Mng thng tin quangTrng Diu Linh B mn TTM- Vin CNTT &TTlinhtd@soict.hut.edu.vn

Mc ch mn hcn Gii

thiu v cng ngh mng cp quang n Gii thiu v cc m hnh mng cp quang n Gii thiu v cc vn trong thit k mng cp quang

Ni dungn Gii

thiu v mng cp quang n Cc kin trc mng s dng cp quang n Cc thnh phn ca mng WDM n Thit k mng cp quang n D phng v khi phc n Mng truy nhp

nh gin im n imHc

qu trnh:30%tra gia k

Kim

cui k: 70%

vin lm tiu lun nghin cu v mt vn v trnh by trc lp

Ti liu tham kho1) Rajiv Ramaswami and Kumar N. Sivarajan, Optical Networks: A practical perspective, Morgan Kaufmann Publishers, 2nd edition, 2002. C th truy cp online t th vin book24x7 trong phm vi trng Bch Khoa 2) Wayne D. Grover, Mesh-based Survivable Networks: Options and Strategies for Optical, MPLS, SONET and ATM Networking, Prentice Hall, 2003 3) Biswanath Mukherjee, Optical WDM Networks, Springer, 2006

Chng 1: Gii thiu v mng thng tin quang

Ni dung Kin trc mng truyn thng Cng ngh chuyn mch knh, gi Mng cp quang Cp quang Cc k thut dn knh dng trong mng cp quang Cc th h mng cp quang Hin trng s dng mng cp quang trn th gii Cc thit b trong mng cp quang

Kin trc mng truyn thng

Central office = Point of Presence (PoP) Xy dng cc kt ni longhaul rt t v vy kt ni ny thng c xy dng vi dung lng di d

Mng thng tin quangn S

dng nh sng truyn tn hiu trn ng truynDng

cp quang dn nh sng

n u

im im

Bng

thng rng Truyn c xa vi suy hao thpn NhcX

l phc tp v cha c b nh quang hc (b nh hin ti lu tn hiu dng in)

n ng

dng cho cc mng trc

Mng thng tin quangUser Local Network User Freq. Convert User

User

User

Local Traffic Blocking Filter

Opt ic Am al pOptical Router/ switch

User

User

User User

Lch s mng thng tin quangn n n n n

1958: Laser discovered Mid-60s: Guided wave optics demonstrated 1970: Production of low-loss fibers Made Made

long-distance optical transmission possible! optical transceivers highly refined!

1970: invention of semiconductor laser diode

70s-80s: Use of fiber in telephony: SONET n Mid-80s: LANs/MANs: broadcast-and-select architectures n 1988: First trans-atlantic optical fiber laid n Late-80s: EDFA (optical amplifier) developed Greatly

alleviated distance limitations!

n n

Mid/late-90s: DWDM systems explode Late-90s: Intelligent Optical networks

H thng truyn dn thng tin quang

Cp quangn n

Truyn tn hiu nh sng trong cp nh sng

mang tnh cht sng: phn xa, tn za, nhiu, phn cc, suy yu, mt mt Gm nhiu bc sng Truyn i theo hng thng

n

Cc ch truyn

Truyn nh sng trong cp quang

Single-mode vs. Multi-moden

Multi-mode (c) Truyn

nhiu tia sng Li ln, ngun sang r Nhiu gia cc ch truyn Sinh li tn hiu sau mi 10km Tc 32-140 Mbpsn

Single-mode (mi) Truyn

mt tia sng Li nh, ngun sng t tin Loi b nhiu Sinh li tn hiu sau mi 40km Tc vi trm Mbps

