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Đề tài Truyền thông tin và những ứng dụng của mạng VANET giới thiệu về hệ thống VANET và các nguyên tắc cơ bản và thách thức của VANET, trình bày một lịch sử ngắn gọn các hoạt động của VANET; mô tả các phương pháp để phổ biến thông tin và tập hợp trong VANET cần thiết để hỗ trợ các ứng dụng hiệu quả và tiện lợi và những ứng dụng của VANET. Mời các bạn cùng tham khảo.
BO GIAO DVC DAO TAO TRIAING DAI HQC THANG LONG o0o- CHUYEN BE TOT NGHIVI TRUYEN THONG TIN VA NIIING irNG D1VNG CUA MANG VANET GM() vial' huirng din Sinh vien air hit'n MA sink vial' Chuyen nghanh : ThS HOANG TRQNG MINH : NGUYEN VAN CONG : A14025 : TIN VIEN THONG HA NO! - 2013 MVC LTC Lta MO tau CHU'ONG TONG QUAN Vt H$ THONG MANG VANET 1.1 GIOI THIU CHUNG Vt MANG VANET 1.1.1 KIthi ni0m 1.1.2 Tgi co hf thong Vanet? 1.2 NGUYEN TAC CO BAN VA THACH THITC 1.3 LJCH St' VA SU' PHAT TRIEN CUA VANET 1.3.1 Tit dA4 den' gifia nhiing nein; 1990 1.3.2 Tit mkt nhiing nOm 1990 den 1.3.3 Kit quci cia ceic dv an hien tai 11 16 1.4 ICET LUAN CHID ING TRUYEN THONG TIN TRONG VANET 17 2.1 GIQI THEW 2.2 DO LUVING Vf mi 17 HIN HANH 18 2.2.1 Cam &in xe 19 2.2.2 Ccic hf that' Ig dinhvi nhtf Li mOt nguiejn thong tin 19 2.3 TRUYEN TAI THONG TIN 20 2.3.1 Ccii thien viec kit not mang 26 2.3.2 Truyea tai thong tin 28 2.4 TONG HIP CAC PHEP DO 30 2.5 TONG H1P D' Lieu DjA LY 33 2.6 ICET LUAN 43 CHVONG NHONG ONG DUNG CUA VANET 44 3.1 GIen TIM 44 3.2 HAN CHE 44 3.2.1 Khci rang 45 3.2.2 Kit not 46 3.2.3 Cgnh tranh 49 3.3 (ING DVNG 50 3.4 BIEN HOA TRUYEN THONG 51 3.4.1 He fixing tip trung khcich chri 52 3.4.2 Mo hinh ngcrng haw 52 3.4.3 TnOn thong VANET 55 3.5 XAC SUAT, TAP HQP THEO VUNG 57 3.5.1 Phcic thcio FM 57 3.5.2 Cc c ban phcir thcio cho kip h9p dir lieu VANET 58 3.5.3 Phcic than trgng that mem 59 3.5.4 Binh thOnh khu vitc ion hon tong h9p 60 3.5.5 Nghien csiu zing dim 61 3.6 TAP HQP THOI GIAN DI CHUYEN 62 3.6.1 nip h9p d4a3 Ira clam mOc 63 3.6.2 Danh gici chilt hi9ng thong tin 65 3.6.3 Ceti' tnic king h9p ∈ me' c 66 3.7 KET LUAN 67 TONG KET 68 THUAT Nal VIET TAT 69 TAI LIEU TRAM 'MAO 71 DANH MIJC IliNH ANH, BANG BIEU Hinh 1.1 Bieu di mink hga cic cinh lbio nguy hiem Hinh 1.2 MO hinh tong quan ye clic giii phip VANET 10 Wnh 1.3 Vi dy h§ thing the nghi§m tgi Michigan (2008) 12 Bing 1.1 I3in di ctia VSC-A eng dgng an town vi kich bin cic vy tai ngn 14 dutrc quan tam nhit Hinh 2.1 frng dieing phi bien dip tren VANET 18 Hinh 2.2 Trao diii thong tin ngim 23 Hinh 2.3 Tang him tOc (10 alit xe teen mlii phan dogn SOTIS 33 Hinh 2.4 H§ thing quan sit hru luvng 35 Hinh 2.5 Tang kip nhim cic bin ghi CASCADE 36 Ifinh 2.6 Cay hi phan 38 Ifinh 2.7 Thivi gian di Tour Eiffel den Arc de Triomphe 42 Hinh 2.8 M§t mting luid duirng phan clip trail tilting 43 Hinh 3.1 M§t 'lc suit dui kit not vo tuyen 47 Hinh 3.2 Phi bien de lieu bing cich se dyng cic chuii vi xe di dOng 48 Hinh 3.3 Anh hir&ng cult cic don vi ben ii throng 49 Hinh 3.4 Phan phiSi cic thiet bi ngang hing teen mOi phin doin duirng 54 Hinh 3.5 The h§ vie how nhit cis tip hip phic thio FM 58 Hinh 3.6 wet him phic thio & tiling thii mem 60 Hinh 3.7 D§ chinh xic cis tin him & xa 62 Hinh 3.8 Ting Nip diem mic 64 Hinh 3.9 Thong tin ci sin & cic cip dO khic nbau 66 CHUONG Tang quan vi he tilting mang Vanet Ltla MO DAU Ngay voi xu the ph& trien mph me ve tong nghe thong tin, dien tai van thong ket hqp v6i sq da clang va phong phd ye phuong tien k3 thuai da tao nen nhung hinh thai phat trien mai nham phuc vu cho den song ngu6i Thong tin lien lac duqc m6 rung v6i nhitng rinh vqc mai hira hen nhieu sq phat trien Mang di dung thy bien xe hai cling la mOt rinh vqc dang duqc cac nu6c phat trien nghien ciru va dua vao sir dung nhi ► dua lei nhfang hieu qui, nhlang diem nhin m6i bu6c phat then cua xe hai Be c6 the hieu has ve sir ph& trien, nhung buem tien cilia rinh vqc tOi mu6n giai thieu t6ng quan ye nhung khai niem, t6ng quan ve m8 hinh by thong cling nhu la ntang cong nghe duqc sir ch,mg m8 hinh mpg mpg di dOng thy bien cho xe hai (VANET) VANET (Vehicular Ad-hoc Network) la mOt (rug dung mang nhu the 1)6 11 mOt he thong mpg s(r dung cac giao tiip khOng day phan tan gift nhieu diem truy c#p Ichic ma khemg can ten bit dr mOt cc; s6 ding c6 djnh lac) Bit cu thiet bj cam tay vii co djnh nio nhu dien thoai di dOng, laptop, may nhin tin, cac tram v8 tuyen ca so deu c6 the la mOt kenh thong tin mang VANET tao thimh mpg town ciu, rung khip mqi nai Cic thiet bj c6 the tich hqp vao cac d6i tuqng di chuyen (xe cu, tau thuyen, ) ho#c tl#t co djnh o cac diem khien cho viec truyen thong ce the dies o mqi lfic, mqi nai M8i phuang den tham gia giao thong (duqc tich hqp mOt thiet bj c6 Wing kit n6i day) lit( thinh mOt nut ciia mpg Bao cio bao gam ba chirong: Chuang 1: Glen thieu chung ve he thong Vanet va cac nguyen tic ca ban va thich thirc ctla VANET, trinh bay mOt ljch sir ngin gun cac hog dOng cilia VANET Chuang 2: M8 to cac phuong phap de ph6 Wen thong tin va t#p Nip VANET can thiet de h8 trq cac img dung hieu qui va tien lqi Chuang 3: Duqc xay dqng tree chuang va tip trung vao cac img dung "Meng an tan" d6 muc tieu chi yeti la hieu qui va tien lgi MOc lqc nghien ciru de hall chuyen de cim minh, nhung !den thirc va th&i gian hp chi nen chuyen de t8i khang tranh kh6i nhfkng thieu set Toi rat mong nhon duqc cac d6ng g6p, nh#n xet tir phia flay co va cac ban CuOi cling t8i xin chfin thimh cam an sir huong din va taco dieu kien ctla thiy Holing