Nghiên cứu sự ảnh hưởng của chuyển động và giao thức định tuyến trong mannet.PDF

DINH TUYEN TRONG MANG MANET 2.1.2 Dinh tuyin Ara trill vector Hooting each Phuang phap nay djnh thy& dqa ten vector khoitng each, ce cei tien ham so v6i phuang phip djnh tuyen dua tren

CHUCING 1 TONG QUAN Vt MANET

Chuang nay trinh bay cac khai niem tong quan nit& ve MANET, cac img dyng trong nhieu Huh vcre cutjc song cua MANET Dting thtri, de cOp den cac thach thirc ma

MANET dang phai 461 mot

1.1 Mit diu

Mang may tinh to lau da ter thank mot phiin khong the thieu d6i veri nhieu vyt din sting, xa hOi Tir cac hg thling mang eye bO den he thong mpg town nhu Internet, mang may tinh dim mpi ngutri tren the gieri den gAn nhau hon MOi ngtan duqc tiep can voi mot ngu6n th8ng tin, tri thirc phong

Xa hOi phat trien, con ngoai von dung kh8ng ngimg, mot ngueri ket noi vao mpg bin cap vet l5/ thi viec di chuyen mem hp se bi han che Nhu cau clOt ra lit vita ket n6i,

vita c6 the di chuyen 6 bit dr tin mot each dun gib Dieu nay khien cho ngluth cling nghiep mang khong day c6 tiem Ming phat trien mph me

MANET let mot kieu mang khong day rat linh hoot N6 11 top hqp elm hai hay nhieu thiet bi doge trang bi khi Ming n6i mang va truyen thong khong day Cac thiet bi nhu vOy c6 the giao tiep yen tit ca thiet bi mang Ichic ngay kip tut trong dai vo tuyen (yang phit sang, pham vi ma thiet bi mang 46 nhon biet duqc) hay mot thiet bi vo tuyen khic nAm ngotli dai vet' tuyen cua chin vai dieu kien c6 cac node trung gian de chuyen tiep th'Ong tin ter node ngu'6'n den node dich Thiet bi ho trq MANET da clang

va sir dyng kha ph6 bien nhu laptop, dien thoai di dOng Internet Vi co nhieu uu the vuqt trOi va nhittng thach thirc can gilti quyet, ngity nay MANET da va dang duqc

nghien ciru trien khai titbit conga mot s6 ntrac ma ph6 bien la MANET dk biet hau ich trong cac Ung dung nhu khic phyc tham hpa thien nhien, qu6c phong, y te, hOi

nghi nen c6 xu huang (mg dyng rung tai tren the giai

TONG QUAN VE MANET

Ilinh 1.1 sMo hinh mb lib khcii niem MANET

Trong MANET kh8ng ton tai khii niem quirt ly top trung N6 dim bito mang se khong hi s$p vi truing hqp nit mpg di chuyen ra ngoai khoting truyen din ctia cac nut mong khac Nut mong co the ra vao bat cu lac nio Do khoang truyen din dm nut mang lit han cht nen chfing trao deri thong tin bang phuong phap truyen gen tin qua nhieu btrerc (Multihops) De lam duce dieu nay, thi tat ca ale nut mang phai ce khi nang chuyin tiep gen tin den nut mong khic, do voy tat ca cac nut mong trong MANET c6 the hoot dOng nhtr may tram vi router Nut mong co the bao gam met router va met may tram lien ket yen nhau MOt router thus hien cac giao thirc dinh tuyen, may tram

di Ong c6 dia chi IP

MANET cling ci khi niing thqc hien thay dOi ve cAu hinh mang va khic phtic str

c6 cua nut mpg thong qua till' tuc cau hinh Ini mpg Vi du: Neu nut mang rbi Mei mang se gay ra six ceo lien ket, nut mang bi anti huerng ea the yeu au duimg dinh tuyen

va van de se duqc giii quyet Dieu nay se gay ra tre tren mang, tuy nhien yea nguai sir dung MANET yin hoot dOng binh thuong

MANET c6 nhieu uu diem cim mong truyen thong vo tuyen thong thutmg: lien

ket gifts cac nut mang duqc hinh Wirth ngay khi chimg nim trong khoimg truyen din cim nhau

1.3 D#c diem

MANET thuimg duqc mo to c6 cau truc mang they dii do stir thay doi vi tri dui cac nut mpg Cac giao thirc djnh tuyen c6 ca the tv phat hien cac thay d6i ve djnh tuyen thong qua cac thultt town (firth tuyen thong thueng nhu vector Idioang cach vi tang thai cac lien ket MOt &lc diem !chic cila cac net mang trong MANET: bj ON han ve kha nang dm CPU, X) nher, dung lizong pin va bang thong Khi niing Itrong sir dung bj gitri han ;coo theo gi6i han ve khi &Mg truyen din Thiel N truy nhop, men truing vo tuyen cling co cac d#c diem d(ic biet ma ngu&i this& k'e can km tam khi dim

ra cac giao they djnh tuyen cho MANET Vi du: cac lien ket mot chi'eu, no St hien trong trutmg hqp 2 nut mpg c6 cong sulk phat khic nhau nen co khoing truyen din khic nhau, chi cho phip mot nut mpg nghe net mpg Ida Lien kit mot chieu chi co trong MANET, khong ton tai trong mang ti bao Sir dung phucmg phip djnh tuyen nhieu buck thi cac nut mang co the tiet kiem duqc Wing luting phit ra

1.4 (rug dyng

MANET duqc Ong dung cho hOi thio, Ong dung trong quail sv N6 cling dirge sir dung cho trutmg hqp trien khai ca so ha tang mang la kW) khan Vi khich hang co the chia se tep tin de lieu o gm bay, sinh vien trao doi thong tin yeti nhau trong tiet hnc Khi may tinh di dOng giao tiep th8ng qua giao di'en mpg LAN vo tuyein, thi nhom cac may tinh de hlnh thinh MANET, khi de may tinh co the truy tulip Internet, tai nguyen tren mang filar may in, may scan

1.4.1 Dick vg Min dip

TONG QUAN VE MANET

Binh 1.2 Ong dung cho chc dick vy khan dip kid cif thien tai

Bit 14 diu khi cep truerng hop khan *thy ra cin ca Au ket hop cha ate Whin vien ciru ha Gill phi, thong thubng la dung thiet bj v8 tuyen Tuy nhien, khi co so hg ding bj hang holk kh8ng cbn host dung thl gill phip Ih gl? MANET chink lh chu trit

Iii nhanh nhAt va pha hop nhAt Dieu nay co the kheing nghia v6i khu vtrc ton that nho, tuy nhien voi than hoe thien nhien c6 khu vtrc anh huerng tan phi rang letn, viec lien lac nit quan tong nen MANET tr6 thanh gill phip httu ich

1.4.2 MY nglei

Trong hOi ngh1, hOi thho an trao 461 thong tin gifts chc dui bieu hap v6i hOi nghj khic Day la mOt nhu eau lbn trong thin dpi phis trim nhanh vi thong tin nhu hien nay, khi ml gill phip homenetwork chua that so sin sang Gill phip hien tgi la

sir dung clic mpg c6 son cho ate dal bieu them do tuy nhien ne co 40 tre lam, vi du gill phip Mobile IP VI MANET la gill phip chi& uu the

HInh L3 ling dung trong ctic h¢i nghi

1(0 rang au hien dien caa may tinh xich toy yr] Ong dung klgong day lam nhu au

ve home network tang coo Viec sfr dung ky thuit al* MANET cho phap Chung ur au hinh va hinh thinh mang, diet' nay tien lqi cho ca ngubi khOng that au am hieu ye mpg cling nhu gam thurc chi phi cho xity dung thief ke mpg Han rata, neu to ce nhu au sir dung may tinh 6 dog so, trutmg huc thi kh6i lirqng thong tin quirt mpg giant xutong ro rat

Rink 1.4 Ong dung cho home networking 1.4.4 Myng cd Wain (PAN)

