I HC BCH KHOA H NI VIN IN T - VIN THNG

ti: THUT TON MENTOR II

Ging vin hng dn: Trn Ngc Lan

Sinh vin thc hin:

1. L Thi Hng KSTN-TVT-K52

2. Trn Hu Cng KSTN-TVT-K52

3. Phm Vn Ch KSTN-TVT-K52

4. Bi Th Th H KSTN-TVT-K52

H Ni, thng 11 nm 2011

2

Mc Lc

1. Gii Thiu ................................................................................................................................................. 3

YU CU CA BI TP ........................................................................................................................... 5

2. L thuyt ................................................................................................................................................... 6

2.1 Thut ton Mentor ......................................................................................................................... 6

2.1.1 Xc nh node backbone v node trung tm ......................................................................... 6

2.1.2 Chuyn yu cu node sang xng sng. ............................................................................... 7

2.1.3 Xy dng cy Prim-Dijkstra vi tham s ........................................................................... 8

2.2 Thut ton Mentor II ..................................................................................................................... 8

2.2.1 t vn .................................................................................................................................... 8

2.2.2 ISP(Incremental Shortest Path) ............................................................................................. 9

3. Trin khai thut ton ........................................................................................................................... 13

3.1. Tng quan v kin trc .................................................................................................................... 13

3.2. Xy dng thi c s ...................................................................................................................... 13

3.2.1 Class Node ................................................................................................................................. 13

3.2.2 Class Arc ................................................................................................................................... 14

3.2.3. Class Graph ............................................................................................................................... 14

3.3. Thut ton ................................................................................................................................... 15

3.3.1 classMentor ......................................................................................................................... 15

3.3.2 Class Prim Dijkstra .......................................................................................................... 16

3.3.3 Class Floyd Warshall ...................................................................................................... 16

3.3.4 Class ISP ............................................................................................................................. 16

3.4. Form chnh ....................................................................................................................................... 18

4 Kt lun ............................................................................................................................................... 21

3

1. Gii Thiu

Nh ta bit, vin thng c hiu l cch trao i d liu thng qua k

thut in, in t v cc cng ngh hin i khc. V h thng vin thng l tp

hp cc trang thit b k thut cung cp dch v vin thng cho ngi s dng.

Ngay t ngy xa xa, nhng ngi tin s bit dng khi bo hiu, nhng

ngi th dn nhng hn o xa xi dng cc ct khi lin lc, bo hiu v

truyn tin. Nhng vin thng c chnh thc s dng khi con ngi pht minh ra

in bo v in thoi. Cng ngh vin thng t ngy cng pht trin nhanh chng

v vt bc, ng dng trong mi lnh vc. Trn quy m x hi, vin thng lm nn

mt h thn kinh thng minh nhy bn trn tri t, lm thay i b mt, tnh cch ca

tng quc gia v t trong n hnh thnh ln mt mng li lin kt mi ngi ca mi

quc gia trn tri t. S hi t cng ngh trong lnh vc vin thng cng s pht trin

tng trng mnh ca kinh t - x hi, nhu cu s dng cng nh truyn d liu ca

con ngi cng tng ln theo hm s m v ngy cng tr nn phc tp, c khuynh

hng k thut cao vi cht lng cao. V vy, vic t chc mt mng vin thng p

ng c nhu cu y v pht trin t chc mng li ny thnh mt thnh phn c

bn quan trng ca x hi thng tin ha cao trong tng lai na l khng h n gin,

n ng mt vai tr rt quan trng.

gii quyt bi ton trn, ta nhn h thng vin thng trn c phng din

phn cng v phn mm:

V phng din phn cng, h thng vin thng gm cc thit b nh:

Thit b u cui thng tin, thit b chuyn mch, thit b truyn dn.

V phng din phn mm, h thng vin thng cho bit cc phn cng

lin h vi nhau th no ( Topo mng, vi topo mng ta s phn bit c

mng AN(Access Network) v mng li), cc giao thc mng, cc giao

thc lin kt, giao thc trao i thng tin (gia hai giao thc ny c

th tch ri, c th kt hp vi nhau), qun l v khai thc mng.