S pht trin ca h thng cp truyn

Cng ngh dn knh trn cpn

TDM: Electronic Time Division Muxa xen k cc bit ca cc lung tc thp vo mt lung tc cao 10 Gbps-40Gbps SONET/SDH

n

OTDM: Optical Time Division MuxCng nguyn tc vi TDM nhng thc hin xen k bit trong min quang hc 250 Gbps ang trong th nghim

n

WDM: Wavelength Division Mux

Truyn nhiu bc sng trn mt cablen n

Simple WDM: t bc sng vi mt tha Dense WDM (DWDM) nhiu bc sng vi mt dy

S dng rng ri trong mng trc, i cp di bin v dn a vo trong mang th

Mng cp quang th h 1n Tn

hiu s dng trn ng truyn l tn hiu quang hcT

l li thp Dung lng lnn ChuynTn

mch v cc chc nng mng thng minh c x l trn min tn hiu inhiu c chuyn sang dng in trc khi c x l

n Thng

dng cng ngh dn knh TDM n S dng rng ri trong cc mng vin thng n VD: SONET/SDH

Mng cp quang th h 2n nh

tuyn, chuyn mch v cc chc nng mng thng minh c thc hin trong min tn hiu quang n Thng dng cng ngh dn knh WDM n Tn hiu thng mt bc sng t u n cuicn

c mt bc sng ri dc theo ng truyn iu kin lin tc v bc sng

n

c a vo s dng v thng c gi l Wavelength routed network hay All optical network

S pht trin ca mng quang th h 2Point-to-Point WDM Line System 1

2

WDM ADM WDM ADM

1

2

Multipoint Network WDM Add/Drop

i Optical Cross-Connect WDM NetworkingOXC

k

V d mng WDM

Cc thnh phn ca mng thun ty quang

Optical Line Terminal (OLT)

n n

Chuyn i d liu u cui sang dng quang Dn knh Khuych i Ghp thm hoc r nhnh mt phn bng thng Chuyn mch quang hc

Optical Line Amplifiern

Optical Add/Drop Multiplexers (OADM)n

Optical Cross-connect (OXC)n

OXC thun quang

Chuyn mch knh, gi Chuyn mch knh l

Knh: ng i t ngun n ch D liu c truyn trn mt knh c nh m bo bng thng khng i cho mi kt ni Bng thng tng ca cc kt ni = bng thng mi link

Chuyn mch gil l l l

Cng ngh chuyn mchn Chuyn

mch knh

Thng thng cc mng cp quang dng cng ngh chuyn mch knh nh tuyn cn c xc nh trc cho tng S dng trong SONET/SDH, WDMn Chuyn

mch gi OPS n Chuyn mch Burst OBS

Chuyn mchn ChuynThc

mch quangOptical switchhin chuyn mch trong min quang hc

n ChuynThc

mch in Electronic switchhin chuyn mch trong min in

Cng ngh chuyn mch quang

Cng ngh chuyn mch inn C

hn cng ngh chuyn mch quang n Vn ang c s dng rng ri hin nay n Hot ngChuynn

i tn hiu quang in

Chim phn ln gi thnh ca switch

Thcn

hin chuyn mch d liu trong min inD liu c chuyn thnh cc dng bit tc 51 Mbps (STS-1) v chuyn mch cc dng bit ny mt cch song song

Chuyn mch vi cc dng d liu tc thp:

n

Chuyn mch vi tc ng truyn 2,5 Gbps hoc hn.

Thit b chuyn i bc sngn

Chuyn d liu t mt bc sng u vo thnh mt bc sng u ra Gii

phng rng buc lin tc v bc sng Tng kh nng tn dng cc bc sng rin

Chuyn i Optoelectronic Chuyn

tn hiu sang dng in Sinh li tn hiu v truyn trn mt bc sng khcn n n

1R: khuych i, khng iu ch li 2R: khuych i, khi phc li dng xung tn hiu 3R: khuych i, khi phc li dng xung v rng xung

Thng

dng hin nay

n

Chuyn i trong min quang Optical

gating, interferometric, wave mixing Cha pht trin

Thit b chuyn i bc sng

Chng 2: Cc kin trc mng s dng cp quang

Cc kin trc mng dng cp quangn

Cc mng dng cng ngh chuyn mch knh cho tng quang

Mng SONET/ SDH Mng ATM Mng WDM n v d liu l cc bust n v d liu l cc gi tin

n n

Optical Bust Switching

Optical Packet Switching

Mng SONET/SDHn

SONET (Synchronous Optical Network)

a ra bi Telcordia, USA dng Bc M a ra bi ETSI, t chc chun Telecom chu u dng chu u, Nht, Vit Nam

n

SDH (Synchronous Digital Hierarchy)

n n n n

S dng cp quang trn cc kt ni Hot ng theo c ch chuyn mch knh Dng cng ngh TDM S dng c ch dn knh ng b ti cc nt

ng h c ng b trn ton h thng D trch mt knh c dn trong knh ln

n n

nh ngha khun dng frame d liu c dn knh Chun SONET/SDH c pht trin kt hp vi mt s topo v phng php d phng ring

