- C6 the to dOng to chirc, quail tri va hoot dung Ichong can can thiep; Thich nghi dugc vgi m6i twang.
2.1.3. Mai Wang truyin din
Trong mOt myng Sensor da lien ket, cac nut mpg thong tin v6i nhau qua moil truing !Nag dAy. Cie lien ket nay ce the la song vo tuyen, hOng ngoyi hay cac tin hieu quang. Viet chip m8i truing thong tin lien quan den you au nhiem vu cim mpg va chimg phai dam bao cac quy djnh quoc to ye th8ng tin trong !thong gian de to the hog dOng dirge 6 mgi non.
Lien ket ve tuyen sir dyng the dii tin c8ng nghiep, khoa hoc va y tigc (Industrial, Scientific and Medical-ISM). Cac el& tin nay dirge thong tin to do trong hiu het the nue/G. Bang phan phoi dui sO quk to nom trong khoan S5 trong quy djnh tin sO chi m mOt s6 dal tin danh cho cac ling dyng ISM (Bang 2.1).
Frequency band Center frequency
6765-6795 kHz 6780 kHz 13,553-13,567 kHz 13,560 kHz 26,957-27,283 kHz 27,120 kHz 40.66-40.70 MHz 40.68 MHz 433.05-434.79 MHz 433.92 MHz 902-928 MHz 915 MHz 2400-2500 MHz 2450 MHz 5725-5875 MHz 5800 MHz 24-24.25 GHz 24.125 GHz 61-61.5 GHz 61.25 GHz 122-123 GHz 122.5 GHz 244-246 GHz 245 GHz
Bang 2.1. Cac dai din danh cho cac sing dyng ISM
MOt so cac diti tin nay di dirge sir dyng cho cac he thong dien thoyi cam tay va myng n0i 130 khong clAy (Wireless LAN). Clic mpg Sensor sir dyng bo thu phat kich
cb nh6, gia r8 va c8ng suit tieu thu eye thip. Do ac hen the ve phi') cling va sir cAn
bring era hieu qua antent va cling suit tieu thu giai ban nen phai bra then song mang thuOc dai tin rot cao (UHF). Cac 130 thu phat sir dung dai tin 433 MHz ISM 6 chau Au
va 915 MHz 6 Bic My. ThuOn iqi chinh cure cac dai tin ISM la sir dung ty do, pht• rung va th8ng dyng. Chimg khong ving khei the tieu bring, do de c6 the phi him vii cac ke hooch fiat hem ming lugng. Mot khac, con c6 cac hyn the khac nhu giii hen cling suit va nhigu gay hai cac img dung dit thin khai do cac Mr tin ISM kh8ng dirge quan 19.
MOt kik truyen th8ng khac trong myng Sensor la si dyng hOng ngoyi. Thong tin hOng ngoyi dirge sir dyng to do va co kha Wing chOng nhigu ti• the thiet bj dien. Cie b0 thu phat hang ngoyi c6 gia thanh r8 va a chi Mo. New nay, cac may tinh xach tay, may tinh am tay va dien tho3i di dung dlu c6 ding giao tiep hong ngoyi. Tri ngai
chinh cua viec sir dung hing ngoai lit yeu eau phiii c6 mOt dutmg nhin thing giffa nai giri vu nai nhan. Dieu nay lam cho hing ngoai Ithe duqc sir dung trong trang hqp mpg Sensor.
MOt hutmg phitt trien clang quan tam IA the vi hat thong mirth (smart dust mote), mat he thing aim hien, firth town vA th8ng tin ty dung, sir dung mai twang truygn din quang hqc. CO hat phtrcmg phap truyen thong tin: thir nhat lk truyen thong thy dOng su
dung mOt may phim chieu c6 ding tam then chit nhat (Comer-cube-retroreflector (CCR)); thu hat la buy& thong tich eye sir dung the diode lazer vu the guang chuyin dOng. Hien nay the diode lazer tai nai phut dugc gin tren bang mach, c6 the chuyen dung lai chum sang vao chinh xac nai nhan.
Cic Ong dung dk biet doi hai mai twang truyen din phac tap hon. Vi du, vii cud img dung duel hien thl mai truang truyen din lk mai twang nuoc. Do dtt phki sir dung bac n butm sang did de di xuyen trong nuttc. Vol the yang khi hau khic nghiet hay cac yang Chien stir, thl phki vucrt qua dupe the sai 18i vu nhigu 16n. Ngoki ra, the antent dm Sensor thip hen vi c6 can suit bac xa nh6 hen the thiet 1)1 va tuyen Ichk. Do d6,m8i twang truyen thong phki dirge hg trq bing the phueng thac dieu the vi ma holt ching 161 phu hqp yeti dlic diem tang loaf kenh truyen.