Trong Minh su6t qua trinh t8i lam bito c.ao nay! CHUONG Ting quan ver th6ng mang Vanet CHU•ONG TONG QUAN Vt HE THONG MANG VANET 1.1 GIO1 THIEU CHUNG Vt MANG VANET 1.1.1 Khdi niflm VANET (VEHICULAR AD-HOC NETWORKS) li mpg da cic xe (vehicule) se duqc trang bj thiet bj thu/phit, chang se ter thinh cic node nhu mpg ad-hoc Cic xe se lien lac vai (Car-to-Car Communication), hay M2M (machine-to-machine communication) de chia se thong tin lin ThOng tin ye traffic, ye tinh trang kit xe, thong tin ye tai not giao thong, nguy hiem can trinh M0 chile xe ding c6 the trb thinh mOt Relay Node chuyen tii th8ng tin cho xe khic VANET sfr chum chuin Wifi 802.11 a 1.1.2 Tgi eó h? thong Vanet? — Cong nghiap xe ngiy ding phit trier —S6 vu tai non giao thong, On tic ngiy tang tang —Cic phuang flan thiet bj phut vu cho giao thong chtra tai uu 1.2 NGUYEN TAC CO BAN VA MACH Marc Khii niem co bin cda VANET la khang phi= tap: thuc thi tram deg nghe WLAN dian rang vi khong qui dit, tart li ket n6i giva cic may tinh vii hoot vii intemet, vi vai nhieu cii lien no duqc ip dung len xe cO Diu lien, thong to xem x& den co hOi Neu cic phuong den c6 the truyen thong tnrc tap vii vi v6i co so Ling, meo hinh hob toin moi cho nheng (mg clang an toin cba phuang den 06 the se duqc hinh thinh Thtl hai, nheng thich thac mad da thrqc too Uri phuong tian tee do) cao vi mad trubng tic dOng llrc lan Thir ba, nheng yeu ciu can phii c6 Ye an loin d6i yeti cic frog dung mad, bao gim nheng 10 vqng mad cho phin phii gei tin cao vi dO trg gei tin thip Han naa, phin (mg mb flint cM khich hang vi su gin sit caa thing giim sit dem lei 10 vqng cao ye an ninh vi sir rieng tut Them chi ngiy nay, chiec xe too vi phial tick luqng bfm de lieu, mac thl de lieu thubng china mOt chi& xe nhit ce VANET, dim nhin (kha Whig nh$n biet xung quanh) cue cic phuang tian giao thong vi cue lii ACC duqc tang len ding Ice Truyen thong VANET c6 the thuc hian true till) gala cic xe nhu Owen th8ng "mOt buoc", hoot phuang tian ce the truyen lai bin tin, da cho phdp truyen thong "da Woe De tang yang phtl sang hoc dO ben yang cult truyen thong, chuyen tie') lc ben thrtmg c6 the duqc trien khai Co so tang ben throng clang c6 the duvc sfr dung nhu mOt deg vio internet vi da de lieu vi th8ng tin net cinh c6 the duqc thu thap, luu Ire vi "6 mqi nor, vi du ca so ling mang cue coag nghe ditat town dim may sip tad CHISONG Tang quan ve he thong mung Vanet N6 dim bao ring mpg lien kit gift cic xe se thfic diy manh me b6i su phong phi caa cic Ung dung co the dugs kich hoot Truoc het, cic ting dt,mg an toan chb dOng, tirc la cic ting dung phong ch6ng tai nun se duqc hiding lqi mOt cich true dip tfr truyin thong Thir hai, bang cich thu thilp dtt lieu twig thii giao &Ong ter mOt yang rung han, luu luqng giao thong c6 the dirge cal thief', thstri gian di chuyin c6 the duqc giim cling nhtr nheng lchi thii hY cic phuang lien Nhu n6 di duqc ghi chinh xic nhu cic nguyen cult he th6ng giao th8ng thong minh (Intelligent Transportation System World Congress) nam 2008: Tiet kiem th6i gian Cic 16p (mg dung "an tan" vi "hien qui" c6 the duqc sfr dung de phan loci cdc Ung dung dlra tren mix dich chinh cia chimg Tuy nhien, cic khia can't an toile vi hieu qui khong the quan niem nhu cic tinh Wing tech r6i hoiln town R8 tang, tai xe c6 the din den tic giao thong MOt bin tin th8ng bio mOt vu tai non ce the duqc xem nhu la mOt thong bio an town * diem quan sit caa xe gin d6 Ban tin Wang tu c6 the duqc nhin cic phuong lien xa han nhu mOt diu veto de tinh toin mOt 10 trinh thay the mOt (mg dung hieu qui giao thong - ••• • 1, %••• ■-• / /1111 / ' r ollw—••■••411111 1■ _ "111"1111111 rrn 40 Ifinh 1.1 Bilu (IS minh has cdc cdnh bdo nguy hiim Trong khii niem don giin, thiet ke vi tan khai cic VANET la met luc kq diy thich thirc ve ky thust va kinh to Mich thirc chinh ve ky thuUt bao g6m cic vin de sau: — Cie Sc il dam c6 ham cda kenh v8 twin dien Cic kich ban hien mia VANET vbi nhieu die diem khong thu0n lqi cho vies phit trien truyen th8ng khong diy, vi du: nhieu doi tuqng phin inh co the lam suy giam dO mph vi chit luqng ctia song tin hieu nhen duqc Ngoai ra, tinh di dOns cia cic dii CHISONG TOng quan ve hg thong mong Vanet trung xung quash ho#c chting tv gfri vi tv nkftn, hilt' Ong mb din phii duqc dua vio sv tinh toin don vj phOi bqp Vilc sir trung trvc tory& vi —Thies mOt sv quin dtmg ding bing vi hilu qui bang thong mkt kenh lchang day li mOt nhilm vp kh6 khan mOt mong ur t6 chrrc vi phan cep hoin toin Vi$c thieu mOt thvc the c6 Wing ding bO h6a vi quip cic sv ki/n truyen tid cara cic of khic co the din den sir dung kenh kern hilu qui vi din den s6 hrqng lon cic vv va ch?m g6i tin Ring mfr ring, vi sw da ding cast Min kiln —Mb di ding cao, yen mdi trnimg Nheng thich th(rc cia mOt mong tg t6 clac plan cep duqc die bilt nhin manh den t6c dO cao Tinh di dOng cao li mOt thich thirc cho cic thuig toin t6i uu 1#p nhim s6r dung tot ban bang thong kenh hoc sb dung cic tuyen dutmg duqc dinh nghTa tru6c de chuyen tiep thong tin —An ninh vi nhu cis rieng hr vi cfc m6i plan tam C6 mOt thich thirc ve can d6i gifts nhu ciu ve bio m#t vi tinh rieng tu MOt mkit, ben nh(in mu6n dim bio ring c6 the tin liking ngu6n thong tin Wit khic, sir tin luting d6 c6 the mau than voi cic yeu ciu rieng to cfia ben gtli limb ding C6 mOt nhu ceu cho truyin thong tieu —Tien chain boa so chuin cho phep VANET lim vile qua cic kieu khic vi cic chuin caa OEM Tuy nhien, chic chin ring OEM se