Kh nng khi phc sau li nhanh < 60ms

Mng SONET/SDHn

STS-1 dng cc Virtual Tributaries (VT) truyn cc tc nh hn VT1.5,

2, 3, 6 (tc 1.5, 2, 3 , 6 Mpbs) VT1.5 cha tn hiu khng ng b DS1n

STS-x dng ng gi cc tn hiu DS-x VT1.5

cha tn hiu khng ng b DS1

n

STM c dng cho cc tn hiu E1, E3, E4 Virtual

Container (VC) tng t VTDS-x E-x

Mng SONET/SDH

Mng SONET/SDH

Cc thnh phn v topo mng SONET

Cc thnh phn v topo mng SONETn TopoRing, Mesh

Point-to-point, linear ADM

n ADM: n DCS:

Add/drop muxtch cc lung d liu nh vo ng truyn

Ghp,

Digital Cross-connect

Chuyn

mch in iu khin bng phn mm Cho php gp (grooming) hoc tch cc lung d liu nh n mc DS-x Chuyn mch cc lung ny gia cc cng

Mng SONET hnh vng: Unidirectional Path Switched RingA-B B-A Bridge Path Selection W B Bridge A-B A B-A Path Selection fiber 2 D C fiber 1 P

Failure-free State

Mng SONET hnh vng:Working Protection

Bidirectional Line Switched Ring2-Fiber BLSR

B

AC C A A

C

AC C A

D

Mng ATMn ATM53

(asynchronous transfer mode) n Truyn cc n v d liu t bo (cell)bytes Khng ng b C th dng h tng l mng SONET/SDH kt ni cc node ATM vi nhau trn giao din UNI Cc cell ATM c ng vo trong cc frame SONET/SDH

Mng ATM

Mng WDM Wavelength routed network Mt bc sng l n v bng thng nh nht Chuyn mch bc sng

Wavelength continuity Rng buc s lin tc v bc sng dc theo mi kt ni

Wavelength conversion Chuyn i bc sng gii phng rng buc ti mt s im

Trin khai IP trn nn WDM

IPOptical (WDM)

(d)

IP/ATM/SONET/DWDM

IP/SONET/WDM

Cc kiu kin trc

IP/WDM vs. IP/OTNIP/OTN (m hnh a, b, c) IP (hoc ATM, SONET/SDH) ng vai tr l mng truy cp ca mng OTN Mng li OTN c th cu hnh c nh cc chuyn mch quang Optical Cross-connect (OXC). Chc nng chuyn mch, d phng, thit lp kt ni c thc hin bi OXC ca tng quang

IP/WDM (m hnh d)Router IP kt ni vi nhau trc tip bng ng cp quang D liu IP c truyn thc s trc tip trn cc bc sng mkhng ng gi trong mt khun dng khc.

Tng quang ch bao gm cc phn t th ng khng cu hnh li c: cp quang, MUX, OADM, khuych iChc nng chuyn mch, d phng, thit lp kt ni c thc hin nh IP hoc giao thc b tr nh MPLS

IP/WDM: u nhc imu p ng c nhu cu bng thng ngy cng cao ca tng IP nht l t cc ng dng Hight Definition TV IP-routers c cc giao din quang OC-48c/OC-192c c th tp hp d liu c hng trm Gbps truyn trn cp quang iu khin vic thit lp kt ni t u n cui s dng ch thc hin tng IP tp trung, hiu qul

NhcCng ngh to cc cng router IP c dung lng ngy cng ln c nhiu terabit s c nh hng n hiu sut, tnh an ton v tc ph hi ???