6 thtri dpi thong tin till 1 ngubi an mang then nhieu c8ng cu h8 trq cho Ong

viec (dien thaii, Palm .) khi chang duqc lien kit v6i nhau hlnh thanh mpg a nhan PAN thi a) rang mang lai Mau tien ich han cho ngubi sit dung PAN Li mpg di gang

do con ngubi klgong the ng6i yen melt cht3, tuy nhiin khi kit neoi vai ming PAN khic can trq glop ala MANET

TONG QUAN VE MANET

Binh 1.5 Ong dm cho wing ai Man 1.4.5 Hi thing nkung (anbetkd system)

Ngly cling c6 nhieu may mac can kit n6i yen nheng vat xung quash Uri then

nhu au cos MANET No c6 the la d6 choi co kith !ging kit a& mpg, twang tic duqc vbi home network de tim kiim (lit lieu ben Internet hock c6 the kit n6i vai din thoai,

c6 the dieu chinh volume cutt TV khi c6 cuOc gqi din dip (mg nhiiu nhu ciu cM ngueri sil dung

1.4.6 Ming xe 4 (vehicular network)

VANET (Vehicular MANET Network) goi la mpg xe cO MANET, la he thing ming khong can co se ha tang, dugs tao thinh tfr oic phuong tien xe c0 luu thong tree dirtmg Ch(mg duqc trang bi thiit bi thu phat di c6 the lien lac, chin se vi trap d6i thong tin vii nhau gieng Whir mat nut trong MANET Thong tin trao d6i trong ming

VANET bao gem thong tin ye luu luvng xe cO, doh trang ket xe, tai nail giro thong,

nguy lam can trinh va al nhang djch vy thong thiriong nhu djch vq da phuong lien, Internet

Binh 1.6 Ong dung cho wing xe 1.4.7 Mang cdm biin (sensor network)

Mang cam Men khong day la met ung dung then hlnh mkt MANET Hien nay di c6 nhdmg gain tam ding ice cho sit phit tan kilo man nay, chit yeti li trong gain sit, cong an, tinh bio, kilo c6 hqc, nghien citu dia I Cic bit cim Wen c6 the to kich thtroc nho nhung kha Laing truyin thong va luu tri tuong &Si tot Trong quail sit di dung nhing may m6c hien dal nhung kich a gin nhu hat bui nen Ai phuong nit khe phit hien vi phi hay chimg

Trong Huh Arc y te, ale b0 cam bien cho ph6p giant sit lien tuc thong tin lieu chum ire MI song Trong tong nghe thuc phim, k9 thuot ship cam bien duqc ip dung

de gum sit chit Itrqng to the gitip ngin mitt cic sin phim khong chit yeu citu nth tang mirk thou min cho khich hang Trong ding nghiep, the bit cam biota to the giim

xic dinh chit luqng dit tr8ng vi dO im, chimg ding ce the phit hien cic hqp chit kink Ngoii ra, cic b0 cam Wen ding duqc sus dung rang trong th8ng tin thin ties vi moi trutmg

1.5 Nhttng thick thin 661 vet MANET

L5.1 C7s1 phi cho vifc drag this se

taw het the MANET this nghiem hien nay du dna tea bang tin ISM De ngin

ngira nhilu, MANET phii host dung qua met so dii phi cu the No d6, duqc cep phit Ph6 tin khong chi duqc cAp phit vi giim sit chot the ml con cin phai dtrqc frit phi

1.5.2 Co chi tray nk#p

TONG QUAN VE MANET

Khong gitmg nhu mang to bao, trong MANET khong co sir dieu khien tip trung

va dOng bo toim cvc Do d6 cac phucmg phap da truy nh#p truyen thong nhu TDMA vi FDMA khong con thich hop nut Ngosi ra, nhieu giao thirc dieu khien truy nh#p phuong tien MAC (Media Access Control) cling khong giai quyet dirge sir di dOng elm aft mang Do v#y, cac icy thuot 1#p ljch trinh vi djnh thin de h6 thy QoS gip nhieu kh6 khan

Trong MANET, do cimg mOt phuong tien truyen thong dirge chia se boi nhieu ben tham gia nen dal tic truy nhkip den kenh chung phai dugc thvc hien theo kieu phan

bo nh6 sir h6 trg cua giao thirc MAC Giao thirc MAC phai tinh den truy nh#p kenh trong khi dOng than phiti tint' duce sq xung dOt vOi cac nut Ian c#n Do va'y, khi firth toast thiet ki cac giao thirc MAC cho MANET phai tinh den khi riling di chuy'en, van

de du cu& An va cac van de lien quan khic

1.5.3 Dfrth tuyin vd chuyln flip gdi tin trong MANET

13#c tinh dOng cim MANET gay ra sq thay den thtemg xuyen va kh6 dorin try&

cua topo mang, lam tang do kh6 va dO phirc tap de djnh tuyen gifts cac nut di dOng Nhieu giao thirc vi thuot toan djnh tuyen di dirge de xutit cho MANET, thy nhien mai giao thirc lai co mot hart the rieng Do vf)y, nghien ciru ve cac giao thirc djnh tuyen trong MANET la mOt van de rat quan trong

1.5.4 Hiss cud sir dung nguein nuoi

HAu het cac giao thirc trong mang hien nay khong quan tarn den fieu ton niing

lircmg nguon nuoi vi ciic may chic vi ciic b0 tinh tuyen thubng duct gia djnh la tinh va dugc cap nguon tir ngu6n dien chinh Tuy nhien, cac thiet bi di dOng hau het dugc cap nguon ti nguon nag dOc lip Kg thulit nguiln nuoi vim thirimg di chin hun so yen ky

thuat vi xis ly Thai gian cap nguon dm pin loyi tot nhu Li-ionh hien nay cling chi ttii

da tir 2 den 3 gib (hien nay da co mOt se• laptop co thbi gian sir dung len den 8h, tuy nhien gia thinh van con kha cao) Sv gi6i hart than gian hog dong nhu the mai len tinh can thiet phai bao ten tot nguon nuoi Difc biet, din yen MANET, do cac this& bi di ding phai thirc hien vai tr6 cim ca he thOng diu can (twang tic ngueri dimg khi thvc hien cac img dung nguai dimg) lim vai tr6 cua mOt he thing trung gian (chuyen tiep gei tin) nen se tieu ton niing lin:mg nguon nuoi mOt cach dang ke, d#c biet la cac nut trung gian

1.5.5 Dr tittle TCP

TCP (Transmission Control Protocol) la met giao thirc cutn-cuSi duqc thiet ke phvc vv viec dieu khien nghen va dieu khien luting trong mang TCP la met giao thirc huffing lien ket nen can c6 met giai doan thiet lop ket not uu tien cho viec truyen dtY lieu Ket not bi loci be khi viec truyen da lieu hoin think Val intend hien nay, giao thirc mang IP li phi ket not nen an co met giao thirc truyen din luremg ket not ding tin coy qua met giao thirc mang khong tin coy Tuy nhien, TCP gii sir ring cic nut trong tuyen la tinh nen viec dieu khien nghen vi dieu khien luting chi duqc thvc hien cic nut ngu6n vi dich

TCP dip vio viec do dac thin gian thin trinh-RTT (Round Trip Time) vi mirc ton tht gel de ket luon la cif) nghen mach xiy ra trong mang hay khong TCP kh8ng the phiin biet duqc sq co tinh di Ong vi skr nghen mang Cic nut chuyen dieing trong met kit not c6 the giy ten thAt gel vi liun cho RTT dii hon Do voy, an co met

so cii lien de bio dim ring giao thirc any& din thvc hien tot ma thong inh larding den thong ligmg truytn thong cu6i-cu6i