mu6n too vii sv kbic hilt v6i cling nghl VANET Nhung raw tieu niy li c6 ye se kh6 khan Mich thfrc chink ye mat klub ti xi —Phan tich vi xic dish &Nov cic lqi ich cult VANET cho an toils giao thong vi hien qua vin tii Cho den nay, rit it vile da duqc thvc hi¢n de dinh gia tic dung c6a VANET nhu mOt ngu6n thong tin ve hinh vi lii xe Re ring, nhung thich thirc lien quan vile giii quyet vin de dinh gii tic ding li m8 hinh c6a cic khia conh lien quan den yeti t6 ngutri —Phan tich vi xic dinh thrqc dic m6i (plan he chi phi - lqi lick adia VANET Do thieu cic nghien ciru ye lqi ich c6a VANET, v#y plan tich chi phi - lqi ich kh6 ce the duqc thvc hiOn Chien luqc trien khai thiet ke cho load hinh VANET li kitting dra tren mOt cc s6 141 tong hoc mOt nhtt cung cop dich vp nio Vile thiet bj VANET ce dirge hay kh8ng phv thuOc vio cic d6i tic truyen thong, cic hi thong mong hiln thOi c6 the h8 trq duqc hay khOng —Nhing VANET kJ& trac hi thong giao thing thing minh VANET la mOt phlin cua mOt hi thong giao thong thong minh noi mi Wing yes t6 khic duqc sinh boi diet' khien den giao thong hay cic cic load bin tin bio CHUt5NG TOng quan ve he thong mpg Vanet hieu khic COng nhu vay, giao thong ci nhan vi Ong cling phii duac nim tii khoin mOt kiln cich chung Bei vay, he thing hqp tic Nit sir cin duqc phit triin Nhu co the thiy tfr danh sich tan etc ring (twig, ky thuat vi vie khia cunh kink to xi hOi, linh Arc (mg dung xe vi cic Ong nghe lien mpg dua tren ding nghe tren mOt no lirc lien nginh truyin thong vi mang, thiet bj dien ter tong xe, quin vi van hinh throng b0, cling cep cic th8ng tin vi dick vv Do de VANET ce the duqc xem nhu li mOt phin quan tong cia he thing giao th8ng dieing minh (Intelligent Transportation Systems) (ITS) Trong 'chi nhiiu du in khic da thio luan chi& luqc tan lchai oho VANET, cic nghien c(ru chi yeti giii quyit nhitng thich thee ky thuat Hien nay, mOt sir thay dii to rich dip can "ter dm% led" co dien Bing cich tap can "te tren xuong" Ly tueng nhit, ci hai phuang phip tiip can cutii ring se gap nhau• nhang gi duqc goi li mOt yeu ciu cho viec tan khai mang lui lqi ich co the duqc hi trq bOi nhing tier b0 cong nghe 1.3 LOCH sir VA skr PHAT MIEN CUA VANET Lich sir cea viec sir dung song v8 tuyin vi hing ngoai cho truyin thong gifts xe vei xe vi xe vei ben dueng gin lien vei sir phit trim ctia 14 thing giao thong th8ng minh Nhu them khio Shladover vi tong Lasky vi Ravani, cic khii niem ca ban oda tu dung Ma dueng b0 nhu viec se dung the ky thuat truyin %Ong vi dieu Ichien di giao thong duting b0 an tan, hieu qui vi than thien vei mOi truing Sau de, vac cam' nheng am 1960, he thing tu dOng hes dating b0 dva tren song v8 tuyin duqc phit triin vi cheng minh Ki hY do, co rat nhiiu de lieu dugs quan sit: Chi di chinh li an tan, hieu qui vi than thien voi mOi trubng, tong tam lien tuc thay doi theo thin gian Vi du, thei gian diu he thing hueng din tuyin dueng da duqc dieu tra Sau do, he thing thu phi, nghien ciru lii xe tu dOng tre nen ph6 ban Nghien ciru vi phit trier o khu vuc khic nhau, chi yiu my, Nhat Bin, vi Chau Au, mi can o cic nai khic tren the giOi cing co anh huong l>e tii de duqc dinh diu bei sir tap 'chic cia t8 vi cic cling ding giao thong van tii MOt chi di nhit quin theo thei gian li "ngan sich - se tri phi?" MOt mat, nginh cong nghiep to vi dien ter nghi ng6 cic ca se hu tang dog rung cho he thing dueng cao tic thong minh (Intelligent Vehicle - Highway Systems) (IVHS) se khong bao gib thich hien thuc Mat khic, cic dan vi chi quin dueng cao tic nghi nge lieu tong nghe IVHS se cung cep giii phip thuc ti cho cic vin di dueng cao tic thqc sir Trong phin du& day, se di cap din cic hoot dung buec tien quan tang lien quan din VANET CHISONG Ting quan ve hg th6ng mane Vanet 1.3.1 TIr &iu din giea nhihog nano 1990 O My, mot ho thing hutmg din &Ong dien to (Electronic Route-Guidance System) (ERGS) d8 duqc de xuit Rosen: "He thing djnh hutmg diem den Ngutri dieu khien xe nhap vito mOt mA, dal dien cho dja chi dich c0a minh vao thiit bj xe Sau d6 phuang tien tien den mil diem giao ma dich duqc chuyin den atic tram ben dtrong tai de n6 duqc giai ma, theo mOt chtrong trinh ltru tat, va mOt chi din dinh tuyen duqc truyen lai cho chiec xe." He thing truyen thong sbr dung tin só 170 kHz clOng Ang-ten yang duqc lip d*t tai nut giao %Ong va gin vao phia sau caa xe Tic dO truyin catlieu bao cao la 2000 bit/gialy Nhung nhang n8 luc ERGS bj chim dirt cac ca so hu tang ben duong dit tien Tai Nh.t Ban, he thing dieu lchien giao thong te tan dien (CACS) duqc thuc hien 1973-1979 ca quan deg nghiep Khoa hac va C8ng nghe dui BO Thucmg mai va C8ng nghiep Quic ti (MITI) Muc lieu cua CACS duqc trinh bay Kawashima vin hien luc sau han 30 Min: —Giant un tic giao thong dubng Xi; —Giam thai gay bbd su tic giao thong; —Phong ngta tai non; —Nang cao vai fro cling ding va xa hOi cila t6 Be flat duqc muc lieu nay, bin muc tieu thuat di duqc de ra: — Huang din lai xe di then cac tuyin chgmg thich hqp nhit de tranh On tic va nhiim khOng khi; — Cung cep th8ng tin lieu ich de hi trq lai xe an town; —Uu tien cac xe ding cling hotic truing hap khan cep; —Cung cap thong tin kip thin cho ngutri lai throng hqp khin cap Cac du an CACS ding duqc thuc hien thi diem vei 98 thin bi ben dtrong A 330 xe tht? nghiem (Nakahara vi Yumoto) Dii vai truyen thong ben throng thi xe, cac tram ben dubng str dung Ang ten Ong cac phucmg tien giao thong sa dung Ang-ten 101 cho tic dO truyen tai ctia