Li ni uS pht trin ca Internet, truyn thng v cng ngh thng tin kt hp vi nhng tin b k thut gn y to iu kin cho cc th h cm bin mi vi gi thnh thp, kh nng trin khai qui m ln vi chnh xc cao. Cng ngh iu khin v cm bin gm cm bin dy, cm bin trng in t, cm bin tn s v tuyn, cm bin quang in v hng ngoi, laser radar v cm bin nh v dn ng. Cc tin b trong lnh vc thit k cm bin, vt liu cho php gim kch thc, trng lng v chi ph sn xut cm bin ng thi tng kh nng hot ng v chnh xc. Trong tng lai gn, mng cm bin khng dy s c th tch hp hng triu cm bin vo h thng ci thin cht lng v thi gian sng. Cng ngh iu khin v cm bin c tim nng ln, khng ch trong khoa hc v nghin cu, m quan trng hn chng c s dng rng ri trong cc ng dng lin quan n bo v cc cng trnh trng yu, chm sc sc khe, bo v mi trng, nng lng, an ton thc phm, sn xut, nng cao cht lng cuc sng v kinh tVi mc tiu gim gi thnh v tng hiu qu trong cng nghip v thng mi, mng cm bin khng dy s mang n s tin nghi v cc ng dng thit thc nng cao cht lng cuc sng cho con ngi. Trong ni dung ti liu ny, trnh by v cc k thut xy dng mng cm bin khng dy, cc giao thc thit k t n gin n phc tp. Bn cnh l cc ng dng ph bin c nhiu tim nng ng dng trong thc t. Mt ci nhn tng qut v cng ngh mng cm bin khng dy. Em xin chn thnh cm n s hng dn nhit tnh ca thy Vng Pht, s gi m v gp ca thy h tr rt nhiu em c th hon thnh ti ny.CC T VIT TT DNG TRONG TI LIUT vit tt Ngha ting Anh Ngha ting VitACK Acknowledge Gi xc nhn ngAES Advanced Encryption Standard Tiu chun m ha tin tinAPI Application Programming Interface Giao din lp trnh ng dngAPS Application Support Sublayer Lp ph cung cp ng dngATM Asynchronous Transfer Mode Ch truyn bt ng bBE Back-off Exponent Thi gian ch c truy cpBTS Base Transceiver Station Trm thu pht c sCAP Contention Access Period Thi gian tranh chp truy cpCCA Clear Channel Assessment c nh knh truyn trngCDMA Code Division Multiple Access a truy cp phn chia theo mCFP Contention Free Period Thi gian tranh chp t doCID Cluster Identity M xc nhn ClusterCSMA Carrier Sense Multiple Access a truy cp cm bin sng mangCSMA/CA Carrier Sense Multiple Access with Collision Avoidance a truy cp cm bin sng mang trnh ng CSMA/CD Carrier Sense Multiple Access with Collision Detection a truy cp cm bin sng mang pht hin ng CTS Clear to send Sn sng nhnCW Congestion Window Ca s tranh chpDCE Data Circuit-Terminating Equipment Thit b kt cui knh s liuDSSS Direct-Sequence Spread Spectrum Tri ph chui trc tipDTE Data Terminal Equipment Thit b u cuiDTMC Discrete-Time Markov Chain Chui Markov thi gian ri rcE2E End-to-End u cui ti u cuiFDMA Frequency Division Multiple Access a truy cp phn chia theo tn sFFD Full-Function Device Thit b chc nng y GTS Guaranteed Time Slot Khe thi gian m boHbH Hop-by-Hop Truyn tng bcIEEE Institute of Electrical and Electronic Engineers Vin k thut in v in tIrisNet Internet-Scale Resource-Intensive Sensor Networks Services Dch v mng cm binti nguyn ln mc lin mngITU International Telecommunication Union Lin minh vin thng quc t

