Định tuyến trong mạng cảm biến và so sánh bằng mô phỏng.PDF

Han nfta he dieu hinh cho mpg cam bien khong day con c6 the h8 trq nhang tay chon cho he thong, then hinh la quan ly su dung riling Itremg hieu qui, quan ly vi dieu Ichien the thanh phan

Del Hnr Th5ng I.nng Al 7776 Tian Ting CHI O'NG 1 TONG QUAN MANG CAM BIEN KEIONG DAY

MOt mang cam hien !thong day li met mang bao gem nhieu mit cam hien nhe c6 gii thimh thip, vi tieu thy Wing lucmg it, giao dip thong qua the ket n6i !thong day, c6 nhiem vy cam hien, do doe, tinh win nhiim myc dick thu th$p, tip trung dit lieu a dua

ra the quyet djnh town cyc ve mei trueng ty nhien

Nherng not cam bien nhe bet My bao gom cic thinh

Cic 130 vi zit 19 rat nhe, b0 nhe glen han,b0 phin cam bien, be thu phit khong day, nguan nuoi Kich thu6c cua cic con cam bien nay thay dei tir to nhu hap giiy cho den nhe nhu hat byi, thy thuetc vio tang irng ding

Khi nghien cuu ye mang cam bien Wag day, met trong nhUng dic diem quan tong vi then chat de li th&i gian song cea the con cam lien hay chinh la sly gi6i han

ve nitng luqng cea chting Cic nut cam bien nay you ciu lieu thy cong suit thip Cic nit cam bien hoot dOng c6 gi6i han vi n6i chung la khong the thay the duqc ngu6n cung cip Do de, trong khi mang truyen thong tap trung vio dat duqc cic djch vy chit luqng cao, thl the giao thirc mang cam bien phii tap trung diu lien vio bio town ding suit

Mang cam hien c6 met so dic diem sau:

+ CO 'chi Wing tlr t6 chirc

+ Yeu ciu ft hoac khong c6 sy can thiep Oa con ngu&i

+ Truyen thong ves tuyen vi truyen da buerc

+ Trion khai so luqng lan tren pham vi rOng

tai HQr Thing I.nng Al777F Tign Time + Nang lugng, b0 nh6, !chi Wing xir ly c6 ham

+ Cau hlnh thin:mg xuyen thay d8i do m8i truirng hoc nut mpg

+ Quang ba trong phi= vi hgp va djnh tuyen multihop

Cac gi6i han ve mat nitng lugng, cong suit phat, b0 nh6 va cong suit tinh toan Chinh nhfing dac firth nay da dua ra nhftng chien luqc mei va nhang yeu ciu thay d6i trong thiet Ice mpg cam bien

1.2 C.Iu trfic mang cam bign

1.2.1 Cdc yiu to" dnh hurting din cdu trac mom cdm bun

Cac ciu trec hien nay cho mang Internet va man ad hoc khong day lchting dimg duqcho mang cam hien kh8ng day, do mOt s6 15 , do sau:

➢ S6 lugng cac nut cam bien trong mang cam hien c6 the ion gip nhieu lin s6

lugng nut trong mpg ad hoc

➢ Cac nut cam bien a bi 16i

➢ Ciu tic mpg cam bien thay d6i kha thtrimg xuyen

➢ Cac nut cam bien chti yeu sir dtmg truyen thong kieu quang ba, trong khi hiu

het cac mpg ad hoc diu dtra tren viec truyen diem-diem

➢ Cac nut cam bien bj gi6i han ye riling lugng, Icha riling firth town va b0 nh6

➢ Cac nut cam hien c6 the khong c6 so nhon long town ciu (globalidentification)

(ID) vl chting c6 mOt so luqng len mio dau va mOt so lugng len cac nut cam 'nen

Do v$y, ciu tnic !twig moi se:

➢ Ket hop yin de nimg lugng vi !chit Wing (firth tuyen

➢ Tich hop da lieu va giao thirc

➢ Truyen nang lugng hieu qua qua cac phtrong lien khong day

➢ Chia se nhiem vo gran cac nut lan c$n

➢ Cac nut cam lien duqc phen b6 trong mOt sensor field nhu hinh (1.1) MOi mOt

nut cam hien ce khit fling thu dial) der lieu vi dinh tuyen lei den cac sink

Plait lane Thing I.nng A17776 Tien Wing

Hinh 1 Lau Thic ?ming cam biin

Dit lieu duqc djnh tuyen 13i den cat sink b?ri met cAu trim da diem nhu hinh ve tren Cac sink c6 the giao tiep van cac nut quitn It nhiem At (task manager node) qua

mpg Internet hoac ye tinh

Sink 11 met thvc the, tui d6 th8ng tin duqc yeu citu Sink c6 the la thvc the ben tong mpg (la met nth cam bien ) hoac ngoiti ming Thvc the ngoli mpg ce the 11

met thiet bj thvc sv vi dv nhu may tinh zilch tay ma tuong tac vai mpg cam bien,

hoac cling don than chi la met gateway ma n6i Arai mang khitc lan hon nhu Internet

nai ma cac you cAu thvc sv doi yea cac th8ng tin thy tie met vai nut cam bien trong

mung

1.2.2 Glerri thitu ye wit aim biin:

a.Ciu to cda nit slim Min nhw mu:

Mai not cam bien ducrc cau thinh bei 4 thinh phAn co ban nhu ar hinh (1 2)•

don vj cam bien (a sensing unit), don vi zu ly (a processing unit), don vj truyin dan (a

transceiver unit) va be nguOn (a power unit) Ngoiti ra c6 the c6 them nhUng thilnh

phAn khic thy thuOc vio tang ling dung nhu 11 he thong djnh vj (location finding

system), bO phat ngu6n (power generator) va bO Oen di dOng (mobilizer)

nal 14nr Thang i.nng Al 7776 —Phi Tian 'fling

HO thief dinh nj BO Phan di 4+ 1 4

Don si rim biOn

Dorn sit 13; Don vi truyen dan

rim biOn ADC lit it Bothuphit

Luti

Minh 1.2.Cau tgo nut cam bien

Cac don vj earn bien (sensing units) bao g6m cam bien va 1,0 chuyen doi tuong

tv-s6 Dva tren nhftng hien tuqng quan sit duqc, tin hieu Wang tv Mo ra bfri sensor

duqc chuyin sang tin hieu so beng b0 ADC, sau d6 duqc dua vao b0 xer ly Dan vi xir

1S, thutmg duqc ket hqp v6i b0 luu trft nhe (storage unit), quyet djnh cac thit tuc lam

cho cac net ket hqp yeti nhau de thvc hien the nhiem vu djnh sAn Phin thu phat v8

tuyen ket noSi cac nut do mang

MOt trong s6 the phin quan tong that ciut mOt nit mang cam lien la bet nguon

Cac b0 ngu6n thuerng duqc h6 try boi the be phOn loc nhu la to bao Wing luqng mjtt

trai Ngoai ra cling c6 nhftng thenh phin phu lchic phv thuOc vao tong ling dung Hiu

het cac ki °mot djnh tuyen va the nhiem va cam bien cis mang deu yeu cau c6 do

chinh the cao ye vj tri Cac be phi') di dOng d8i lic can phiti djch chuyen cac nut cam

hien khi can thiet de thvc hien the nhiem vu di An djnh Tit ca nhftng thinh phin thy

can phai phft hqp v6i ldch 0 tang module Ngoai kich cdr ra cac nut cam hien con mOt

s6 rang buOc nghiem ngat khac, nhu la phai lieu thu rat it Wing lucmg, hops dOng 6 mot

dO cao, c6 gia thanh thip, c6 the qr hot dOng, va thich bien v6i sv hien d6i cia mai

tnremg

Dei 1-hr Thing I.nng Al 7778 -Rid Tan Wing_

b MOt so lopi nut mpg:

Hinh 1.3.Ntit "King thuac hp Mica Mote

Ho nut inking nay nom trong clir an nghien ciru Mkt trutrng dai hoc california tCY

co& nem 1990, sir dung vi xir 19 cita Anne!, su dung he ditu hanh TinyOS

Des led

Hinh 1.4.Ntit ngng EYES

Nig mpg nay phitt trien tai mOt to chim cita chau au trong dv an s* dung nang Wong hieu quit cita mang cam hien - Energy efficient sensor network (EYES) Nit mang sir dung vi dieu lchien MSP 430 clia Texas, cd khe riling ket nei them cam hien Nit mpg nay sir dung vi dieu khien CC1010 cita chipcon, tich hop thiet N troy& din

vo toy& vi cam bien nhiet do

c Vi xtr 19

Vi xir lt la thiet bj quan bong nhit trong nut mang cam hien khong day, thqc hien thu thap dit lieu HI cac not, sau de xt1 lt truck khi girl di, va nhan da lieu tar cac nut khic Nguyen nhan nd ducat lira chon trong cac he theng nhang la mem deo trong ket neli yeti cac thiet bj lchic nhu thiet bj cam hien, tieu thy Jiang ltrqng thip nhir lchi nang chuyen sang the do nge khi de chi co mOt phlin caa vi dieu lchien hoot dOng, hon nita

Dal I-Inr Thing I.nng Al 777h -Rid Tan Wing

thutmg c6 b0 nh6 tich hqp ngay ten b0 vi xir 19 MOt dtic diem rat duqc ngutri lop trinh ye'u thich la khi tiling lop trinh bang ng6n net bOc cao (C, C++)

B6i v$y khi xay dung nut mung viec xem zit hieu suet cim vi xir 1St, hieu qua nang Itrqng va gia thanh la rat quan trcmg

d Bi) oh&

Dirge sir dung de km tit de lieu thu tt7 cac nut cam Bien, hoc goi de lieu tir the nut khae, ce 2 loci kien true b0 nh6 11: kien true havard va ld'en true von newman, diem khic nhau ells 2 kien true nay la trong Id& true havard thi by nh6 der lieu va chuong trinh tach biet nhau khi de de lieu thutmg dirge hira trong RAM can chuong frith dtrqc chira trong ROM hotic b0 nhe FLASH, con trong kien true von newman thi

de lieu va chuong trinh dirge km cling v6i nhau, thin:mg la tren RAM, nhugc diem dm n6 la dit lieu se bj mitt khi tit ngu6n, bOi vtiy chuong trinh hottc he dieu himh thuang duqc luu tra ten ROM, EEPROM, hoc b0 nh6 flash ( gin tuang to nhu EEPROM) Yeu eau kich thuOc b0 nh6 va Wing lugng lieu thu tuang ling vOi yeu eau ye di lieu

cua ling dung eM nut mpg

e Thiit bj giao dip

La thiet bj duge sir dung de trao d6i de lieu gifts cac nut don v6i nhau, trong d6 moi true:mg kitting day 11 duqc ua dung hcrn ca, do co the la song vo tuyen, truyen thong quang, song sieu am, al trutmg cling duct sir dung trong mOt vai ling dung dtIc biet Trong d6 s6ng vo tuyen cung Dip dii thong 16n voi the dO di lieu cao a pith hqp nhit cho hau het cac ling dung cim mpg thong day Trong dO cac nut yeu eau ca chirc nang nthim va truyen de lieu (dieu chi, gill dieu che, lchuech dui, lqc, trOn ) sau de chuyen luting bit, byte ho(te khung thinh song vo tuyen, thong thuong 2 thiet bj nay thubng dirge kit hqp thinh mOt thiet bj duy nhat, bei vOy thutrng thi tai mOt thai diem thong the thtrc hien dring then vita truyen vire nhOn de lieu, ma truyen va nh#n se dirge luan phien nhau dirge dieu Ichien bOi he dieu himh nhong