bao cao la 4.8 kbps Tai chat' Au, de an Prometheus (chuang trinh giao &Mg chAu Au vai gia cao nhit chua mang lui hien qua vi an tan) ichoi xutmg vao nom 1986 va mit nom 1988 c6 * nghlit kich thick host ding nghien dru va phat tan rah vuc deg nghe th6ng tin va twin th8ng di dung cho xe c6 ding ca va nhang duOng Prometheus di drat hi trq boi 19 quic gia chau Au vb cac Oy ban cling ding Chau CHUONG NHONG LING DWG CUA VANET 3.5 XAC SUAT, T4P HcfP THEO VUNG MOt vein de quan tong ala tip hqp de lieu VANET la sv danh gia ye chit luqng hoc cep nhit thong tin tong hqp: Trai nguqc voi quan sat nhit, gia trj tang hqp khong the duqc so mirth Ulm tiep dtra tree Whin thoi gian Cac ban tem tit vi dv, tong s6 dja diem d6 xe met se phis c6a ph6 duqc too bdri xe thuOng sir kheng phai c6 phien bin cip nhot c6a tit ca cac de lieu co so c6 sin VI viy, tip hqp nhieu lin cho cung mOt khu vtrc c6 the ten tai, dtra tren cac diem Ichac nhau, nhung c6 kha Wing chin cheo kien thirc Quyet djnh gift lai cai nao dtra tren dfk lieu co ban la kh6 khan, nett khOng phiti la khemg the VI viy, lam the nao xe duqc cung cip hai phien ban clia cung mOt tong hqp va nen quyet djnh cai nao cin gift (va ph6 bit% n6)? De tra 16i cho cau bed nay, phai mo rung Sr tuOng du lien duqc neu chuong phi Bien thong tin va thito Juin chi flit hon ve mOt ke hooch, ban du duqc de xuit Lochert Cach tie') can cho thiy vin de c6 the duqc lchic phvc neu ca hai quan sit va tjip hqp don 16 kh8ng mang gia trj quan sit trqc tiep, nhung thay vi ce ch(ra mOt gia trj xip xi hinh thirc cOa mOt phac thao cai goi la tang thai thai mem Trong phac thao tang thai mem vin 'thong cung cip mOt cach de so mirth chit luqng c6a hai tap hqp trtrc tiep, cho ph6p mOt cai gi d6 tit hon: nhieu tip hqp cho cung mOt khu Arc c6 the duqc sap nhip, mang loi mOt str kit hqp mai mi ch(ra thong tin cua bit hqp nao Do d6, khong cin phai quyet djnh tang hqp c6 chfra thong tin cip nhit 3.5.1 Phdc thdo FM Phic thao thai mem la mOt phien ban ma rung va sea d6i bin phac thao FM Cac phac thao FM ban du duqc gioi thieu b6i cimh co stY du lieu, NH Flajolet va Martin MOt phac thao FM dal dien cho mOt xip xi dm mOt se nguyen ducmg truting bit S = se, , s,, chieu dai w throng bit duqc Uteri to bang !thong tit ca cac vj tri De them mOt x yeu t6 de phac thao, n6 duqc brim mOt ham barn h V e mitt hlnh hoc, ham barn di plain ph6i tich cvc diu s6 nguyen, xic suit ma gia trj bitm h(x) caa x la bing i la duqc dua bOi deg thir P(h(xi) = 24.(31) Han shoo sau d6 duqc that lip (VOi xac suit 2', c6 h(x)>w, tnthng hqp nay, hoot dOng kh6ng duqc thvc hien.) MOt him brim v6i cac thuOc tinh cin thief c6 the dg ding duqc bit nguen tir mOt ham blim ph6 bien IA du thong nhit phin ph6i chugi bit bing citch ding vj tri cua cacl- bit die lien chugi du li gia trj brim Flajolet vi Martin li mOt xip xi C(S) c6a 56 luqng cac Kit qui quan tong yeu to dac duqc them vac de phic thio co the thu duqc tir chieu dai c6a chugi ban diu Ichong bj gian doan, duqc dua 57 MIXING NI-ONG ONG DIJNG CI:JA VANET E E No I KwA s i4.1 = 0) U {w)), (3.2) Z(S) 2z (s) — (3.3) C(S) 0.77351 Phuang sai (khit 16n) cia Z (S) c6 the duqc gilun bing cich sir dung ban phic thbo song song, bing cich s6 dyng mOt ky th4t goi 1a tinh xic suit trung binh ngiu nhien (PCSA) De blot them chi tiet, xem Flajolet and Martin phic thbo m duqc sir dung, PCSA mang lni mOt sai so chuin khoing 0,78 / I m Phic thao FM co the duqc sip nhip de ce duqc t6ng so cic yeti t6 rieng biet duqc them vio bit Ick xe nio sO de chi don &in bang mOt ph6p toin OR Quan tong la, bang each ciu true cia n6 c6 that ket hqp nhieu lan nhang ban phic thbo twang tq hocthem cic yen t6 di c6 sin mOt lin nee 'thong lam thay dui ket qui, bit ke la cic hoyt dung dinra thutmg xuyen hoic theo dui n it rp ~ 3.5.2 Ctic ban pink thao cho tflp hop dtt Iiin VANET Vai muc dich ctla cuOc thbo luin don gian, xem zit mOt loci cic he th6ng thong tin giao thong cu the: gib sir rang dang quan tam den vies ph6 bien s6 nai de xe mien phi Doi yeti th6i diem nay, b6 qua thuc to la s6 hrqng thay dei theo tit& gian Buck diu tien, sir dung mOt phic thbo (hoic PCSA, hocmOt top hqp cic bin phic thbo) cho me i Boon du6ng Gib dinh rang mOt chi& xe c6 the quan sat sO Wang nai xe mien phi tai nai n6 di qua, vi du bing each thu thip de lieu tar cam bien vbo nbeng nai d6 xe Sau di qua mOt (loan &Ring WA ID vb quan sit duqc x diem d6 xe mien phi ten de, mOt chitc xe c6 the them cic bO de lieu (r, ), , (r, x) de phic thbo cho r, bling each aim n6 vb thiet lop s6 bit tucmg img h(V17,2) h(17, 1 17,4) 1 co I o Phisc thao trtretc tigp nhilin Phac thao sat nhOp eau Otto nh4In iii Philo Maio de truyen h(17,1) h(17,2) h(17,3) h(17,4) h(17,5) Ifinh 3.5 The` hg va hqp nil& cinz Op hop ph& thew FM Cac phic thbo luu tre cac &>}n throng cuc be duqc quang bb dinh kiy tai cac net lin can bang mOt buac nhiy Sau ben nhin, nhin duqc vb phic thao chit phuang duqc sap nhip bang cich tinh toin phep toin OR cac bit illnh 3.5 minh hqa cho the 58 CHYONG NHONG UNG D1,JNG CVA VANET tuc Hai xe to, A va B, c6 the quan sit dOc 1(1p tren cang met /loan du/mg (veri ID 17) A quan sit ben dja diem d8 xe mien phi vi de bam thinh (17.1 ), , (17.4) phic thio cho do?n du/mg 17 B quan sit c6 Wan diem de xe mien phi, vi de be sung them (17.1 ), , (17.5) neu A vi B g#p, vi nit#n duqc met truyin c6 china phic thio cua B, kit hqp n6 v6i cic bit vi c6 duqc mOt phic thio m6i, thay the cii truck de Re ring, dieu c6 the duqc 