LAN Local Area Network Mnh ni bLEACH Low-Energy Adaptive Clustering Hierarchy Cu trc phn bc tng thch, nng lng thpLQI Link Quality Indicator B ch th cht lng lin ktLR-WPANs Low Rate Wireless Personal Area Networks Mng WPAN tc thpMAC Medium access control iu khin truy cp mi trngMANETs Mobile ad hoc Network Mng ad hoc di ngMIB Management Information Base C s thng tin qun lMiLAN Middleware Linking Application and Network Phn mm lin kt ng dng v mngNAV Network Allocation Vector Vector phn phi mngNB Number of Back-off S ln back-offNM Network Management Qun l mngNMS Network Management System H thng qun l mngOS Operating System H iu hnhPAN Personal Area Network Mng c nhnPEGASIS Power-efficient Gathering in Sensor Information System Tp trung hiu sut trong mng cm binPHY Physic Layer Lp vt lPSDU PHY Service Data Unit n v d liu lp vt lRED Receiver Energy Detection Pht hin nng lng my thuRF Radio Frequency Tn s v tuynRFD Reduced-Function Device Thit b chc nng hn chRFICs Radio Frequency Intergrated Circuits Mch tch hp tn s v tuyn

RFID Radio Frequency Identify Device Thit b nhn dng bng sng v tuynRTS Ready to send Sn sng giRVF Routing Vector Field Trng vector nh tuynSAP Service access point im truy cp dch vS-MAC sensor MAC Giao thc MAC cho cm binSMACS Self-Organizing Medium Access Control for Sensornets iu khin truy cp t sp xpcho mng cm binSNMP Simple Network Management Protocol Giao thc qun l mng n ginSPIN Sensor Protocols for Information via Negotiation Giao thc thng tin cm binthng qua s tha thunSTEM Sparse Topology and Energy Management Qun l nng lng v cu hnh ri rcTDD Time Division Duplex Song cng phn chia thi gianTDMA Time Division Multiple Access a truy cp phn chia theo thi gianTOM Telecom Operation Map Lc cc hot ng vin thngTS Timeslot Khe thi gianUDP User Datagram Protocol Giao thc cho dch v truyn datagramWAN Wide Area Networks Mng din rngWPAN Wireless Personal Area Network Mng khng dy c nhnWSNs Wireless Sensor Networks Mng cm bin khng dyZDO ZigBee Device Object i tng thit b ZigBee

Chng 1 TNG QUAN V MNG CM BIN KHNG DY

1.1 Gii thiu: Mng cm bin (sensor network) l mt cu trc, l s kt hp cc kh nng cm bin, x l thng tin v cc thnh phn lin lc to kh nng quan st, phn tch v phn ng li vi cc s kin v hin tng xy ra trong mi trng c th no .Mi trng c th l th gii vt l ,h thng sinh hc. Cc ng dng c bn ca mng cm bin ch yu gm thu thp d liu, gim st, theo di ,v cc ng dng trong y hc.Tuy nhin ng dng ca mng cm bin ty theo yu cu s dng cn rt a dng v khng b gii hn. C 4 thnh phn c bn cu to nn mt mng cm bin: Cc cm bin c phn b theo m hnh tp trung hay phn b ri Mng li lin kt gia cc cm bin( c dy hay v tuyn) im trung tm tp hp d liu (Clustering) B phn x l d liu trung tm Mt node cm bin c nh ngha l s kt hp cm bin v b phn x l, hay cn gi l mote. Mng cm bin khng dy(WSN) l mng cm bin trong cc kt ni gia cc node cm bin bng sng v tuyn.1.1.1 Cng ngh Sensor Network: Trong mng sensor network, cm bin c xem nh l phn quan trng nht phc v cho cc ng dng. Cng ngh cm bin v iu khin bao gm cc cm bin trng in t; cm bin tn s v tuyn; quang ,hng ngoi; radars; lasers; cc cm bin nh v, dn ng; o c cc thng s mi trng; v cc cm bin phc v trong ng dng an ninh, sinh ha .. Ngy nay, cm bin c s dng vi s lng ln. Mng WSNs c c im ring ,cng sut b gii hn, thi gian cung cp nng lng ca ngun (ch yu l pin) c thi gian ngn, chu k nhim v ngn, quan h a im-im, s lng ln cc node cm bin Cm bin c th ch gm 1 hay dy cm bin.Kch thc rt a dng , t nano (1-100nm), meso (100-10000nm), micro (10-1000um), macro(vi mm-m) Do c tnh ca mng WSNs l di ng v trc y ch yu phc v cho cc ng dng qun s nn i hi tnh bo mt cao. Ngy nay ,cc ng dng WSNs m rng cho cc ng dng thng mi, vic tiu chun ha to s to nn tnh thng mi cao cho WSNs. Cc nghin cu v WSNs c th chia ra lm nhiu phn, cc s liu thng k gn y cho bng 1.1:

