A cikin tsarin EPON, daOLTan haɗa shi da yawaONU(Raka'o'in cibiyar sadarwa na gani) ta hanyar POS (mai raba na gani na gani). A matsayin ainihin EPON,OLTNa'urorin gani kai tsaye za su shafi aikin gaba dayan tsarin EPON na 10G.
1. Gabatarwa zuwa 10G EPON mOLTna gani module
Simmetrical na 10G EPONOLTna gani module yana amfani da uplink fashe liyafar da downlink ci gaba da watsa yanayin, wanda aka yafi amfani da Tantancewar / lantarki hira a 10G EPON tsarin.
Bangaren karɓar ya ƙunshi TIA (amplifier transimpedance), APD (Avalanche Photodiode) a 1270/1310nm, da LA guda biyu (masu haɓaka haɓakawa) a ƙimar 1.25 da 10.3125 Gbit / s.
Ƙarshen watsawa ya ƙunshi 10G EML (Laser-absorption modulation Laser) da 1.25 Gbit/s DFB (laser rarraba ra'ayi), kuma tsayin raƙuman fitarsa shine 1577 da 1490nm, bi da bi.
Da'irar tuƙi ta haɗa da da'ira ta dijital ta APC (Automatic Optical Power Control) da kuma da'irar TEC (Rayya ta Zazzabi) don kiyaye tsayayyen tsayin iska na Laser 10G. Ana aiwatar da sa ido na watsawa da karɓa ta microcomputer guntu guda ɗaya bisa ga ka'idar SFF-8077iv4.5.
Domin samun karshenOLTTsarin gani yana amfani da fashe liyafar, lokacin saitin liyafar yana da mahimmanci musamman. Idan lokacin daidaita liyafar ya daɗe, zai yi tasiri sosai a hankali, kuma yana iya haifar da fashewar liyafar ba ta aiki da kyau. Dangane da buƙatun ka'idar IEEE 802.3av, lokacin kafa 1.25Gbit / s fashe liyafar dole ne ya zama <400 ns, kuma fashewar liyafar dole ne ya zama <-29.78 dBm tare da ɗan kuskuren 10-12; da 10.3125 Gbit/s Lokacin saitin liyafar fashe dole ne ya zama <800ns, kuma fashewar hankali dole ne ya zama <-28.0 dBm tare da ɗan kuskuren 10-3.
2.10G EPON ma'auniOLTna gani module zane
2.1 Tsarin ƙira
Simmetrical na 10G EPONOLTModulu na gani ya ƙunshi triplexer (modulu ɗin fiber guda uku), watsawa, karɓa, da saka idanu. Triplexer ya ƙunshi lasers biyu da na'urar ganowa. Hasken da aka watsa da hasken da aka karɓa an haɗa su cikin na'urar gani ta hanyar WDM (Wavelength Division Multiplexer) don cimma nasarar watsa bidirectional na fiber guda ɗaya. Ana nuna tsarin sa a hoto na 1.
Bangaren watsawa ya ƙunshi lasers guda biyu, waɗanda babban aikinsu shine canza siginar lantarki na 1G da 10G zuwa sigina na gani, bi da bi, da kuma kiyaye ƙarfin ƙarfin gani a cikin rufaffiyar madauki ta hanyar da'irar dijital ta APC. A lokaci guda, microcomputer mai guntu guda ɗaya yana sarrafa girman yanayin halin yanzu don samun rabon ƙarewar da tsarin ke buƙata. Ana ƙara da'irar TEC zuwa da'irar watsawa ta 10G, wanda ke ƙarfafa ƙarfin fitarwa na laser 10G sosai. Bangaren karɓa yana amfani da APD don canza siginar fashe da aka gano zuwa siginar lantarki, kuma yana fitar da ita bayan haɓakawa da tsarawa. Don tabbatar da cewa hankali zai iya kaiwa ga madaidaicin kewayon, wajibi ne don samar da matsa lamba mai ƙarfi ga APD a yanayin zafi daban-daban. Kwamfuta mai guntu guda ɗaya ta cimma wannan burin ta hanyar sarrafa da'irar babban ƙarfin wutar lantarki ta APD.