IP-over-OTN: Pros and Consu Kh nng cu hnh c ca mng li OTN em li tnh mm do Li OTN c th phc v nhiu mng khc nhau ATM, Frame Relay, SONET/SDH.l

NhcCc tng gia IP v WDM to ra overhead d liu v iu khin. Vn iu khin lung d liu c thc hin c 2 min l (i) Mng IP nh tuyn d liu gia cc IP router (c ni logic vi nhau thng qua cc OXC) l (ii) Mng quang to lp cc lightpaths gia cc router IP l D liu khng c nh tuyn hiu qu ton cc

l

Optical Burst Switching Mng quang chuyn mch burst K thut cho php chuyn mch vi n v nh hn mt bc sng K thut dung ha gia OPS v cc k thut chuyn mch knh quang Mt tp cc gi c kt hp ti bin mng to thnh burst Mi burst c phn iu khin v phn d liu

Optical Burst Switching Phn iu khin c truyn trn 1 knh quang ring v c x l trong min in ti mi router OBS Phn d liu c truyn trn mt knh quang khc lun trong min quang t u n cui OBS s dng bng thng hiu qu hn cc cng ngh chuyn mch knh quang OBS i hi chuyn mch tc cao hn Vn nghin cu: thit lp knh d liu cho burst, x l phn iu khin trc khi d liu n

Optical Packet Switching Mng quang chuyn mch gi quang D liu c chia thnh cc gi nh Mi gi c nh tuyn c lp ti cc nt Khng thc t Tc x l gi ti cc nt phi rt nhanh Cn chuyn i OEO x l phn iu khin ti cc nt hiu qu thp khi packet rt nh so vi burst

Cc tiu lun Ch 1: Tm hiu cc gii php d phng mng Ch 2: Tm hiu v Optical Burst Switching Ch 3: Tm hiu v Optical Packet Switching Ch 4: Tm hiu v mng truy nhp s dng cp quang (FTTx) Ch 5: Tm hiu ng dng MatPlan (dng cho Matlab) thit k mng cp quang

Chng 4: Thit k mng cp quang

Thit k mng WDMn WDM

knh n ng i ca d liu t u n cui phi c xc nh trc khi truyn n Cc vn thit kThit

hot ng theo c ch chuyn mch

k vt l: thit k ng i cp, im t nt mng Thit k logic: xc nh cc lightpath cn c nh tuyn v gn bc sng S dng cc b chuyn i bc sng

Thit k mng WDM-V dCho trc topo n Cho trc yu cu thng lngn WA-CO:

x1 Gbps WA-CA1: x2 Gbps WA-CA2: x3 Gbps WA-TX: x4 Gbps CA1-GA: y1 Gbps .n

nh tuyn cho cc thng lng ny

NSFNET Traffic Matrix (11:45 PM to midnight, ET, Jan. 12, 1992)

58

Thit k mng WDM V dWA MI NY NJ

PA UT CA1 CO NE IL MD

CA2 GA TX

Thit k mng cp quang WDMn n n

n

Thit k tng WDM Cn c yu cu thng lng ca tng trn SONET/SDH hoc IP Cn c vo gii hn s cng gii hn s lightpath dng ti mi nt V dCho trc A-B-C ni vi nhau bng cp quang WDM A,B,C ni vi cc router Mi cng router = 10 Gbps = 1 wavelength Thng lng yu cu:n n n

A-B: 50 Gbps B-C: 50 Gbps A-C: 50 Gbps

Thit k ng i cho cc thng lng ny

Thit k mng cp quang WDMn

Khng dng OADM

Thng lng A-C s i trn link AB xung router B (chuyn i OEO) ri li i t B-C 10 bc sng t router A n router B 10 bc sng router B n router C A, C: 10 cng router B: 20 cng router 5 chuyn i OEO 5 bc sng t router A-B 5 bc sng t router B-C 5 bc sng i thng t router A n C khng xung router B OADM phi dng ti B r nhnh thng lng xung router B A, B, C: 10 cng router Khng c chuyn i OEO

n

Dng OADM

n

Gi ca thit b OADM vs. cng router

Thit k mng cp quang WDMn

Lightpath: Mt

kt ni bng 1 bc sng gia 2 im Lightpath c th tri di qua nhiu cp nh cc OADMn

Lightpath Topology Xc

nh cc lightpath ca tng WDM tha mn ma trn thng lng Logical topo, virtual topon

Topo vt l Topo

ca cc cp

Thit k mng cp quang WDMn Thit n Thit

k vt lk cc ng i cp, v tr t cc nt

Thit Cho

k logic

trc cc nt truy cp (router), topo ca cp quang Cho trc ma trn thng lng yu cu (gia cc router) Yu cun