Bng 1.1 : Cc lnh vc nghin cu v WSNs Cc nghin cu gn y pht trin thng tin cng sut thp vi cc node x l gi thnh thp v c kh nng t phn b sp xp ,la chn giao thc cho mng, gii quyt bi ton quan trng nht ca mng WSNs l kh nng cung cp nng lng cho cc node b gii hn .Cc m hnh khng dy, c mch tiu th nng lng thp c u tin pht trin. Hiu qu s dng cng sut ca WSNs v tng qut da trn 3 tiu ch: Chu k hot ng ngn X l d liu ni b ti cc node gim chiu di d liu, thi gian truyn M hnh mng multihop lm gim chiu di ng truyn, qua gim suy hao tng cng ,gim tng cng sut cho ng truyn. WSNs c phn ra lm 2 loi ,theo m hnh kt ni v nh tuyn m cc nodes s dng:loi 1(C1WSNs): S dng giao thc nh tuyn ng Cc node tm ng i tt nht n ch Vai tr ca cc node sensor ny vi cc node k tip nh l cc trm lp (repeater) Khong cch rt ln (hng ngn mt) Kh nng x l d liu cc node chuyn tip Mng phc tploi 2(C2WSNs) M hnh a im-im hay im-im, 1 kt ni radio n node trung tm S dng gia thc nh tuyn tnh 1 node khng cung cp thng tin cho cc node khc Khong cch vi trm mt Node chuyn tip khng c kh nng x l d liu cho cc node khc H thng tng i n gin Tiu chun tn s ang c p dng cho WSNs l IEEE 802.15.4.Hot ng ti tn s 2.4GHz trong cng nghip, khoa hc v y hc(ISM), cung cp ng truyn d liu vi tc ln n 250kbps khong cch 30 n 200 feet. Zigbee/IEEE 802.15.4 c thit k b sung cho cc cng ngh khng dy nh l Bluetooth, Wifi ,Ultrawideband(UWB), mc ch phc v cho cc ng dng thng mi. Vi s ra i ca tiu chun Zigbee/IEEE 802.15.4, cc h thng dn pht trin theo hng tiu chun, cho php cc cm bin truyn thng tin qua knh truyn c tiu chun ha. Nhiu nghin cu trong lnh vc mng mobile ad hoc (MANETs). WSNs tng t nh MANETs theo mt vi c im .C hai u l chun mng wireless ,multihop . Tuy nhin , cc ng dng v k thut gia hai h thng c khc nhau. Dng thng thng ca WSN l a ngun d liu truyn n ni nhn, khc hn im-im trong MANETs Cc node trong WSNs t di ng, trong khi ad hoc cc node l di ng Trong WSNs, d liu t cc cm bin ch yu t cc hin tng. s kin th gii thc. MANETs ch yu l d liu. Ngun gii hn, nng lng trong WSNs c qun l s dng rt cht ch.Trong MANETs c th khng b rng buc bi ngun cung cp do cc thit b thng tin c th c thay th ngun cung cp thng xuyn bi ngi dng S lng node trong WSNs rt ln, MANETs t hn . =>Do s khc bit gia 2 m hnh giao thc m cc giao thc nh tuyn trong MANETs khng th p dng hon ton cho WSNs. Tuy nhin WSNs c th coi nh mt phn trong MANETs (ad hoc) .1.1.2 ng dng ca mng cm bin : Qun s : theo di cc mc tiu, chin trng, cc nguy c tn cng nguyn t, sinh ha,. Mi trng : gim st chy rng, thay i kh hu, bo ,l lt, Y t, sc khe : gim st bnh nhn trong bnh vin, qun l thuc, iu khin t xa, Gia nh : ngi nh thng minh, iu khin cc thit b in, h thng si m, Thng mi : iu khin trong mi trng cng nghip v vn phng, gim st xe c , giao thng,