1.5.6 Club lufmg dick vp (QoS)

Khi nang cung cap QoS cua met mang phv thuec vio cic dk tinh ben trong cfia toin be the thinh phin mang, tir cic lien ket truyen phit den tang MAC vi tang mpg Cic ket not khong day c6 niing hp thip vi hay thay doi, ti le 18i cao Cic topo mpg Ii deng vi c6 tY le mat goi cao Cic giao thirc MAC dip tren truy nhOp ngiu nhien khong

he toy QoS

Cic giao thirc MAC QoS giii guy& van de ve xung det phtrang tien, h6 trq truyen thong unicast tin coy, vi cung cap viec dq trey tai nguyen cho cic luu Itripg thou gian thvc trong mei twang kh8ng day phin tin Riit nhieu cic giao thirc MAC vi cic cii tien dirge de xuat de cung cap viec dim bio QoS cho luu Itopg thed gian thvc trong mei truang khong day phin tin bao gem giao thirc GAMA/PR vi co the xung det BB

1.5.7 Tinh an loin vd bdo mkt

M6i truing vo tuyen trong MANET la "mei ngon bdo be" cho cic cuec dui cong ma° dank do dAc tinh quing bi ciut no Cic giao thirc djnh tuyen trong MANET can c6 ho trq tinh nAng xic thvc, mA him de ning cao tinh an toin, hien ntig cua mpg

TONG QUAN VE MANET

TONG KET Chuang nay da trinh bay nhang ly thuyet tong quan ve MANET Trong MANET, topo ming thuang xuyen thay &Si Do vay, cac giao thfrc djnh tuyen trong MANET can giii quyet stir di chuytn cfia nut, ring buijc rang lugng, bang thong

CHUONG 2 DINH TUYEN TRONG MANET D#c tinh dOng cua MANET gay ra str thay d6i thutong xuyen va kh6 down twee

cua topo mpg, lam tang dg kh6 va do phirc top de djnh tuyen giaa cac nut di &Ong Nhieu giao thirc djnh tuyen duqc dua ra, toy nhien, chimg van gap phai mOt s6 han chi that djnh Chucmg nay trinh bay 4 loci giao thee trong MANET: OLSR, AODV, DSR

va DYMO

2.1 Giao thee djnh tuyin d diin

Hien nay, cac giao thirc djnh tuyen dua ra vei MANET deu dqa tren mOt giao thirc djnh tuyen c6 dien lam thuot town ca ban Do de, viec tim hien nghien cuu the hoot dOng cc ban dm cac giao thee nay IA het sire can thiet

Giao thirc c6 dien nhu: djnh tuyen theo vector khoang each, djnh tuyen theo tong thai lien ket da duqc se clung tir rat lau vi da ter nen rat quen thuOc Tuy

cac giao thee nay chi thich hop cho eau tree mpg firth, hoot dOng hieu qua er MANET c6 toe dO di chuyen thap, cau true mong it thay deti Ngoiti ra, giao thirc nay hoot (long phv thuOc vAo ban tin dieu Ichien djnh tuyen, nen yeti 56 Itumg nut mong tang, you cau trao d6i gifts cac net mong tang len, thong tin cep nhot djnh tuyen km, chimg se tieu ton bang thong, nting ltrong va CPU Bei vi hai loci giao thirc djnh tuyen tren duy tri djnh tuyen den tat ca cac nut mong, net khong quan tam nut mong c6 tham gia truyen thong tin trong mong toi moi then diem hay khong Hon nfta, giao thtic djnh tuyen co

dien rang butjc lien ket phai la hai chieu, nen an c6 nhUng cai thien nhAt djnh cho thong tin vo tuyen not chung vi MANET nal rieng

2.1.1 Dinh tuyin Ara tat hating thdi lien kit

Phucmg phap djnh tuyen dva tren tong thai lien ket dua tren gia dm mei lien ket (cost) va net mong phiti duy tri cau tnic mpg hart chinh vei tham s6 nay Tham s6

"gia" se duce cap nh(it bang each mai not mong se gin thong tin quang bit mOt each lien tic "gia" cua cac lien ket xuat phat tir ne tai tat ca the nut mong khac sir dung thuot town flooding Mei net mong khi then duce cac thong tin nay se cep nh(it cau trite mong va sir dung thuot town tim duting di ngiin nhat de chon nut mpg tiep theo cho &rang djnh tuyen den nut mpg khfic Lien ket c6 the c6 gia khong chink xac do nhieu nguyen nhan nhu tre dtamg truyen, sr phan tach cua mong Cac eau hinh mong thay d61 c6 the hinh thanh djnh tuyen khep kin (loop), toy nhien, dirtmg djnh tuyen kieu nay c6 th6i gian tan toi ngin vi chCmg se hi x6a ngay khi ban tin da di qua toan bo mong

DINH TUYEN TRONG MANG MANET

2.1.2 Dinh tuyin Ara trill vector Hooting each

Phuang phap nay djnh thy& dqa ten vector khoitng each, ce cei tien ham so v6i phuang phip djnh tuyen dua tren tang the*, lien ket: mtii nut mpg chi giam sat gie dui lien ket xuit phat tir nO, ve khong queng be thong tin den tit ce nut mang; ne giri queng be deu On den nut lien earth thong tin ve khoimg each ngin nhAt tin nut khec trong mang Nut mang khec khi nhon duce thong tin nay se tinh town Iii bang dinh tuyen thong qua thuk toan tim throng di ngin nhit

Giao thirc nay hoot dOng hieu qui hon, don glen hon va yeu eau it by nha hit frit hon Song, ne ce the sinh ra dutmg djnh tuyen 1chap kin ce thbi gian rim t i thay d6i dei non khk nhau, vi bang djnh tuyen c6 the xiy dung tir th8ng tin di ton tai lau qua tren mang (khong duqc c#p nhk)

2.2 Giao that Malt tuyin cho MANET

2.2.1 Clic yiu ciu cluing

Do cac nut trong MANET luon di dung vit c6 nhien d#c tinh khk biet nen khong the ep dung cac giao thk dinh tuyen thong thutmg Cac MANET thirtmg dirge dfic trtmg bai mOt topo dOng do cac net di chuyen lam thay doi vi tri vitt 19 dm chimg DOi yen MANET, giao thirc djnh tuyen dOng to ra hieu qui ve phu hqp hon cac phuong phap djnh tuyen dye tren vecto khoeng each vi tang thai lien ket Thach thirc trong viec thiet ke cac giao thin djnh tuyen le khi 'ing cop nhot duqc mire di dOng ciut nut

mang Chich mire di dOng nay le nguyen nhen lam thay doi thin by eau trim topo dui

mang Mgt not di clOng thutmg bj gitii hart bin kite nking xi! Iy cita CPU, dung ltrqng luu try, cong suit nguen ve dei thong

M8i trutmg troy cop, moi trutmg v8 tuyen cong co nhOng thuOc firth dkic biet ci ►

phei chit y khi duet ke cac giao thirc cho MANET Vi dy cac duong truyen vo Ming Nhing &Ong truyen nay xuit hien khi hai nut ce tiding det khic nhau ve cho phep chi mOt nut nghe duce nut kia Nhung chimg cling c6 the xuit hien do nhieu tir min truting xung quanh Da ch#ng trong mai Huang vo tuyen c6 the gay ra Wing ich cong suit truyen ve tang ich cong suit do mOi quan he can bk hai gifta veng phu sting ve cong suit phat ra Bing each su dung da chking, cac nut c6 the truyen cac gei tin di sir dung cong suit ra thip

Hinh 2.1 M8 to cac true ca ben c6 the sir dung de dOe to m8i throng MANET True &Au tien le so cac irk trong mang True thfr hai le tic dO ma tai d6 topo inking thay d6i True thir ba le tai hru luqng trong mpg Khi moi twang di chuyen tir gOc

dm 3 trnc, van de djnh tuyen tit nen Ic.h6 khan han Tang se nut, tang tee do thay dig topo (nghia IA tang filth di dOng ciut nut), hoac tang tai Itru luqng mong muen tren mang la thich thirc dei v6i cac giao thin trong MANET

Hinh 2.1 He ton da ca ban me ki moi inning MANET

You cau dei voi mOt giao thirc djnh tuyen cho MANET la gi? Sau day la mOt se you cau quan trong:

• Hoot dong phan tan: Giao thirc djnh tuyen trong MANET phai II giao thirc phan tan yeu cau dO tin c#y cao Do cat nut 11 di dOng nen giao attic djnh tuyen t#p trung la khong phe hqp M8i nut mong phai dii th8ng minh de t4to

cite quytt djnh djnh tuyen ml dung cac net lan

• Khong lap yang: De fling cao chat Itrqng hoot dOng, giao thirc djnh tuyen can dam bito dubng djnh duqc cung cap khong bj lap yang, dieu nay se lam gram Ian phi bang thong vi cong sat tieu hao cua CPU

• Sir dung cac sieu Tat ca cac giao thirc hien cto deu gia djnh rang tic nut

di dOng lit c6 ding cac dac firth dua tren ban chat elm mong ttr t6 chirc la tip hqp tint tic net ngang hang Mac di► dieu nay c6 the clang trong mOt se truing hqp, tuy nhien, c6 truing hqp ma 6 de mong ca cac nut c6 bang thong cao, ngu6n nu8i On djnh, lien ket khong day tee dQ cao han so vol cac nut khac Cac not nhu v#y duqc gqi II cac sieu nat Cac mang t‘r t6 chile trong truing hqp nay thutmg c6 cau frac 2 mac: vimg backbone vit vimg

DINH TUYEN TRONG MANG MANET

phy Wing backbone bao g6m cac sidu nut Them vio d6 cac sieu nut thuang duqc gia djnh IA c& de di chuyin thiip han cac not thuang de duy tri

su 6n djnh cita backbone Ctic nut thtrang khong can co quyet djnh djnh tuyen

• Hoot dOng dua tren yeu au: Tel thieu hoa phial thong tin dieu khien trong mang, giao thirc djnh tuyen thuOc nhOm djnh tuyen theo yeu cAu co the dap img duqc dieu nay NO chi tim dtdmg khi can thiet vi khong quang bi thong tin dieu khien lien tic

• Tinh tien phong (proactive): Trong mOt se twang hqp, tre km do host dOng dip ten yen cAu IA khong chip nhon duac Do d6 phai sit dung tinh tien phong neu tai nguyen ctia mang (ye m*t giai thong) niun trong khoang cho phdp

• H6 trq cac lien ket met chieu: Mai twang vo tuyen ce the la nguyen nhan hinh thanh cac lien ket theo mOt huang Sir dung kieu lien ket nay va kieu lien ket hai chieu se ding cao hien nang ciut giao thirc (Unit tuyen

• Bao met: M6i truang vo tuyen rat de 131 tilt cong, khai thic thong tin, do d6

ma hOa vi chug thuc la cach bito mot thong thutmg nhAt duqc ap dung hien nay Win de la viec phan 134 cac kh6a va cac not trong MANET

• Bao tom nang Nat mang trong MANET co the IA may tinh xach tay hay loci client nho gqn khk nhtr PDA thtrimg co gi6i hin ve thai gian sir dung caa pin, nen can c6 chi de cher (standby mode) de tiet kiem nang luqng Do do, giao thirc djnh tuyen sir dung an he trq the dO char caa nut mang

• Nhieu duang djnh tuyen: Nhim giam se Ian tac dOng do str thay d6i ve cAu tnic mpg va khi nhieu duang djnh tuyen bi nghen Neu nhu met duang djnh tuyen khong sir dung duqc ngra thi met duang djnh tuyen khk co the thay the Nhu vety, giao thus khang an khai tao lai tha tic tim dtrong

Ciao thee AMY tayia tress MANET

• HO trq QoS: Co nhiEu loci QoS can duqc str h6 trq cua cac giao thirc djnh tuyen, no phi thuOc vim raw dich cogs mang; ching han, 116 trq luu ltrqng thin gian thqc

2.2.2 Ph& loci

De so sich vi phan tich cac giao thirc djnh tuyen cho MANET, cac phuong thirc

phan loai hqp l5/ 11 rat quan trqng Cac phuong thirc phan loai giap cho cac nhl nghien

cuu vi cac nha this& ke hieu doge nhang dac mrng khic nhau va mOi quan hg gita cac

giao thuc Cac dac trung nay chit yeu lien quan den viec tap him thong tin djnh tuyen, den vai tit ma met nut co the dim nhan trong qui trinh dinh tuyen

2.2.3 Dinh tuyin theo beteg, 4nIs tuyin Ono yht eiju vd t nh tuyin lai

Met trong nhang phuong thftc ph6 bien nhat de pain loai cac giao fink dinh tuyen cho mang MANET la clua tren viec thong tin dinh tuyEn dirge tap hqp va doge duy tri nhu the nao boi cac nut di dOng Sir ding phuong thirc nay, cac giao thirc Binh tuyen cho manh MANET doge phan chia nhu With 2.2

Minh 2.2 Phan loci cac giao Mac djnh tuyin trong MANET

• Cac giao thirc djnh tuyen theo bang (table-driven): Trong phuong phip djnh tuyen theo bang, cac node trong mang MANET lien tic dinh gia cac tuyen

tot cac node de duy tri tinh Wong thich, cop nhat cfm th8ng tin djnh tuyen

Vi v4y, nits node nguiin co the dua ra molt dtrbng djnh tuyen ngay lop tire !chi can Trong cac giao thirc djnh tuyen theo bang, tat ca cac node can duy tri th8ng tin ye cau hinh mpg Khi eau hinh mang thay riot, cac cop

DINH TUYEN TRONG MANG MANET

nhat dirge truyen Ian trong mang nhiim thong bao st ir thay doi Flau het cac giao tithe djnh tuyen theo bang deu ke thira vi siza doi dac tinh tucmg thick tir cac thuot toan chon throng din ngin nhat trong cac mpg hilu tuyen truyen th6ng Cac thuat tan (filth tuyen theo bang ducrc sir dung cho cac node cap nhot trang thai mpg vit duy tri tuyen bit ke c6 hit lucmg hay khong Vi v$y, tieu de thong tin de duy tri cau hinh mang d6i veri cac giao thirc nay thtrimg la 16n MOt so giao thirc djnh tuyen dien hinh theo bang trong MANET Giao thirc djnh tuyen khong day WRP (Wireless Routing Protocol), djnh tuyen vector khoang each tan tu dich DSDV (Destination Sequence Distance Vector), djnh tuyen trang thai ten tin lien ket OLSR (Optimized Link State Routing), djnh tuyen trang thai gee rung (fisheye (Fisheye State Routing)

• Cfic giao thirc djnh tuyen theo yeu au (on-demand): Trong phurcmg phip djnh tuyen theo yeu au, cac dtrimg din dirge tim kiem chi khi can thiet, host dOng tim tuyen bao gom ca tha tic the djnh tuyen Thu tic tim tuyen ket thitc khi mOt tuyen khong dirge tim they hoc khong c6 tuyin khi dung sau khi xac minh tan WO tap holm v1 tuyen Trong mang MANET, cac tuyen hoot dung c6 the ngimg do tinh di dOng ciut node.VI vay, thong tin duy tri tuyen la tOi quan trong d6i yea ac giao thirc djnh tuyen theo yeu au So veil cac giao thirc djnh tuyen theo bang, cac giao thirc djnh tuyen then you au thuang co tieu de trao d6i thong tin djnh tuyen nhO bun VI voy, ve mat nguyen tic, cac giao thirc nay a kha nang mer tong tot ham d6i v6i ac giao thirc djnh tuyen theo bang Tuy nhien, van de Ian nhit ciut cac giao thire djnh tuyen theo you au la tre" do tim kiem tuyen tram khi chuyen tiep th8ng tin dO lieu Vi du ye mOt so giao thirc djnh tuyen theo you cau glint giao thirc djnh tuyen nguin dOng DSR (Dynamic Source Routing), giao thirc djnh tuyen vector khoitng each theo yeu au AODV (Ad hoc On- demand Distance Vector routing) vi giao thin djnh tuyen theo thir to tam thai TORA (Temporally Ordered Routing Algorithm)