2.2 Aiwatar da liyafar fashe mai ƙima biyu
Bangaren karɓar simmetric na 10G EPONOLTModuluwar gani yana amfani da hanyar karɓar fashe. Yana buƙatar karɓar sigina na fashe na ƙimar nau'i biyu daban-daban na 1.25 da 10.3125 Gbit / s, wanda ke buƙatar ɓangaren karɓa ya sami damar bambance siginar gani na waɗannan ƙimar mabambantan guda biyu da kyau don samun tsayayyen siginar lantarki. Tsare-tsare guda biyu don aiwatar da liyafar fashe-ƙira biyuOLTAna gabatar da kayan aikin gani anan.
Domin shigar da siginar gani yana amfani da fasaha ta TDMA (Time Division Multiple Access), ƙimar fashe haske ɗaya kaɗai zai iya kasancewa a lokaci guda. Ana iya raba siginar shigarwa a cikin yanki na gani ta hanyar 1: 2 mai rarraba na gani, kamar An nuna a cikin Hoto 2. Ko kuma yi amfani da na'urar gano sauri mai sauri kawai don canza siginar gani na 1G da 10G zuwa siginar lantarki mai rauni, sa'an nan kuma raba wutar lantarki guda biyu. sigina tare da ƙima daban-daban ta hanyar babban bandwidth TIA, kamar yadda aka nuna a hoto 3.
Makirci na farko da aka nuna a cikin Hoto 2 zai kawo wani asarar shigarwa lokacin da hasken ya ratsa ta hanyar 1: 2 mai rarrabawa na gani, wanda dole ne ya kara girman siginar shigarwa, don haka an shigar da amplifier a gaban mai rarraba na gani. Sigina na gani da aka ware daga nan ana fuskantar canjin gani / lantarki ta masu gano ƙimar ƙimar daban-daban, kuma a ƙarshe ana samun nau'ikan siginar siginar tsayayye guda biyu. Babban hasara na wannan bayani shine cewa ana amfani da amplifier na gani da 1: 2 mai rarrabawa na gani, kuma ana buƙatar masu ganowa guda biyu don canza siginar gani, wanda ya kara daɗaɗɗen aiwatarwa kuma yana ƙara farashin.
A cikin tsari na biyu da aka nuna a FIG. 3, shigarwar siginar gani kawai yana buƙatar wucewa ta hanyar ganowa da TIA don cimma rabuwa a cikin yankin lantarki. Jigon wannan bayani yana cikin zaɓin TIA, wanda ke buƙatar TIA don samun bandwidth na 1 ~ 10Gbit / s, kuma a lokaci guda TIA yana da sauri amsa a cikin wannan bandwidth. Ta hanyar ma'aunin TIA na yanzu ne kawai zai iya samun ƙimar amsa da sauri, ana iya samun garantin hankali da karɓa. Wannan bayani yana rage yawan rikitarwa na aiwatarwa kuma yana kiyaye farashi a ƙarƙashin kulawa. A cikin ainihin ƙira, gabaɗaya muna zaɓar tsari na biyu don cimma liyafar fashe-ƙira biyu.
2.3 Zane na da'irar hardware a ƙarshen karɓa
Hoto na 4 shine da'irar kayan aiki na ɓangaren fashewa. Lokacin da aka sami fashewar shigarwar gani, APD tana canza siginar gani zuwa siginar lantarki mai rauni kuma ta aika zuwa TIA. TIA tana ƙara siginar zuwa siginar lantarki na 10G ko 1G. Ana shigar da siginar lantarki na 10G zuwa 10G LA ta hanyar haɗakarwa mai kyau na TIA, kuma siginar lantarki na 1G yana shigarwa zuwa 1G LA ta hanyar haɗin kai mara kyau na TIA. Capacitors C2 da C3 sune masu haɗakarwa da ake amfani da su don cimma 10G da 1G AC mai haɗakarwa. An zaɓi hanyar haɗin AC saboda ta fi sauƙi fiye da hanyar da aka haɗa DC.
Duk da haka, haɗin AC yana da caji da fitarwa na capacitor, kuma saurin amsawa ga siginar yana tasiri ta hanyar caji da lokacin fitarwa, wato, siginar ba za a iya amsawa cikin lokaci ba. Wannan fasalin ya daure ya rasa wani adadin lokacin daidaitawar liyafar, don haka yana da mahimmanci a zabi girman girman capacitor na AC. Idan an zaɓi ƙaramin capacitor na haɗin haɗin gwiwa, za a iya rage lokacin daidaitawa, kuma siginar ta hanyar sadarwaONUa kowane lokaci ramin za a iya samun gaba ɗaya ba tare da shafar tasirin liyafar ba saboda lokacin daidaitawar liyafar ya yi tsayi da yawa da isowar ramin lokaci na gaba.
