Del Hnr Th5ng I.nng  Al 7776  Tian Ting CHI O'NG 1. TONG QUAN MANG CAM BIEN KEIONG DAY 1.1 G161 thieu Trong nhitng nom gin ctay, rit nhieu mang cam bien khong day da vi dang duqc phit then vi then khai cho nhieu the irng dyng khic nhau nhu: theo d8i sly thay doi cea mei trubng, !chi Mu, giim sit cic met ton van stir, phat hien vi do than viec tin cong bang hat nhan ' , sinh hoc vi hoi hoc, chuin doin sly hang hoc cita may mac, thief N, theo diu vi giim sit cic bic sy, benh nhan cling nhu quitn 19 thu6c trong the benh vien,theo dai vi dieu lchien giao thong, cic phucrng lien xe c0 Han nita vii sty tien be c8ng nghe gin day vi hei ty cea hg thong cic cong nghe nhu Icy thu$t vi dien tu, cong nghe nano, giao flip khong day, cong nghe mach tich hqp, vi mach phin cam hien, xir 19 vi tinh town tin hieu da tao ra nhang con cam hien c6 kich think nhe, da chtic !tang, gii thimh thip, cong suit lieu thy thip, layn tang lchi nang img dyng rOng rai dui mang cam hien khong day. MOt mang cam hien !thong day li met mang bao gem nhieu mit cam hien nhe c6 gii thimh thip, vi tieu thy Wing lucmg it, giao dip thong qua the ket n6i !thong day, c6 nhiem vy cam hien, do doe, tinh win nhiim myc dick thu th$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. Chuyen de tat nghiep  1 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. Chuyen di tot nghiep  2 Plait lane Thing I.nng A17776  Tien Wing I Sink t o Mit dm bitm * SIddin 0 Treeing dm ban Ngizbi skim 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). Chuyen de tot nghiep  3 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 B+ gain Bo phat nmOn 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. Chuyen de tat nghiep  4 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. Giao di. kit cim tart Ames nvei Amen da 'in ara SO* 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 Chuyen de tot nghiep  5 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: Chuyen tdt nghiOp  7 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 M u " ( • 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. Chuyen de tot nghiep  10 [...]... 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. .. 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... 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... 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 , 3 kHz 30 kHz 300 Ma 3 MHz 30 MHz 300 MHz 3 GHz 30 GHz 300 GHz VLF LF 100 km 10 Mr MF Hon HF 100m VHF 10m UHF 1m SHF 100M EHF I an I mm VLF = Tan s6 cvc thap LF = Tan s8 drip MF = Tan so trung binh HF = Tan so cao VHF = Tan s6 rat cao UHF = Ten s6 cvc cao SHF = Tan so sieu... 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... 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... 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... -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... 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... 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 . 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. 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. 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