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11
ThiThitt kk mmngng truytruy nhnhpp
2
ThiThitt kk mmngng WAN WAN
MMngng WAN WAN cc ccuu trtrcc tt nhnhngng ngngkktt nnii ringring. Do . Do vvyy ccnn phphii thithitt kk TTii uu chchtt llngng hohott ngng
TTii thithiuu gigi ththnhnh
CungCung ccpp ddchch vv
ChoCho phphpp dd phngphng vvnn hohott ngng cc khikhicc hhngng hhcc
23
MMngng truytruy nhnhpp vv mmngng xngxng ssngng
WAN WAN cc thth chiachia rara ththnhnh 02 02 phphnn MMngng xngxng ssngng (backbone) (backbone) nnii cccc trungtrung tmtm chchnhnh
MMngng truytruy nhnhpp linlin kktt cccc iimm cucuii ttii nntt backbone backbone ggnnnhnhtt
LinLin kktt truytruy nhnhpp cungcung ccpp kktt nnii nnii hhtt, , linlin kktt xngxngssngng cungcung ccpp kktt nnii ngng ddii
CC haihai mmngng uu ccnn phphii thithitt kk
ii vvii mmii loloii ss ddngng cccc nguynnguyn ttcc khkhcc nhaunhau
4
NguynNguyn ttcc thithitt kk1.1. ThiThitt kk tttt phphii cc nhinhiuu ththnhnh phphnn cc ss ddngng tttt2.2. TrongTrong mmngng iinn thothoii ss ddngng phphii caocao (( gigimm gigi
ththnhnh))-- trongtrong mmngng dd liliuu, , ss ddngng phphii nhnh (( gigimm trtr))3.3. MMcc tiutiu ss ddngng 50% 50% trntrn tttt cc cccc linlin kktt (( cncn bbngng
gigi/tr/tr))4.4. MMcc tiutiu cc ccngng tt ngng ccngng tttt ss ddngng ddii mmcc 50%50%5.5. SS ddngng cccc trungtrung tmtm lulu llngng -- llyy rara tt ttnhnh totonn trtrngng
ss6.6. CnCn nhnhcc ss ccnn thithitt vvii ngng ngngnn, , kinhkinh tt tt cccc ngng
ttcc caocao vv ss ddngng7.7. PhPhnn llnn gigiii thuthutt thithitt kk ccnn llpp llii ngng ddngng aa rara
cccc kktt ququ tttt nhnhtt
35
TruyTruy nhnhpp vv xngxng ssngng (1)(1)
Access
Backbone
6
TruyTruy nhnhpp vv xngxng ssngng (2)(2)
IXC1 POP
IXC2 POP
LECCentralOffice
LocalLoops
IXC1 Backbone
IXC2 BackboneAccess lines to IXCs
To otherLEC COs(often SONET ring)
47
DD trtr
IXC1 POP2
IXC2 POP
LECCentralOffice1
LocalLoops
IXC1 Backbone
IXC2 Backbone
Access lines to IXCs
To otherLEC COs
Your Site
LECCO2
IXC2 POP
8
GiGi titinn truytruy ccpp cccc bb ll ngng kk GiGi titinn truytruy nhnhpp cccc bb tngtng lnln
0.020.040.060.080.0
100.0120.0140.0160.0180.0200.0
83 85 87 89 91 93 95 97 99
Year
Local ResidentialInterstate Residential
59
VV dd thithitt kk mmngng truytruy nhnhpp cccc bb (1)(1)
600060007711
800080006611
13000130005511
900090004411
11000110003311
12000120002211
BWBWnnTT
40040077
1327132740040066
168916892136213640040055
20242024255125511427142740040044
2714271432433243204420441483148340040033
122512251526152620312031216821682814281440040022
162916292112211266766713281328198519851929192940040011
77665544332211
Lu lng (i xng)(Ch : Site 1 l hub)
Gi thnh (i xng) $ cho lin kt 56kbps
10
SS ddngng vvii nntt ll iimm ttpp trungtrung
$1929
$1985
$1328 $667
$2112
$1629
1526
1225
1929
6671328
1985
1225 1327
1629
1328
1483
667
$9650 $8660 $7659 (OPTIMAL)