1.2 Tng quan v k thut WSNs: Nh cp phn trn, mt vi mng cm bin dng giao thc x l ti node ngun trung tm, mt s dng giao thc x l theo cu trc hay gi l x l trc ti node. Thay v gi i d liu n node chuyn tip, node thng dng kh nng x l ca mnh gii quyt trc khi pht i.Vi dng c cu trc, d liu c x l n mc tt nht nh lm gim c nng lng cn dng v bng thng knh truyn. Mt vi k thut v tiu chun ph hp vi mng cm bin nh sau: Cm bin:1.2.1 Cc thnh phn c bn cu trc mng cm bin : Cc thnh phn c bn v thit k trng tm ca mng WSNs cn c t trong ng cnh ca m hnh WSNs dng 1 (C1WSNs) c gii thiu phn trc. Bi v y l m hnh vi s lng ln cm bin trong mng, chi d liu nhiu, d liu khng tht hon ho, kh nng hu hng cc node cao, cng nh kh nng b nhiu ln, gii hn cng sut cung cp,x l, thiu thng tin cc node trong mng. Do vy, C1WSNs tng qut hn so vi m hnh C2WSNs.S pht trin mng cm bin da trn ci tin v cm bin, thng tin, v tnh ton (gii thut trao i d liu , phn cng v phn mm).

Hnh 1.1 : M hnh mng cm bin thng thng Hnh 1.1 cho thy m hnh cu trc ca mng cm bin thng dng. Cc cm bin lin kt theo giao thc Multihop, phn chia Cluster chn ra node c kh nng tt nht lm node trung tm, tt c cc node loi ny s truyn v node x l chnh. Nh vy, nng lng cng nh bng thng knh truyn s s dng hiu qu hn. Tuy nhin, c th thy cu trc mng phc tp v giao thc phn chia Cluster v nh tuyn cng tr nn kh khn hn. Mt vi c im ca mng cm bin : Cc node phn b dy c. Cc node d b h hng. Giao thc mng thay i thng xuyn. Node b gii hn v cng sut, kh nng tnh ton, v b nh Cc node c th khng c ng nht ton h thng v s lng ln cc node.

Hnh 1.2: Cc thnh phn trong mt Node Cc thnh phn cu to nn mt node trong mng cm bin nh trn hnh 1.2: Mt cm bin (c th l mt hay dy cm bin) v n v thc thi (nu c) n v x l n v lin lc bng v tuyn Ngun cung cp Cc phn ng dng khc

Standards for Transport Protocols Mc ch thit k WSNs l pht trin gii php mng khng dy da trn tiu chun v hao ph l thp nht, p ng cc yu cu nh tc d liu thp-trung bnh, tiu th cng sut thp, m bo bo mt v tin cy cho h thng. V tr cc node cm bin hu nh khng xc nh trc, c ngha l giao thc v gii thut mng phi c kh nng t xy dng. Cc nh nghin cu pht trin nhiu giao thc c bit cho WSNs, trong vn cn bn l nng lng tiu th phi thp nht n mc c th. Ch yu tp trung vo giao thc nh tuyn, bi v nh tuyn c khc so vi cc mng truyn thng ( ph thuc vo ng dng v kin trc mng).

Hnh 1.3: Giao thc chung cho mng cm bin. Giao thc mng cm bin gm lin lc trong mng v qun l. Giao thc lin kt trong mng gm cc lp nh m hnh OSI. Layer 1 : lp vt l: cc qui c v in, knh truyn , cm bin, x l tn hiu Layer 2 : lp lin kt d liu : cc cu trc khung, nh thi Layer 3 : lp mng : nh tuyn Layer 4 : lp chuyn vn : truyn d liu trong mng, lu gi d liu Upper Layers : phc v cc ng dng trong mng, bao gm x l ng dng, kt hp d liu, x l cc yu cu t bn ngoi, c s d liu ngoi .