14 di 1#p lai bit dr nao c6 xe a to dip (mg, de th8ng tin a xe tiep tic c6 the duqc kit hqp, trap dei, vi truyin lai, qua de licit liiy "kien thirc" teng hqp Luu jr ring cic be de lieu bilm (r, i) la gi8ng het cho nhitng quan sit 'chic nhau, gia trj quan sit duqc xic djnh nhit lam the nao de be de lieu dupe them vao Neu mqi ngtai quan sit se dung cling met ham ham, cling mOt so dja diem de xe mien phi tren can met doa ► dueng se thiet 1#p cic bit Luang a Cic thu#t toin ca ban hien nay, cic bit met lin duqc thiet 1#p se khOng bao gib duqc bo, va de phic thio kh8ng the Ilan giam gii tri Do de biy gib lam the nao de me ring ciu tree de lieu de khic phuc han chi 3.5.3 Pluic than trgng thai mem MOt bit bao gib ding duqc fiat lip, cic ban phic than se dpi dien cho tit ca cic gii trj kitting quan sit thiy cua tong down duang De khic phuc vin di nay, met phuang phip cin thiet de loci b6 cic quan sit ce Dieu duqc thuc hien bing cich thay cic phic thio FM ban diu Su dung bO dem nhe chi& dai n bit thay vi mOt bit nhit tai mei chi se vi tri Cic be dem dai dien cho met thei gian tem tai (TTL) - bit de Cic hoot ding thiet lip mOt bit de sau quan sit duqc thay khoing 0, the bing cich thiet lip cic troy c#p Wang ling voi TTL, t6i da, T: = 2° -1 Cic canh bio c6 china nlang ban phic thio duqc gei deu (W Chi dm truOc gui mOt cash bit° v6i thong tin ttY ca sat de lieu di biet, tit ca cic be dem dm ban phic thio tai dja phuang diu dOn duqc giam di met, neu gia tri cfia be dem khic khOng Khi kit hqp met ban phic thio di nh#n duqc vao ca so du lieu di biet, cic phep toin OR dtrqc thay the bang thu#t toin tOi da Lung vj tri Dieu mang lei met Min the ala tang thai mem ye phic than FM, d6 cic yeu t6 duqc dua vao truOc de bj chit sau TTL caa da het han, tnY n6 duqc him mai WA met quan sit mei hon Sip nh#p duqc m8 to hinh Xe nh(in dugs met temg hqp tir B xe, vi c#p nh#t phic than mpg thii mem dia minh cho phe hqp 59 CHUONG NHCING trNG DI VING CUA VANET Phac that) trutm kid tiAp nhen O a I Philo thao sat nh ► p sau tiep nhen Pluto Mao de tory& Hinh 3.6 Kit hop phac than a trgng thai mem De c6 duqc gia tri hien tali t mOt phk thio trung thai mem, thuilt tam yin ca bin Idiong thay d6i, vi tri chi s6 nho nhit c6 gia tri khOng duqc xac dinh va su ding Luu Sr ring dieu phii ganh chiu mOt s6 chin trg neu mOt vi tri bit khong that 10p cac quan sat moi han Ter 1th vi di tren: quan sat nhCmg nod dir xe, gia sfr ring king c6 quan sat nio flip tic duqc thqc hien mat thiet 1#p mOt vi tri bit ci the (vi di, bbd vi khong mOt chr5 drS xe mils phi duqc barn veld n6) Neu vi tri di duqc d#t mOt tang hqp, sau d6 gia tri TTL se giim theo Uri gian cho den n6 den gia tri kung 3.5.4 Binh thank khu vim Ian hen king hpp Dva tren phac thio tang thai mem, t#p kip thu b#c c6 the duqc thqc hien theo catch sau Tnrac tien, cin meth thang phiin cip cac khu vqc thqc hi'e'n t#p hap MOt khu Arc c6 dO phan cip cao han thong thu6ng bao gam hai ho#c nhieu khu vvc cip dual Dai vai mgi khu Arc tren ting cip cia he th6ng phan cep, Thqc hien cac thea thu#n cho mOt phac thio trung thai mem dth dien cho cac gia tri (tang hqp) cho khu Arc Bit kSr quan sat duqc thqc hien cho met sa h tri nao lap tic co the duqc ket hqp vao m8i tang hqp c6 chia cac vi tri Kit hqp thong tin ve mOt nhieu ving phi vio mOt t#p hqp tom han c6 the duqc thqc hien cing met cach chinh xac nhu sap nh3p lud ban phac thio cho cing mOt khu vqc: bang cach tinh tom t6i da vi tri cis 'thing bin phac thio than mem Ti cac d c tinh di a:4 a tren, clA clang thiy ring cac tip hqp duqc hinh thimh theo cach bao gam cac phep tir tit cal cac khu vvc phtut cia no, theo di cac thong tin mei c6 the duqc them vio bit ki tic nio Bit IcSr nao nhon dulqc phac thin 1#p tire c6 the duqc kit hqp van tang hqp lin han bao gam cac Wing cia bin phac thio nh#n duqc Dieu di mang cic thuOc tinh mong mu6n duqc de c#p ten: kung cin phii virt b6 mOt nhing t#p hqp thay the nhieu cho cing met khu vqc mat c6 the ket hqp chimg de c6 duqc mot tong hqp mil, c6 the dg Id& de hien thi vimg phi sang tat han vi cung cip han thong tin cep nh#t cia khu vqc han bit kir thinh phin ca nhOn d6 duqc hinh 60 CHLrONG NHUNG ONG DVNG COA VANET Tat lai yeti vi du ting dyng ye tinh nai d8 xe mien phi, nhang t6ng hop se ce tong s6 cac diem d8 xe milli phi tong khu vyc tuang ung ThOng tin ve cac khu Arc quy m8 nho dien hinh duqc luu gift vOng len Qin gin han, xe to di m xa han se tri va phan phei cdc tong hqp tOt han tren quy m6 caa khu vue krn hon 3.5.5 Nghien thu fin dyng De b6 sung cho cac thito lu#n IS/ thuyet tree, met lc& qua vi dy fir cac nghien dru m8 phong duqc thuc hien Lochert, su ding mOt mei tru6ng ma pheng tuang to nhu met tree myc 3.2.2, v6i tS, 14 them nhop 20% thief bi VANET cling mOt thimh ph6 So sail ket qua dot duqc voi top hqp xac suit de ce &WC mOt giao thuc tham chieu t6i uu Trong giao thuc nay, thong tin duqc ph6 hien b6i cac earth bao dinh kjr Tuy nhien, giao attic t6i uu khong quan tem den nheng giai han bang thong thuc te Trong m8 phong kich thuac cita gei vii so hrqng thong tin trao dOi gifta cac nut la dOc lip Giao thuc tham chieu khai thac thyc te va kh8ng tAng hap tit cit thong tin Thay vao d6, nh#n duqc "tong hqp" bao g6m c#p nh#t gia tri cia nut giri tit ca cac dia diem RO rang, thyc hien giao thuc tOi uu tham chieu la a clang m8 phong, nhung khong phai thuc te Tuy nhien, n6 cfing ph6 hqp nhu la met tieu chuin veil mOt giao thuc thuc te dya ten cac cash bito va co s6 dift