
???
48
SONET ???????????

• ???(Photonic Layer)
• ????????????
• ??(Section Layer)
• ?????? STS-N ??
• ???(Line Layer)
• ????????????
• ???(Path Layer)
• ???????? PTE (Path Terminating Element)?????????
  

49
2.6 ??????2.6.1 xDSL??

• xDSL ????????????????????????,???????????
• ????????????????? 3003400 kHz ????,??????????????
  ?????? 1 MHz?
• xDSL ???? 04 kHz ????????????,???????????????????
  ????
• DSL ???????(Digital Subscriber Line)????? DSL ???
  x ????????????????????

50
xDSL ?????

• ADSL (Asymmetric Digital Subscriber
  Line)????????
• HDSL (High speed DSL)???????
• SDSL (Single-line DSL)1 ????????
• VDSL (Very high speed DSL)????????
• DSL ISDN ????
• RADSL (Rate-Adaptive DSL)????? DSL,? ADSL
  ?????,?????????)?

51
ADSL ???????

• ADSL ??????????????????????????(?????,???????????)
  ,???????????????????????????????
• ??,0.5 ????????,????? 1.5 2.0 Mb/s ???? 5.5
  ??,????????? 6.1 Mb/s ?,???????? 3.7 ???
• ????????????0.4??,???6.1 Mb/s???????????2.7??

52
ADSL ???

• ??????????????
• ??????? ISP,????? ISP ????
• ADSL ????(??)???????? ADSL ??????
• ??????????????? DMT (Discrete Multi-Tone)????????
  ?????????????????

53
DMT ??

• DMT ?????????????,? 40 kHz ????? 1.1 MHz
  ??????????????,?? 25 ??????????,? 249 ???????????
• ??????? 4 kHz ??(???? 4.3125 kHz),????????(??????)
  ????????????????????????????????????????

54
DMT ???????
??
????
????
????


??
(kHz)
0
4
40
138
1100
55
ADSL ????

• ????????????????(??????????????????????),?? ADSL
  ??????????????????????????
• ? ADSL ???,?????? ADSL ?????????????????????????,?
  ??????????????????
• ADSL ??????????????????????????? ADSL?
• ???????? 32 kb/s ? 6.4 Mb/s ??,??????? 32 kb/s ?
  640 kb/s ???

56
ADSL ???
?? ADSL ????
? ISP
??????
?? ???
PS
ATU-C
???
PS
ATU-C
ATU-R
?????
ATU-C
????
??????
DSLAM
?????????? DSLAM (DSL Access Multiplexer) ??????
ATU (Access Termination Unit) ATU-C(C ????
Central Office) ATU-R(R ???? Remote) ????? PS
(POTS Splitter)
57
??? ADSL ADSL2(G.992.3 ? G.992.4)ADSL2(G.992.5
)

• ????????????????????,ADSL2 ????????? 8 Mb/s???
  800 kb/s????? ADSL2 ??????? 1.1 MHz ???2.2
  MHz,?????? 16 Mb/s(????????25 Mb/s),??????? 800
  kb/s?
• ???????????? SRA (Seamless Rate
  Adaptation),????????????????????,??????????
• ????????????????,???????????????????????

58
2.6.2 ???????HFC (Hybrid Fiber Coax)

• HFC ???????????????? CATV ?????????????????
• HFC ????? CATV ?,???????????????????
• ??? CATV ???????????????,?????????????????????????
  HFC ????? CATV ?????,

59
HFC ?????

• (1) HFC??????????
• HFC ??? CATV ????????????????,??????????
• ?????????????? AM,?????????????
• ??????????????(fiber node),?????? ODN (Optical
  Distribution Node)???????????????????????????????
  

60
(2) HFC ?????????
????
???
????
??
???
???
????
???
???
???
61
(3) HFC ???? CATV ??????,?????????
????
?? ??
??????
????
??
??(MHz)
5 40 50
550 750 1000
62
(4) ??????????????

• ????? UIB (User Interface Box)???????,?
• ????????????(set-top box),?????????????
• ???????????????
• ???????????????????

63
???????(cable modem)

• ????????? HFC ???????????
• ???????????????????????????? 3?10 Mb/s??,???? 30
  Mb/s,???????? 0.2?2 Mb/s,???? 10 Mb/s?
• ????????????????????????????,????????,??????????

64
HFC ??????

• ???????,???????????????????????
• ????? 450 MHz ?????????????? 750 MHz ????? HFC
  ?(????????????????????? HFC ????),????????????
• ?????????????????????

65
2.6.3 FTTx ??

• FTTx(???)????????????????????? x ????????
• ???? FTTH (Fiber To The Home)????????????????????
  ???????
• ????? FTTB (Fiber To The Building)??????????????,
  ????????????????
• ????? FTTC (Fiber To The Curb)???????????????????
  ?????