Khi lira chqn thiet bi truyen nhan can Itru y viii dtIc diem sau:

• rding phuc vu cho 16p ten (MAC), cho phep lop nay dieu !chi& goi

de lieu

✓ Tiet hem rding lugng vi sir dung nang lugng hieu quit do Ming lugng

tieu thu nhieu nhitt tong nut mong la do viec truyen nh3n vo tuyen

✓ Tan s6 s6ng mang vi da kenh truyin tong tnty&t nhen phii phu hqp vei yeu cau eM ling dung

Chuyen d tot nghtep

Del Hey Thing I.nng Al 77Th -Rill Tian Wing

✓ Ric do da lieu Wang Ong v6i tin s6 song mang v8 bang tin cling v6i viec dieu the va ma hOtt du lieu, tOc dO nay cO the thay d6i bang dieu the

holtc thay d6i toe dO ctia ky tv

✓ Dieu the va ma hed

f Cam Min

CO rat nhieu loai cam bien, tity vao loci (mg dyng tong mkutg cam bien ma ta ceo cfic cam bien twang ling, that:mg la dva vito kieu host dOng dm cam bien, tich eve- thy dOng, pham vi giam sat /tang Itrong tieu thy, gia thanh va kich thuerc Thuerng thi viec lira chyn cam hien Ichong phtic tap nhu b0 nh6 va vi air lt

g Nguen nuoi

Lit thitnh phan cot yeu cua mang cam bien, tong de 2 van de can quan tam li 'chi Wing luu ter vi cung cap nang lugng, va Icha ruing thay the ngu6n.Thuting thi nguOn day thuting li pin, vi !chi rang thay the tong net mpg la kh8ng the do dja hinh hien khai va se nut mang len, do v$y phiti chqn nguem on djnh co lcha rang host dOng phi hqp v&i ye'u cau cua ling dung vi m8i trubng host dOng

h Phin mom

He dieu hanh nhimg, dieu Ichien vi bio ve truy cop tai nguyen vi quan lt cho phep phep ngtrei dimg cling nhu h8 trq thi kinh xir IY vi giao tiep gifta citc qui trinh Tuy nhien chirc Ming chit yeu la thi hinh lenh, bat vay he thong Ichong you cau quit nhieu tai nguyen de h8 trq nhu met he dieu hitnh holm thien

Han nfta he dieu hinh cho mpg cam bien khong day con c6 the h8 trq nhang tay chon cho he thong, then hinh la quan ly su dung riling Itremg hieu qui, quan ly vi dieu Ichien the thanh phan ngosi vi: cam bien, thiet bj vo tuyen, djnh that Bei v$y you cau cho by dieu hanh cho mpg nhimg la caw trOc don gian vi ho trq quitn 11 nang luqng

ma Ichang ten nhieu tai nguyen he thong nhu b0 nhe vi thin gian xir

1.2.3 DOc diem cilia cdu franc myng aimblew

Nhu tren ta di biet 4c diem dm mpg cam bien la bao gOm met s6 limn len cic nut cam bien, cac net cam bien c6 giOi hsn vi rang buec ve tai nguyen biet lit Ming lucmg rat Wait khe Do do, du true mpg mei co dac diem rat khac v6i cic mpg truyen thong Sau day ta se phan tich met s6 4c diem not Wit tong mpg cam bien nhu sau:

Hai Hor Thing Long Al 777A -MI Tan Thng

• IChi Wing chju 161 (fault tolerance):

MOt s6 cic nut cim bien c6 the Wong hoot dOng era do thieu ning lucmg, do

nhftng hu h6ng vet 19 hok do inh huing cia m8i truting Khi nAng chju 18i the hien a

viec mong van hoot dOng blnh thuing, duy tri nhftng chic nAng mia no ngay ci khi

mot so nut mong khong hoot dOng

• Khi nAng me rOng:

Khi nghien cuu met hien tuong, s6 Wong cic nut cam bien duqc then khai ce the

den hang tram nghln nut, phi thuk vio ding img dong con so nay c6 the vuqt qui hang trieu Do d6 cau frac mpg mai phii c6 khi Wing ma rOng de c6 thE lim viec vii

s6 lugng 1&n cic nut nay

• Gii thrinh sin xuat :

Vi cic numg cam bien bao gOm met s6 Itrog 16n cic nut cim bien nen chi phi con m6i nut rat quan Mpg trong viec dieu chinh chi phi cirri toin mong Neu chi phi coca

toin Truing dat han viec then khai sensor theo kieu truyen th6ng, nhu vey mong Ichong

co gii thinh hqp lt Do voy, chi phi cia m8i nut cam bien phii gift 6 mire thap

• Ring butjc ve phan cung :

VI s6 lucmg cic nut trong mpg rat nhieu nen the nut cam bien can phii c6 cic ring buOc ve phan cung nhu sau : Kich tuck phii nhi, tieu the nth% lucmg thap, c6 khi nang hoot d'Ong 6 nhftng nol c6 mot dO cao, chi phi sin xuat thip, c6 khi ning to tri vi hoot dOng !thong can c6 ngutri kiem soar, thich nghi v6i mei truing

• Mai throng hoot dung:

Cic nit cim bien duqc thiet lip day dk, rat gin hok troc tiep ben trong cic hien Prang de quan sit Vi the, cherig thuang lim viec mi kh8ng can Om sit a nhing vimg xa x8i Cluing c6 the lim viec 6 ben trong cic may moc lan, 6 dueri day bien, hok trong nhftng vimg 8 nhiem h6a hoc hok sinh hqc, a gia dinh hok nhftng tea nhi 16n

• Phucmg tien truyen din :

(3 nhftng mpg cam bien multihop, cic nut duqc ket non bang nhftng phucmg tien

khang day Cic dutmg ket nen nay c6 the to nen boi song vo tuyen, Wing ngooi hoc

nhftng phuang tien quang hqc De thiet lip so hoot dOng th6ng nhat cia nhftng mpg nay, cic phuong tien truyen din phii duce chop phii phi hqp tren toin the glen Hien

tai nhieu phin cung dui the nut cam hien doa vio thiet ke mach RF Nhftng thiet bj cim bien !tang Iuqng thap ding b0 thu phit v8 tuyen 1 kenh RF hoot den a tin s6

Chuyen tot nghiep

Dal Thng Long Al 7776 -Rni Tien Tang

916MHz Met each Ichic ma cac nut trong mang giao tiep vai nhau bang Wing ngoai Thiet ke may thu phat vo tuyen dimg hong ngoai thi gia thinh re vi de ding han Ca hai loci hung ngoai va quang deu yeu eau be phat va thu ram trong pham vi nhin thiy, the la c6 the truyen anh sang cho nhau dirge

• Cau hinh mpg cam hien (network topology):

Trong mang cam hien, hang tram den hang nghin nut dirge trien khai teal twang cam bien Chung dirge trien khai trong yang hang chuc feet cim nthi nut Mat de cac nut c6 the len tai 20 nut/m3 Do so lugng cac nut cam hien rat lbn nen can phai thiet lap met au hinh On djnh Chting ta c6 the kiem tra cac van de lien quan den viee duy tri va thay doi ciu Hit 6 3 pha sau:

➢ Pha tien then khai vi trien lchai• cac nut cam bien c6 the dat len xen hofte xip

theo tat ti,r tren tnr&ng cam bien Chang c6 the dupe trien khai bang each thi tir may bay xueng, ten lira, hoc c6 the do con ngtrai hoc robot dSt tang cai met

➢ Pha h3u trien khai: sau !chi thin khai, nhitng sv thay dei eau hinh phu thuec vio

viec thay d6i vi tri cac nut cam hien, Ichit Ming dal trang thai Ichong ket not (phu thuec vio nhieu, viec di chuyin cac vet can ), nimg lugng thich hap, nhUng sv

va item vu ev the

➢ Pha then khai lai: Sau ;chi then khai eau hinh, ta van co the them vio the nut

elm bien Ichic di thay the cac nut gap sv c6 hose thy thuec vito sv thay d6i chirc Ming

• St: fieu thy Ming lugng (power consumption) :

Cac nut cam hien Ichong day, c6 the coi la met thiet bj vi dien ter chi e6 the dirge trang bj ngu6n Ming lugng gill han (<0,5Ah, 1.2V) Trong met s6 ung dung, viec 136 sung ngu6n wing lugng Ichong the dive hien dirge VI the Ichoing that gian song cua

cac nut cam hien phu thuec manh vito tiled gian song cim pin mang aim hien multihop ad hoc, m6i met nut ding met vai tr6 kep vita Ich6i t3o vita djnh tuyen dry

lieu Sv true tic cim met vai nut cam bien c6 the gay ra nhung thay ded ding ke trong eau hinh ve yeu cau djnh tuyen lai cac g6i vb to chirc lai mpg Vi voy, viec duy tri vb quitn 1S, ngu6n Ming lugng &mg met vai tth quan tang D6 IA 19 do vi sao ma hien nay nguoi ta dang top trung nghien cuv ve cac gill thuot va giao thirc di thiet ke tip& cho mang cam hien Nhiem vu chinh cim cac nut cam hien trong taxiing cam bien la phat hien ra cac sv Iden, thus hien xir 19 da lieu cuc be nhanh Chang, va sau de truyen aq

lieu di VI the sr fieu thu nang lugng dirge chia ra litm 3 vimg: elm bien (sensing), giao tiap (communicating), va xir 19 dit lieu (data processing)

Chuyen de tot nghiep

1)ei 1-inr Thing Inng Al 7776 -Rai Tan Tang

1.2.4 Hai can frac 40c dung cilia mgng cdm bit%

a Gin tric phing

Trong ciu true phing (flat architecture) (hInh 1.5), tit ca cac nut deu ngang hang vu thing nhit trong hInh clang ve chin Ming Cac nut giao tiep vii sink qua

multihop sir clung cac nut ngang hang lam 1,0 tiep song Vii phwn vi truyen c6 djnh, cac nut gin sink hon se dam Igo vai tr6 cla 10 dip song dOi yid mOt sti Itrqng len

ngu6n Gil thiet ring tit cl cac nguan deu dung cimg mOt tin s6 de truyen du lieu, vi

vkly c6 the this se thin gian Tuy nhien each nay chi c6 hieu qui vii dieu kien ll c6

nguen chia se don le, vi du nhu thin gian, din so

Mu"( • Twa con

Hinh 1.5.C6u Ink phang cua mgng cam biin

b Ciu talc tang

Trong ciu true tang (tiered architecture) (hinh 1.6), cac cum duet to ra gulp cac tai nguyen trong cimg mOt cum gui dit lieu single hop hay multihop ( toy thuOc vim kick cer cua cum) den mOt net djnh sin, thubng gqi la nut chit (cluster head) Trong ciu true nay cac nut to thlnh mOt he thong cap b$c ml 6 d6 m6i net Cr mOt mire xlc djnh thirc hien cac nhiem vu da djnh sin

Dai 14nr ThAng I.nng Al 7776 -Rni Tign Ting

•

Tr "( TIM COI • Tarn "All

Hinh 1.6.Cau Ink tang cita numg cam biin

Trong cau true tang thi chk nang cam hien, tinh than va phan phoi dfir lieu khong dung deu giera cac nut Nhitng chile niing nay co the phan theo cap, cap thip nhat thvc hien tit ca nhiem vv cam hien, cep gifts thvc hien tinh than, va cep tr.& cimg thvc hien phan phei di

Mcmg cdm biin xdy dung theo cau tnk tang hogt Ong hifu qud hen cau tnic pitting, do cdc Ill do sau:

Cau trim ding co the gitim chi phi chi mang cam hien bang viec djnh vj cac tai

nguyen 6 vj tri ma chting hog dOng hieu qua nhat RO rang la neu trien khai cac phin citing thong nhit, mei nut chi can mOt Wong tai nguyen tei thieu de thuc hien tit ca cac nhiem vitt Vi s6 lucmg dm nut can thitt phu thuOc vao yang phit song xac djnh, chi phi ciia tan mpg vi the se khong cao Thay vac) do, neu met

só luqng 16n cac nut co chi phi thip duqc chi djnh lam nhiem vu cam bien, met

se luqng nhe hem cite nut co chi phi cao han duqc chi djnh de phan Lich dii djnh vj vi dung b0 thoi gian, chi phi cho town mang se giam di

• Mang eau trim tang se c6 Si the, cao hem cau true mang phAng Khi can ph& tinh town nhieu thl mOt 10 V: nhanh se hieu qua horn, phv thuOc vac, thiri gian you cau thvc hien tinh town Tuy nhien, vai cac nhiem vv cam hien can hog dOng trong Ichoing thin gian dai, cac nut lieu thv it nAng luong pha hqp v6i yeu cau xir 15r tei thieu se hog dung hieu qua hon Do vay v6i cau frac tang ma cac

chi= niing mpg phan chia era cac phen cimg dii duqc thiet ke rieng cho tang

chirc nAng se lam tang Wei the) ctia mang

Ve dO tin cay: mang cam hien pith pha hqp v6i v6i se ltrqng cac not yeu cat thda man dieu kien ve bang thong va DIM gian sting Wri mang cau Irk

tai Hnr Th5ng I.nng Al 777h -Hai Tign Tang

phiing, qua phan Lich ngued ta da xic djnh thong luqng t6i uu ala mai nut tong mang c6 n nut la x = ;Tr trong d6 W 11 do rOng bang tan ciut kenh chic se Do d6 khi kith ddr mang tanglen thi thong Wong caa =Si nut se giim ve 0

• Viec nghien ciru cac mang cau tnic tang dem lai nhitu trien vong de 'chic phyc van de nay MOt cach flip can 11 dung met kenh don le trong eau true phan cap, trong d6 cac nut 6 cap thip hon tao thinh met cum xung quanh tram etc Nan

met tram g6c dOng vai tr6 11 cau n6i v6i cep cao hon, cap nay dam bao viec

giao dip trong cum thong qua cac be ph$n halt tuyen Trong twang hop nay,

dung luong curt mang tang tuyin tinh v6i s6 luqng cac cum, v6i dieu !den a s6

luqng cac cum tang it that phii nhanh bang n Cac nghien cuu Ichac crn thir cach dung cac kenh khic nhau er cac mtic khic nhau caa cau tnic phin cep Trong truerng hop nay, dung luqng caa m6i 16p tong cau tnic tang vit dung luqng ctia m6i cum trong m6i 16p )(tic djnh la dee 1#p v6i nhau

Tom lai, viec tuong thich gifts dac chtic Wing trong mang c6 the dot duqc khi dung cau tnic tang D#c biet ngubi ta dang tap trong nghien cuu ve Mc tien ich ve tim dja chi NhOng chic Wing nhu voy c6 the phan phoi den moi nut, met phan phan b6 den tap con ells cac nut Gia thiet ring ctic nut deu Icheng c6 djnh vit phai thay del dja chi met each djnh ki, sy can bing gigra nhang bra chon nay phy thuOc vio tin se thich hop

cua chirc rang cap va tim ldem Hien nay cfmg dang co rat nhieu mo hinh tin} hem dja chi trong mang cau true tang

1.3 (ling dyng

Nhu tan ta di de cap den cac link Arc ung dung mang cim bien Ichong cLiy.Cy the ta se xem xet k5' met s6 (mg dung nhu sau de hieu ro sy can thiet elm mang cam

biE'n Ichting clay

Cac mang cam bien c6 the bao g6m nhieu loci cam bien khac nhau nhu cam bitn

dOng dit, cam bien tir trigmg t6c de thy mak tip, elm bien thi giac, cam bien h6ng

ngoai, cam bien am thanh, radar ma c6 the quan sat yang rOng the ditu kien xung quanh da clang bao gem:

✓ Nhiet de

✓ DO Am

Sr

✓ chuyen dOng ctia xe cO

✓ Dieu kien firth sang

✓ Ap seat

✓ Sy hlnh thanh at

tai Hnr Thing I nng Al 777A -Rid Thin Time

✓ Mire nhiiu

✓ Str c6 mat hay ving mat met din tuqng nao do

✓ Mire ting suit tren cac d6i tuqng bj gin

✓ Dk tinh hien tai nhu the de, chieu va kich thutsc cita doi tuqng

Cac nut cam bien c6 the duqc sir dung de cam hien lien tuc hoar la phat hien sir kien, so nhen clang Sv kien, cam hien vi tri va dieu Ichien ctic be be phan phat dung Kith niem vi cam hien va ket not khan day cita nhOng nut nay him hen nhieu vimg ling dung mei Chang to phan loci cac (mg dung nay trong quan dei, m6i tnrbng, sire Ich6e, gia dinh vi the Milt vvc thtrong mai Idtac

1.3.1 Ung dyng trong qudn

Mang cam hien !thong clay c6 the tich la met phin tich hqp trong he thong dieu lchien quan dei, giam sat, giao tiep, tinh toan thong minh, trinh sat, theo doi muc lieu Dec tinh triEn khai nhanh, to to chirc va c6 the bj 16i cita mpg cam bien lam cho chang him hen Icy thuat cam hien cho he th6ng trong quan dOi VI mang cam bien dva tttn sv tri6n khai clay dac ciut cac nut cam hien c6 sin, chi phi thip va sr phi hay cita met vai nut bed quin djch !thong art hueng den host dOng cita pan dOi ding nth: sir phi hity cac cam hien truyen thong lam cho khai them mang cam bien la ung dung tot dei vei chien trueng MOt vai ung dtmg quart dei cua mang cam hien la quan sat lvc luqng, trang thiet bj, dan duchy, theo doi chien trueng do tham dja hinh va lvc luqng quan djch, mix lieu, viec danh gia mire dO nguy hiem ciut chi& tratmg, phat hien va

do tham viec tan cong bang h6a hqc, sink hoc, hat thin

a.Ghim sat Ivy luvng , trang that bj vi don dirge:

Cac ngtrei lanh dao, si quan se theo doi lien tuc tang thai lye luqng quart Ali, dieu kien va sy c6 sin ciut cac thiet bj va dan duqc trong chien trtamg bang viec sir dung mang cam hien Quan dei, xe cO, trang thiet bj va dan duce c6 the gin lien v6i cac thiet bj cam hien nho de c6 the thong bao ire tang thii Nhang ban bao cao nay duqc tap hqp lai tai cac nut sink de gni tei lanh dao trong quan dOi Dft lieu cling c6 the duqc chuyen tiep den cac cap cao hon

✓ Giam sat chien throng: dja hinh hiem lit, cac tuyAn dutmg , dutmg men va cac

ch6 eo hgp co the nhanh cheng duqc bao phit btri mang cam bien va gin nhu co the theo doi cac hoot dung cita quip djch Khi cac host dOng nay duqc me rung

va ke hooch hog dOng mei duce chutm N mot mpg mei c6 the duqc trien khai bit cir thei gian nao 'chi theo dOi chien tnrtmg

Rai I-Inr TWAng I.nng Al 777h -Rai Tan Tang

✓ Giam sit dja hinh va lye luong quart djch: mpg cam bien c6 the duqc then

khai b nhCmg dja hinh then chin vi mOt vai nai quan tong, cac mit cam hien

can nhanh chong cam hien cic dit lieu tilt t(ip trung dft lieu giri ve trong vai phut

truck khi quan djch phit hien vi ce the chin lai chting Hirsh (1.7) cho to hinh

dung ducm ve ting dung caa mang cam bien tong host dOng quitn dOi

Hinh 1.7.1ing dung trong qudn tlgi

✓ Dinh gii str nguy hiem cim chien new: try& va sau khi tin deg mang cam

bien c6 the duqc triEn khai b nhCmg yang inn tieu de niun duqc misc dO nguy

hiem cua chien twang

✓ Pith hien va tham do the At tan Gong bang Ma hoc, sinh hoc Ws hat nhfin

Trong the cuOc chien tranh Ma hoc vi sinh hoc dang glin ke, mOt dieu rat quan

tong la sum pith hien ding lac vi chink )(tic cic tic nhan 46 Mpg cam bien

trien khai b nfrang vung ma duqc sir dung nhu la he thong canh bio sixth hoc va

h6a hoc c6 the cung cap cic thong tin mang Sr nghia quan tong ding I& nhim

tranh thuang vong nghiem trong

MOt vii img dung moi trutng cua inking cam bien bao gam theo doi sum di at

coa cic loci chim, cic dOng vat nho, cic logi con tang, theo doi dieu kien men throng

link 1.8.Cin dyn theo dei di ch en cilia don v (it

ma inh huOng den mita ming vi vat nail; viec tad lieu, cic thiet bi do dac Ion d6i yeti viec quan sat dien tich len tren trii dat, sq than' do cic hinh tinh, phit hien sinh-h6a, nong nghiep chink xac, quan sit m8i tubing, trii dat, m6i truemg vimg bign vi biu klu quyen, phit hien chiy rung, nghien cuu khf tuqng hoc vi dia It, phit hien 18 hit, sip chit sv phirc tap ye sinh hqc mkt moi tieing vi nghien ciru str 8 nhigm

❖ Pith hien chiy vi the not cam hien ci the duqc trien khai mOt each ngau nhien, ci chien lucre vOi mot de cao tong rung, cic nit cam bien se de tim nguin gic cim lira de thong bit° cho ngutri sir dung biet trait IN lira Ian rOng

khong !dem soft duqc Hang trieu cic not cam hien ci the ducat trier khai vi

tich hqp sir dung he thing tin s6 khong day hoac quang h9c Cling vay, chang c6 the duqc tang bi each thirc sir dung Gong suit ce hieu qui nhu la pin mat trbi bbl vi cic not cam bien bi be lai khong c6 chi hang thing vi hang nam Cic nut cam bien se cOng tic vOi nhau de thvc hien cam bien phin bi vi khic phvc kW) khan, nhu cic cay vi di ma ngiln ter tam nhin thing cia cam hien co day

MOM MINIO

Hinh 1.9.1ing clung trong moi tnremg

❖ Phat hien 18 lut: met vi du d6 la he thkg bao tieing duqc Men khai tai My Met vii loci cam bien duqc then khai trong hg thing cam bien luqng mua, mitt

nu6c, thtri tiet Nhttng con cam bien My cung cap th8ng tin de trip trung he

theing ca s6 drr lieu da duce djnh nghia trtroc

1.3.3 thy Amy trong chdm sac sac Moe

Melt vii irng dung ve sirc khoe de6i vei mpg cam bien la giam sat benh nhan,

cac trieu chimg, quitn ly thutc trong benh vien, giam sat sv chuyen don va xe lt ben trong cua con trimg hoc the Ong vet nhe lchk, theo doi va kiem tra bac si va benh nhan trong benh vien

Theo clei bac si va benh nhan trong benh vien : moi benh nhan duqc gin met nut cam bien nhe va nhg, m6i met net cam bien nay c6 nhiem vu rieng, vi du c6 nut cam hien xac djnh nhjp tim trong !chi con cam bien !chic phit hien ap suit mau, bac si cling c6 the mang net cam bien de cho ck bac si khac xac djnh duqc vi tri dm hp trong benh vien