lieu di biet, nhftng chiec xe khong bao gib c45 thong tin tOt han Dinh gia ca hai de an ten va tham lchao cite giao thuc t6i uu v6i mOt ling dung Wong Chia nh6 cac khu vyc ph6 256 khu vqc nhe, ma chung to sift dyng nhu la dia diem nhit MOt qua With ngiu nhien don gian tao met gia tri thin gian cho m8i vtIng 'chic nhau, c6 the "do" nhfing chiec xe vUng tucmg (mg Dieu ce the duqc hieu la "dem" s6 dia diem d xe milli phi khu Arc nay, gin vOi vi dy duqc sir dyng tren Tuang to nhu vey c6 the coi la met m8 hInh trOu Wang cho bit lcSr khoang th0i gian lu?mg lchtic Lien quan den 016i gian m8 pheng twang d6i ngin 15 phitt, nhitng thay d6i cita cac tham s6 m8 pheng rit nhanh chang Thiet 1#p nhu v#3, la nit khe khan cho mOt giao thuc ph6 bien ma cin phiti theo d8i chimg Ngoai cac tham s6 Wen thien theo th6i gian rieng cita mink Dieu cho tinh town dpi dien tuang d6i "phin nho cis nai 418 xe phi" va de phalli biet gifta tinh huOng ma khong c6 thong tin va gia tri ph6 Wen la s6 IchOng Hinh the hien mOt khu vyc duqc tong hqp ten b6n khu vyc tong m8 phong Hlnh m8 to lam the nao gia tri tong hqp mkt khu vqc duqc met chi& xe mOt khu Arc Ichac khoing each khoing km thiy duqc Dieu duqc so stinh voi giao thuc tham chi& tOi uu vi gia tri thqc stir meo pheng khu vyc quan sat D6i yeti ca hai de an t#p hqp xac suit va tham Ichito CAC giao thuc toi uu, co mOt khoing th6i 61 CHUONG NHONG IYNG DUNG CUA VANET gian re rang cho viec yen chuyin th8ng tin th8ng qua VANET Doi voi de an tang hqp phic thao tang thii mem, ding c6 met sv chilm trg nhat dish truck gia tri giam dm, tucmg Ong vOi thei gian can thiet cho phan cUa thai me'm cult cac bit kheng can thiet lip NO cling khong ding ngac nhien Uri c4 nheng giao thfrc tai uu tai lieu thaw khuo khOng phai luc nio ceng c6 thong tin day (II Neu c#p nhOt chi tren cac be ph#n cua khu vrc thi t#p hqp tang sa hien tai vi dl lieu lchOng phai luc nao cling la dien hinh cho town bO tang hqp Tuy nhien, ink tinh phin anh tinh hinh thvc stir khu Arc theo m8 hinh tat, dieu Ong c6 the thytrong cac truing hqp khic Hinh 3.7 flu chink xac tong hqp v xa Tom lai, tap hop xic suit dva tren phic thao c6 the dugs se dung de tgo tftp hqp gall yen ly thuyet co the dot dtrqc Day la mOt kit qui rat ding lchich le, de nhan marl ring cac thu#t tan de xuat la mOt each phe hqp de vuqt qua khe khan chung thtemg gip cua phin ph6i, tap hqp de lieu kheong phe hqp qua trinh pk6 hien 3.6 T4P HOP THOI GIAN DI CHUAN T#p hqp theo vung la rat thich hqp neu mOt Ong dung yeu eau tom tit qua cac khu vrc Tuy nhien khong phai la truing hqp cho mOt img dung cu the, n6 c6 mOt s6 han the Whit djnh De xay chrng mOt he thong deng, hqp tic djnh huang dueng dva tren VANET, mOt each tie') c#n chung la de phin phai thong tin ye th?ii gian di lai doc theo (loan dating Trong truing hqp nay, tom tit qua cac khu Arc khong gift') de Trong mOt s6 khai niem chic chin duqc chuyin nhuqng, (ho#c (rung binh) tang thei gian di lai met khu Arc khong phai la mOt khai niem hitu fah Vi 4y, Si Wong la can thiet ph& giiun so luqng dit lieu thin gian di lai vei khoing each cling tang, yin cung cap thong tin hen ich cho nguei nhan Bay gib chOng to thio lufm mOt each dip c#n chi flit dif duqc phic thito chuang phi hien thong tin Ban du n6 duqc trinh bay Lochert va di khic phuc nheng van de t#p hqp 62 CHUONG NHONG ONG D1,JNG COA VANET dt•i veri tnrtmg hqp co the dui dit lieu thtri gian di loi h8 trq guy& djnh chuyin Wong du mg bO lir Meng chinh la sir dung xttp xi Oa mpg luai dutmg bO vci khoitng cach cang tang 3.6.1 TOp hpp Ara tan aim mac Y Mang ca ban cult chucmg trinh tang hqp la dip vao cid gai la diem m6c.Citc diem mac mpg huh duang be, dien hinh la cac nut giao diem Cac diem mac duqc xac djnh tren nhieu cip de cua met he thong phan cap mong Wei dulmg be cip cao nhit, day la nheng nut giao cua cac tuyen &Ong chinh ho#c during cao tac Cie cap thip han bao gam tit ca cac diem mac mix cao ham cOng vai nut giao thong cua cac throng nh6 hon Mirc thip nhit la mOt doi dien cua town be mong ltrai dutmg be (5 t8 di qua met door dutmg c6 the too mOt quan sat thtri gian di loi gifts hai diem mic Ilan can Thong tin duqc phan phOi phom vi gin N6 duqc stir dung Uri xe de tinh town thoi gian di chuyin gitta cac diem mOc cua cap tren trwc tiep, qua d6 tem tit thin gian di chuyin khu Arc Hinh anh th8 tren thoi gian di loi duqc phan phoi met dien tich lon han so voi quan sat xe ca nhan NO Ong duqc sit dung de tinh town thtri gian di chuyin gitta cac diem mac cap tren ttvc tiep cua he thong phin cip, va dr nhu 4y Hinh 3.8 cho thiy mOt vi cho he thing plan cip nhit Thtri gian di loi gitta hai diem mac Eiffel Tower Arc de Triomphe duqc xfic djnh Hai diem mac cao cip duqc kit not tilting qua met so toy& du?mg c6 the dOi yeti cac diem mac cip thip han, day chi boi cac yang ton Th6i gian di lid glum nhang dja dank thip han mitt duqc Wet den, hoc la t6 nhang quan sat truc tiep ho#c t6 tip hqp duqc nh#n hoctruck day di tinh cip thip han Thai gian di chuyen duqc tang hqp tir Eiffel Tower va Arc de Triomphe la th6i gian di loi duc theo My& dutmg la th6i gian di chuyen tai thieu gitta hai diem va cot ban, nen tit ca cac thong tin tren tit ca cac du6ng c6 the c6 gitta hai diem mac cho mOt lien ket "ao" ket not chimg 63 CHIANG NHUNG UNG DVNG C1:JA VANET Huth 3.8 Tong hpp aim mek Czech tiep cOn co the duqc ghi nhu sau Mang luai duOng bet c6 the duqc xem nhu la mOt dung d6 thj G (E, V) bao geNm cic nut v E V va phin down duang