1
2
7
6
5
4
3
1
2
7
6
5
4
3
1
2
7
6
5
4
3
VV dd thithitt kk mmngng truytruy nhnhpp cccc bb (2)(2)
611
VV dd thithitt kk mmngng truytruy nhnhpp cccc bb (3)(3) NNuu nhnh lulu llngng tngtng lnln 50%, 50%, linlin kktt (1,4) (1,4) vv (1,7) (1,7) phphii
ggpp ii mm bboo mmcc ss ddngng ll ddii 50%50%
1225 1327
3258
2656
1483
667
$10616
1
2
7
5
4
3
1327
1629
1328667
$8865 (OPTIMAL)
1
2
7
6
5
4
3
6
1929
1985
Ci thin
12
GiGiii phphpp cc thth (1)(1) CyCy ngng ngngnn nhnhtt ((ddngng thuthutt totonn DijkstraDijkstra))
ss ddngng ngng ththpp TTnn kkmm ( dung ( dung llngng bb phph))
CyCy baobao trtrmm nhnh nhnhtt ((ddngng thuthutt totonn KruskalKruskal)) GiGi ththnhnh hihiuu ququ hnhn trtr caocao do do ddii ngng ddii
ThoTho hihipp ((ddngng thuthutt totonn PrimPrim--DijkstraDijkstra)) KKtt ququ tttt hnhn phphcc ttpp ttnhnh totonn caocao hnhn
713
GiGiii phphpp cc thth (2)(2)
TTmm kikimm ththuu oo nhnh ll CayleyCayley: : VVii n n nntt, , cc tttt cc nnnn--22 cycy baobao
trtrmm khkhcc nhaunhau
KhngKhng khkh thithi vvii bbii totonn ththcc tt
PhngPhng ththcc khkhcc? ?
14
MMtt ttcc , , mmtt trungtrung tmtm VV dd bbii totonn chocho 19 19 nntt cc uu nnii vvoo
hub hub LuLu llngng ii nn hohocc tt mmtt nntt ll 1200 bps/1200 bps/nntt,, 4 sites 4 sites cc thth chiachia ss mmtt ngng dydy Dung Dung llngng ccaa linlin kktt ll 9600 bps9600 bps GiGiii hhnn mmcc ss ddngng ll 50% 50% linlin kktt, , ss
ddngng 50%50%
GiGiii thuthutt nnoo ss cc ss ddngng??
815
MMtt ttcc , , mmtt trungtrung tm(2)tm(2)
GiGi titinn thithitt kk hhnhnh saosao $26,358$26,358 ss ddngng ngng 12.5%12.5%
MST MST gigi $18,730$18,730 DDngng ttii 4 4 linlin kktt trongtrong Uses multiple (up to 4) Uses multiple (up to 4)
links on some legslinks on some legs
PrimPrim--DijkstraDijkstra cycy gigi $15,930$15,930 Using Using = 0.3= 0.3 Hundreds of designs testedHundreds of designs tested
16
MMtt ttcc , , mmtt trungtrung tm(3)tm(3)
VVii n n nntt , , cc nnnn--22 cycy baobao trtrmm khkhcc nhaunhau 20201818 = 2.621 * 10= 2.621 * 102323
yy ll mmtt ss khkh llnn
ViVicc chiachia nhnh khngkhng gigipp cc nhinhiuu NhNhmm 4 4 cc thth ththcc hihinn nhinhiuu ccchch (2.546 * 10(2.546 * 101010 ccchch))
ChaCha ccpp nn nhnhmm 3 3 v..vv..v
917
BBii totonn cycy baobao trtrmm ttii thithiuu cc trtrngng ss(CMST)(CMST)
ChoCho NNtt trungtrung tmtm NN00 TTpp cccc nntt khkhcc (N(N11, N, N22, , NNnn)) TTpp cccc trtrngng ss chocho mmii nntt (w(w11, , , , wwnn)) Dung Dung llngng ccaa linlin kktt WW Ma Ma trtrnn gigi ththnhnh Cost(i,jCost(i,j))
TTmm TTpp cccc cycy T1, T1, , , TkTk
Sao Sao chocho: : MMii NNii thuthucc vv mmtt TjTj vv mmii TjTj uu cc chchaa NN00 ThoTho mnmn mmii quanquan hh sausau
>
0,iTii
j
Ww
Trees Linksl
ll endendCost )2,1(min
18
DDngng bbii totonn CMST (1)CMST (1)
Rng bucw1 = 100 W = Dung lng ca (N0, N1)w2 + w3 + w4 = 65 < W = Dung lng ca (N0, N3)
10
19