Trn phng din phn mm, xy dng mng, ta phi xy dng c cu

hnh ca cc phn t mng. MENTOR (Mesh Network Topology Optimization

Routing) l mt thut ton rt hu ch cho vic thit k mng thng tin v n khng

ph thuc vo c im ca bt k mt cng ngh hay kin trc mng no. N ch ph

thuc vo nguyn tc thit k mng. MENTOR c th ng dng cho nhiu loi mng,

c bit l mng ATM (Asynchronous Transfer Mode). V chng trnh MENTOR l

mt ng dng tin hc trong vic thit k Topology cho mng bng chnh thut ton

MENTOR.

4

Trong ti ny yu cu chng em vit mt chng trnh MENTOR nh th.

Chng trnh chng em vit trong thi gian ngn v kin thc c hn nn c rt nhiu

nhng hn ch nht nh nh ch c tnh cht m phng, cc gi thit, iu kin cha

hon ton ging vi yu cu thc t. Tuy nhin, chng em hy vng chng trnh ny

cng gip mi ngi nm c qu trnh xy dng Topology cho mng.

Trong qu trnh thc hin bi tp ln, chng em xin cm n s tn tnh gip

ca c Trn Ngc Lan gip chng em hon thnh bi tp ny. Chng em rt mong

nhn c nhng li khuyn t thy chng em c th khc phc c nhng ci

cha lm c trong ti chng em c th hiu su sc hn v thut ton cng

nh chng trnh MENTOR trong xy dng Topology cho mng vin thng, ng

thi hiu r hn v mn hc T chc v quy hoch mng vin thng.

Chng em xin chn thnh cm n c!

5

YU CU CA BI TP

Vit mt phn mm to topology mng vin thng theo thut ton MENTOR

2.

nn : S lng nt trong mng:

Cost: Chi ph kt ni gia cc nt l mt ma trn [nxn]

Req: Ma trn [nxn] yu cu

Pc, W, R/D: Cc tham s xc nh nt BackBone

: Tham s xc nh cy

: H s s dng bng thng

Cmax [nxn]: Gi tr ti a dung lng ca lin kt gia cc nt( hiu dng)

- Tm cy kt ni cc nt, cho bit cy l dng MST hay PST, MENTOR.

- Tng chiu di cy, chiu di ng i

- Direct link: Tm kt ni Direct link

- ng i trn cy

Tt c th hin trn mn hnh ha.

6

2. L thuyt

2.1 Thut ton Mentor

2.1.1 Xc nh node backbone v node trung tm

Xc nh MAXCOST

Xc nh node backbone tho mn iu kin nw(i) > w

Xc nh node truy cp ca node backbone xc nh

Tm node trung tm ca node cha phn loi, tnh merrit t tm node backbone trong tp cha xc nh , cp

nht li danh sch backbone v node truy cp

Tnh moment ri xc nh node root

Bt u

Mentor

Kt thc

Hnh 2.2.1 Lu thut ton xc nh node backbone

Bc 1: xc nh node backbone tha mn tiu chun trng s:

+ Trng s ca mt node l tng ca tt c cc lu lng vo v ra node

+ Trng s chun ha da vo node i l NW(i) = W(i) / C

+W l tham s

+ Node c NW(i) > W c chn lm node xng sng

Bc 2: xc nh MAXCOST

+ MAXCOST = maxi,j cost(Ni,Nj) = maxi,j

Bc 3: Xc inh node truy cp ca node backbone xc nh

+ Tt c cc node khng tho mn tiu chun trng s v gn node xng

sng s c chn lm node truy cp

7

+ gn c nh ngha l khi gi lin kt t node truy cp e n node

xng sng l nh hn mt phn ca gi lin kt ln nht. cost(e,Ni) <

MAXCOST * RPARM, hay < MAXCOST *

RPARM.

Bc 4: xc inh node backbone v truy cp cho nhng node cn li thuc tp

M

+ Tm trung tm ca trng lc (xctr, yctr).

- xctr =

- yctr =

+ Khong cch ti CG

- dcn =

- maxdc = max(dcn)

- maxW = max (Wn)

+ Tnh merit

- merritn =

+ Phn loi cc node cn li

- merrit a ra gi tr cn bng gia v tr gn trung tm v trng s ca

n.