• Cac giao thirc djnh tuyin lai (hybrid) duqc de xuit de ktt hqp uu diem cim 2 logi giao thirc tren va khic phgc cac nhtrqc diem Gila chimg Thong thuimg, cac giao thirc lai duqc trien khai trong mpg ci ciu trim phan cap Cfic giao thirc dinh tuyen theo bang va theo yeu au duqc trien khai trong cac cap thich hqp MOt si vi dv ve giao thirc dinh tuyen lai ghep: giao thirc djnh tuyen vimg ZRP (Zone Routing Protocol), giao thirc djnh tuyen tong thai lien ket dua tren vimg ZHLS (Zone-based Hierarchical Link State routing)

va giao thirc djnh tuyen mmig thy bi'en lai HARP (Hybrid Ad hoc Routing Protocol), v.v

2.2.4 Ceu Ink vd plain be din &ink 4nk hryin

MOt phuong thirc phan logi khac la dua tren vai tre co the ce cim nut trong ea cher' djnh tuyen Trong giao thirc dinh tuyen ding 130, tit ca cac nut di (long c6 cling vai tri va chirc Ming WRP, DSR, AODV va DSDV la nhftng vi dv v'e djnh tuyen ding 130

Ck giao thin nay thuting gia djnh ring ciu tnic mpg la phing Trong mOt giao thfic djnh tuyen bit ding be, mOt se nut dam nhon vai tr6 quan 19 va eh& nang khk nhau Thuat toan phan tan duqc sir dung de km chop dm nut (tic biet nay Trong mOt so truing hqp, cac phuong phap djnh tuyen bit ding 130 gin lien v6i ciu trOc mpg phan clip de de clang t6 chirc vi quail 19 cac nut Cac giao thirc dinh tuyen bit ding bt) co the duqc phan chia dip tren viec to chirc cac nut di (Jong, chirc Ming dinh tuyen va quart 19 duqc thuc hien nhu the nao Theo di, cac giao thirc djnh tuyen bit ding 130 trong MANET duqc chia thanh djnh tuyan phan cap theo vimg, dinh tuyen phan cap theo nh6m va djnh tuyen theo nut lei

Trong cac giao Mire djnh tuyen theo Wmg, cac thuit toan xay dung Wing khk nhau duce trien khai cho viec to chirc nut; vi dv, mOt so thuat town xay dung vimg sir dung thong tin vi tri dja 19 Khai thac hien qua vier phan chia wing se giam duqc ding

ke tieu de de duy tri th8ng tin dinh tuyen Cac nut di dOng trong cimg met Wing biet dtremg den cac nut khac se co chi phi nh6 han so v6i viec duy tri thong tin dinh tuyen ten tat ca cac nut trong Man mpg MOt s6 nut hogt (long nhu la gateway va dam then

truyen thong lien Wing ZRP va ZHLS la hai giao thin djnh tuyen theo Wing cho MANET

Cac giao thirc djnh tuyen theo thorn sir citing thuot Mart xay dung nh6m cho viec bAu chon truing nhem (cluster-head) Cac nut di dOng duce thorn thanh cac thorn,

DINH TUYEN TRONG MANG MANET

tnrang nh6m d6ng vai trb quan 15, thanh vien va dam nh#n chic nang djnh tuyen Clusterhead Gateway Switch Routing (CGSR) limOt vi du caa dinh tuyen theo them Trong ale giao thirc djnh tuyen theo nut lei, cac not dac biet duqc tv dOng lva chqn de gip thinh 1 backbone trong mpg Cac nut "backbone" dam nhk cac vai fro dac biet, nhu la xay dung va theo dbi dtrimg djnh tuyen, quang ba g6i tin dft lieu Core-Extraction Distributed MANET Routing (CEDAR) la min vi du dien hinh cos lo3i djnh tuyen nay

2.2.4.1 Khai this cic metric lining cho dinh thy&

Cac metric sir dung cho viec xay dung tuyen duong c6 the duqc sir dung de phan loci cac giao thirc djnh tuyen trong MANET GAn nhu mqi giao thirc djnh tuyen cho MANET sir dung "s6 chking" lam metric Neu c6 nhieu tuyen duong c6 sin, tuyen nao

ce s6 chking nho nhAt se duqc lva chip Neu tit ca cic lien ket khong day c6 cimg xic

suit I6i thi dtrimg djnh tuyen ngAn se On djnh han dui ng djnh tuyen dai va 0 the giam tieu de luu lucmg, giant xung dOt gei tin Tuy nhien, gia (firth ce cimg xac sulk 16i 0 the khong tin tai trong MANET Theo d6, str On djnh lien ket phai duqc can nhic trong pha xay clung tuyen &rang Vi du, Associatively Based Routing (ARB) va Signal-Based Routing (SSR) duqc de xuAt de sir dung str On djnh lien ket va dO mph tin hieu nhu 11 mOt metric cho dinh tuyen

V6i su ph6 bien cita din toan di dOng, mOt s6 ung dung di dOng ce the co cac yeu cAu QoS khac nhau De dap img cac you cAu nay, cac metric QoS Wang 1mg len duqc sir dung cho viec djnh tuyen vi chuyin tiep goi tin trong MANET Giong nhu mpg c6 day, cic giao thirc dinh tuyen QoS cho MANET ce the sir dung cac metric, nhu la bang thong, tre, tre jitter, ti le 16i gel tin va chi phi Vi du, bang thong va dO 6n dinh lien ket duqc sir dung trong CEDAR lam metric cho viec xay dung tuyen dutmg 2.2.4.2 iforc luryng topo, dich, vj tri cho djnh tuyen

Trong mOt giao thirc dinh tuyin theo topo cho MANET, cac nut tap hqp thong tin topo mpg cho viec djnh tuyen Ngoai cac giao thirc djnh tuyen theo topo, mOt s6 giao thirc djnh tuyen theo dich duqc de xuAt cho MANET Trong cac giao thirc nay, mOt nut chi can biet next-hop tren dui ng dinh tuyen khi chuyen tiep gei tin ten dich

Vi du, DSR la giao thirc dinh tuyen theo topo va AODV, DSDV la giao thirc djnh tuyen theo dich Viec sin ce caa he thAng dinh v1 toll) cAu (GPS) ho#c cac he thting djnh vi ttrcmg ducmg cho phep cac nut di dOng truy nhap thong tin vi tri dia 1S , mOt each a clang Trong cac giao that djnh tuyen theo vi tri, mei quan he ve vi tri gift cac

nut chuyen tiep g6i tin va nut dich, ding v6i sir di chuyen cua nut, c6 the duqc sir dung trong ca quit trinh khiun pha tuyen va chuyen tier) goi tin Location Aided Routing (LAR) vi Distance Routing Effect Algorithm for Mobility (DREAM) la cac giao thirc dinh tuyen theo vj tri cho MANET

Sau day la mOt s6 giao thirc djnh tuyen duqc de xtuit cho MANET

2.3 Optimized link state routing (OLSR)

OLSR la giao thirc dinh tuyen theo bang va la mOt stir ten tru cim giao thirc tying thai lien ket c6 dien, hoin toan thich hqp cho mung di dOng MANET OLSR tot thieu hoa tieu de dinh tuyen bang each chi sir dung cac not duqc chun de" phat trim Ian luu luqng dieu khien, duqc gui 11 Chuyen tiep da diem MPR (Multipoint Relay) K9 thu$t nay giam thing ke so lucong you au truyen lui de phat trim lan mOt ban tin tai tft ca cac not trong mpg