Bng 1.2: Cc giao thc c th dng cho Lower-layer WSNs

Bng 1.2 nu ra mt s giao thc lp thp c th ng dng cho WSNs. So snh gia cc chun , mc ch ca ng dng, tiu chun cho thit k, khong cch truyn v bng thng ti a. Mc d cm bin c gi thnh ngy cng thp, nhng vn cn thiu cc tiu chun mng cho WSNs,iu ny l mt yu t gy cn tr s pht trin mng cm bin cho mc ch thng mi.Routing and Data Dissemination Giao thc nh tuyn cho WSMs ri vo 3 nhm: d liu trung tm, kin trc mng, v cn c vo v tr. Cc qui c v tp hp d liu kt hp d liu n t cc ngun khc nhau qua ng truyn. iu ny cho php hn ch s d tha trong mng, lm gim s ng truyn, gim nng lng tiu th. Vn quan tm trong x l ni mng , ngay khi d liu ang c truyn nhm tng hiu qu s dng nng lng ca ton h thng. Bng thng b gii hn, kh nng cung cp cng sut ti cc node b hn ch hay gi thnh cao. gii quyt vn ny, cn c qu trnh x l trc ti ngun trc khi chuyn qua cc node ln cn, ch truyn thng tin tm tt, ngn gn, tng hp nht.Sensor Network Organization and Tracking Cc vn lin quan s sp xp mng v s theo di v gim st bao gm qun l nhm cc cm bin, kh nng t phn chia nhm , xy dng phin lm vic.Computation Tnh ton lin quan n tp hp d liu, dung hp, phn tch, tnh ton cu trc, v x l tn hiu.Data Management Qun l d liu ph thuc vo kin trc d liu, qun l c s d liu, k thut truy vn v lu tr d liu.Trong mi trng mng truyn thng, d liu c thu thp n trung tm lu tr khi c yu cu c gi i. Trong cc mng phc tp hn, cc yu cu theo thi gian thc, cn c cc k thut c xy dng dng cho cc m hnh lu tr d liu phn b. D liu cn c nh ch s cho vic kim tra (theo khng gian v thi gian) hiu qu hn.Security Bo mt l mt phn quan trng trong WSNs, s chc chn, nht qun v s sn sng ca thng tin. 1.2.2 Cc thch thc v tr ngi: WSNs thc s tr nn rng khp trong cc ng dng, mt s thch thc v tr ngi cn phi vt qua: Chc nng gii hn, bao gm c vn v kch thc Yu t ngun cung cp Gi thnh cc node Yu t mi trng c tnh knh truyn Giao thc qung l mng phc tp v s phn b ri cc node Tiu chun v quyn s hu Cc vn m rng

Chng 2NG DNG MNG CM BIN KHNG DY WSNs l s tp hp cc kch thc nh gn (compact-size), c th l cc node cm bin vi gi thnh thp, c kh nng lm vic trong iu kin mi trng t nhin hoc o c cc thng s khc v a nhng thng tin n trung tm cho cc x l ph hp. Cc node trong mng WSNs c th lin lc vi cc node xung quanh n, v cn c th c cc x l d liu thu uc trc khi gi n cc node khc. WSNs cung cp rt nhiu cc ng dng hu ch.2.1 Cc m hnh phn b: Nh c cp trong chng 1, m hnh WSNs c xy dng ch yu theo 2 loi: Category 1 WSNs (C1WSNs): h thng li kt ni a ng gia cc node qua knh truyn v tuyn, s dng giao thc nh tuyn ng. Category 2 WSNs (C2WSNs): m hnh im-im hay a im-im, ch yu l cc lin kt n (single-hop) gia cc node , dng giao thc nh tuyn tnh.

Hnh 2.1: Dng 1 WSNs , lin kt multipoint-to-point, multihop dng nh tuyn ng

Hnh 2.2: Dng 2 WSNs lin kt point-to-point , Star nh tuyn tnh Theo cch khc, c th chia m hnh theo 2 dng hp tc (cooperative) v bt hp tc (noncooperative). Trong dng hp tc cc node chuyn tip thng tin cho cc node ln cn. Cn trong dng bt hp tc , cc node truyn thng tin trc tip ln trung tm m khng qua cc node ln cn.

Hnh 2.3: Cc node theo m hnh hp tc v bt hp tc Mc d cn c cc cch phn loi m hnh khc, tuy nhin theo 2 dng C1WSNs v C2WSNs l tng qut nht cho cc cch cu hnh mng WSNs. Cc ng dng c xy dng da trn cc m hnh ny.

2.2 Cc ng dng ca mng WSNs: Chia ra 2 loi ng dng theo m hnh: h thng im-im dng nh tuyn tnh v h thng phc tp dng giao thc nh tuyn ng. S hi t ca Internet, thng tin v tuyn, v k thut thng tin to cho cng ngh cm bin s pht trin y tim nng. Phn cng WSN, c bit l cc vi x l gi thnh thp, cm bin nh gn, phn thu pht v tuyn tiu th cng sut thp tr thnh cc tiu chun chung.Mng cm bin thng thng hot ng tn s 900MHz (868-v 915-MHz), h thng thng mi (IEEE 802.11b hay IEEE 802.5.4 ) trong dy tn 2.4-GHz. Trong nhng nm gn y, cc nghin cu v WSN t c bc pht trin mnh m, cc bc tin t cc nghin cu ha hn tc ng ln n cc ng dng rng ri trong cc lnh vc an ninh quc gia, chm sc sc khe, mi trng, nng lng, an ton thc phm v sn xut... Cc ng dng ca mng WSNs thc s ch b gii hn bi s tng tng ca con ngi. Sau y l cc ng dng ph bin nht ca WSNs: ng dng trong qun s v an ninh quc gia Gim st chin trng Bo v an ninh cho cc cng trnh trng yu ng dng trong qun i Thng tin, gim st, iu khin Theo di mc tiu Pht hin phng x ht nhn Gim st di nc, trn khng H thng radars R sot bom mn