- Trng s nhng node cha c phn loi, chn node c thng cao

nht v chuyn node ny thnh node xng sng.

- Phn loi cc node mi thnh cc node truy cp.

- C tip tc cho n khi tt c cc node c phn loi.

Bc 5: Tm node trung tm

+ la chn node xng sng trung tm vi gi tr moment nh nht n trung

tm

- Moment(n) =

2.1.2 Chuyn yu cu node sang xng sng.

8

+ xt ei l node truy cp ca node bi, bi l node trc trong cy. V d xt

e1,e2,b1v b2 nu b1 = b2 th khng chuyn yu cu ca e1 v e2 sang b1 v b2,

v ngc li.

Hnh 2.1.2 v d v chuyn yu cu

2.1.3 Xy dng cy Prim-Dijkstra vi tham s

+ cc node u vo l node backbone xc nh trn v root l node trung

tm.

+ Thut ton:

- Nhn Prim = minneighbors dist(node, neighbor)

- Nhn Dijkstra = minneighbors [dist(root, neighbor) + dist(neighbor, node)]

- Nhn Prim-Dijkstra = minneighbors [* dist(root, neighbor) +

dist(neighbor, node)]

2.2 Thut ton Mentor II

2.2.1 t vn

Sau khi chng ta thit k xong mng, chng ta xem xt xem lu lng s i qua u.

a ra mt vn m trung tm chnh l cht lng hot ng ca thut ton nh

tuyn.

Nu ch s dng thut ton Prim Dijkstra, s lng lin kt l t nht m vn m

bo c mt v ch mt ng i duy nht gia 2 node bt k. Tuy nhin vi thit k

nh th, s tn ti nhng lin kt m lu lng i qua n rt ln, iu ng ngha

vi vic khng m bo tnh n nh cho mng

9

Hnh 2.2.1v d mng backbone sau mentor 1

Nh hnh v trn, ta c th thy lin kt gia node 8 v 9 c lu lng i qua ln do

yu cu t cc cc node backbone 9, 2, 14 n node backbone 8, 4. Trong khi , lin

kt gia 2 node 2 v 14 li t do ch c cc yu cu i t node 14 n cc node cn li.

khc phc iu ny, chng ta c th thm cc lin kt trc tip gia cc node. V

d, node 14 v node 4. Nh vy, mt s yu cu t mt s node (VD: node 2, 14) s i

qua lin kt mi ny.

Tuy nhin, nu thm cc lin kt trc tip ny th kh nng mt s lin kt c t

trc s gim lu lng (VD: trong trng hp ny l lin kt 9 8, 9 2) i lc lu

lng ny tr v 0. Hay ni cch khc, thut ton nh tuyn s tm thy ng i

ngn nht nhng ng i c th khng tm thy ng kh thi cho thit k mng

ca chng ta.

Nh vy, cn ci thit gii thut mentor thm cc lin kt trc tip nhng vn phi

xem xt lun n gii hn ca thut ton inh tuyn. Kt qu l thut ton Mentor II

ra i.

2.2.2 ISP(Incremental Shortest Path)

10

y l bc ci tin p ng phn no yu cu trnh by trn. Mc ch ca

thut ton ISP l xc nh tt c nhng cp c th s dng lin kt trc tip thay cho

ng hin thi.

Bt u

Xc nh sp_dist[][], sp_pred[][].

i=0;S(i)

J=0;D(j)

i< numBackbone

j< numBackbone

Xc nh S_list && D_list

Cp nht sp_dist[][] &&

sp_pred[][]

Tnh maxL[n][m]

Sp xt theo th t gin dn cc cp c maxL[n][m] > D

J++

i++

Kt thc

+ u vo l cc thng s kt thc thut ton Mentor

no yes

noyes

ISP

Hnh 2.2.2 lu thut ton ISP

2.2.2.1 Ma trn khong cch thut ton Floyd Warshall

thc hin iu ny ta cn c 2 ma trn

11

Khong cch ng ngn nht Shortest-path distances gia 2 node i,

j(sp_dist)nxn

Ma trn con tr node trn ng i ngn nht gia 2 node i, j(sp_pred)nxn

Hai ma trn ny lun c cp nht sau mi ln thm lin kt. Cch xy dng ma trn

ny vi th bt k rt ging trong thut ton Floyd Warshall

Hnh 2.2.2.1 v d xy dng sp_dist[][] v sp_pred[][]