BASUMA (BMWA)-Gerrnany Heath Cate Monitoring of Mabee Patients

Hinh 1.10.0ng dung trong chdm sex sue khoe

1.3.4 Ty' Ong hod gia dinh vd dien din dyng

Gia dinh la lchong gian ling dung rat lan cho the mpg cam bien lchong day Nhieu Crag dung cong nghiep vita &Km m8 to c6 m6i lien he tuong fir trong gia dinh

Vi du met he th6ng HVAC duqc hang bi yen the be On nhiet va chting rung Ichong day

tai I-Inr Thing I.nng A17776 -Rill neon Tiing

co the bao ye cac pheong duOi anh ning met troi cua ng8i nhl - se hieu qua han mOt ngoi nha chi trang bj mOt hi) 6n nhiet don co day

MOt (mg dung duqc dieu khien chung tir xa, men PDA loci thiet bi c6 the chi khong dieu khien TV, May nghe DVD, din am thanh Tutu va cac thiet bj dien tir gia dinh Ichfic nhung yin cac bong den, cac drill cira, va cic o khofi cling duqc trang bj yeti mOt ket nei mang cam bien kh8ng day Vii dieu khien chung tir xa, mOt be c6 the dieu IN& nen nha tir tien ich tren ghe Tuy nhien, Icha ning hip din nhfit den tir six kit hqp nhieu dich vv, giong Mut cac ainh cira to dOng deng khi TV duqc bet, hoec ce the

to dOng ngung he thting giai tri gia dish khi mOt cuOc duqc nhon tren may dien thoth hok chuong cira keu Vii chiec can va may tinh ca nhan ca hai dirge ket not voi nhau thong qua mOt ming cam !then khong day, sin Ong ciia met vet co the duqc tlr dOng ghi 13i khong can yeu can su can thip bang tay

MOt mzc dich 16n dui cac ming cam hien khong day trong gia dinh duqc mong ch6 la cac thiet bj ngoth vi may tinh ca nhan, giting nhu cac keyboard va mice khong day Cac img dung nay dem Iii uu diem giii thip va mac lieu thu nguan thip la dieu kien thiet yeu cua cac ming cam bien khong day fing dung khac trong gia dinh la cac citing cu thong tin dua tren cam bien (sensor-based) ma tic dOng vi lam viec tong sinh

ro ret cling nhau de thal min chi nha Cac mang nay la met mir rOng cua cac dung cu thong tin duqc de xuAt b6i Norman

Ck d6 chai mieu to mOt thi tnrong len Ichfic cua cac mpg cam bien khong day

Danh sfich cac do chai c6 the duqc them ho(ic cho phep nh6 cac ming cam bien khong

day la bj gidi hp chi bid slit ttemg tucmg cim con ngutti, va phim vi tir cac xe hcri va tau thuyen duqc dieu khien bang vo tuyen thiong thiremg den cac tit chart tren may tinh ten dung cic bO joystick vi bij dieu khien khong day MOt ph(un vi hip din dec biet la cic may tinh ca nhan — cac fro chcri nang cao, ton dung sue manh tinh tom ala mOt may tinh 6 gin de nang cao chit luqng ngay tth ban than tr6 chai Vi dv, nhen ding vi tong hqp givng nen c6 the duqc that hien bei vi tri cac microphone va speaker trong fro chai, cong vii cac b0 bien d6i analog-to-digital va digital-to-analog phi' hqp, nhung tin dung mot ket nei khong day den may tinh, c6 the thvc hien cac chin nang nhen ding va tong hqp Nhb thay the cac mach dien nhen clang vi king hqp den nay con N gi6i han vii gifi tuang dii dit, bing viec sir dung sire mph tinh toin (manh han nhieu) hien tai trong may tinh, chi phi cac fro chai co the duqc giani (tang ke, trong khi cai tien nhanh thong ve kha niing va that thi coa tre chai NO cling có the dua ra dO phirc tip cila tre chai ma tren thvc to khong ducm b6 xung trong cac icy thuet !chic

Hne Th5ng 1.nng Al 7776 Tian Wing

Ong dung gia Binh Ian hon Id* la met ma rOng dui dac diem RICE (Remote Keyless Entry) duqc tim they tren nhieu 8 t8 Val cac mang cam bien kh8ng day, A khoi kh8ng day, cac cam bien cira ra vito va cira s6, va cic be dieu khien bong den khong day, chit nha co met thiet bj tucmg to Whit met key-fob vai met node barn KM barn node, thiet

bi khoi tat ca cac cira ra vio va cira s6 trong nhit, tit heu het cac bong den trong nha

(trir met vai bong den ngit), bat dm bong den an toitn ngoiti nha, va thiet lap he thong HVAC den the dr) ngit Ngutri sir dung nhan met tieng beep met lin hei dap the hien

tat ca da thvc hien thinh &mg, vi nghi ngcri holm toin, nhtr vay fled nha an toin Khi met cith cira hang Ichling the ma, hoc van de tan tai, met min hinh hien thi tren thiet

bj chi thi nai bi hong Mang c6 them tri c6 the ten dung met he thong an ninh gia (firth day de de phit hien met cira so bj gay ho*c ch6 hong khic

Ben ngoiti ng8i nha, cac khi Wing location-aware cita cac man can bien Ichong day phe hqp yeti met tap Uric nhau cua cac host deng consumer-related, bao gem du ljch vi mua sam Trong cac img di,mg nay, qui trinh dinh vi ce the duqc sir dung de cung cep th8ng tin context-specific den ngubi tieu dimg Trong truang hqp cite ngu&i huang den vien du ljch, nguOi sir dung chi duqc cung cap thong tin lien quan den quang canh hien tui, trong truing hqp cite nhan vien ban ban hang, ngual sir dung duqc cung cep thong tin lien quan den sari pan trtrac mat bao gAm cac Ichoin mua

bin va lcheu hao dac biet va trq

1.3.5 Gam sat va dleu laden cony whin)

MOt nha may c8ng nghiep, c6 quy mo reng dieu hinh c6 met phang dieu 'chi& tuang dei the, xung quanh c6 cac this& may mec twang dei 16n PhOng dieu khien c6 cac thing 116 chi bio va cac may hien thj de mei to Dung thai cac thiet bi (trang thai cac van, trang thai this& b1, nhiet de va ap suit cita nguyen lieu dirge ltru tni, v.v ), dsu

vio cac thiet bi de dieu khien cac be truyen dOng trong cac may mec (cic van, cac bep

lb, v.v ) ma tic deng den trang thai dirge theo dOi the may m6c Cac cam bien m8 to trang thai the may m6c, cac ket quit hien thj cita chimg nem trong phimg dieu khien, cac thiet bj dau vito dieu khien, va cac be truyin deng trong cac may tit ca Wong di

re khi dirge so sash vai chi phi cite cac dutmg day boc kim loai ma dirge sir dung de truyen thong gift Chung Tiet kiem chi phi ding k'e dirge hob tat neu met phuang tien 'thong day re c6 sin di cung cep kik truyen th8ng nay Beri vi thong tin duqc truyen thong la thong tin trang thai, no thubng thay d6i cham Vi v3y, trong the dO van himh binh thuang, thong lugng da lieu dirge you caw cita mang tuang dei chOm, thing dO

tin cay dirge you caw cua mang lai rat cao Mang cam bien kheng day ciut nhieu node,

Hne Th 5ng Lnng Al 7776 Tign TAng

cung cap nhieu duang dan djnh tuyen ban tin cim qua trinh truyen thong multi-hop, c6 the Ilan duqc cac yeti ciu nay

MOt vi de ve di& khien cong nghiep khong day la qua trinh dieu khien b6 tri anh sang quang cao Rat nhieu phi ton trong qua trinh cai dat cac b6ng den tong mOt to& nha lan lien quan den viec dieu khien cac bong den — ncri ma cac chuyen mach co day, yeti cac bong den duce bat va tit cling nhau, dieu khien bong den, v.v MOt he thong Wong day c6 tinh mem deo co the ton dung mOt b0 dieu khien handheld co the duqc lap trinh de dieu Wan mOt s6 luting cac bang den tong mOt then nhieu each lchic nhau g'ain nhu vo hen, tong khi yin cung cap mac dg an ninh duqc yeti ciu bai mOt ix) phan lip dat quang cao

Them mOt vi du nfta la viec sir dung cac mang cam bien !thong day tong cac img dung an toan cong nghiep Cac mang cam bien Ichong day c6 the tan dung cac cam hien de phitt hien se hien then cim cac chit dOc hai hoac cac vat lieu nguy hiem, cung cap qua trinh phat hien va nhon clang som cac khe ha hoac phat hien tran cac the nhan hoa hqc hoc sinh hoc tuft khi thiet hai nghiem trqng co xay ra (va truOc khi the chit nrcrt ra ngoiti Wing kiem soat) Bei vi mang Ichong clay co the sir dung cac thuot toan djnh tuyen phan tan, co nhieu dirt:mg djnh tuyen, va co the to chfta tnj va to duy td, cluing c6 the co gian tong mat ngoai dm qua trinh bimg no hoac cac thief hai lchac den may cong nghiep, cung cap cac thim quyen vai thong tin tang thai may quyet djnh duai cac dieu kien rat lch6

CHUONG 2 KIgN TROC MO HINH PHAN LOP COA MANG CAM BIgN

Trong chuang tnrec chting ta da xem xet ve cac khIi niem tong quan nhet ve

mang cam bien Chuang nay chfmg ta se di sau vao tim hieu mo hinh phan lop va cic

giao thirc dac trung cita mang cam bilk

Men true giao thfrc ip dung cho man cam bien duqc trinh bay trong hinh (2 1)

Kik trtic nay bao gOm the lop va the mat piling quart lt Cac mat piling quan lt nay

lam cho the nut c6 the lam viec ding nhau theo each c6 hieu qui nhat, djnh tuyen dit

lieu trong mang cam hien di dOng va chia se tai nguyen gifts the nut cam bien

Hinh 2.I.Kien Ink giao rink 'ming cam bien

✓ MOt phang quan 13, cling suit : Quin 1St each cam bien sir dung nguOn /tang

luqng cua no Vi du : nut cam bien co the tit b0 thu sau lchi nhan duqc met bin

tin Khi mire cling St dm con cam bien thap, no se broadcast sang nut cam

bien ben canh thong bao ring mire rang luqng cita no thip va no khong the

tham gia vao quit trinh djnh tuyen

✓ M4t phang quern lir di Ong : co nhiem va pith hien va ding ky sir chuyen dOng

cita cac nut Cac nut gift viec theo d5i xem ai la nut hang thincita chting

✓ Ad& phang pan ly nhiem tie Can bing va sip xtp nhiem vu cam bien giita the

nut trong met vang quan tam Khang pith tat ca cac nut cam bien lieu thvc hien

nhiem va cam hien b cimg met thtti diem

nal tine Thing I.nng Al 777A -Rill Tan Wing

✓ L6p vat ly : c6 nhiem vu lira chqn tin so, tao ra tan s6 sang mang, phat hien tin

hieu, diEu ch'E va ma has tin hieu Bang tan ISM 915 MHZ duqc sir dung rung rai trong mang cam bien Vzin de hieu qui nang lucmg ding can phai duqc xem xet 614 vat lt

✓ Lop lien kit di? lieu : lap My c6 nhiem vu ghep cac luting dft lieu, phat hien clic

khung (frame) da lieu, cach truy nhop &rang truyen va diet' lchien 16i Vi m8i

truerng c6 tap am va cac not cam bien c6 the di dung, giao thirc diEu !chi& truy

nhap mei trtrimg (MAC) phii zit den vim de ding suat va phai c6 !chi nang t6i thieu hoi viec va charm vEri thong tin quing bi ciut cac not lan can