Koyaya, ƙananan ƙarfin ƙarfi zai shafi tasirin haɗin gwiwa kuma yana rage kwanciyar hankali sosai. Babban ƙarfin iya rage jinkirin tsarin kuma ya inganta ji na ƙarshen karɓa. Don haka, don yin la'akari da lokacin daidaitawar liyafar da azancin liyafar, ana buƙatar zaɓin madaidaicin haɗakar da capacitors C2 da C3. Bugu da ƙari, don tabbatar da kwanciyar hankali na siginar lantarki na shigarwa, mai haɗawa mai haɗawa da mai daidaitawa tare da juriya na 50Ω an haɗa su zuwa mummunan tashar LA.
LVPECL (Low Voltage Positive Emitter Coupling Logic) kewaye wanda ya ƙunshi resistors R4 da R5 (R6 da R7) da tushen wutar lantarki na 2.0 V DC ta hanyar fitowar siginar bambanta ta 10G (1G) LA. siginar lantarki.
2.4 Sashe na ƙaddamarwa
Bangaren watsawa na simmetric 10G EPONOLTTsarin gani ya kasu kashi biyu ne na 1.25 da 10G masu watsawa, wanda bi da bi suna aika sigina tare da tsayin 1490 da 1577 nm zuwa ƙasa. Ɗaukar ɓangaren watsawa na 10G a matsayin misali, siginar sigina daban-daban na 10G suna shiga guntu CDR (Clock Shaping), AC-haɗe zuwa guntu direban 10G, kuma a ƙarshe an shigar da shi daban a cikin laser 10G. Saboda canjin zafin jiki zai yi tasiri mai girma akan tsayin iska mai fitar da Laser, don daidaita tsayin daka zuwa matakin da ka'idar ke buƙata (ka'idar tana buƙatar 1575 ~ 1580nm), ana buƙatar daidaita aikin halin yanzu na da'irar TEC, don haka cewa za a iya sarrafa tsayin fitarwa da kyau.
3. Sakamakon gwaji da bincike
Babban alamun gwaji na 10G EPON symmetricalOLTTsarin gani ya haɗa da lokacin saitin mai karɓa, ƙwarewar mai karɓa, da watsa zanen ido. Gwaje-gwaje na musamman sune kamar haka:
(1) Karɓa lokacin saitin
Karkashin yanayin aiki na yau da kullun na fashewar ƙarfin gani na -24.0 dBm, ana amfani da siginar gani da ke fitowa ta hanyar fashe hasken a matsayin wurin farawa, kuma module ɗin yana karɓa kuma yana kafa cikakkiyar siginar lantarki azaman ƙarshen aunawa, yin watsi da lokacin jinkirin haske a cikin fiber gwajin. Auna 1G fashe lokacin saitin liyafar shine 76.7 ns, wanda ya dace da ma'aunin duniya na <400 ns; lokacin saitin liyafar 10G shine 241.8 ns, wanda kuma ya dace da ma'aunin duniya na <800 ns.
3. Sakamakon gwaji da bincike
Babban alamun gwaji na 10G EPON symmetricalOLTTsarin gani ya haɗa da lokacin saitin mai karɓa, ƙwarewar mai karɓa, da watsa zanen ido. Gwaje-gwaje na musamman sune kamar haka:
(1) Karɓa lokacin saitin
Karkashin yanayin aiki na yau da kullun na fashewar ƙarfin gani na -24.0 dBm, ana amfani da siginar gani da ke fitowa ta hanyar fashe hasken a matsayin wurin farawa, kuma module ɗin yana karɓa kuma yana kafa cikakkiyar siginar lantarki azaman ƙarshen aunawa, yin watsi da lokacin jinkirin haske a cikin fiber gwajin. Lokacin saitin liyafar fashe na 1G shine 76.7 ns, wanda ya dace da ma'aunin duniya na <400 ns; lokacin saitin liyafar 10G shine 241.8 ns, wanda kuma ya dace da ma'aunin duniya na <800 ns.