ng dng trong bo v mi trng Pht hin hot ng ni la Gim st chy rng Gim st dch bnh S dng hiu qu ti nguyn thin nhin Cm bin dng trong nng nghip Pht hin ng t .. ng dng trong thng mi iu khin khng lu Qun l cu ng Qun l kin trc v xy dng iu khin nhit Qun l ti trong tiu th in nng H thng t ng Cm bin cc cht ha hc, sinh hc, nguyn t Thu thp d liu thi gian thc Cc h thng nhn dng bng sng radio (RFID tags) Qun l nng lng iu khin nhit Qun l sn xut Robot t hnh o lng kh gas, nc, in H thng x l vt liu (ha hc, gas, nhit ) .. ng dng trong y hc Cm bin gn trc tip ln c th ngi Chm sc sc khe Phn ng vi dch bnh Phn tch sc khe c nhn An ton thc phm Phn tch nng cc cht Gim st bnh nhn, nhn vin y t . ng dng trong gia nh iu khin t xa cc thit b in trong nh H thng t ng trong gia nh, cnh bo an ninh Gim st an ninh .. ng dng trong nghin cu2.3 Cc v d v ng dng dng 1 WSN (C1WSN) : C1WSN ng dng trong cc mng m cc node khng c gim st (unattended), WSNs c bit c hiu qu trong qun s v dn s, gim st cc hot ng chin trng, an ninh v ng ph vi dch bnh. Do c im s node rt ln, phn b ri, s qun l cht ch cc node rt kh khn, cc node phi c kh nng t phn b cu trc, dng giao thc nh tuyn ng a d liu v trung tm theo cc ng i tt nht.2.3.1 ng dng qun s, an ninh v thin nhin: Trong phn ng vi dch bnh, thm ha thin nhin lng ln cc cm bin c th t trn khng, mng li cc cm bin s cho bit v tr ngi sng st, vng nguy him, gip cho ngi gim st c cc thng tin chnh xc m bo hiu qu v an ton cho cc hot ng tm kim. S dng mng WSNs hn ch s c mt trc tip ca con ngi trong mi trng nguy him . ng dng an ninh bao gm pht hin xm nhp v truy bt ti phm. Mng cm bin qun s pht hin v c c thng tin v s di chuyn ca i phng, cht n v cc thng tin khc Pht hin v phn loi cc cht ha cht, sinh ha, sng v tuyn, phng x ht nhn, cht n Gim st s thay i kh hu, rng, bin. Gim st xe c trn ng Gim st an ninh trong cc khu vc dn c, thng mi Theo di bin gii kt hp vi v tinh

Hnh 2.4: ng dng WSNs trong an ninh quc gia v lut php

Hnh 2.5

Hnh 2.5 a ra cc v d v ng dng cm bin trong qun s .Cc cm bin trang b trn cc phng tin k thut phc v cho vic gim st cc hot ng chin trng.2.3.2 ng dng trong gim st xe c v thng tin lin quan: Mc tiu ca cc h thng ny l thu thp thng tin thng qua cc mng cm bin, x l v lu tr d liu ti trung tm, s dng d liu cho cc ng dng cn thit. H thng c lp t dc theo cc ng chnh, mng cm bin s tp hp d liu v tc lu thng, mt xe, s lng xe trn ng. D liu sau c truyn n trung tm d liu x l. Mng theo di lin tc, cung cp thng tin cp nht thng xuyn theo thi gian thc. Cc thng tin thu c dng gim st lu lng , iu phi giao thng hoc cho cc mc ch khc.