✓ Lop wing : Lem mang ctia mpg cam bleu duqc thik ke tan theo nguyen tic

sau :

o Hieu qua Wing luting luon luon duqc coi la vim de quan Mpg

o Mang cam bien chu yOu la tap trung da lieu

o Tich hqp da lieu chi di:cc sir dung khi no khOng can tit sum cOng tic c6 hieu qua ciut clic not cam bien

✓ Lop truyiln tai : chi can thiet khi he thong c6 Ice hoach duqc truy cap thong qua

mang Internet hoc cac ming ben ngoli

✓ Lop ring dung : Tut theo nhiem vu cam bien, cac loci philn mem irng dung Ichic

nhau c6 the duqc xay dung va sir dung 6 lErp irng dung

Trong mang cam bien thich thirc chn yeu la My dung duqc mo hinh kien irk

truyen nhan dam gian, gia thinh re, nhung yin phiti du hieu qui dE dip img duqc you

citu djch vu mkt *rig dung duqc trien khai

Trong kenh truyen v8 tuyen song dien ter lan truyen to do giOa tram thu va phit, boi vay kenh vo tuyen la moi twang truyen chung khiing chi cho mang cam bien ma cho nhieu img dung khicothir di dOng, phit thanh truyen hinh

a Phan chia tin so

Viec ltra chip ten s6 sir dung lit rat quan trong trong thiet ke he thOng Ngoai trir cOng nghe bang rung hiu het cac he thOng v8 tuyen host dOng vdri tan s6 &DM 6GHz

Flai Mar Thing Lang A17776 -Rill Tign Ting

Dai truyen th8ng ve twin dai tin sir doing thuimg tir VLF tai EHF Viec lea chon

he tan so nham tranh nhigu gitta ngutri ding va cic he th6ng khic nhau, mOt vii dii tan duqc danh rieng cho mOt vii he thOng dic biet, a chiu au GSM c6 the hoot dOng dii tan GSM 900 (880 — 915 MHz) va GSM 1800 (1710 — 1785) MHz Ben quilt d6 ITU con quy djnh did tan mien phi dinh cho cong nghiep, nghien ciru khoa hoc va Y hoc goi tit la ISM nghia la via dai tan nay duqc thy 9 sir dung ma khong can so cho phep cita chinh phu, biri of y n6 nit phO bien kheng chi cho mpg cam hien ma trong ca cic ding nghe Icheing day khic, vi do Mr tan 2.4 GHz ISM duqc sir dung trong IEEE 802.11, Bluetooth va IEEE 802.15.4

VHF = Tan s6 rat cao

UHF = Ten s6 cvc cao

SHF = Tan so sieu cao

EHF = Tan s6 tort icS, cao

b Diiu chi vh gird diiu chi

Trong tinh town truyen th8ng s6 no thao tic ten du lieu s6 do linh hoot trong xir 19 tin hieu s6 va ti so gifta tin hieu ten tip cao VI co ban tin hieu s6 la mOt chugi Id to thuang la bit, nhom Id to nay duqc inh xa tacmg img vii mOt s0 (long song c6 chieu dai giei han, dO dai nay goi la thin gian k9 to Khi de dip ten ttic dO du lieu trong truyen nhin hoc dieu the to can phan biet nfrang thong so sau:

+ TOG dO Ict to duce dinh nghia bang nghich di° cia than gian 1(9 to, trong dieu the bit n6 can goi la toc dO bit

+ Toe dO clit lieu la s6 bit duqc truyen di trong mOt giay

Qua trinh dieu the thoc hien ta.i It truyen, ben nhjn mu6n khoi phoc lai kt to tir (long sting nh(in duqc can pith inh xo (long sting nhikr duqc ten kt to ttrong img, buoy

nay dirge gqi la giai dieu chi Do tin hieu c6 the bj sai lech di trong qui trinh truyen nen to c6 khai them tec dO lei lct tir va tee de gi bit

Thong thueng Mr& khi dot lieu duqc dim vio be dieu the s6 na duqc ma hi% de

de clang cho viec khoi phuc tin hieu nhjp tth dau thu Trong phin thir nghiem sir dung nut mang CC1010EB cita Chipcon he trq ma h6a lieu NRZ va Manchester Met so

kr thuet dieu chi s6:

1 1 111Piii 11 11 1 1 Ii i 11 11 111'i

V

1 0 20 30 50

Ms*

Hinh 2.3.Khoa dich pha PSK

Hinh 2.4.Kh6a djch tan so FSK

c Hien qui cis truyin sing vi an

Khi truyen tit tram phut tai tram thu tin hieu c6 the bj meo do tic ding tits mot twang truyen hoc do 16i cis be thu trong qua trinh giai ma va diEu chE Nhang th8ng s6 ca ban an quan tern khi dart gia hieu qua ctia kenh truyen vo tuyen la stir phan xa, giao thoa, suy yeu tren dueng truyEn, in va 16i tuong quan

d Truyin gel vi ding b4

L6p lion kit der lieu sir dung ciu tnic gen hotic khung nhu la don vi truyen nh#n ca ban, tram phut thyc hien xir ly diEu chE va gill diau che Tram thu can phai hi& chic chin thuOc tinh cite dung sing tai de ce the phut hien ra khung tai bao gOm din so, pha, bit hoc kt ty bit du hoc ket thus khung Do di no phai ding b0 gida sing mang va ding ho he thing

e Chit liming cis kenh v6 tuyin

Khac vii kenh ci day, kenh truy'E'n vo tuyen throng c6 chit luqng kern, tic dO bit/kY to cao Tren thut to chit luqng ctia kenh truyin phy thuOc vao rat nhieu thong s6 bao gam: tan se, khoang each fru*, tec dO truyen, m8i twang, cong nghe sir dung

Aqt vat dr dam quail trong caa lap vet 1 f ttrong mew cam biin hi:

+ Tieu thy nling luqng thip

+ TruyEn cong suit thip tuong img Arai khoang each truyen ngin

+ Phan ding c6 the boat dOng trong che de tiet hem Ming lugng

+ Tee dO dit lieu thip tir vii chyc ten vii trim kilobits tren giay

+ Ciu too don gian va gia thanh re

+ C6 lchit Wing chju dyng sy thay d6i tits moi twang cao

Del 14nr ThAng Long A17776 -Rill TVA Wing

2.1.2 Lep Hen kft dfr it u va the tyc them nh4p mot twang

Day 18 phin khi quan tong lien quan nhieu tea phin sau cua chuyen de nay nen to

se tim hieu chi tiet hon cic phin khk, do ne c6 lien quan t6i giao thirc dinh tuyen se tim hieu 6 chuong sau

Thu tvc thi'm nhap mei truerng thvc hien nhiem vv die'u Ichien nit khi thim nhop mei trueng truyen vo tuyen Phin nay dm hieu nen tang cita thit tvc thfun nhop mei tut:mg, nhftng yeu ciu vi cic yin de co bin ma thit tic tit nh4p mei trtr?mg gtip phii tong mang cam Bien kh8ng diy

a Yeu au vi lieu chi thiit kg the tpc them nh3p mei truimg

Mvc dfch cia thit tic thfirn nh#p mei twang la truyen gOi tin mOt each hieu qui,

On djnh Xung dOt ce the xiy ra nett nhu giao attic thim nhap mei trutmg cho phep 2 hay nhieu nut giri der lieu tai cling mOt th6i diem, xung dOt cc!, the li nguyen nhan lim cho tram thu Ichong the nh#n eft lieu chinh xitc

Hog dung vi hieu suit ctia thit tvc thim nhop men mu:mg phi thuCic khi nhieu vito 16p vot 19, km nffa mang WSN cling g(ip phii nhitng yin de ma mang lchong cry mAc phii d6 Mi Mc dO mpg, mat tuyen, sv suy giam tren dutmg truyen, each thirc dieu che, tin se sir ding vi khoing cich gifta tram thu, phit

Trong phucmg phip trinh xung dOt CSMA (da truy cop cam bien song mang), mei

nut nghe ngong mod trubng truyen truck khi truyen dft lieu di Neu nhu mei truong dung bOn no se hoin viec girl g6i tin lei de trinh xung dot vi yeu ciu truyen lai

Hinh 2.S.Md hinh yang xung dot gicia ccic nut mgng

VI di gii sir net A bit diu truyen eft lieu cho nut B, mOt lit sau nut D ding quy& djnh truyen de lieu cho nut B, boi vi D Ichang nhfui they nut A dang hoot dOng khi D bit eau truyen, du lieu xung dOt tai B ye ci 2 gni de lieu deli khong sir ding duqc, Uri vay sir dung phucmg phip CSMA trong twang hop nay van khOng trInh duce xung

Dal Hoe Than Long Al 7776 -Rid TVA Tung

dot, day ggi la hien tuqng An nut tong mpg cam lien, hien ttrgng nay chi dugc khac phvc bai giao thirc djnh tuyen phan cep cut lop mang se duqc trinh bay 6 phan sau MOt vi dv lchic the hien nhuqc diem dm phucmg phip nay la: gia sir B truyen dO lieu cho A, met lit sau C men truyen dtt lieu cho D, tuy nhien C nhan they B dang host dOng nen se ch6, mac de C van c6 the giri eft lieu cho D ma khong anti hating gi tai dft lieu nhOn duet tai A

Trong m8i twangc6 day vi dv nhu mang ethernet khi tram giri tin hieu, neu phat hien xung dot tai dau thu n6 lop tic dimg viec gui tin hieu l3i, dk diem nay ggi la phat hien xung dOt (CD — collision detection) nhe vio ph& hien stir thay dei dien the tren dueng truyen, tuy nhien phuang phip nay khong luting duqc sir dvng tong mei trutmg khong day do viec truyen nhOn tong med tru?mg vo tuyen trong man cam lien thutmg la bain song cong, nghia la chi sir dvng met kenh truyen tai mOt thtri diem n6 chi girt hoc nhOn tin hieu, do d6 khi c6 xung dot ri5i thi van khong tranh duqc

Mot dee diem khic khi thiet ke thu tvc tbim nhop mei throng lit luu luqng luting

do lieu tong mang, vi dv vei loci dte tucmg giam sit theo chu icjr thi luu lugng mang thap, nut chit yeu a chi dO nghi, thy nhien vei loci del tucmg giam sat sv hen, vi dv nhiet dO trong rung thi bai town tit nen khi pink tap, vi birth thu?mg luu luting mang rat it, nhtmg tai khu vim 'city ra chay, luu luqng mang tang dot lien

b Mat se thi bp &Lim nh$p mai trotting diin hinh

The tic them nh#p mei trueng ve ca ban mi duqc chia ra 3 to is thu tvc phin chia

co dinh, the Mc phin chia theo yeu cau, vi the tvc toy ckip niau nhien

+ The tic phan chia co djnh: tai nguyen duqc phan chia cho thing nut me khong sq xung dOt Khi de kenh truyen se duqc phan chia theo than gian (TDMA), theo tan s6 (FDMA), theo ma CDMA

+ The tic phan chia theo yeu cau, cho phep ck nut sir dvng tai nguyen khi c6 yeu cau sir ding, the the nay c6 the chia thinh thzi tyc tap trung va thu tyc phdn

tong the tic dieu !chi& talp trung nut se giri you cau tai net trung tam va cher tra lai, tong twang hqp duqc phep n6 se giri mOt ban tin ;tic nhon duqc phep tai net da giri you eau cling WA thong tin tai nguyen n6 duqc phep sir ding, vi dv nhu so luqngva vi

tri cut ck khe than gian tong he thong TDMA Trong trutmg hqp nay nut trung tam thuang Mn nhieu nang luqng, bei v#y tong giao thirc nay thutmg thi nAng luqng cim nhOng net trung tam duqc cung cap nhieu han cic net thong thutmg Trong giao thirc phan tan gin twang ti tiler the bai tong token bus Khung token se lan luort luu hinh tong mOt yang kin la mOt nhom cac nit man, mOt chuang trinh quan lSt yang dOc

tai 1-19r Th5ng I.nng Al 777A Tin Wing

biet clang de phat hien 184 va tai tao the bai khi thy ra sv co, nhuqc diem coa no la cac nut phai a trong tinh tang nhon dit lieu, them vito de viec bao tri va duy to tuyen khi hinh ding ming thay d8i la kha phirc tip