2.3.1 Bits chpn Multipoint relay

MPR la de t6i thieu hos overhead khi phat thin Ian ban tin trong mung bang caich

giam Si, lan truyen lui trong ding mOt vimg Mtn not trong mung lira chqn mOt top hqp cac not hang x6m trvc tiep ciut ne de lam MPR Hang xOm coa not A ma khong dim trong tip hqp MPR ciut A c6 the nhOn vi xir ly cac bin tin quing ba nhtmg khong the

truyen cac bin tin quang hi nhon duqc dr A

Hinh 23 Qua trinh phat tran lan bcin tin awing bet

INNH TUYEN TRONG MANG MANET

Mai nut Iva chon tip hqp MPR tir than hang xOm tnrc tiep (one-hop) caa ne Tip hqp MPR cua nut A, ki hieu la MPR(A), la tip con caa tip hqp cac hang xOm tnrc tiep dm A, phai thaa man nhung dieu kien sau: mai nut trong hang xOm hai buec (two-hop) caa A phai c6 met lien ket trot tiep den MPR(A) Tip hqp MPR cang nh6 thi tieu de luu Wong dieu khien caa giao thirc djnh tuyen cimg nh6 Mai nut phai duy tri thong tin ve tip hqp hang xOm ma chimg chon lam MPR T$p hop nay goi la "MPR selector set" dm mat Ma

Hinh 2.4 Bdu chpn MPR

Trong OLSR, mOi nut truyen bin tin Hello djnh ky (vi dv met giay mat ban tin) tren mOi giao dien caa nat Mvc dick chinh cua ban tin Hello cho phop mai nut ce the kham pha tuyen tnrc tiep tOi hang x6m caa no Ban tin Hello dugc quang ba tang chOng met (hop-by-hop) va phiti Icheng dugc truyen truec do Ban tin Hello bao gam ten caa nut khoi too, hang xOm tnrc tiep ma mit khei to truyen ban tin kham pha, va cac nut ma nut khoi to chon lam MPRs Khi met nut nghe thAy ban tin Hello, n6 kiem tra lieu ban tin de ce phii dugc phut sinh tir hang xem mei hay khong, va neu dung, nut se cop nhOt vao danh such hang x6m ttuc tiep cita nut Ban tin Hello rid quan tong trong viec ha trg khai niem MPR Mai nut kiem tra ban tin Hello thin dugc tir hang xOm caa ne de xem n6 lieu c6 dugc Iva chon lam MPR cua bit kt hang xOm nao Musing Neu vay, nut se phut tan Ian cac c#p nh#t djnh tuyen dugc phut sinh tir cue hang xOm ma da chon ne la MPR Mai nut cling c6 the kham phi lieu ck nut c6 la hang xem hai birec tir ban tin Hello, bei vi danh such ck hang xOm hai bulk dA dugc liet ke trong ban tin Hello dm net hang thin trim tiep cua no Mai nut Iva chon MPR

tren cc so hang xem hai bu6c, do vfty mil hang xem hai butc phai nh#n duqc ban tin MPR

2.3.2 Truyin bb bin tin ilidu Hain topo (Topology control)

Ban tin dieu Ichien topo duqc truyen di voi mvc dich cung cap cho m6i net trong mang cac th8ng tin lien ket trang thai day de de cho phdp tinh toan duqc tuyen duang

2.3.3 rink todn tuyIn

Th8ng tin trang thai lien ket dua ra duqc thvc hien thong qua trao d6i djnh ky cac ban tin, cling giting nhu eau hinh giao dien cea cac not, bang djnh tuyin elm mOi net

co the duce tinh toan

2.4 Dynamic source routing (DSR)

Giao thee dinh tuyen ngu6n clang DSR la giao tittle dinh tuyen don gian va hieu qua Giao thee nay duqc thi'et ke de sir ding trong the MANET v8 tuyen da chting c6 the da di chuyen cao cua cac net Cac net nay ph6i hqp vdi nhau de chuyen fitly the goi tin Do v#y goi tin co the duce chuyen den cac net khong nom trong vimg phe sang cea chinh net do Khi cac net trong mpg di chuyen, tham gia hoc rei khoi mang thi toan b0 cac the we djnh tuyen duce )(tic dinh va duy tri mat each tv dOng beci giao thin djnh tuyen DSR

DSR bao gam 2 cc the cc bitn: Kham pha tuyen (Route Discovery) va Duy tri tuyen (Route Maintenance) Kham pha tuyen va Duy tri tuyen host dOng horin toan theo you eau

2.4.1 Dinh tuyin nguin

DSR phat hien vi sir clang cac tuyen ngu6n Net girl tin se phai nom three toan b0 thOng tin ve trinh tv sip xep dm cite elAing (vi tri the nit) cea mang tai mat not dich Mtn gel tin duqc djnh tuyEn se mang thong tin ve danh sach cac ching nay trong tieu

de U'u diem quan tong cart the toe dinh tuyen ngulin la the net trung gian khong an phat duy tri viec cap nhk thong tin dinh tuyen ;chi chuyen titp cac gel tin bai vi ban than cac g6i di mang thong tin quytt djnh viec dinh tuyen (danh sach day di cac nit theo trinh tn ma gai phai di qua)

Viec t$p hop thong tin ve topo mang tai net nguon ciut mot gin cho phep not ngulin phan phat cac gei tin met each hieu qua trong mang Dieu nay rat thich hqp vai viec quan ly tai nguyen trong MANET

DiNH TUYEN TRONG MANG MANET

Giao thirc djnh thy& dra ten the tuyen ngu6n con c6 them 2 lqi ich Thir ni t, giao that c45 the chimg mirth duqc met each don gian tinh Ichong lip yang bei vi tuyen nguian duqc sir dung dieu Mien djnh tuyen the goi Thir hai, moi fiver' nguen lit met ban ke ski

ve met throng truyen cv the, tin coy de truyen the thong tin qua mang

DSR sir dung cac thy& nguon vi mOi gei duqc djnh my& dva tren met tuyen nguen Icharn phi duce, thy nhien nhUng cai thien gAn day deli yen DSR da cho phip hiu het the goi tin khong phai mang theo phi!' tieu de chira thong tin diry du ve tuyen nguen

2.4.2 Khans pith tuyin

Kham pha tuyen duce thvc hien bang.each phat bin Ian yeu cau qua mon de tim kiem melt tuyen toi dich nit° db Trong dung don gian nhit, not nguen A muen kham pha met tuyen tai nut dich D thi A se phat quang bi goi tin Yeu cAu tuyen RREQ va goi nay tiep tuc duqc quang ba beri cac not tnmg gian cho den khi no den dirge not

dich D Trong cu the nay, nhitu t6i tru hos duce sir dung de giOi Nut tin s6 vit phom

vi ctia cite Kham phi tuyen

Khi met nut S muen girl met goi tin den D, dau tien no se at vito phisn tieu de caa goi tin d6 met tuyen ngu6n trong de chi ra thb to ciut cac chin ma g6i tin se phiti

di qua Thong thuang, nut S se dot duet met tuyen nguen thick hop thong qua vies tim kiem trong Be nha tuyen cita n6 the tuyen di biet fru& day Tuy nhien nets khong tim

ditty tuyen nao trong Be nh6 tuyen, ne se khei to alit tut Tim kitm tuyen dOng de tim

ra met tuyen ngu6n tai D Trong hiding bp nay to gqi not S la flat nguen con not D la not dich trong thu tvc Khim pha tuyen

Trubc khi khei too met g6i tin RREQ, not nguiin chen met nhon clang yeu au (Request_id) dOt trong g6i tin RREQ C(Ip <dia chi nut nguen, nhOn clang yeu au> la duy nhAt

A "A" A "A, B" A "A, B, C" A "A, B, C, D"

I id=2 I id=2 I id=2 I id=2

Ifinh 2.5 Kham phci tuyin trong DSR

Hilt 2.5 mirth hip qua trinh Kham pha tuyen don gian, nut A co ging khim phi tuyen tai nut E De kheri dau Kham phi tuyen, A truyen met tin bao RREQ M6i tin bao RREQ than dang not nguan vi dich cita Khim phi tuyen Nhan don yeu cau duqc xac djnh boi nut nguen ciut Yeu au Met RREQ bao gem met ban ghi danh sach dia chi ctia tong nut trong gian ma tin bao RREQ da di qua Gil tri ban du ctia ban ghi tuyen la met danh &etch tong