DDngng bbii totonn CMST (2)CMST (2)
Mc tiu: Ti thiu gi thnh ca cc lin ktGi = C(N0,N1) + C(N0,N3) + C(N2,N3) + C(N3,N4)
20
ThuThutt totonn CMST (1)CMST (1)
1.1. SSpp xxpp cccc ccnhnh theotheo thth tt gigi tngtng ddnn2.2. LLyy ccnhnh cc gigi nhnh nhnhtt khkhii danhdanh sschch sspp xxpp3.3. ThmThm ccnhnh vvoo cycy kktt ququ nnuu nhnh ccnhnh nnyy
khngkhng nnii haihai nntt nnii rrii hohocc thmthm ccnhnh nnyyvvoo khngkhng vvtt ququ gigiii hhnn dung dung llngng. Quay . Quay trtrllii bbcc 22
11
21
ThuThutt totonn CMST (2)CMST (2)GiGi ss W=3, W=3, mmii nntt cc wiwi=1, =1, vv ccuu
hhnhnh mmngng sausau ::
KhngKhng chchnn(( nnii rrii))
88(2,3)(2,3)
--1515(0,5)(0,5)--1212(2,5)(2,5)
ChChnn1212(0,4)(0,4)BB WiWi > 3> 31010(1,5)(1,5)
KhngKhng chchnn(( nnii rrii))
99(0,3)(0,3)BB WiWi > 3> 388(1,4)(1,4)
ChChnn77(4,5)(4,5)BB WiWi > 3> 366(3,5)(3,5)BB WiWi > 3> 366(3.4)(3.4)
KhngKhng chchnn(( nnii rrii))
66(0,2)(0,2)BB WiWi > 3> 355(2,4)(2,4)
ChChnn55(0,1)(0,1)ChChnn44(1,2)(1,2)ChChnn33(1,3)(1,3)
QuyQuytt nhnhGiGiCCnhnh
0
1
2
3
4
5
3
5
6
7
10
126
5
1512
9
8
8
4
6
22
GiGiii thuthutt EsauEsau--Williams (1)Williams (1) EsauEsau--Williams Williams ttoo rara cycy baobao trtrmm cc trtrngng
ss (CMST)(CMST) SS ddngng hhmm thotho hihipp XyXy ddngng nhnhngng cycy tttt
12
23
GiGiii thuthutt EsauEsau--Williams (2)Williams (2) MMii cycy bbtt uu tt mmtt nntt TTnhnh hhmm thotho hihipp chocho mmii nntt
ThoTho hihipp(N(Nii) = ) = minminjj[Cost(N[Cost(Nii,N,Njj)] )] Cost Cost (Comp(N(Comp(Nii),N),N00))
NNuu thotho hihipp ll mm, , vivicc ghghpp llii ll cc llii CCngng gigi trtr mm ccngng cc llii
ViVicc ghghpp chch cc phphpp nnuu nhnhW(Comp(NW(Comp(Nii)) +)) +W(Comp(NW(Comp(Njj)) ))
13
25
NhNhnn xxtt vv gigiii thuthutt EE--WW
ThoTho hihipp kktt hhpp haihai ththnhnh phphnn A A vv B B ttnhnhcc vivicc tititt kikimm bbngng ccchch ii qua qua nntt hhngng xxmmthaythay vv ii nn nntt trungtrung tmtm
GiGiii thuthutt kktt ththcc khikhi tttt cc cccc thotho hihipp uu lldngdng hay hay danhdanh sachsach cc thth kktt hhpp hhtt
GiGiii thuthutt heuristic heuristic khngkhng mm bboo chocho kktt ququ ttiiuu
mm bboo rrngng cycy thotho mnmn rrngng bubucc dung dung llngng
26
VV dd EsauEsau--William (1)William (1)
W=3, W=3, mmii nntt cc wiwi=1=1
thotho hihip(1)=p(1)=minminjj Cost(N1,NJ)Cost(N1,NJ)-- Cost(Comp(N1),trung Cost(Comp(N1),trung tmtm))==minminjj Cost(N1,N3) Cost(N1,N3) --5 ( 5 ( vv Comp(N1) Comp(N1) cc chchaa N1N1))=3=3--5= 5= --2 (2 (vv nntt hhngng xxmm ggnn nhnhtt ll N3N3))
thotho hihip(2)=4p(2)=4--6= 6= --22
thotho hihip(3)=3p(3)=3--9= 9= --66
thotho hihip(4)=5p(4)=5--12= 12= --77
thotho hihip(5)=6p(5)=6--15= 15= --99
thotho hihip(5) p(5) ll nhnh nhnhtt
ChChpp nhnhnn linlin kktt (5,3) (5,3) chocho gigiii phphpp
vv thotho mnmn rrngng bubucc trtrngng ss trongtrong
ththnhnh phphnn vvii nntt 5 5 vv 3.3.WiWi=W=W55+W+W33=2
14
27
VV dd EsauEsau--William (2)William (2)