+ Thit tic troy cop new nhien cac nut hoitt dOng plan tan hoan town, phuong phip diu tien va tai gib van dirge sir ding la ALOHA, trong thu tic ALOHA mot nit khi truyen dcr lieu n6 girl di ngay Hip tic, lcheng he c6 sv lien he vii cac nit khac Uri vay khi ruing thy ra xung dot la rat cao, khi phat hien xung dot phia nh$n se gai mot xac nh$n cho thutic tinh ciut g6i tin nhOn, phia giri se cher mot thai gian ngau nhien va bit dim truyen

c Thu tyc them nh3p mai truang trong myn cam biin

Trong mang cam bien khang day yeu ciu diu tien va quan trong nhAt la can bing nang lucmg glita cac nut mang, sir dung nang lacing hieu qua trong thiet ke, lva chip thit tic them nh3p tad twang va kha nang thiet lap lii tuyen khi topo ming thay en

Nhu da tim hieu a nhUng phin trtrac rang lacing cita nit tieu thu cha yen do truyen hooc nhOn dit lieu th8ng thueng quit trinh truyen th8ng gam 4 trang thai: truyen, nlan, rai va the dO ngi Trong d6 the dO truyen va nhOn la Mn nhieu rang ltrong nhAt, dva vao hog dOng ciut giao thirc them nh$p men throng to c6 the nhOn Only mat so van de va mic tieu thiet ke cita giao thirc MAC:

+ Xung dot: khi /ay ra xung dOt thi vita ton rang luqng tai ca nth Win va nai thu va nang lam ding de phat lai g6i tin d6, bei v#y can phai loci be xung dOt, tuy nhien nau c6 the dam bao luu luqng ctia mpg cam bien du thip thi xung dOt gin nhu duqc be qua

+ Nghe taping: mac du khung Unicast gui tir mot nguan tai met dich, tuy nhien

vi kenh vo tuyen la mai tnrbng chung cho tit ca cac nit hang xim ciia no boi v3y chimg deu nhen duqc tin hieu tir cac nit di va be qua tau chung lchong phai la dich tai, viec nay cling ten kha nhieu rang luqng Tuy nhien d8i khi viec My la het sic can thiet khi thu thap thong tin ve hang xi:5m de xac djnh luu lacmg Men tai h8 trq cho rime dich quitn

+ Nghe ngOng a the de rai: khi mot nit 6 trang thai rai n6 sin sang nh$n dO tuy nhien trong nfrang ming luu lucmg it thi thai gian cher nhOn do lieu ton kha nhieu nang luong

+ MOt th8ng s6 quan tong nem ngoiti nang lacing ra la you eau chuang trinh Ichong phirc taw, xir ding it tai nguyen nhu b0 nha, vi xir 15r

flan H9r Th5ng 1.nng Al 777A -RAI TiOn 'fling

Thu tic than nhap m8i throng mia mang cam bien thuemg duqc chia vio 2 nhem thu tic chinh la: thu tic cash tranh, va thir tic 1#p lich

2.1.3 Tha tyc cynh tranh

Trong thu tic conk tranh, cc( hei truyen de lieu chia deu cho tat ca cic nut hang x6m Neu chi c6 mot nut hang x6m an truyen du lieu thi khong van de gi, tuy nhien neu c6 2 ho(ic nhieu nut mu6n truyen khi de chang phai cash tranh veri nhau de gianh quy&I truyEn dtt lieu, 2 giao thirc quan tryng coa nh6m giao thirc nay la ALOHA va CSMA ma ta da c6 dip de cep 6 phan truck

* Thit tic CSMA: Trong thu tic da truy cap cam bien song mang Wirth xung dot CSMA — CA(Carrier Sense Multiple Access with Collision Avoidance) MOt van de

gip phai v6i d6i turyng lam sit theo si kien, binh thutmg thi nut mpg 6 trang thai r6i trong met then gian dal, n6 chi bit diu host dOng khi c6 sir kien ben ngoii tic dOng, khi sir kien d6 xay ra gas nhu tat ca cac nut deu mu6n truy&I dft lieu met cich ding then, do vOy se do ra nhieu xung dot, au nut c6 gang giri dft lieu theo chu kjr thi Icha nang lap lai xung dOt la rat cao neu Wong c6 qui trinh them de xay ra Sau day ta se

tim hieu nguyen ljr lam viec ca ban cua giao thirc da truy cap cam bien song mang nay Ban dau khi met nut nh#n gdi da lieu mei de truyen di, ne eh& met then gian tre new nhien, mix dich cua viec lam nay nhim lim gam tinh d6ng be cim cac nut khi phit hien sir kien say ra (vi neu khi 2 nut xay ra xung dot ma trong lan thir titp theo neu c6 ding then gian cher thi van khong trinh khdi xung dot), trong then gian chtr nem nhien d6 nut c6 the at 6 hang thai neu, trong thbi gian nghe ng6ng nut se thirc hien cam bien sting mang Neu nhu m8i truling truyen dang bin, sau met s6 lean thir ma van khong thinh ding n6 se dung lai va cher met then gian ngeu nhien, phi thuOc vio sot lan thu va thai gian ngit ells nut, sau d6 ne lai titp tic nghe ngeng m8i trutmg, car nhu vay khi ten met gi6i his ntio d6 ma van lch8ng thinh ding thi g6i se bj be qua Trong mem hqp m8i twang rei, nut se gin bin tin RTS va chuyen sang trang thai cher, trong

throng hqp khong nh#n duce bin tin CTS, hoci c6 ban tin CTS cho nut 'chic thi n6

se quay lai qui trinh cher mot thin gian ngiu nhien va thu lai Con neu nh#ri duqc bin tin CTS, ne se giri &Et lieu di vi cho ban tin ACK

Tay tang trutmg hqp ma CSMA c6 the thay don then gian cher, thai gian nghe ng6ng la ngiu nhien hay c6 djnh MOt dieu can luu y la can phan biet thu tic CSMA —

CA trong mang khong day va thu tic CSMA — trong mpg c6 day, ve cc bin thi 2 thi

tic nay gi6ng nhau la deu dua vio viec aim bien sang mang, tuy nhien thu tic truy cap CSMA — CA chi duqc gqi la trinh xung dot, do neo 'thong the phat hien khi ceo xung dot xay ra, do the dO truyen la bin song c8ng, nut mang tai met then diem chi c6

Dei 1-inr Th5ng i.nng Al 7778 -Rid Tin Thng

the thu ho#c phit di? lieu Do v#y trong lop trinh djnh tuyen sir dung thin Ate thim nhop mOi tru?mg nay thutmg sir dung mOt then gian trg ngau nhien de giam tinh thing WO giita cac nut, shim tang hieu qua tranh xung dOt

Thiet bj duy tri ba thong so NB, CW va BE, trong d6 NB dem s6 thou diem rat lui,

CW chi ra kich thuerc elm cira s6 xung dOt hien tai, BE la so mil cua theri diem nit lui

hien tai Khi c6 met gen du lieu de truyen di, cac th8ng so nay duce kheri tao Wong

img von: NB=O, CW=2 va BE=macMinBE (trong d6 macMinBE la thong so curt giao

thirc) Thiet bj se cher ngau nhien trong r th6i diem nit lui tiep theo trong khoing [0, 2 1'

— 1] , khi de n6 thuc hien cam bier song mang, tau moi trtrerng rOi n6 se giam CW, va cher teri thai diem rot lui tiep theo va xem xet lei men trutmg truyen met lin nfta, neu

mai throng yin r6i thi thiet 1)] se bit Mu truyen du lieu cos no Trong twang hqp phit

hien ra m8i truerng dang ban thl so then diem roi NB va so mu BE tang len va CW

duqc $t lui CW=2, neu NB vuqt qui ngtrCrng thl khung der lieu duqc be qua, qui trinh

truyen that bai Cu nhu v#y cac bare duce lap lui

Yu diem cita thit We nay la xip xep qui trinh truyen tai cac nut hang thorn di lchong thy ra xung dOt tai dau thu Tuy nhien no cfmg c6 mOt vai nhuqc diem d6 la phirc tap tong thiet d(it va bio tri viec sip xep, lap ljch (ki thuftt da truy cop phin chia theo then gian TDMA thubng dugc sir dung veil loci thu tuc them nh#p m8i tniemg nay)

a Th6 Ale LEACH

Chills' dill ar tlinh

Pisa a; tilt Rut host Ong

Quyit dials tbinb

nit ;Aft*

l'Sn TS I

Hinh 2.6.77u tyc LEACH

1 tai Hnr Th5ng i.nng Al 77Th -Hui Tign Tiing

Thu tic nay thueng duqc sir dung trong mpg ma cite nut co fling Iuggg tieu thu nhu nhau NO phin yang the nut that'll the lien cung, moi lien cung do se chan ra melt nut gqi la nut chinh se thuc hien viec zap zip va bao tri thong tin dm cic nut trong lien cung, cic nut con loi trong lien cung de gqi la cic nut thinh vien duqc gin vac) khe thin gian Wang img de trao d6i do lieu vOi nut chinh Ntit chinh se tip hap dft lieu trong cluster loi gAi true tiep hoc qua not trung gian de truyen dot lieu ve tram ca se Nhu voy Wing luang tieu thu trong raring nay la bat din xung, nut chinh se tieu ton nhieu tiling luang han cic nit thanh vien, do ngoai viec girl dft lieu ve trim dr se n6 can awe hien chic ning lien lac va dieu lchien hoot dOng cua cic nut thanh vien Trong khi fling hong tieu thu tai cic not thanh vien se duce tiet hem rat nhieu do khoing cich v6i nut chinh glut hon rat nhieu so voi tom co se de lchic phtic tInh tong tieu thu Wing hong bit can dOi nhu vOy c6 the cif sau mOt lchoing thin gian thi cic not

My to dinh gii fling lucmg va thay doi nut chinh Wan phien

b Thu tyc SMACS

Thu toe t r t6 chirc dieu khien troy cop mei trueng SMACS ve bin chat la su ket hap gifta viec lchim phi clic nut lin On va pit chia TDMA cho the nut d6, giao thirc nay duqc xity dung dtra ten mOt s6 gia thiet:

+ Dii tan sir dung duqc chia thimh nhieu kenh nho va nut co the sir dung de

trao d6i vai bit ky mot khitc

+ Tit ca cic not trong mpg cam bien la c6 djnh

+ Cie nut chia the khung dft lieu c6 dO dai c6 djnh, Ichong can thiet la tat ca the nut deu gieng nhau

Mix dich cim SMACS la phit hien ra cic mot hang xem va thitt l$p lien ket hoc kenh truyen toi nut d6, trong de dit lieu chay theo mOt chieu, neu 2 nut deu mu6n truyen do lieu cho nhau thi phai sir dung 2 kenh lien ket viec nay se dam bio trinh

duqc xung dOt

Gil sir nut x muon thiet dOt mOt lien ket de trao dOi dit lieu vol nut y, n6 se nghe ngeng diti tin co djnh trong mOt khoing thin gian ngiu nhien, nen lchong nhin duqc gl trong thin gian d6, n6 se girl mOt ban tin mei girl do lieu r6i thong bio tea the nut hang xem Khi nut hitng x6m z nhfut duqc ban tin mei ctia x n6 se che mOt thin gian nem nhien va try lei china dja chi ctia no, dja chi dm not mbi va s6 hang xem n, khi xrthOn duqc bin tin tri kri cua nut y, ne se mei y thiet lop lien keel y se tra kin bing ban tin chin thong tin ve khe thin gian va tan s6 sir dm