Tm cc lightpath cn thit lp ( kt ni cc router), cha quan tm n ng i c th ca cc lightpath

Lightpath Topology Design (LTD)

n

nh tuyn cc lightpath ny trn cc cp quang c v xc nh bc sng cho chng

Routing and Wavelength Assignement (RWA)

Lightpath Topology Design (LTD)n n n n

Bi ton tng i n gin Cho trc ma trn thng lng gia cc nt (router) Cho trc cc router Yu cu: Xcn

nh cc lightpath no cn xy dng gia cc routerLightpath chnh l cc link o gia cc router l nt ca topo o

nhn

x thng lng vo cc lightpaths

Phn b thng lng ca mi cp router vo cc lightpath

n n

Rng buc Cc

thng lng yu cu c tha mn

Mc tiu Gim

thiu tc nghn ti trn cc lightpath l nh nht C th c cc mc tiu khc ty bi ton.

Lightpath Topology Design (LTD)n Bi

ton LTD l bi ton multi-commodity n Thng c gii bng cch s dng phng trnh tuyn tnh (LP) m hnh ha n S dng cc cng c gii LP gii n C th dng cc heuristic gii khng ti u.

RWACho trc cc lightpath v topo cc cp, v tr cc chuyn mch quang n Yu cun Xc nh ng i cc lightpath trn topo cc cp Gn bc sng cho tng lightpath Wavelength

Routing Assignment

n

Mc tiu Dng t bc sng C th c mc tiu

nht khc ty bi ton

n

Rng buc Hai

lightpath khng th cng dng 1 bc sng trn mt link Nu khng dng b chuyn i bc sng th mt lightpath phi dng cng mt bc sng trn tt c cc link dc theo n.n

Dng hay khng cc b chuyn i bc sng? S lng bao nhiu? Thng

b hn ch

RWAn

gim phc tp nh tuyn v Gn bc sng thng c gii trong 2 bc ring bit n nh tuyn Fixed

path routing, Alternate-path routing, adaptive routing multicommodity flow formulation, randomized routing

n Gn bc sng S dng thut ton t mu th, First Fit and Random Fit, Least Used, Most Used, Min Product, Least Loaded, Max Sum n

Gii hai bi ton ng thi s em li kt qu ti u hn, nhng y l bi ton NP-y nn kh c th c li gii chnh xc

nh tuyn ng cho mng cp quangn

Pht biu bi ton Cho trc mt mng ang c ti C thm 1 yu cu kt ni mi t s nh tuyn cho yu cu kt ni ny

d vi bng thng w

n n

Rng buc Khng Tit

thay i cc kt ni ang tn ti trong mng

C nhiu tiu ch nh tuyn khc nhaukim ti nguyn nht Dnh nhiu kh nng chp nhn cc yu cu khc trong tng lai nht

n

nh tuyn ng kh phn b ti nguyn ton cc mt cch ti u nh nh tuyn tnh

Chng 5: D phng v khi phc

D phng v khi phc

Khi nim c bnn n n n n

Tnh sn sng Cc loi li D phng vs khi phc D phng dnh ring D phng chia s

D phng trong SONET/SDH P-cycle

Khi nim c bnn

Cc s c trn mng lm gin on hot ng ca mngt cp Hng thit b

n

Thi gian gin on cng nh cng tt

Mean Time to Repare: MTR

n

Tnh sn sng ca mng cng cao cng tt

Mean Time between Failures: MTF

n

Kh nng duy tr dch v khi xy ra li Survivability

nh hng ca vic gin onImpactPacket (X.25) Disconnect Social/ Business Impacts FCC Reportable

CallDropping Trigger Changeover of CCS Links May Drop Private Line Disconnect Voiceband Calls

1st AP Range 0 S 50 200 2 10 msec msec sec sec S c trn mng lm thit hi v tin

"Hit"