CCpp nhnhtt thotho hihip(5)=7p(5)=7--9= 9= --22vv LinLin kktt ngngnn nhnhtt tt 5 5 ll (5,4), (5,4), (Comp(5)=9,n(Comp(5)=9,nt 5 t 5 thngthng qua qua nntt 3 3 nn trungtrung tmtm))
thotho hihip(3)=3p(3)=3--9= 9= --66
thotho hihip(1)=3p(1)=3--5= 5= --22
thotho hihip(2)=4p(2)=4--6= 6= --22
thotho hihip(4)=5p(4)=5--12= 12= --77
LLyy thotho hihip(4) p(4) nhnh nhnhtt
ChChpp nhnhnn linlin kktt (4,2) (4,2) vv thotho mnmn rrngng bubucctrtrngng ss WW44+W+W22=2
15
29
VV dd EsauEsau--William (4)William (4) VV nntt 5 5 vv 3 3 ii qua qua nntt 1 1 nn trungtrung tmtm
CCpp nhnhtt thotho hihip(5)=7p(5)=7--5=25=2
CCpp nhnhtt thotho hihip(3)=6p(3)=6--5= 15= 1
thotho hihip(1)=4p(1)=4--5= 5= --11
thotho hihip(2)=4p(2)=4--6= 6= --22
thotho hihip(4)=6p(4)=6--6=06=0
thotho hihip(2) p(2) ll nhnh nhnhtt nhngnhng
thmthm linlin kktt (2,1) (2,1) ss ttoo ththnhnh phphnn vvii 5 5 nntt vi vi phphmmrrngng bubucc wiwi W.
TTpp titipp theotheo ss bbtt uu vvii nntt nnyy. .
4.4. ThiThitt kk ll kktt ththcc khikhi xyxy ddngng cycy MST MST trongtrongmmii ttpp vv uu cc thmthm nntt trungtrung tmtm C.C.
16
31
NhNhnn xxtt gigiii thuthutt SharmaSharma
BB : : NNuu cccc ggcc ll khkhcc bibitt vv hhmm gigiththnhnh ll nn vv oo tuytuynn ttnhnh, , gigiii thuthuttSharma Sharma ttoo cccc cycy CMST CMST khngkhng cctt nhaunhauvvii iiuu kikinn ll cccc ggcc trungtrung tmtm nhnh hnhn
Sharma so Sharma so vvii EE--WW
EE--W W chocho kktt ququ tttt hnhn trongtrong phphnn llnntrtrngng hhpp
32
VV dd Sharma (1)Sharma (1)
2
10
3
4011
6
18
13
5
1
1912
14
9
15
7
16
8 17
0011114433
10102277
151599
12121414191911885566
181813131717
SSpp xxpp cccc ggcc
17
33
VV dd Sharma (2)Sharma (2)
Cost= $16021 Cost= $16021
S1S1 = N17 = N17
34
NhiNhiuu ttcc linlin kktt (1)(1)
TrongTrong ththcc tt, , cc rrtt nhinhiuu ngng khkhcc nhaunhau chchnn llaa DS0 @ 64kbpsDS0 @ 64kbps
N x DS0N x DS0
T1 @1.5 MbpsT1 @1.5 Mbps
T3 @ 45 MbpsT3 @ 45 Mbps
v..vv..v
18
35
NhiNhiuu ttcc linlin kktt (2)(2)
DD nhinnhin ll chchngng tata mumunn cycy truytruy nhnhpp ssss ddngng ttcc caocao ggnn ggcc vv ttcc ththppnn cccc ccnhnh
Gc
36
BBii totonn CMST CMST aa ttcc (1)(1)
ChoCho:: TTpp cccc nntt NN00, N, N11, , , , NNnn TTpp cccc trtrngng ss chocho mmii nntt (w(w11, , , , wnwn) )
TTpp cccc loloii ngng LL11, L, L22, , , L, Lmm Dung Dung llngng WW11, W, W22, , , W, Wmm Ma Ma trtrnn gigi ththnhnh C(i,j,kC(i,j,k) ) chocho gigi ccaa linlin ktkt loloii
LLkk gigiaa NNii vv NNjj
19
37
BBii totonn CMST CMST aa ttcc (2)(2)
TTmm cycy cc ggcc ttii NN00 vvii nn nhnh linlin kktt saosaochocho
concon chchu(Nu(N)) w(i) < w(i) < WWLink(NLink(N, , pred(Npred(N))))
VV LinksLinksc(end1c(end1LL, end2, end2LL, , typetypeLL) ) ll nhnh nhnhtt
38
GiGiii thuthutt MSLA (MultiMSLA (Multi--speed Local Accessspeed Local Access
1.1. nn nhnh mmii nntt, , linlin kktt nhnh nhnhtt ll nnii nn nnnntt trungtrung tmtm..