Del Mar Thing Lang Al 7776 Tign Time

Giao thirc nay cho phip thiet diit lien ket c6 djnh gifta cac nut ce djnh, do do viec khirn phi thong tin ye cac nut hang xi:5m duqc thyc hien lien tic de Wang thich khi eau hinh mpg thay doi Hon the ctia thu tic nay la phirc top trong xir ly gifta cac nut,

do v#y khi lya chip thu tic nay an can nbirl gifta tong nitng luong can khi thyc hien thu tic va truyen nhon der lieu so v6i cac phuang phap khic, uu diem coca phuong phip nay nhu cac thu tic xep ljch khic la frith xung dot Mt

c thu tic Wang thich luu luqng truy c#p mei tru?mg

Thu tic TRAMA thyt hien vier phap ding cho phep cac nut truy &Op kenh truyen

de tranh xung dot, giao thirc nay gia sir tit ca cac nut du dOng b0 thtri gian va chia thai gian thai gian dm:cc chia thanh thai diem truy cjip ngau nhien MOt nut se quimg

bi thong tin cim no t6i cac nut hang xtrm, bao gOm ca thong tin ve lap ljch elm no Dya

va cac thong tin nay cac nut se sir ding thu$t tan phan tan de xitc djnh khe thei gian

va ke hooch them nh#p de truyen - nh#n dft lieu va kt hoach chuyen sang tong thai ngii cua nO Nhuqc diem dui thu tic nay khi Ong ve tinh Win va b0 nher boi v$y yeu eau mang co tai nguyen du lan

Plink 2.7.Thu tyc TRAMA

2.1.5 Chu& thd 4w thdm nh4p moi tnrd‘g IEEE 802.15.4

Phi= vi Ong ding cua thu tic IEEE 802.15.4 di:9c then khai cho mong cam bien

kheing day, mang trong nha, lc& nii that bj veri PC va bao mat hau hit nhttng ung

ding nay yew cau Mc dO thap, lchong dad hoi qua cao ve dO tre, d#c biet nang luyng fieu thy that)

a Min &tic m;ng vai tra vi Ulu nut mpg

Tren lap mpg co 2 id& nut: Nut da nang, nghia la no co the hog dOng dam nhiem vai tre cua nhieu clam Ming khic nhau, Ideu nut tit* 2 la nut co chile nang gi6i han n6 chi cep the hog dOng nhu mOt thiet bj

MOt thiet bj phiti lien ket vai men dieu khien, trong mang hinh sao thiet bj dieu lchien c6 the hog dOng dva tree lien kit 1-1, hoc da lien ket nhu trong mang ca nhan MOt thiet bj dieu hinh thuang thvc hien nhang nhiem vv sau:

+ NO Tidbit nhOng thiet bj lien ket yeti n6

+ Cap dja chi cho nhang thiet bj do, tit ca ck nut IEEE 802.15.4 co 64 bit dja chi, dja chi nay cfmg ea the ngin hon toy theo yeu au cita ung dung

+ Trong the dO bho hieu IEEE 802.15.4 no pith mOt khung bao hieu thong bao cho the nut, va thiet bj dieu hinh co the rcfr 19 nhang you citu cua cac nut trong the khe Mai gian duqc chi ra trong tin hieu Mang NM

+ NO trao dOi dft lieu vai the thiet bj ngang hang vai no

b Ciu tree sieu khung

Thai am &II ate 710i aim thy ging el

Ip nh sian Klw sbbi crank trny

11164 bto

Hinh 2.8.Cciu ink sieu khung

Tram dieu hank trong mang hinh sao khi hog dOng a the dO thong bho no to chile kenh truy c#p va truyen dr lieu

Mqi sieu khung deu co dO dal nhu nhau, tram dieu hanh bat du m64 sieu khung bang each gin mOt khung dfi lieu canh Wm, khung canh bio nay se chira du lieu m8 to thong tin dO dai va nhang thong tin lien quan khic a nhang sieu khung nip theo

+ MOt sieu khung duqc chia Minh 2 khoing: host dOng va Ichong hog dOng

Trong thai gian kh8ng hog dOng, tat ca the nut bao gom ca nut dieu khien se 6 tmng thai ngit, khi thai gian Icheang hog dOng ket thAc n6 1$p Mc bj &nit thIrc de nhtin thong

Dal Nor Thing Long Al 7776 -Rid Tiign Wing

tin thong bio tir net dieu hinh, that gian Ichong hog dOng nay ding co the duqc be qua

+ Thai gian hog dOng duqc chia thinh 16 khe, khe dau lien lit khung cinh bio, nhftng khung con lai &Km chia thinh 2 vling, that diem canIt tranh truy cap sau d6 ll cac khe that gian "dim bio" DO dii dm that gian hog dOng vi Ichong host dOng ding nhu dO dii cita mai khe vi so khe that gian c6 the dieu chinh duqc bang chuong tranh

Nut dieu bluth hog dOng trong toin be thin gian host dOng, n6 lien lac yeti cic thiet bj hog dOng trong khe thin gian dim bio khi duqc phep Trong hau het khe thin gian dim big ne c6 the chuyen sang the dO net Trong khoing thai gian canh tranh truy cap, thiet bj c6 the tit the dO truyen nhOn nett Ichting co du lieu de truyen

c Quin I* thbi Wan dim bio

Nut dieu hanh se phin khe thin gian dam bio cho thiet bj khi c6 yeu cAu trong ichoang thai gian quilt tranh, mOt c6 dugc sir dung de chi ra khe thai gian yeu ciu la khe nhan hay truyen dCr lieu Trong khe truyen de lieu thitt In se truyen g6i eh net dieu hinh vl ngtrqc lai trong Outing hqp la khe nhan Khi nhan duce g6i tin yeu cau ngay lip tirc n6 se giri g6i tin ACK thong bio ring n6 di nhan &Km you ciu, khi net dieu hinh dil tit nguyen n6 se phin Ichoing that gian bio hinh cho nut, ne se the thong tin m8 tit ve Ichoting that gian bito hanh trong khung thong bio nip theo, phan thong tin m8 a ve that gian bio hinh n6 se chi ra dja chi cea nut girt yeu ciu, so luqng

vi vi tri cea khe that gian trong khe that gian bio hinh trong siou khung Vi thiet N c6 the sir dung khe that gian duqc phin de Neu Ichong de tit nguyen no se giri mOt thong bio la khe that gian di het, khi de thiet bj se cha giri lai yeti cau vio lan sau

d Thu tyc truyin de Iltu

Gil sir thiet N c6 dft lieu main giri tai nut dieu hinh, neu nhu thiet b1 di duqc

phan khe that gian dam bio, no se hog dOng trtrec khi khe that gian bit diu vi ngay lOp tire truyen de lieu mi IchOng he c6 thao tic them d6 tranh xung dqt Trong tratmg hqp thiet bj chua duqc phin khe that gian n6 se giri god de lieu tai thai diem canh tranh truy cep sir dung giao thirc da truy 4p cam bien song mang, sau do net dieu Unit giri ACK

Trong throng hqp de lieu truyen ifs nit dieu hinh tot thiet bj, neu thiet bj cti duqc

phan trong khe that gian dim bio thi du lieu se ducat truyen ngay lOp tirc ml khong can yeu can xic then

flat Hnr Th5ng I.nng Al 7776 -Rini Tan TAng

Trong twang hqp phO Win nhit khi nut dieu hanh !thong the sir dung de nhon trong khoang then gian dam bito, thl mOt the tuc bit tay duqc thuc hien giaa thiet bj va tram dieu hitnh, tram dieu hanh se giri met thong beo vimg dem da lieu cho thiet bi bao gam ca dja chi ciut thiet 131 trong truang (lilt chi mkt khung thong bao Trong thvc to khi thiet bj tim thiy dja chi ells no trong twang dja chi n6 se giri mOt goi da lieu you au doc biet trong khoang thbi gian canh tranh Tram dieu hinh se tri leri bing ban tin ACK va sin sang nh(in dtt lieu t6i Trong trutmg hqp Ichong giri thanh cong thiet bj se

girl lai yeu ciu trong nhOng sie'u khung tiep theo

e Khe that gian trong giao they da tray cep cam biin song mang

Khi mOt nit giri dit lieu hok thong tin quirt ly, dieu lchien di trong khoimg thai gian canh tranh truy cap n6 sir dung giao thtic da truy cep cam bien sang mang, de

giam xac suit xung dOt giao thirc da truy cep cam hien song mang frith xung dOt (CSMA —CA) sir dung mOt thbi gian tre ngiu nhien Khe thbi gian trong gian down quilt tranh truy cep duqc chia thinh ck khe that gian nho hcm, gqi la tiled diem rot lui, ttrcmg img vai dO dai cua khoang 20 kenh va khe thbi gian trong giao thirc CSMA —

CA ttrang img yea thbi diem rat lui

f Chi de 'thong cinh bin

Ben canh the dO citnh bao trong IEEE 802.15.4 can de suit giao thirc chi do kh8ng canh bao, mOt vii diem Iduic nhau ca ban giaa 2 the do nay la:

+ Trong the dO khong canh bao tram dieu hanh lchong giri khung cinh bao, str ving met al poi tin canh bao duqc thiet bj ton dung trong khoang then gian nay de Clang b0 vOi tram dieu hanh

+ Mai goi giri fir thiet bi !thong sir dung khe CSMA — CA do kh6ng co clang b0 trong thbi diem rut lui, them vao de thiet hi chi thi hanh duy nhat met lin them da

mai throng, neu kenh rei thl qua tranh thim nh#p thanh cong

+ Tram dieu hanh pith boat dOng theo chu k5r nhung thiet bj thi co the hoot

dOng theo 1#p lich ciut rieng no, no chi host dOng khi, co goi da lieu hok goi dieu

lchien can guff di hoc co da lieu duqc giri tai chinh no fir tram dieu lchien

2.2 Giao that (tong bt) thal gian

Vert de theri gian nit quan trong trong nhieu img dung va giao thirc trong mang

cam hien Cac nut co the do that gian bing cach ding cac xung dang ha ctic b0 lay tir

ck b0 dao dOng Boi vi cac pha ngiu nhien lam djch chuytn va lam tr8i toc do da b° dao dOng, do v#y died gian cuc 130 ciut cac not se bit diu sai khk di lam cho mang mit

Dei Hnr Th5ng I.nng Al 777h -Rhi Tian Ting

di st deng be Do vjy viec deng be thai gian c6 vai to rat quan trong trong host deng cua mang cam bien

Deng be th&i gian la phucmg thirc cho phip cac thuc the rieng biet trong met nhOm deng be xung ding he cua chting hoac ding be vai that gian Wan cau phei hqp (UTC) Phan nay se giii thich tai sao an deng be that gian va dua ra met s8 giao thirc ding be Witte nhau

Tpi sao can ding bP thei gian trong mpng cam Nin ?

