W. (mg dung nhu vey la jr tuong cho cac mpg cam bien khOng day S6 luqng clit lieu
4.3.Giao fink djnh twin trong mang WSNs
Dinh tuyen trong WSNs gip kh6 khan 16n la to su can bing gitka dO nh#y vi firth hieu quit. Su can bing giea dec tinh gioi hon kha Wing xir ljr vi thong tin cea cac node cam Bien von phin overhead cin thiet. Trong WSNs, overhead (CO the coi la chi phi quan (low tinh dua tren bang thong sir dung, c8ng suit tieu thu vi yeu ciu xur
lSr node di dung. VI neu overhead qua lan gay Ring phi bang thong, 'tang luqng, thoi gian xir 1SI, tang dO trg g6i tai node niumg chit ltrong dl] lieu tot hon. Ngtrqc lai, overhead nhe thi thin gian )(Cr 1S/, bang thong, dO trg thip tuy nhien chit hrqng c6 the giam. Thach thec cea giao th(rc djnh tuyen chinh la tim ra gill thtifit de can bang &Ling yeu du nay.
Mang WSNs c6 mOt s6 d.fc thing co ban curt mang ad hoc. Do de c6 the xem xit cac giao thirc cac djnh tuyen mpg ad hoc fru& khi ap dung vio WSN. Giai thulit djnh tuyen cosi mpg ad hoc chia theo ba diing: proactive, reactive vi hybrid.
— Proactive (Ichai too truac) con gai la table driven, clua tren su phin phat theo chu ky thong tin djnh tuyen de dg duqc cac bang djnh tuyen nhit quan vi
chin!' xac den tit ca cac node curt mpg. Ciu frac mpg c6 the la phiing hay 36
phan cap. DAng phuang phap nay cho ciu frac phing co khi Hang tim ra duqc duang di tai uu nhit.
— Reactive (phan (mg) xay dgng tuyin den mOt dich den nao do theo nhu
Giai thuit nay thuang khang xay dgng thong tin chung di qua tit ca cac node
cita mong. Do do chting do ten djnh tuyen dOng de tim ra throng di gitta nguOn va dich. Giii thuit djnh tuyen reactive thay dei theo tech ma chin dieu khien qui trinh flooding de giam thong tin overhead vi tech cic tuyin duqc tinh town va xay dtmg lei khi lien kit khong thgc hien duqc.
— Hybrid (hgn hqp) dga tren ciu truc mang di to filth an djnh va kha 'tang ma rung cho cac mang co kich thuac 16n. Trong nhang giai thutit ding nay, mong dugc phan chia thank cac cluster. Do sO luqng lan vi tinh di dung, mong co tinh dOng khi cac node vao hay tech ra khai cac cluster. Giai thuit hybrid co the dugc dung theo ma hinh djnh tuyin proactive ChM dung cho ben trong cac cluster vi djnh tuyen reactive dung lien kit gitta cac cluster.
Overhead giao thirc djnh tuyen thuang tang nhanh khi tang kich thuac vi dic tinh dung cue mong. Overhead Ion co the chi& mOt plan lon tii nguyen dot mang. Han nita, cic giao thirc djnh tuyen truyin thing trong nhOng mong 16n yeu ciu sir lien ket thgc gift cac node. Viec dung nhemg k5 thuit nay lam tang overhead cho djnh tuyen vi thoi gian hOi tg. Thgc te, n4c du cic kg thuit djnh tuyen truyin thang thich hqp hoot dung trong mai Maw mong ma kha Wing tinh town vi thong tin dm cac node mang khi tat, nhung hieu qui cult cic k5 thua)t nay bj hen chi vai mong WSNs. Do do, cac k5 ththu djnh tuyen mai cho mong WSNs phii c6 dugc sir can bing gitta tinh tai uu va hieu qui hoot dung.