2.2. VVii mmii nntt, , ttnhnh dung dung llngng cncn rrii (n) = (n) = WWll wwnnvv tt pred(npred(n)=0 )=0
3.3. TTnhnh totonn thotho hihipp chocho nntt nn-- llii chch ccaa vivicc nniinntt n n vvii i i thaythay vv nnii vvii nntt trungtrung tmtm ((tngtng ttnhnh EE--W) W)
thotho hihippnn(i(i) = c(n,i,L) + Upgrade (i, ) = c(n,i,L) + Upgrade (i, wwnn) ) c(n,0,L)c(n,0,L) thotho hihipp (n)=min(n)=minkk thotho hihippnn(k(k) )
HHmm CCpp nhnhtt Upgrade() Upgrade() ttnhnh gigi ththnhnh thmthm vvoo thmthm wwnn nn vv chocho linlin kktt nnii i i vv 0 0 bbngngccchch ii ngngcc llii hhmm titinn bbii
4.4. ThmThm ccnhnh nn khikhi nnoo thotho hihipp nhnh hnhn hohoccbbngng 00
5.5. XyXy ddngng cycy vv nn nhnh loloii linlin kktt trntrn mmii ccnhnh
20
39
GiGiii thuthutt MLSA: MLSA: VV dd (1)(1)
ThiThitt kk ccuu hhnhnh linlin thngthng nnii nntt 1,2,3,4 1,2,3,4 ttiinntt trungtrung tmtm 00
TrTrngng ss vv cccc loloii linlin kktt
40
GiGiii thuthutt MLSA: MLSA: VV dd (2)(2)
GiGi linlin kktt
21
41
GiGiii thuthutt MLSA: MLSA: VV dd (3)(3)
TrTrngng ththii bbtt uu
42
GiGiii thuthutt MLSA: MLSA: VV dd (4)(4)
XemXem xxtt uu nnii 4 4 thngthng qua 3qua 3
22
43
GiGiii thuthutt MLSA: MLSA: VV dd (5)(5)
VV nnii 4 4 thngthng qua 2qua 2
44
GiGiii thuthutt MLSA: MLSA: VV dd (6)(6)
thotho hihipp44(3) = (3) = CC( 4,3,0 ) + Upgrade( 3,0 ) ( 4,3,0 ) + Upgrade( 3,0 ) CC(4,0,0 ) = 4 (4,0,0 ) = 4 + 0 + 0 -- 7 = 7 = --3. 3.
KhngKhng ccnn ccpp nhnhtt linlin kktt (3,0)(3,0) thotho hihipp44(2) = (2) = CC( 4,2,0 ) + Upgrade( 2,0 ) ( 4,2,0 ) + Upgrade( 2,0 ) CC(4,0,0 )= 6 (4,0,0 )= 6
+ 8 + 8 -- 7 = +7 7 = +7 CCnn ccpp nhnhtt linlin kktt (2,0) (2,0) tt loloii 0 (4.8K) sang 0 (4.8K) sang loloii 1 (28K)1 (28K) Upgrade(2,0) = Upgrade(2,0) = CC(2,0,1) (2,0,1) -- CC(2,0,0) = 15 (2,0,0) = 15 -- 7 = 87 = 8
thotho hihipp44(1) = (1) = --1 1 TTtt nhngnhng khngkhng tttt bbngng nnii thngthngqua qua nntt 33
23
45
GiGiii thuthutt MLSA: MLSA: VV dd (7)(7)
KKtt ququ cucuii ccngng
46
ThiThitt kk truytruy nhnhpp cccc bb nhinhiuu trungtrung tmtm
iiuu gg ss xxyy rara nnuu nhnh cc nhinhiuutrungtrung tmtm?? PhPhii xyxy ddngng rrngng thaythay vv cycy
nhnh nghnghaa : : RRngng F = ( V,E ) F = ( V,E ) ll thth nn khngkhng cc chuchu trtrnhnh..