❖ Mang cam bien can lien ket vat the giai thuc de biet khi nio met hien ttrqng

xity ra

❖ Djch vu ca bin chinh cua mang cam bien la tich ho de lieu Do de can deng

be gifts cic nut de c6 the tich hqp da lieu truyen den Sink

❖ MOt vii giao thtic yeu eau ding be thai gian: quin 19 eau hinh mang

❖ Cic nut cam bien thutmg nh6, gii thinh thip nen be dao gang thubmg khong

chinh xic, han naa chimg bj gioi han ve &Mg luqng nen thuang c6 the de sleep

de Het ldem nang luqng

Sau day, ta xit vi du don giin minh hoa sir can thiet cia de chinh xic ve th&i

gian nhu sau (hlnh 2.9)

Hinh 2.9.Xdc clinh pie din cita Om thank a xa beri mat day sensor

Met sting am phit ra ttlr met nguim am 6 lchoing cich xa the gong den met day cic sensor vi ta c6 the Ink doin g6c tai trong tnrbng hqp nay m8i mot sensor deu biet vi tri cult cltmg va luu lei thei gian den dm am thanh Trong truang hqp cu the Mar hinh ye, g6c 0 c6 the duqc xic djnh khi d va x da Net, dimg cong thirc luqng giitc:

x=d * sinO do de 0 = arcsin(d/x)

Dal Mr Thing 1.nng A1777h Tign Time

Khoitng each gifta the sensor co the xic djnh tit cac vi tri da biet ctia cac sensor

vl x c6 the thu duqc tit dO loch thbi gian t A gifts cac Ian cam biAn cfla sensor va von tac cita am thanh c 330m/ s , sir dung Ong dint :

CAn phai chti y ring thtri gian dimg trong mang cam bien phii 11 theri gian tv nhien (physical time), da la hai mit cam bien phii c6 sr cam bien nhu nhau ye is va is cfra mOt mit cam bien cing gin \red Is trong thin gian thvc (real time) hok thbi gian town cau phai hop (coordinated universal time — UTC) tang tat Then gian to nhien phai duqc phin biet v6i Ichai niem ve thbi gian logic (logical time) la thbi gian ma cho phep quyet djnh viec sip xip cac sum kien trong ho thong phan ha tilumg !cluing can thiat phai chi ra bat ki sv lien quan nao den then gian thvc

2.2.1 Dow ha Sc mit cam blin va sr chthh sac

Hiu het cac thiet bj clang ha cita cac nut cam bien va may tinh diu c6 cau to giOng nhau Mai nut c6 mOt b0 dao dung 6 mOt tan so xac djnh va met may dem xung dao dOng Phan mem ctia cac nut chi truy nhklp tai gia trj cua b0 dem nay vi th&i gian gifta hai lin tang nay quytt djnh each giiti quyet van de then gian: cac sv kien xay ra gitta hai lin tang nay !thong the duqc ph$n bi'e't tir cac nhin thbi gian ctia chimg BO dao deng thutmg c6 dO tr8i, doll sv djch nglu nhien so v6i tan so ten danh nghia, hay can gqi la do loch clang ha Dieu nay phu thuOc vio sv khong tong suat cita tinh the, hay cac dieu kien min twang nhu ap sat, nhiet de do vey viec trier khai mpg cam bien ten thvc to khic nhieu so yeti trong phOng thi nghiem DO loch clang ha duqc do bring ppm (parts per million), n6 dua ra con s6 ve s6 dao dOng them vio hok so dao dOng N mit ma clang ha tao ra tong luqng thbi gian din cho 1 trieu dao dOng a toe dO danh

Tan s6 dao dOng thay dui theo then gian C6 2 kik thay

• Thay dai ngan hen: do thay &Si nhiet de, do thay dai tong din 1p nguen cung cap, 1p suit Ichong khi

❖ Thay dui din han: do sv lao h6a cita cac bO dao dOng

Dal 14nr Thing I.nng Al 7776 -Rhi Tan Ting

Ngu&i ta thuang gia dinh tan só cac be dao ding la on dinh vira phai trong pham vi tir vii phitt den vii chuc phut Dieu nay cling n6i len rang cac tilt* toil ' (long 1,0 thin gian phai ding bo vii phid mOt lan de theo kip su thay dOi dm tan s6 Vi the giao thirc tang thtri gian la nit can thiet

MOt dieu can quan tam nfta la bao lau thl giao thirc dong be thtri gian chay mOt Ian? Gia sir met nut chi dieu chinh de dich pha i 0 va thc do troi cua dao dOng la x ppm co dinh, de chinh xac you cau la 8 s, thl sau khoang thoi gian khoang s can thiet phai thing bij lai V6i x = 20ppm, dO chinh xac la is thi sau 50s phai ding 1,0 lai Cac mo hinh hien 41 ngay nay deu c6 ging ink Itrqng chinh xac khong chi N i ma con Oi de keo dai chu Id truOrc khi phiti ding be lai MOt Ian nUa phai nhan manh ring quit trinh ding be met lan khong c6 hieu qua vi toc do troi thay clOi, va thutrng thi ta gioi han duqc tOc dO ten len nhat pi > 0 ma thee man

H

1 + pi dt at) 1 + pi

Ging thirc nay con dung de xac dinh tan s6 ding be

222 Bong 6¢ theri gltm trong mon° cam Min

Trong mang cam Bien c6 mOt so disc diem ma anh hutmg den you eau thiet ke cita cac thu$t toan dOng b0 then gian:

➢ Thuat tan phrli phit hop vOri pham vi mang mutilhop rang 16n, cac nut bi rang

buOc ve mat Wing luring Yeu cau ve pham vi bao ham ca se, Wring cac nut trong mang va mat do cac nat

➢ Yeu cau ve do chinh xac c6 the thay doi khitc nhau tir mili gily cho den hang

gily

➢ !Chong sir di,mg them phan cling chi gianh cho muc dich &mg bo vi ton chi phi

va neng luqng them vao cho phan phu do

➢ Muc dO di dOng la rat thip

➢ Hau nhu khong c6 gidi han tren c6 dinh ve tre truyen g6i v1 phu thuOc 16p

MAC, 161 cac g6i, va truyen lai

➢ Tri troy& gifts hai nut hang x6m la khong ding ke MOt khoitng cach 30m can

10^-7s vi van thc anh sang la c =3.10^8m/s

CO rat nhieu giao thirc ang b0 thtri gian truyen thiing c6 ging gift viec ding bei gift cac nut 6 moi thin diem nhung lai khong quan tar' n den !tang luqng va cau hinh

nal 1-Inr Thane I.nng Al 7776 -Rai Tign Tang

mang cho nen khong the ap citing vao mang cam bien VI disc diem cita mang cam bien cho nen giao thirc eking b0 thei gian can cho y ve the yin de ve de chinh xac, chi phi rang Itroug va cac you eau ye be ruin

Phuong phap co ban de d8ng b0 thei gian tong mang cam bien la cong the gitta cac nut trong town mang Thiet lap moi lien he cop day (pair-wise) gifta cac nut trong mang sau de me rOng ra toan mang

CO hai cach thiet lap so cong tic gifta hai nut trong mpg de la deng be* gift ben

gfri va ben nhen (Sender-Receiver) va gifts ben nhon va ben nhOn (Receiver-Receiver)

D6ng b0 gifta ben gfri va ben nhan yeu can lien ket hai chieu gitta hai nut lan can Trong phucmg phap demg b0 gifta ben nhen va ben nhen, nhieu nut nhen cua the g6i c6 nhin thai gian nhu nhau d6ng b0 vei nhau ma khong you call thing be vOi ben gin (n& gfri goi tin broadcast den hai nut A va B, sau de A va B to deog 1)0 v6i nhau kitting an den Sc) Hai phuong phap nay duqc mieu to nhu hinh (2.10)

B

B

A 4‘

Ifinh 2.10.D ang ba ben phcit/ben *In vet ben nhdn/ben nhdn

2.2.3 Giao that dong NI gift ben nh(ln vd ben phat

Trong giao thirc nay, mOt nut goi II ben nhan, trao dei gei du lieu vori net khic goi la ben phit, lam cho ben nhan d6ng be WA ding he cfut ben phat Giao thee ding b0 gitta ben nhan va ben phat nbi chung la dei hen dtr?mg not 2 chieu gifta cac nut lan

cert

Dien hinh cfut giao thirc clang b0 gift ben phat va ben nhOn la Lightweight time synchronization protocol (LTS) Giao thirc nay dua ra bOi VAN GREUNEN va RABAEY de deng b0 citing h6 cua mang voi ang h6 cfla cac nut tham chieu, vi do nhu c6 the c6 1)0 nhOn GPS Trong kin heat dOng n6 dieu lchien cac nut de sir clortg Wing luqng hieu qua va dat duqc dO chinh xac cao, va dua ra nhang gioi hart tuang dui

chinh xac ye cac phin cfmg co se va the he thong LTS kh8ng yeu au phai update ding he eve be va ne cling khong tree luqng t6c dO tr8i thvc so

Dal Fine Thing Long Al 777h -RAI Tiln TAng LTS chia qua trinh deing b0 lElm 2 giai down:

❖ Giao thirc d6ng b0 2 chieu de deng b0 2 nut Ian can

+ De gitt cac nut hoc mOt tip hqp cac nut can quan tam Clang be theo met tham chieu chung, LTS xay di,mg mOt cly phin tan tir cac not tham chieu den tat ca cac nat Neu Sic lei khi deng 1)0 single-hop la dOc lap, pit phei y het nhau va c6 trung binh la 0 thi cac nut la cna thy cling dirqc ding b0 vei lei bing 0 nhung syr thay dei la tong the thay d6i dqc theo dubng truyen tir nut tham chi& den nut la VI vay su thay doi nay c6 the tai thieu hoa bang viec tim ra ciy phan

tan c6 chieu cao nhe that

Ding b# 2 chau

Diu tien chung to se nghien cuv ye deng be hai chieu (hinh 2 1 1)

Sau khi qua trinh 6Mg b0 lei duqc Ichei dOng a not i, goi da lieu you &au dew b0 &nye djnh clang tai thbi diem tl voi thbi gian Li(t1) Nat i dieu lchien cac gei qua he thOng host dOng va cac nein xep Tre dubng truyen c6 the bien thien rat nhieu Khi nut

i gel bit diu tien tai thbi diem t2, nut j nhon bit cuoi ding ciia gei t.i t 3 = t2 + T -F tp

,trong de T la tre debug truyen va tp la then gian truyen gei (chieu dai cua goi tinh theo bit)

Al 7776 Tan Wing f)ei 1-Tor Thing 1.nng

I

g6i bong be) djnh

g6i Ydri nh5n th&i gian Mt') ti

chuyin giao g6i 68 truyen

h4 th8ng host bong, truy nthip

nhin thbi giant,(18) —ow —is

Hinh 2.11.Hogt dung ctia viec (long b0 ben phcit/ben nhan

Sau da met thin gian, tai thai diem t4, g6i dif lieu den duqc bio hieu den ling dung hoc he thOng host dOng cim nut j qua met qua trinh ngit, sau da duqc &nit du tai then diem t5 yeti thbi gian Lj(t5) Tsi t6, not j djnh dkuig g6i phitc dap vii thai gian Lj(t6), va dieu WU& gei do den he thong host dOng dm n6 va ngan xep numg Goi nay bao gbm ca thin gian truttc d6 11 Lj(t5) va Li(t1) Nut i ngirng nhan g6i vio th&i diem t7 (t6 cOng vOi mao dau cim msng hotic he thOng host dOng) vi &nit deu tai thin diem t8 yeti then gian Li(t8) Bay gib ta se Olin tfch vi sao not i nhat' m str hieu chinh ciut

no De c6 , chting ta gia sir khang c6 bit 16 sir ten nil) gitta cac clang ha trong khoang thbi gian tir tl den t8, do d6 0 = * ) vii cac nut

va tren thtrc to nut i u6c dotin 0 bang viec vat dofin