2.2.2.2 Th t xem xt cc cp cnh

Chng ta sp xt cc cp cnh theo th t bc nhy. V coi l th t cn xt xem

c thm lin kt trc tip hay khng

Hnh 2.2.2.2 v d v sp xp cc cnh theo th t

2.2.2.3 Xt cnh thm vo

Khi xem xt liu c thm lin kt trc tip gia node ngun S v node ch D

di lin kt SD = L. ta xy dng s_list v d_list

o s_list vi ngha tp node c hng li nu mun i n node khc

nu dng lin kt trc tip SD

12

o d_list vi ngha tp node c hng li nu mun i n node

khc nu dng lin kt trc tip DS

Vi ngha nh trn, cch xy dng s_list v d_list nh sau:

o Thm node vo s_list nu: sp_dist[node, s] + L < sp_dist[node, d]

o Thm node vo d_list nu: sp_dist[node, d] + L < sp_dist[node, s]

Hnh 2.2.2.3 v d xy dng s_list[] v d_list[]

Xem xt tt c cc cp (ni, nj) trong ni thuc s_list v nj thuc d_list. Khi

, lu lng (ni, nj) s chuyn sang lin kt d nh nu

sp_dist[ni, s] + L + sp_dist[d, nj] < sp_dist[ni, nj]

di ln nht cho c th n nh lu lng (ni, nj) chuyn i theo ng ny l

maxL = sp_dist[ni, nj] - sp_dist[ni, s] + sp_dist[d, nj]

iu ny c ngha l nu o di lin kt (ni, nj) n nh trong khong (L, maxL) th

lu lng s chuyn i theo ng i SD mi ny

Vi mi cp (ni, nj) ta s c s maxL. Ta sp xp cc cp ny theo th t t

trn xung

maxL(P1) = 2000

maxL(P2) = 1800

maxL(P3) = 1800

maxL(P4) = 1700

y, nu chn gi tr cnh l bao nhiu s quyt nh c bao nhiu cp (ni, nj) c th

s dng lin kt ny. V d SD = 1750 th c cc cp P1, P1, P3 s dng lin kt mi

ny.

13

3. Trin khai thut ton

3.1. Tng quan v kin trc

3.2. Xy dng thi c s

3.2.1 Class Node

+ Thuc tnh:

o public const int isRoot = -1; o public const int unknown = -2; o public const int drawIndex = 0x10; o public const int drawWeigh = 0x20;

// thong so co ban

o public int index; // thu tu node o public int x, y; // toa do o public double weigh; // trong luong nut o public int priority; // >=0 neu la nut truy

nhap, = index la backbone, -1 neu la goc, - neu chua xac

dinh

// Ket noi voi cac nut khac

o public int numNode; o public List otherNodes; o public List send, recv; o public List distance; o public List connected;

+ Operator:

o public Node(int _index, double _weigh, int _priority = Node.unknown, int _x = 0, int _y = 0, int _numNode = 0, List _otherNodes = null,

List _send = null, List _recv = null, List _distance = null, List _connected = null) {}

//hm to o public bool IsOne(Node other, int r = 50) {}

o public void SetPosition(int _x, int _y) {}

o public double GetDistance(Node Other) {} // Ly ta thc

trn Decac(cha b thay i bi mentor)

o public void ConnectNodes(Node Other) // chi dung trong ham CreateNodes. nhu vay se dung thu tu luon - chu y la

no phai connet voi chinh minh

o public void DrawNode(Graphics Grfx, int draw, double div = 2, int r = 7) {} //v node // Hm ny s hin th node vi mu sc ca node v s th t tng ng vi node