ChCh : : RRngng khngkhng ccnn thithitt phphii linlinthngthng
24
47
MMtt ss kk hihiuu::
TTpp cccc site site xngxng ssngng (B(B00, , , , BBmm) = B) = B
TTpp cccc nntt truytruy nhnhpp (N(N11, , , , NNnn) = N) = N
TTpp cccc trtrngng ss chocho mmii nntt truytruy ccpp (w(w11,,,,wwnn))
NgNgngng trntrn ccaa trtrngng ss, W., W.
Ma Ma trtrnn gigi ththnhnh Cost(i,j) Cost(i,j) chocho gigi gigiaa cccc ccpp site site xngxng ssng/truyng/truy ccpp..
48
BBii totonn truytruy nhnhpp cccc bb aa trungtrung tmtm(MCLA)(MCLA)
TTmm ttpp cccc cycy TT11, , , , TTkk saosao chocho
(1)(1) MMii cycy cc ngng mmtt site site backbonebackbone
(2)(2)
(3)(3)
Wwji TN
i
25
49
NhNhnn xxtt BBii totonn phphcc ttpp hnhn nhinhiuu so so vvii bbii totonn
mmtt trungtrung tmtm
GiGi ss chchngng tata cc n n nntt truytruy ccpp vv chchngng tatamumunn chiachia rara ll 03 03 ttpp. . SS ccchch chiachia cc thth ll
TToo rara 3 3 bbii totonn CMST CMST cc thth cc gigiiibbngng gigiii thuthutt EsauEsau--WilliamsWilliams
n
k
kn
kn
2
50
EsauEsau--Williams Williams HHngng xxmm ggnn nhnhtt(NNEW)(NNEW)
VVii mmii b b thuthucc B, B, llyy SSbb={ n={ nN | Cost(n,b) < N | Cost(n,b) < Cost(n,bCost(n,b) ) bbB}B}NNuu n n cc khokhongng ccchch nhaunhau gigiaa mmtt vvii nnttbackbone, backbone, thmthm n n vvoo mmtt SSbb mmtt ccchch ngnguu nhinnhin
DDngng EsauEsau--WilliamsWilliams xyxy ddngng CMST CMST chocho mmii ttppbbSSbb..
26
51
VV dd NNEW (1)NNEW (1) Gi s
Cu hnh nh c v ti slide tip 3 nt backbones, B = { 9, 10, 11 } 9 nt truy nhp N = { 0, 1, , 8 }
Trng s mi nt bng 1 tr nt 4 v 5 c trng s bng 2 Hm gi thnh C( i, j ) c tnh bng khong cch vt l
gia nt i v j Dung lng ca lin kt l W = 3
Cc bc Chia ra thnh ba tp nt Dng EW tm MST dung lng cho mi tp
52
VV dd NNEW (2)NNEW (2)
BBcc 1: 1: XXcc nhnh ttpp ddaa trntrn vivicc ttnhnh nnttlnln ccnn ggnn nhnhtt
V d : Xt nt 3C(3,9) = 2
C(3,10) = 3C(3,11) = 4
S9 = { 3 }
27
53
VV dd NNEW (3)NNEW (3)Bc 2: Xy dng tm MST dung lng (dng EW)
54
VV dd ttii saosao NNEW NNEW khngkhng hihiuu qqaa
2
1
10
6
9
7
5
4
38Nt 8 gn 1 hn 2Nhng d nht tibackbone la qua 2 tnt 9
Bi hc: V tr ca cc nt truynhp khc khng th b qua
28
55
EsauEsau--Williams Williams aa trungtrung tm(MCEWtm(MCEW)) PhPhtt tritrinn bbii KerschenbaumKerschenbaum and Chou and Chou
(1974)(1974)
ThayThay ii hhmm thotho hihipp
56
MCEW (2)MCEW (2)
TrongTrong EW, EW, HHmm thotho hihipp TrTr() () ll
Tr(NTr(Nii) = ) = minminjj[Cost(N[Cost(Nii,N,Njj)] )] Cost (Comp(NCost (Comp(Nii),N),N00))