2nd Range

3rd Range

4th Range

5th Range

6th Range

5 min

30 min

Yu t th trng ca Survivability Quan

h vi khch hng Li th cnh tranh Li nhunBt

li Phi tng chi ph mng c tnh t phc hi sau li u im To cc dch v cao cp em li li nhun lnn n n

Dch v dnh cho doanh nghip Dch v cho cc t chc y t Dch v dnh cho cc t chc chnh ph

Vn

hnh phc tp hn

Network Survivabilityn n

Tnh sn sng 99.999% Thm

(5 con 9) => di 5 pht gin on/nm

Cn c k hoch i ph vi liti nguyn thay th, pht hin li v t ng nh hng cc lung d liu vng qua li thit b thay th khi s c xy ra

n

Khi phc: Ch b sung bng thng, Tit kim ti nguyn Chm

thi gian gin on ln

n

D phng: fast time-scale: Chun

b sn ti nguyn d phng thay th ti nguyn chnh khi xy ra s c Chuyn lung d liu t ng truyn b li sang ng d phng khi c s c xy ra Nhanh: 10s-100s of ms

S cn Cc

loi s c

S

c thnh phn: trn link, nt, knh WDM, phn mm S c h thng: Thm ha c th hy hoi ton b trung tm kt nin Li

n vs. nhiu li ng thi

4.39

cp t/nm/1000 dm cp Thng thng gi thit mng ch c li nn D

phng v khi phc c th thc hin nhiu mc

Tnh sn sngAvailability l xc sut thit b hot ng bnh thng

Availability =

Reliability Reliability + Recovery

nh lng tnh sn sng99% 99.9% 99.99% 99.999% 99.9999% 2-Nines 3-Nines 4-Nines 5-Nines 6-Nines 5,000 Min/Yr 500 Min/Yr 50 Min/Yr 5 Min/Yr 0.5 Min/Yr

n Mi

thnh phn ca mng c tnh sn sng 99.99% n One cut off call in 8000 calls (3 min for average call). Five ineffective calls in every 10,000 calls.

V d mng PSTN

NI0.005 % AN 0.01 % NI : Network Interface LE : Local Exchange LD : Long Distance AN : Access Network

PSTN End-2-End Availability 99.94%

NI0.005 % AN

LE

Facility Entrance 0.005 %

Facility Entrance

LE

0.01 %

LD0.02 %

0.005 %

Source : http://www.packetcable.com/downloads/specs/pkt-tr-voipar-v01-001128.pdf

Cc phng php bo v mngNetwork Survivability Architectures RestorationSelf-healing Network Re-Configurable Network

ProtectionProtection Switching

Mesh Restoration Architectures

Linear Protection Architectures

Ring Protection Architectures

Phn loi cc phng php d phngn Theo

topotnh: link, on, ng

Vng Tuyn

n TheoD

s dng ti nguyn

phng dnh ring D phng chia s

Topo d phng - vngn Cc

nt c ni vi nhau qua cc link to thnh vng trnD

liu c truyn theo chiu ngc li khi c s cW D E Working L L E W Protect

W

E

E

W

Topo d phng Tuyn tnhD phng theo link

D phng theo ng

D phng theo on

D phng dnh ring vs. chia sn D

phng dnh ring phng chia s

Mt

ti nguyn d phng ch dng bo v mt ng truyn chnh ti nguyn d phng c th c dng trong nhiu ng d phng bo v nhiu ng truyn chnh

n D

Mt

n D

phng chia s c tc khi phc chm hn d phng dnh ringMt

thi gian thnh lp ng d phng t cc ti nguyn d phng khi s c xy ra

D phng dnh ring vs. chia s

Bng thng cn thit cho cc ng bo v trn link chung v3-v4

D phng trong SONET/SDH

D phng 1+1 theo link ca SONET/SDHD liu c truyn ng thi trn c ng chnh v ng d phngWorking

TX BR Protection TX

RX SW RX

Working RX SW RX Protection TX TX BR

D phng 1:1 theo link ca SONET/SDHD liu c trn ng chnh v chuyn sang ng d phng khi c s c

TX Bridge TX Protection

RX SW RX

RX SW RX

Working

TX Brigde

Protection

TX

APS Channel

Automatic Protection Switching ca SONET/SDHTc khi phc 60msUnidirectional path-switched ring UPSR 1 cp cho working, 1 cp cho protection