14

3.2.2 Class Arc

+ Thuc tnh:

o public Node destination, source; //so thu tu 2 diem source, destination

o public double distance; //do dai canh: distance

o public double c; //dung luong 1 lien ket

o public double ratio; //dung luong cuc dai ung voi moi lien ket (tinh theo %)

o public double capacity; //dung luong tren canh nay voi moi lien ket capacity = c * ratio = 2 * 60%

o public double flow; //tong luu luong tren canh nay: flow

o public int paths; //so luong lien ket song song: paths

o public int priority;

o public const int drawDist = 0x01; o public const int drawCap = 0x02; o public const int drawFlow = 0x04; o public const int drawPaths = 0x08;

+ Operator:

o public Arc(Node _source, Node _destination, double _flow = 0.0, double _c = 2.0, double _ratio = 0.6, int _priority = Node.unknown) {} // hm to

o public void DrawArc(Graphics Grfx, int div = 2) {} // v cnh

o public void DrawParameter(Graphics Grfx, int draw, int div = 2, int r = 8) {} //v cnh, hin thi cc thng s cnh

3.2.3. Class Graph

+ Thuc tnh:

o const int MAX_X = 1500, MAX_Y = 1500; o public List LN; o public List LA; o public int numNode = 0, numArc = 0; o public double cost = 0.0; o public int root = -1; o private Random rd = new Random();

+ Operator:

o public Graph(){} // hm to

15

o public void CreatNodes(int _numNode) {} // Khi to node trn mt phng ta cng cc tham s

tng t class node

o public void AddNode(Node node) {} // Thm node mi vo hnh

o public void ChangeDistNode(Node n1, Node n2, double dist) {} //Thay i khong cch gia cc node

o public void DeleLightBluelArcs() {} o public void AddArc(Arc arc) {} o public void AddArc(Node source, Node destination, double flow

= 0.0) {} // Thm cnh vi cc tham s cnh: node ngun, node ich,

flow

o public void ChangeFlowArc(Arc arc, double flow) {} // Thay i flow

o public void ChangePriorityArcs() {} o public void DrawPath(Graphics Grfx, List nodes, int div

= 2) {} // v cnh

o public void CopyFromGraph(Graph _graph) {} o public void CopyToGraph(Graph _graph) {} o public void AllCopyFromGraph(Graph _graph) {}

// copy ton b graph ti tng vng nh o public void ClearGraph() {} o public double TotalCost() {}

// Tnh tng cost o public void DrawGraph(Graphics Grfx, int draw, int div = 2) {} o protected int Compare(Arc x, Arc y){}

// so snh cc cnh

o public void SortDistArc(List Arcs){} // sp xp cc cnh

3.3. Thut ton

3.3.1 classMentor

+ K tha t class Graph

+ Thuc tnh

o private double[] merit; o private double[] moment; o private double[] dc; o private double W; o private double C; o private double R; o private double MAXCOST = 0;

+ Operator

o private void FindAcessNode(Node node) {}

16

//chua add canh nhe. moi chi chinh nut truy cap thoi

o public void Process(Graph _graph, double _W = 4.0, double _C = 2.0, double _R = 0.3) {}

// hm ny c l xc nh node backbone v node trung tm

o public Mentor(){}

// hm to

3.3.2 Class Prim Dijkstra

+ Thuc tnh:

o private int[] convertIndex; //anh xa nguoc. tu index cua node => thu tu luu trong List node (chu y la gio no khong theo thu tu)

o const int vc = 2000000000; o private double alpha; o private int start; o private double[] label; o private bool[] free;

o public double[] dist; o public int[] pred;

+ Operator:

o public PrimDijkstra() {} // Thut ton chnh

3.3.3 Class Floyd Warshall

Tm ng i ngn nht, gia 2 node bt k, lu vo mng sp_dist, lu li truy vt

sp_pred v s node i ti node ch sp_hop.

+ Thuc tnh:

o private int[] convertIndex; //anh xa nguoc. tu index cua node => thu tu luu trong List node (chu y la gio no khong

theo thu tu)

o const double vc = 2000000000.0; o private double[,] sp_dist; o private int[,] sp_pred; o private int[,] sp_hop;

+Operator:

o public void Process(Graph _graph, double[,] _sp_dist, int[,] _sp_pred, int[,] _sp_hop){}

//Th tc x l x l chnh, thao tc trn th graph.