Hnh 2.6: H thng cm bin trn cc ng cao tc.2.4 Cc v d v ng dng dng 2 WSN (C2WSN) : Cc ng dng dng ny dng m hnh im-im (hay m hnh sao), vi cc lin kt n v tuyn nh tuyn tnh. C2WSN ng dng trong iu khin t ng cc ta nh, cng nghip, y t, iu khin ni c tr Cc ng dng gm iu khin nh sng, nhit , an ninh, mi trng, cm bin trong y khoa, iu khin t xa trong gia nh hay cng nghip, Nhiu ng dng c xy dng theo chun IEEE 802.15.4 (ZigBee). ZigBee cung cp t tng tc v p ng c cc c im ca lin lc v tuyn (RF).ZigBee c th c xy dng trong nhiu mng khng dy vi gi thnh thp, tiu th t cng sut ngun vi s lng ln cc node. Vn quan tm l chun ny cha nhiu giao thc , tc d liu v cc tn s thch hp p dng rng ri. Gia ZigBee v Bluetooth v cn bn c nhiu im khc nhau v dng cho cc mc ch ng dng khc nhau. ZigBee c thit k cho mi trng chu k nhim v thp, nh tuyn tnh hoc ng, nhiu node cng hot ng. Trong khi Bluetooth c thit k cho ng dng i hi cht lng cao (QoS), chu k nhim v thay i, tc d liu va phi, s node gii hn. Mi cm bin c mt b dao ng ng thc b x l chnh sau mt khong thi gian nht nh sang ch lm vic.

Hnh 2.7: Thi gian hot ng pin trong Bluetooth(BT) v ZigBee So snh thi gian hot ng pin trong 2 chun Bluetooth v ZigBee. Hnh 2.7 cho thy thi gian hot ng pin ca chun ZigBee cao hn so vi Bluetooth.2.4.1 iu khin cc thit b trong nh: ng dng WSN cung cp iu khin, bo qun, tin nghi v an ninh.

Hnh 2.8: Cc ng dng iu khin Cc node cm bin c lp trn cc thit b , v tr cn thit, sau kt ni thnh mng truyn d liu v node trung tm. Mt kh nng c th pht trin l cc cm bin theo di y t c gn trc tip ln c th ngi bnh o c thng xuyn cc thng s v huyt p, nhp tim,2.4.2 Cc ta nh t ng: ng dng cung cp kh nng iu khin, qun l, to s tin li trong kim sot, an ninhQun l nhiu h thng cng lc, h thng chiu sng, nhit , an ninh, gim st nhn vin, qun l hiu qu tiu th nng lng trong ta nh, gn cc chip ln hng ha,gim c thi gian kim trac th d dng c thc hin bng C2WSNs v cng ngh ZigBee. c im ni bt l dng cc cng ngh microsensor tiu th rt t cng sut, thu pht v tuyn , k thut lin lc v cm bin khng dy a chc nng. Cc cm bin kt hp nhit , nh sng, m thanh, v tr Giao din mng v tuyn Nng lng hot ng lu di Phn mm iu khin cho cc ng dng

Hnh 2.9: iu khin nh sng trong phng.2.4.3 Qun l qu trnh t ng trong cng nghip:

Hnh 2.10: Cc ng dng trong cng nghip. Cc ng dng trong sn xut cng nghip gm iu khin, qun l, hiu sut v an ton. Cc cm bin t trong mi trng lm vic gim st qu trnh sn xut, cht lng sn phm, kim sot mi trng lm vic, qun l nhn vin,d liu c a v trung tm ngi qun l c th a ra cc quyt nh kp thi. Trn hnh 2.10, cc node cm bin kt ni thnh mng li gi d liu n node trong tm ,s dng giao thc nh tuyn tnh.2.4.4 Cc ng dng trong y hc: Mt s bnh vin v trung tm y t ang ng dng cng ngh WSNs vo tin chn on, chm sc sc khe, i ph vi cc dch bnh v phc hi chc nng cho ngi bnh. WSNs cho php theo di tnh trng ca cc bnh nhn kinh nin ngay ti nh, lm cho vic phn tch v iu tr thun tin hn, rt ngn thi gian iu tr ti bnh vin. WSNs cn cho php thu thp thng tin y t qua thi gian di thnh cc c s d liu quan trng, cc bin php can thip hiu qu.

Hnh 2.11: Cc ng dng trong y khoa.2.5 Kt lun: T cc kh nng ng dng rng ln ca WSNs c th rt ra kt lun: Bt c u con ngi mun theo di, quan st, phn ng vi nhng s kin hay hin tng trong mi trng c bit no h c th dng mng WSNs.