TTnhnh gigi titinn cccc linlin kktt ttii nntt hhmm xxmm so so vviigigi ii ttii nntt trungtrung tmtm
MCEW MCEW HHmm rrngng bubuccTr(NTr(Nii) = ) = minminjjCost(NCost(Nii,N,Njj) ) dist(Comp(Ndist(Comp(Nii), ), Center(NCenter(Njj))))
29
57
MCEW (3)MCEW (3)
Ban Ban uu, , ttpp Center(NCenter(Nii) ) ttii trungtrung tmtm ggnnnhnhtt
NNuu kktt hhpp NNii vvii NNjj, , nngnng ccpp Center(NCenter(Nii) = ) = Center(NCenter(Njj))
ChCh : : HHmm thotho hihipp kktt hhpp gigi titinn vvhhmm khokhongng ccchch
58
MCEW (4)MCEW (4)
MCEW MCEW chocho kktt ququ tttt hnhn NNEW NNEW nhngnhng llii gigi ththnhnh khkh nhnh
< 1% < 1% chocho ss llngng site site llnn
30
59
ThThcc tt
BBii totonn ththcc tt ththngng cc nhinhiuu rrngng bubucckhkhcc GiGiii hhnn ss nntt trntrn cycy truytruy nhnhpp
GiGiii hhnn ss bbcc nhnhyy
GiGiii hhnn ss kktt nnii nntt
NhNhngng linlin kktt hay hay nntt khngkhng tin tin ccyy
60
CCii thithinn thithitt kk mmngng cccc bb
ThiThitt kk mmngng truytruy nhnhpp cncn cc mmtt ss thithiuusstt NhNhnhnh cc ququ nhinhiuu nntt
CyCy truytruy nhnhpp cc ququ nhinhiuu bbcc nhnhyy
v..vv..v
31
61
NhNhnhnh cc ququ nhinhiuu nntt
EW EW kikimm tratra nnuukktt hhpp trtrngng sskhngkhng vvtt ququngngngng
CCchch gigiii quyquytt: : KhngKhng chocho phphppghghpp haihai ththnhnhphphnn mm vvtt ququgigiii hhnn vv ss nntt
62
CyCy truytruy nhnhpp cc ququ nhinhiuu bbcc nhnhyy
CCchch gigiii quyquytt: : GiGiiihhnn susu ccaa cycyxyxy ddngng bbii EWEW
MMii nntt cc mmtt gigi trtr susu
Ban Ban uu gigi trtr thithittllpp bbngng 11. . CCpp nhnhttgigi trtr susu khikhi nhnhghghpp cccc ththnhnh phphnn; ; so so ssnhnh vvii mmccngngngng
32
63
NNtt cc ququ nhinhiuu linlin kktt
CCchch gigiii quyquytt: : GiGiiihhnn bbcc ccaa nntt
Ban Ban uu gigi trtr thithittllpp bbngng 11. . CCpp nhnhttgigi trtr khikhi nhnh ghghppcccc ththnhnh phphnn; ; khkhngng chchpp nhnhnnghghpp nnuu nhnh vvttmmcc ngngngng
64
NNtt trungtrung tmtm cc ququ nhinhiuu linlin kktt (1) (1)
CCchch gigiii quyquytt: : ThayThay ii gigiii thuthuttEW, EW, thmthm mmttthngthng ss thaythayii hhmm thotho hihipp. .
33
65
NNtt trungtrung tmtm cc ququ nhinhiuu linlin kktt (2) (2)
GiGi ss cc mmtt nntt trungtrung tmtm vv EW EW ttoo raracycy vvii ququ nhinhiuu linlin kktt nn nntt trungtrung tmtm..
KhuyKhuynn khkhchch vivicc ghghpp bbngng ccchch thaythay iihhmm thotho hihipp Tradeoff( Nj, Nk ) = Cost( Nj, Nk ) - Cost(
Comp(Nj), Center(Nj) ) Dng > 1 Vic la chn gi tr s quyt nh bc ca nt
trung tm