//Lu gi tr tr v _sp_dist, _sp_pred, _sp_hop

3.3.4 Class ISP

Trin khai thut ton ISP:

17

+ Thuc tnh:

o private int[] convertIndex; //anh xa nguoc. tu index cua node => thu tu luu trong List node (chu y la gio no khong

theo thu tu)

o private List findArc; o private double[,] sp_dist; o private int[,] sp_pred; o private int[,] sp_hop;

o private List d_list; o private List s_list; o private List req_len; o private double esilon = 0.001;

o private double d; // = 1.0 neu muon cho qua 100%. o private double alpha;

o private double[,] NA; o double[] LW;

o public int maxNumberOfAdd = 0; o private int numberOfAdd = 0;

+ Operator:

o private bool ChangedDistArc(Arc arc) {} //t gi tr cho cnh (ni, nj)

o public void UpdatePath(int src, int des, double flow){}

//Trn ng i t node ni n node nj th tt c cc

cnh c update lu lng mi, cc nh c update

trng s mi

o public void UpdateFlowGraph(){} //Update tt c cc cp (ni, nj). Th tc ny s gi

void UpdatePath

o private int CompareHop(Arc x, Arc y){} //So snh cc cp nh (ni, nj) theo s lng bc

nhy

o public void Process(Graph _graph, double _alpha = 0.4, double _d = 0.5){}

//X l chnh trn th backbone vi cc tham s

alpha v d

o private void FindPath(int src, int des){} //Tm ng i ngt nht gia 2 node backbone

(optional)

18

o public void MainFindPath(Node src, Node des, List _path){}

//Tm ng i gia 2 node bt k (optional). Th tc

ny gi void FindPath(){}

3.4. Form chnh

Hnh 3.4.1. Giao din chnh ca chng trnh

Cc chc nng:

1. Chn cc thng s u vo.

19

- Nhp s lng node (mc nh l 90). Chng trnh s to ra N node c

nh s t 0 n N-1.

- La chn cc thng s u vo:

o H s dng trong thut ton Mentor

o R: Bn knh ca mng truy nhp

o D: H s s dng dng trong thut ton Mentor

Ngoi ra, gi tr W: ngng la chn node Backbone xc nh theo d

liu ca bi tp.

2. Thc hin

Sau khi thit lp cc thng s, ti Box Control, ta ln lt thc hin cc chc

nng cn thit:

Mentor: Xc nh cc node Backbone v node truy nhp

PrimDijkstra: Thit lp mng gia cc node Backbone

Next: Thm ng (theo thut ton Mentor 2)

Back: Quay tr v trng thi trc khi Next

Hnh 3.4.2. (2a) La chn thng s u vo (2b) Thc hin

20

Hnh 3.4.3. Thay i cc thng s

- hin th cc thuc tnh gia cc nt mng: ch ph, lu lng, W, CMax, hay

ng qu ti ta nh du vo cc trng nh bn cnh nhng thuc tnh mun

xem.

21

Hnh 3.4.4. Thuc tnh mng v thit lp

Chng trnh cn cho php tm ng gia 2 nt bt k c ni vi nhau nh

hnh 1 l nt 67 v 16.

4 Kt lun

Qua bi tp ln ny, chng em phn no hiu r hn v thut ton

MENTOR v cch hnh thnh cy theo thut ton MENTOR cng nh xy dng

cy PST v MST. c bit, chng em c c hi lm vic trn ngn ng lp trnh

C#, mt ngn ng kh mnh trong lp trnh hng i tng vi ha tt.

Qua bi tp ln, chng em mt ln na pht huy v rn luyn k nng lm vic

nhm v c lp cho mi c nhn.

Tuy nhin, nhm cng c nhiu hn ch cha lm c trong bi tp ln ny,

l mi ch lp trnh c mng Backbone, cha lp trnh c mng Access

(truy nhp).

Do thi gian c hn, nn qu trnh thc hin khng trnh khi sai st hoc

cha c nh mong mun. Chng em xin ha s lm tt hn vo cc bi tp ln

khc.

Chng em xin cm n c Trn Ngc Lan gip chng em trong qu trnh

thc hin bi tp ln ny.