Cov photoelectric converter yog ib qho khoom siv zoo ib yam li lub hauv paus ntawm lub ntsej muag MODEM (digital modem). Qhov sib txawv ntawm lub hauv paus ntoo MODEM yog tias nws txuas nrog rau fiber ntau kho qhov muag kab, uas yog cov teeb liab kho qhov muag. Gigabit optical fiber transceiver (tseem hu ua photoelectric converter) yog Ethernet ceev nrawm nrog cov ntaub ntawv sib kis ntawm 1Gbps. Nws tseem siv CSMA / CD nkag tswj kev siv tshuab thiab yog sib xws nrog Ethernet uas twb muaj lawm. Nrog kev txhawb nqa ntawm cov hlua hluav taws xob, Muaj peev xwm ua kom yooj yim kho kom ceev cov qub Ethernet thiab tuaj yeem tiv thaiv tau qhov peev txheej ntawm cov neeg siv. Tam sim no, Gigabit network thev naus laus zis tau ua cov thev naus laus zis zoo tshaj plaws rau kev tsim kho tshiab thiab kev hloov pauv, thiab kev ua tau zoo ntawm cov kab hlau sib txuas ua ke kuj tau nce. Lub hauv paus ntsiab lus: Raws li Shannon' s theorem, kev sib raug zoo ntawm cov kab bandwidth thiab channel muaj peev xwm: C = Wlog2 (1+S / N) (bps) …………………… .. (1) qhov twg C yog cov peev txheej hauv channel, W yog qhov dav dav, N yog lub suab nrov, S yog lub teeb liab lub zog, thiab S / N yog lub teeb liab-rau-nrov piv. Nws tuaj yeem pom los ntawm (1) tias cov peev xwm ua tau channel tuaj yeem txhim kho los ntawm kev nce qib ntawm bandwidth channel thiab lub teeb liab-kom-suab. Cov tam sim no muaj kev sib tw sib txuas ua ke kom txhawb nqa cov kev pabcuam hauv high-speed network yog cat5, super cat5, thiab cat6, nrog lawv cov bandwidth ntau ntawm 100MHZ, 100MHZ thiab 200MHZ. Vim tias Gigabit Ethernet twisted-khub cabling tus qauv 802.3ab yog raws li kev siv 4 khub ntawm cat5UTP, bandwidth ntawm Qeb 5 UTP yog 1 / 100MHZ. Yog li, tsuas yog los ntawm qhov kev pom ntawm bandwidth, kev xaiv ntawm Pawg 5 twisted khub tuaj yeem ua tau raws li cov cai ntawm Gigabit network daim ntawv thov. Xav pom dua los ntawm qhov pom ntawm qhov taw qhia-rau-lub suab nrov. Gigabit tes hauj lwm xav tau ib txhij siv plaub khub ntawm UTP cable rau cov ntaub ntawv loj khiav ceev sib kis tau. Cov teeb liab thiab suab nrov muaj feem xyuam rau cov cwj pwm hauv qab no ntawm lub cable feem. Cov kev txwv no yog: Attenuation: hais txog ntawm qhov teeb meem xa hluav taws xob raws qhov txuas. Rov Qab Poob (RL): Qhov xav txog ntawm lub teeb liab xa hluav taws xob vim muaj qhov tsis sib xws ntawm cov yam ntxwv ntawm kev cuam tshuam ntawm lub cable thiab kev cuam tshuam ntawm txoj kab txuas txuas los ntawm tus qauv ntsuas. Nyob ze-kawg lub pob taws poob (NEXT): Zoo ib yam li lub suab nrov, nws yog lub teeb liab cuam sib kis tau kis los ntawm cov kab sib txuas. Qhov zoo li ntawm lub teeb liab liab yog vim muaj kev sib txuas ntawm qhov sib txuas winding khub hauv UTP los ntawm capacitance lossis inductance. Cov khub sib txuas ntxiv ntawm cov kab sib chaws (Powersum): hais txog cov lej sib txuas ntawm lwm qhov peb khub ntawm cov xov tooj ua haujlwm ntawm lwm qhov peb khub ntawm cov xov hlau nyob hauv ib puag ncig uas plaub UTP khub tau siv los xa cov ntaub ntawv tib lub sijhawm. Xws li lub teeb liab sib kis yog T, thiab plaub qhov yam ntxwv saum toj no tau sawv cev los ntawm A, R, NE, thiab P feem, tom qab ntawd: Singal (f) = f1 (T, A) ………………. 2) Suab nrov (f)) = f2 (R, NE, P). ……………… .. (3) Cov sib luag (2) thiab (3) sawv cev rau lub suab tau txais thiab cov suab nrov, ua rau. Cov txwv tsis pub A, R, NE, thiab P hauv ob qhov kev sib luag yog txhua qhov Function ntawm kev ua haujlwm f zaus. Yog li no, ob daim qauv hauv qab no rau kev suav qhov kev sib txig ntawm lub suab nrov-rau-suab nrov tau txais: Los ntawm ob daim qauv no, nws paub tias txhawm rau txhim kho cov teeb liab-rau-suab sib piv, nws yog qhov yuav tsum xaiv UTP nrog cov tsis zoo xws li A, R, N, P kom nce S thiab txo kom tsawg N. Cov qeb kev siab dua ntawm UTP, cov npoo ntau dua ntawm cov tsis suav saum toj no los ntawm tus nqi txwv tsis pub tshaj tus qauv, thiab nws cov haujlwm zoo dua. Txij li qee qhov tsis muaj tseeb ntawm cat5UTP tau cuam tshuam zoo heev los ntawm kev tsim kho zoo lossis ib puag ncig, thiab feem ntau tsis ua tiav raws li cov kev xav tau ntawm cov qauv xov hluav taws xob, cov lus qhia luv luv ntawm cat5UTP raug txhim kho los ntawm super-qeb 5 UTP. Yog li ntawd, supercat5 thiab cat6UTPtuaj yeem ua tau raws li lub teeb liab kom suab nrov. Txij li qhov ua tau zoo ntawm cat6UTP yog txhawj xeeb txog super cat5, thiab cat6UTP kuj tseem tuaj yeem ua tau raws li cov kev thov hauv lub network siab dua yav tom ntej, yog li ntawd, Cat6UTP thiab nws cov neeg txhawb zog txuas thiab ntsaws yuav tsum nyiam nyob rau hauv qhov xwm txheej tam sim no. Qhov no tseem nce qhov yuav tsum tau ua tiav ntawm cov kab hluav taws xob sib xyaw ua ke.