Khi met nut nhan duqc ban tin RREQ nay (vi du nhu not B trong vi du), neu no

la dich ciut Kham phi tuyen, no se giri loi ban tin Tra leri tuyen RREP tai kheri to cita Kham phi tuyen, chuyen ban copy ciut ban ghi tuyen duqc Ong den tir RREQ; khi nut

nguon Tilton duqc RREP, n6 cat gift tuyen nay trong Be rifles tuyen a sir dung khi girl cac goi tin tiep theo tai dfch nay

Mot khic, nett met nut nhon RREQ ma da then duqc met ban tin RREQ khic tir nut nguen, mang theo nhihtg nhan dong yeu du va dia chi dich giemg nhau hok neu dia chi rieng cita nut nay da nim trong bao do tuyen dui RREQ, n6 se tir chei You cau Neu Ming, nut nay se gin dia chi rieng cita n6 vao ban ghi tuyen trong ban tin RREQ va tiep tic quang bi net Trong vi du, nut B se quang ba ban tin RREQ, no se duqc than 6 nut C, nut C va nth D ding voy, ne se broadcast Yeu cau, ket qua la copy dui You du se duqc nhan beri nut E

Trong viec ban tin RREP ter 10 nut nguen trong the tuc Kham phi tuyen, citing hon nut E tra liri not A trong hinh 2.5, nut E se kiem tra Be nher tuyen ciut no xem lieu

co met tuyen ngtrqc vat nut A, va neu tim duqc no se sir chmg tuyen nay lam tuyen nguen de phan phat cac goi tin bao gem ca gel RREP Neu khong tim duqc met tuyen nguqc trer 10 A, E co the thuc hien thit tuc Kham phi tuyen tir no tai A De tranh khit nang quay loi vo han co the cita dc Khim phi tuyen, no se chen ban tin RREP vao chinh ban tin RREQ cita n6 del ved nut A Sir dung co chat nay n6 ding co kha nitng cOng theo cac goi dO lieu nho khic vi du nhu gei TCP SYN tren met ban tin RREQ Nut E con c6 the dao vi tri sip xep ciut cac cheng trong ban ghi tuyen vi sir dung tuyen

da dao vi tri nay nhu met tuyen nguen del veri cac gei tin mang ban tin RREP ciut chinh nO

Khi kheri too met Kham phi tuyen, nut dang giri se gift loi ban sao ctia pi% tin ban tau trong be nher dem nOi be (Send Buffer) gqi la bi) dem girl Ngoai ra Send Buffer

dm chira cac ban sao dut cac goi tin kh8ng truyen di &Km do chua tim ra met tuyen nguen teri dich MOi goi trong Send Buffer duchy gan cho met than uteri gian chi ra thin gian chimg ton tai trong Buffer va goi tin se bj teal be sau khi thin gian luu loi trong

DINH TUYEN TRONG MANG MANET

Send Buffer qua han; de Send Buffer khong bj trim, ki thuOt FIFO hoac ki thujt Wang ducmg !chic ce the ducat sir ding de truyen cic g6i tin d6 di fru& khi chin het han Trong truemg hop gig tin con Itru lot trong Send Buffer ma chua truyen di duqc thi thinh thoang nut mpg loi thiet lop mai tha We Khitm phi tuyen thy theo dja chi dich cita cic gel Tuy nhien, tan suit khai too cic Kham phi tuyen mdi can phai duqc giai han do ce the xay ra truing hop dich cita thit ttic khiti too tuyEn dif thay va khong the tai duqc Tren thvc ter', do gi6i han ve phom vi truyen din vo tuyen va sv di chuyen elm cic nut trong mang nen nhieu khi eau frac mang bi phan manh, nghia la khong c6 dui tv sap xep dm cic chAng ma qua do gOi tin duqc chuyen tiep tai dich Kieu phin mitnh nhu voy co the hiem gip hoac phi') Bien thy thuOc vao kieu di chuyen

va mot dO ciut cic nut trong mong

Trong thaw hqp vii mai gOi tin, mOt this tve Kham phi tuyen duqc khai too thi mOt so 16n the gOi RREQ khong frau ich duqc truyen tir nut nay tai tat ca cic nut khac trong mang De giam phan phv trOi tieu de do cic Khiun phi tuyEn tree ngtr&i to phai gidi han tan mat Bei too cic Khim phi tuyen tir mot nth bat ki den cimg mOt dich Nat chi duqc phep khai too Khim phi tuyen mai sau khi dqi het khoang then gian t6i thieu can thiet de co the thiet Icy thu tvc Kham phi tuyen mai

Tir ket qua cos viOc kiem tra ban sao the tuyen nguan ghi duqc, thuot toan Khim phi tuyen dit ngAn chOn duqc viOc cic RREQ trong mong DO la mOt thuOc tinh hieu chinh quan tong va lit nguyen nhan too ra thuOc tinh khong lip yang cita DSR Sir dtmg cic nh(in (long yeu cAu la mOt tOi uu don giin khi de cic RREQ ban dill' triti rung hudng ra phia ngoai so vii not nguOn va rut bat sit the gOi RREQ bao quanh lx) khai too

2.4.3 Duy tri tuyin

DINH TUYEN TRONG MANG MANET

Hinh 2.6 Duy tri tuyin, nat C khong thi chuyin step sir A din E qua

lien kit tea buck nhay slip theo D cua no

Khi gin hoitc chuyen tiep mot geoi tin tai dich D nao d6 su dung tuyen nguon, mai

nut se co nhiem vg giam sat va khing dinh rang goi tin d6 di den duce ch•ng tiep theo

tren tuyen ngulin hay chua; gei tin se duqc truyen liti (sau mot sit lin cho phep) cho tai

khi nut nay nhfut duqc khing dinh rang no dA den duqc nut tiep theo Vi dg truang hqp

duqc minh hqa trong hinh 2.6: nut A girl mOt gei tin tai E sir dung mOt tuyen nguon

th6ng qua the nut trung gian B, C vi D Trong trubng hqp nay nut A chill trach nhiem

ve viec nhon gei tin a not B, nut B chju trach nhiem viec nhon g6i tin a nut C, nut C Igi

chju trach nhiem ve viec nh#n gei tin a nut D, vi tin nhu the den nut Si cling nut

D phiti chju trach nhiem ve viec nh#n gen tin 6 net E Trong nhieu twang hqp khing

dinh viec nhOrt gei tin kh8ng inh htemg gi d6i Arai giao thirc DSR do thuc to day la

met phAn cua cac thin tuc lap MAC

Neu ca the nay kh6ng ton tai vi sin co a cac nut thi khi d6 nut gin tin se dimg

mOt bit th8ng tin trong phan tieu de cfia gel tin de you au mOt phtic dip tir not tiep

theo th6ng qua phAn mem d#c biet trong DSR Thong thu?Ing phtic dip qua phAn mem

nay duqc truyen trvc tiep ten nut girl tin Tuy nhien neu dubng lien kit gitta hai nut lit

lien kit don htrang thi phitc dip nay co the phai di qua at nhieu chang khic nhau de

quay lai not gin tin

Neu gal tin duqc truyen Igi qua mOt s6 chOng va vtrqt qua s 0 1A'n cvc dai cho

phep ma van chua nh#n duqc khing dinh tir nut tiep theo, nut nay se gin ban tin brio

16i tuyen RERR quay ter Igi net di gin ban tin ban ditu de xic minh tuyen bi loi tin nut

nao Vi dg trong hinh 2.6 tren : neu nut C khong the truyen tin din nut D tiep theo, C

se girl ban tin RERR ve nut A va ttr?mg trinh ring tuyen tir C den 13 bi dirt Khi de A