e E E V2 kit n6i cic lien ket Cic phan (loan duqc gin mOt s6 w (v1, v 2) tuang Ong vai thOi gian di lai hien tai MOt s6 nut giao thong duqc phan biet nhu la diem m6c E L, L S V MOt tuyen din`mg r (A, B) girra hai diem A vi B 11 mOt chai cua cic m6i (v 1, , v.) nhu v.y ma vi = A, v„ = B vi tit ci cic cep cua cac mOi n6i lien tikp duot ket n6i boi mett down duOng, tire la cho tit ca cac i = n — leo tun tv (vi, vi+1) E E Chi phi cua tuyen throng n-1 I I Oh ••• • Vn) I I := E t=i Cho R(A, B) bieu thj cic thiet cua tit ci cic tuyen duong ter A din B Sau de co the xac djnh duerng nhanh Whit r *(A, B) nhu sau: r (A, B) = argmin I Ir I I rEs(4.8) Ile (A, B)I1 dtrqc sil dung nhu than gian di I* gift hai diem A va B mirc cao han, tirc la, cic hoat dung thuc hien tinh toan mOt tting hqp de xic djnh lir * (A, BM dVa ten thin gian di chuyen thip han he thong pilau cep Bit 10 thuUt tofin djnh tuyen tieu chain nio ciing ce the duqc sir dung de tinh toan Or s (A, B)II Luu si ring no IcheIng c6 lien quan tuyin throng thuc su cho ket quit thOi gian di lai Chi& xe cling xa hai diem m6c, Wiling thong tin hen quan la n6 ce the di ter A den B thOi gian Whit djnh Khi ne den gin han Ichu vut tuang img, n6 se nhon duqc thong tin, sin c6 dia phuang vi chi tiet han Thong tin sau da 06 the duqc sir dung cho djnh tuyen 64 CHUUNG MOM UNG DUNG CUA VANET Thai gian di chuyin la tang hqp nen 'thong tinh cho m8i cep mac Dieu se din den mOt se tip hqp phat trien nhu (n2) vai sO lacing va nhAn Tuy Mien, tong hqp than gian di chuyen gifts cac diem mac xa cling khong don gap nhieu th8ng tin: se co nhieu diem mac lchic "6 era", vil mOt chuii cOa tap hqp tin nhung xe c6 the la xip xi ciut thei gian di loi era cac P xa mac Do de, chi xem xet nhang P khong qui xa Na co the stl dung mOt tieu chuan c6 djnh, giOng nhu mOt khoang each throng bay thing tai da la Op cOt mac ma tip hqp duqc hinh thank ten mOt mire phan cap nhit dinh cua he thOng, ho#c de dank diu cac P mac ro rang tong cic dit lieu ban 0, nhu v#y mOt xip id cua mong luai throng bO ca ban duqc day tri 3.6.2 Think gig chit luvng thong tin Tnrac tinh Wan tang hqp than gian di chuyin giita hai diem mac va yao xe kit& di qua no, mOt chi& xe can co the dinh gia xem kien thirc ve firth tong giao th8ng hien tai cho mOt uac luqng tot T>r quan diem rat chung chung, mOt s6 luqng lon cac doon dm:mg c6 the nom tren mOt tuyin duang c6 the c6 gifira hai diem mac Do da, can thief de xic dinh nheng doon throng c6 khit nAng c6 lien quan den tinh tan thai gian di loi TOng hqp c6 the duqc hinh neu thong tin tren cac doon duang lien quan lien dja phuang 11 c6 sin De Vic djnh t#p hqp cic doon dating lien quan, chung to nhln viio nheng gi pi la tieu chuan thai gian di chuyen dqc theo (loon duang Nhung thai gian di chuyin rat kh6 mA has cac dit lieu ban dating bO vi doi dies cho kY vqng hqp 1S, ctla thei gian di chuyen, vi hien dang duqc sir dung cho he thOng djnh vi dating kW:mg du% dOng MOt each de dang c6 the tinh town cac tuyen duang dot tieu chuan tOi uu r std(A, B) 131 A den B tren co s6 cdc dit lieu tinh chti yen 11 he thOng djnh vi hien toi Doi vii bat 14 tuyen (tut:mg r, n6 ding de ciing tinh toan than gian di chuyen tieu chain r ol Sau da chqn mOt nguang > Xic djnh thiet lip R(A, B) cua doon Ming lien quan gifts hai diem mac A va B bao gOm tit cit cite doon dulmg nam tren mOt tuyin duang mi thai gian di loi cac yeti t6 alit dii han than gian di loi tieu chitin tai uu, tic li, mOt e doon duang R (A, B) neu va chi neu co ton tai mOt tuyen dating (v 1, , vn) VI A den B nhu la mOt phan cua tuyen throng de vi II( Vb • ,V011sid lIrssid(A,B)11stdTieu chuan chi dya ten than gian di chuyen tieu chuin (filth), tip him the doon duang lien quan, khong phu thuOc vio tinh hlnh giao thong hien tai hale Iden thirc hien tai cua xe Thai gian di chuyin tang hqp ttl A den B co the duqc tinh neu thong tin ye cac doon duang R (A, B) c6 sin 65 CHUONG NHONG ONG DIJNG CUA VANET Cau true hing hip dam mec Di thqc hi'e'n t#p hqp thir 14c, mac chi dinh met mire met he th6ng phan cap Cac diem mac cia cap cao ham cling la vien cua tit ca cac cep thip hon Cho met t#p hqp cac diem m6c la Li 1.4c cV > De tgo thisnh met tang hqp tren he th6ng phin cap mire i, nhftng t#p hqp cap i - duqc sir cb,mg gi6ng nhu each quan sat ca nhan cia xe duqc sir dung mac dau tien VI vily, nhing diem mac tren cap i -1 duqc se dung nhu cac nut nhttng than luin tren, va tang hqp thin gian di chuyin gift chimg vao vai fro cua than gian di chuyen dqc theo cac phin down duing ca nhan Hinh 3.9 Thong tin có sand cdc clip 45 kit& Khu vqc ma di cac quan sat ca nhan va t#p hqp duqc quing bi hgn chi dqa tren mire cis ni he th6ng phan cap Quan sat ca nhan duqc philn tan met phi= vi rat hgn the t#p hqp cap cao nhat duqc phan tan tren town be mpg, hinh m8 to dieu Wag tin xung quash chi& xe duel cimg cia cho biet cac khu vrc th8ng tin chi tiet, dieu chink cap 0, thong tin tang hqp cap 1, va th8ng tin tang hqp cap 21a ci sin cho chi& xe Khi xe di den dich cim ni, cac khu vqc thay d6i cho phi hqp Cac diem den cis met chuyin di se kliong phai luc au cling la met mac tri cep cao nhat Tuy nhien, cac th8ng tin tang hqp co the duqc se dung cho quy hogch tuyen during De lam nhu v y, met he th6ng djnh vi se "died' th8ng tin thieu gifta cac diem den cuei cing va diem m6c bang each s* dung than gian di chuyen cac tieu 66 CHISONG NHONG ING DUNG COA VANET chuin mi h6a dlt lieu ban Dieu la hop lSr, bpi vi mOt guy& djnh