Bidirectional line-switched ring BLSR 4 cp: 2 cp cho working, 2 cp cho protection BLSR 2 cp: Bng thng trn mi cp c chia i, vn chuyn working traffic, vn chuyn protection trafic

UPSR vs. BLSR URPS, moi ket noi dung toan bo vong cho trafic theo 2 chieu BLSR: Moi ket noi dung 1 phan cua 2 vong cho trafic theo 2 chieu Co the tai nhieu ket noi hon khi cac diem nguon, dich ke nhau

UPSR

BLSR

P-cycleMng mesh khng c topo hnh vng n To cc vng trong mng p-cycle n S dng c ch bo v theo topo vng n Cc link trn p-cycle v cc on ct p-cycle c bo vn

Bi ton nh tuyn c d phngTm kim ng i chnh v ng i d phng cho mi kt ni n Rng bucn ngn n

i chnh v ng i d phng phi khng b nh hng ng thi bi mt li nHai ng i khng dng chung 1 cp Hai ng i khng dng chung mt thit b

Tc

khi phc chp nhn c ng i d phng khng qu di lm nh hng trn n

Tiu ch Tit

kim ti nguyn tng cng

C 2 dng tnh v ng tng ng vi bi ton nh tuyn thng thng

Bi ton nh tuyn c d phngn HngTch

tip cnthnh 2 bc nh tuyn:

n nh

tuyn cho ng chnh trc sau tm ng d phng

nh

tuyn ng thi cho c ng chnh v d phngn Rt

kh trong trng hp nh tuyn ng

Chng 6: Mng truy nhp

Mng truy nhp quang v dch v Mng truy nhp thu thp d liu t pha ngi dng v cung cp cho mng li Cc dch v ph bin t pha ngi dng in thoi Mng tryn hnh cp Internet trn nn in thoi (xDSL) hoc cp

Cc loi dch v ca mng truy nhp Ban u, mng truy cp c pht trin cung cp dch v VoD, HDTV Hin nay, mng truy cp cn c kh nng p ng cc loi dch v sau:

Kin trc ca mng truy nhp

Kin trc mng truy nhp Hub Nm pha nh cung cp Nm pha ngi s dng Ni vi 1 ngi dng hoc 1 doanh nghip Trong mng broadcast, RN phn phi d liu t Hub n mi NIU Trong mng switched, RN nhn d liu t Hub v phn phi cc lung khc nhau n cc NIU

NIU: Network Interface Unit

Remote Node

Phn loi mng truy nhp

Hai loi mng truy cp ph bin: Mng in thoi Mng truyn hnh cp

Mng in thoi ni b S dng cp xon

Mng truyn hnh cp Dng c cp ng trc v cp quang Hybrid Fiber Coaxial cable: HFC

HE: headend

Mng truy nhp quang: FTTx D liu c truyn trn cp quang trong mng phn phi (distribution network) cho n ONU (Optical Network Unit) Mong mun: Cp quang n gn thu bao nht

Cp quang kt thc mt cabinet, di 1km cui n thu bao dng mng phn phiONU phc v mt s thu bao (8 to 64); t ONU n NIU dng cp ng (di 100m)FTTC(Fiber To The Curb) / FTTB(Fiber To The Building);

FTTCab(Fiber To The Cabinet):

FTTH(Fiber To The Home); ONUs

thc hin chc nng

ca NIUs;

Mng truy nhp quang: FTTx

PON: Passive Optical Network: gia CO v ONU

Mng truy cp FTTx

Kin trc PON Kin trc mng gia CO v ONU RN: thit b th ng, l mt b chia nhnh hnh sao hoc b nh tuyn tnh theo bc sng Tn hiu thng c broadcast gia CO-ONU v chia s bng thng theo c ch TDM ti ONU

Topo PON

Kin trc AF (all fiber) Mt cp cp ni CO vi mi ONU Gi thnh t l vi s ONU v chi ph bo tr cp S dng trong phm vi nh nh doanh nghip

Kin trc Telephone PON (TPON)

WPON (WDM PON)

EPONEPON: PON vn chuyn d liu l cc frame Ethernet

EPON

EPON