DINH TUYEN TRONG MANG MANET

se xoa duang lien ket bj thi nay khei b0 nha tuyen cita no Viec truyen lui bin tin ban tau bay gia la nhiem Ng' vi chirc ning cM cic thu kw lap cao han nhu TCP Trong twang hqp phii girl Iii gel tin tai chinh dich E vi neu trong hi) nha tuyen cita nut A co

met tuyen khic tai E (vi du tir cac bin tin tri IM tuyen tir cic thit tic khan phi tuyen truerc d6 hoic la tir viec nghe 16m duqc the th8ng tin djnh tuyen tir cic ged tin khic) thi no se giri ngay gen tin sa dung tuyen mai do Neu kh8ng no se thuc hien mOt this

tic khim phi tuyen mai tai dich E nal tren

2.5 Ad hoc on- demand distance vector routing (AODV)

AODV cho phep djnh tuyen nhieu buck gifts the nut mung de thiet lop vi duy tri MANET AODV dip tren thuit town vector khoing each nhung thuOc lo3i djnh thy& theo you ciu, no chi yeu cau &rang djnh tuyen khi can thiet Thuit toin djnh tuyen AODV khi phi hqp cho au hinh mang dOng AODV dint is cac tuyen khong 1:4 lip ngay ca khi no dang sira cic lien ket 16i Bai vi giao thirc nay khong you au quing bi

tuyen djnh ky tren thin mpg, nen yeu ciu toin be bang th8ng co sin cho mOt nut di dOng thuc chit lit thip han so veil cic giao thirc khic, nhang giao thirc yeu ciu quing

bi

AODV sir dung lien ket Qs& ximg gifts the hing xam G6i tin kb:sing di theo tuyen

dubng gifts de nut khi mOt trong nhang not de khong nghe duqc tir cite mit khic

Nhang nut khong nim tren cac tuyen duerng hoot dOng; chting se khong duy tri bit al th8ng tin djnh tuyen nio cling nhu khong tham gia vio bit ky su trao deoi bang djnh tuyen djnh ky nio Han naa, meat nut khong phii khim phi vi duy tri mOt tuyen tai nut khic cho tai khi hai nut an giao tiep yeti nhau, trir khi nut do thing vai fro nhu mOt tram chuyen tiep trung gian de duy tri ket not giita hai nut khic Khi mot ket nos cac

be dm nut di dOng dirge thiet lip, mai nut co the nhon thiy cac nut khic trong vimg Ian con ciut no bAng mOt vii ki thuit, bao Own quing bi cue be cic ban tin Hello Bing djnh tuyen ciut cac not trong yang lin On duqc tuo ra toi uu thiti gian dip img Uri vai su di chuyen cac N.) vi cung cap then gian dap img nhanh cho the yeu au thitt lop tuyen mai

Ate tieu chant caa thuit toin AODV:

• Giri broadcast the gei tin khim phi tuyen khi an thiet

• Phan biet gifta phit hien-quin 19 ket not cac be trong Wing lin con vai duy tri topo mpg chung

• Quang ba thong tin ve su thay d6i ket n6i cpc b0 tai cac nut hang x6m ma thuc

su an thong tin

AODV sir dung mOt ca the Itham phi tuyen yea su chi bien ciut thuAt toan DSR Thay vi djnh tuyin ngu6n, AODV tin ttremg vao sq thiet lop dOng cac entry trong Bang djnh tuyen a cac nut trung gian

AODV sir dung s6 thir tit a nut mang dich de &op cho tuyen du?mg lain cop nhOt

va khong hlnh thanh dtrimg djnh tuy6'n khtp kin Han n&a, AODV cling h6 trq djnh tuyen multicast va giai (my& duce yin de dem via hgn trong thu#t tofu) Bellman Ford

2.5.1 flat pith tuyin

Qua trinh ICham phi tuyen duqc Icheri tao bit cir khi nao mOt nut ngulin mu6n giao tiep v6i cac nut mang khac nhung no l3i kW:mg co th8ng tin djnh tuyEn trong Bang djnh tuy6n cua no Mai nut duy tri hai b0 dem: s6 thir tq nut va broadcast ID

Nut ngu6n kheri tao Kham phi tuyen bing cach quiing ba gal tin RREQ toi hang x6m

dm no

RREQ chira cac truang sau:

<source_addr source sequence* broadcast_id dest_addr dest sequence * hop_cnt>

Trong do:

dest sequence: s6 thir tu dich

hop_cnt : 56 chang

RREQ broadcast_id duqc ting len khi nut ngu6n kheri tao mot RREQ meri Mai nut hang )(am khi nhan duqc ban tin RREQ se giri lai mOt bim tin RREP tai nut ngu6n neu

no biet mOt tuyen tai dich, hoc tiep tuc quang ba ban tin RREQ toi not hang x6m sau khi tin hop_cnt Chu y ring miSi nut co the nhon duqc nhieu ban sao cua cimg mOt RREQ tir cac hang x6m Khi mOt nut trung gian nhon duqc mot RREQ, neu no di

DINH TUYEN TRONG MANG MANET

nhin RREQ voi cang broadcast_id vi dia chi dich, nO se loii b6 RREQ do vi kheng chuyen tier) gei tin de naa Neu met nut khong the dip img duqc RREQ, no se theo dOi cic thong tin sau de thiet lip tuyen dubng nguqc cling filer thiet lip tuyen dubng thuin de (kith cho vier truyen gel tin RREP

• Dia chi IP dich

• Dia chi IP nguin

• Broadcast ID

• Thai gian het han ciut entry tuyen dubng nguqc

• S6 the tit cua net nguin

2.5.2 That lip tuyin dwang ngupt

CO hai s6 the to duqc chira trong met bin tin RREQ: s6 thir to nguan vi s6 thir

to dich cu6i cimg duqc hi& boi ngu6n SO the ttr nguin duqc sir dung de duy tri thong tin mei ve tuyen dubng nguqc tOi nguin, vi s6 the to dich chi ra ring tuyen dubng teri dich phii men nhu the nio de ne co the duqc chip nhon beri nguin Khi ban tin RREQ duqc girl tir nut ngu6n toi cic net dich khic nhau, no se ttr ding thiet lip cic tuyin dubng nguqc tir tit ci cic nut d6 tel net nguin De thiet lop tuyen throng ngunt, mOi

net phii ghi 13i dia chi ciut hing xom mi tir de no nhin duce bin sao diu den ale RREQ Cic entry tuyen dubng nguqc duqc duy tri trong khoing thin gian vim de de bin tin RREQ co the truyen tren mang vi tri lbi 131 tel nut girl

Minh 2.7 Thilt 14p tuyin dttemg di ngtipc

2.5.3 Thih l(Ip tuyin &Ong Mu&

Cu6i cling, ban tin RREQ s8 den duqc mOt nut biet duqc tuyen tai not dich Diu tien, nut nhin duqc ban tin RREQ se kiem tra de chic chin ring ban tin RREQ di duqc Win tren met lien ket hai chieu Neu mOt not trung gian co mOt entry tuyen ten dich yeu ciu, no so sanh se thfriu dich trong entry tuyen cila chinh no vai so thin tkr dich trong ban tin RREQ de xac dinh xem tuyen do co dung duqc hay khong Neu so thin tlr dich trong ban tin RREQ Ian han, nut trung gian se khong sir dung tuyen trong bang entry tuyen cum no de dap ling RREQ Khi do, flat trung gian se tiep tuc quang ba RREQ Cac nut trung gian chi Ira 16i khi s6 thir to dich trong bang entry cila no len ham so vai trong bin tin RREQ Neu nut Ming gian co met tuyen hien hanh tel nut dich va nen ban tin RREQ nay chua duqc futon truck do, nut se geri unicast mOt ban tin RREP tai hang x6m ma tit de no nhan duqc RREQ

MOt ban tin RREP chira cac thong tin sau:

<dia chi ngu6n, dia chi dich, thir to dich# so chang, thai gian sing>

Trong khi met pal tin quang ba tel mOt nut co tuyen tel dich, mOt tuyen dubng ngtrqc duqc thief Ilip toi nut ngu6n ctia goi tin RREQ Khi RREP fret 10i not ngu'611, mai nut dqc theo tuyen dtremg thiet lop met con tra thuan tel nut ma tit d6 RREP den, cap nhat thong tin timeout cho cac entry tel nut ngu6n va not dich, ghi lai s6 thin tu dich mai nhit cho tuyen duqc yeu eau Thiet lop tuyen duang thuan khi RREP tin not