cuei cling ye Oen lai cult tuyen (luting la chua cin thiet tai giai down la diy du neu met Iva chip t6t cho cac quyet djnh djnh tuyen ttic sip met c6 the duqc thoc hien Trong xe tiep can diem den clia n6, tuyen dtrOng c6 the duqc cap nhat va loc thong tin chi tiet tr6 thank c6 sin 3.7 ICET LU4N Trong chuang nay, di xem xet mOt s6 khia canh quan tong c ►a cac Ong dung tien lqi VANET Vai tro clia ne ce tiem fling ding ke nhu yeu to thj trtimg la mOt thimh c8ng nhung hgn chi, Icha Wing ten tgi va ket nei cling nhu c.anh tranh Vi co minh hoa lam the nao han che tic dung sau cac Ong dung VANET, d6 cling chi nMng gi nhl cac duet ke giao thirc phai ghi nha bpi canh VANET tren di trinh biy mOt h thOng giao thong co the, de chimg minh ring cic img dung tien lqi rit lch6 ce the duqc thoc hien thong qua c8ng nghe VANET Dac biet, tr tren di trinh bay hai phucmg phap tiep thuat toan co the di thiet ke cac giao tinic truyen thong kha Ming mo rung VANET, va qua d6 chimg minh lam the nao n6 c6 the doSi ph6 voi Igui chi clia no 67 TONG KET TONG KET Chuyen de da gibi thieu ljch sir phit trien caa VANET qua timg giai down cac khu Arc khic Va litm the nao de c6 the truyen duqc dit lieu mpg VANET, chuyen de cling de cep den cach truyen thong tin mpg vi cac vin de han the curt mpg VANET nhu han the lchit tiling cart 'riling, hap the ve lcha !tang kit nAi, cAnii tranh vai cac mang sin Sau mOt th6i gian nghien cum, cac lc& qua the hien tong bac) cao chuyen de duqc tam tit nhu sau: Mang VANET duqc kY vong nhu mOt tang thong minh cho he tilting giao thong hien dui, mOt boat cite tien ich duqc de c#p den cac nghien cim va tan khai he thong duqc tam tit bito cao Tuy nhien, su khic biet ye mai tru6ng img dung, cac c8ng nghe mpg vi kiln tic da d(it cac thach thirc cho cfic nha nghien tiro va hien khai he thong Cac vin de tren duqc neu chucmg nhu phin tien de cho cac vin de duqc gill quyet chtrcmg tiep theo V6i kiln tic dung, mpg VANET bj anh huong hieu 'ging lon nhit bdri cac gill phap truyen thong Cac phuang phi') va tong hqp cac phi') la nhung nguyen tic nen tang cho tiAp c#n xay dung, dish gia cic m6 hinh truyen thong tree cat img dung phoS hien cart VANET Cac img dung dam bao an toim la mOt cac raw tieu then chOt va d#c tha cart he thong truyen thong VANET Vol m8 hinh hqp tic giao thong, cac giai phi!) dua tren he thong lchach chi, cac he thong ngang hang, vi cac giao dip gifts xe vai xe duqc the hien qua cac phmmg an ky thu#t, phuong an tap hqp du lieu va tic thtgit toin dieu lchien nhim dua tic tinh toin vito mai trutrng ting dung thuc te cac kiln thuc thu nh#n duqc thong qua qui trinh nghien tiro va tam tit thong tin, em by vong se dip tic tap cAn cac yin de quan tong trien khai VANET m8i tru6ng thuc to nhu: Cic tic dung du doan, xa, to dOng tam kiem truy nhp, v v 68 THUAT NGIYVLET TAT Tir vier tit ASTM Thutit lige fling anh Thu#t ng& fling vi§t American Society for Testing and Hiep KA 4t lieu vi thir nghiem Hoa ICS, Materials CAMP Crash Avoidance Metrics Partnership TO chirc luting an tan va chum CAN Controller-Area Network Mpg khu vvc dieu khien DHT Distributed Hash Table Phan ph6i bang barn DPP Directional Propagation Protocol Giao attic Ian truyin có huong DTN Delay Tolerant Network Mang tre tong the ECDSA Accredited Standards Committee Dugs tong nhOn NM tly ban tieu chain EEBL Emergency Electronic Brake Light Den NW phanh Wien cep IVI Intelligent Vehicle Initiative Phuang tien th6ng minh NHTSA US National Highway Traffic Safety Administration Ban quan l}+ an toil ' giao thong doing b0 my OEM Original Equipment Manufacturer Nha sin xuit thiet bj g6c PROMETHEUS Programme for European Traffic with Highest Efficiency and Unprecedented Safety Chuang trinh cho giao thong Chau Au yeti Hieu qui an town cao nhit RSE Road Side Equipment Thiet bj ben duang RSU Roadside Unit Dan vi ben &Zing SODAD Segment-Oriented Data Abstraction and Dissemination Phan down du lieu triru ttrang vi ph6 bien THU 1AT NGCT VIET TAT Da truy nhap_phan chia theo th6i TDMA Time Dision Multiple Access TESLA Timed Efficient Stream LossTolerant Authentication Nhan clang ten that tin the theo luting thin gian TIS Traffic Information System HO thong thong tin giao thong 'KT tic TFL Time To Live TWA gian sting VANET Vehicular Ad Hoc Network Mang xe cO Mt dinh VII Vehicle Infrastructure Integration Tich licrp tang xe cO VSC The Vehicle Safety Communication Truyen thong an town phuang tier' WAVE Wireless Access in Vehicular Environment Truy cap Irh8ng day tong moi tnerng xe cO WLAN Wireless Local Area Network 70 gian Mang LAN Wing day TAI LIW THAM KHAO TALI LifIJ THAN" KHAO [1] Vehicular Applicattions and Inter - Networking Technologies — Harms Hartenstein and Kenneth P Laberteaux [2] Gig phip can bang tai sir dung cliu frac thu muc cho mpg ngang hang co cau trac cult Da Cao Minh [3] Trang web http://vi.wildpedia.org 71 ... thong tin lin ThOng tin ye traffic, ye tinh trang kit xe, thong tin ye tai not giao thong, nguy hiem can trinh M0 chile xe ding c6 the trb thinh mOt Relay Node chuyen tii th8ng tin cho xe khic VANET. .. se dung thong tin mOt veng rung lan hcrn cac tinh huing giao thong hien toi MOt vi d i khic, he thing xe eng dung VANET: nhttng thong tin phan loci ve tinh hlnh xe toitn phi Thong tin duqc thu... trinh t8i lam bito c.ao nay! CHUONG Ting quan ver th6ng mang Vanet CHU•ONG TONG QUAN Vt HE THONG MANG VANET 1.1 GIO1 THIEU CHUNG Vt MANG VANET 1.1.1 Khdi niflm VANET (VEHICULAR AD-HOC NETWORKS)