1.Isakhiwo esiyisisekelo se-PON
I-PON (Inethiwekhi ye-Passive Optical)
I-PON iyinethiwekhi yokufinyelela ye-fiber eyodwa ene-bidirectional optical esebenzisa isakhiwo se-point-to-multipoint (P2MP).Uhlelo lwe-PON lwakhiwe itheminali yomugqa obonakalayo (OLT), inethiwekhi yokusabalalisa optical (ODN), kanye neyunithi yenethiwekhi yokubona (ONU) ohlangothini lomsebenzisi wehhovisi elimaphakathi, futhi iwuhlelo lwe-fiber eyodwa bidirectional.Ngaphansi komfula (OLT kuya ku-ONU), isignali ethunyelwa yi-OLT ifinyelela ku-ONU ngayinye nge-ODN.Ehlangothini elikhuphuka nomfula (ONU ukuya ku-OLT), isignali ethunyelwa i-ONU izofinyelela kuphela ku-OLT futhi ngeke ifinyelele kwamanye ama-ONU. .Ukuze kugwenywe ukungqubuzana kwedatha futhi kuthuthukiswe ukusebenza kahle kwenethiwekhi, i-uplink direction isebenzisa imodi yokufinyelela eminingi ye-TDMA, futhi ilawula ukudluliswa kwedatha ye-ONU ngayinye.I-ODN ihlinzeka ngamashaneli okubona phakathi kwe-OLT ne-ONU.Ukwakheka kwereferensi ye-PON kuboniswe esithombeni esingezansi.
Isakhiwo senkomba yesistimu ye-PON
I-OLT itholakala ohlangothini lwenethiwekhi futhi ibekwe ehhovisi eliphakathi.Kungaba i-L2 switch noma i-L3 router, ehlinzeka ngokugxila kwenethiwekhi nokufinyelela, okuvumela ukuguqulwa kwe-optical/electrical, ukwabiwa komkhawulokudonsa, nokulawula ukuxhumana kwesiteshi ngasinye, ngokuqapha nokuphathwa kwesikhathi sangempela.Nemisebenzi yesondlo.I-ONU ibekwe ngasohlangothini lomsebenzisi ukuze iqalise ukucubungula nokuphathwa kwezimpawu zikagesi ezihlukahlukene, futhi inikeza isixhumi esibonakalayo sohlangothi lomsebenzisi.I-OLT kanye ne-ONU zixhunywe isihlukanisi sokubona esinganyakazi, futhi isihlukanisi sokubona sisetshenziselwa ukusabalalisa idatha ye-downlink kanye nokuhlanganisa idatha ye-uplink.Ngokungeziwe kumishini yokugcina, uhlelo lwe-PON aludingi izingxenye zikagesi ngakho-ke alusebenzi.
I-PON isebenzisa ubuchwepheshe be-wavelength division multiplexing (WDM) enenhlanganisela ye-downlink engu-1490 nm/uplink 1310 nm ye-wavelength ku-fiber eyodwa.Ukuqondisa kwe-uplink kuyimodi yokukhomba-kuya-iphuzu, futhi isiqondiso se-downlink imodi yokusakaza.Isibalo esingezansi sibonisa isakhiwo esiyisisekelo se-PON.
Isakhiwo senethiwekhi esiyisisekelo se-PON
Ngaphansi komfula, i-OLT idlulisela amaphakethe edatha kuwo wonke ama-ONU ngendlela yokusakaza, iphakethe ngalinye liphethe unhlokweni onokudlulisela kusihlonzi se-ONU okuyiwa kuso.Lapho iphakethe ledatha lifika ku-ONU, ungqimba lwe-MAC lwe-ONU lwenza ukulungiswa kwekheli, lukhiphe iphakethe ledatha okungelalo, futhi lilahle amanye amaphakethe edatha.
Isiqondisindlela se-uplink sisebenzisa ubuchwepheshe be-Time Division Multiplexing (TDM), futhi ulwazi lwe-uplink lwama-ONU amaningi luhlanganisa ukusakazwa kolwazi lwe-TDM okufanele ludluliselwe ku-OLT.
2.Itheminali yomugqa we-Optical (OLT)
Itheminali ye-optical line (OLT) isebenza ukuze inikeze isixhumi esibonakalayo esibonakalayo phakathi kwenethiwekhi yesevisi ne-ODN, futhi inikeza izindlela ezihlukahlukene zokudlulisa amasevisi ahlukahlukene.I-OLT ngaphakathi yakhiwe isendlalelo esiwumgogodla, isendlalelo sesevisi, kanye nesendlalelo somphakathi.Isendlalelo sesevisi ngokuyinhloko sihlinzeka ngamachweba wesevisi futhi sisekela izinsizakalo eziningi;isendlalelo esiyinhloko sihlinzeka ngokuxhumanisa, ukuphindaphinda, nokudlulisa;futhi isendlalelo somphakathi sihlinzeka ngemisebenzi yokuphatha ukuphakelwa kukagesi kanye nokugcinwa kokulungisa.
Ukuba khona kwe-OLT kunganciphisa ukuhlanganisa okuqinile phakathi kwenethiwekhi yesevisi yongqimba olungaphezulu kanye nesixhumi esibonakalayo esithile, umphathi, inethiwekhi, nokuphathwa kwedivayisi yedivayisi yokufinyelela, futhi kunganikeza isixhumi esibonakalayo sokuphathwa kwenethiwekhi yokufinyelela okuhlangene.
Imisebenzi eyinhloko ye-OLT ihlanganisa: umsebenzi wokusabalalisa ukuhlanganisa kanye nomsebenzi wokujwayela i-DN.
Imisebenzi yokusebenzelana yesevisi ye-OLT ihlanganisa: umsebenzi wembobo yesevisi, umsebenzi wokujwayela isixhumi esibonakalayo, ukucutshungulwa kokusayinda isixhumi esibonakalayo, nokuvikela isixhumi esibonakalayo.
Imisebenzi evamile ye-OLT ikakhulukazi ihlanganisa imisebenzi ye-OAM nemisebenzi yokuphakela amandla.
Amandla okubona akhishwa ku-OLT asetshenziswa kakhulu ezindaweni ezilandelayo.
I-Splitter: Uma inani elikhulu lama-shunts, liba likhulu ukulahlekelwa.
l I-Fiber: Uma ibanga elide, ukulahlekelwa okukhulu.
l I-ONU: Uma inombolo enkulu, amandla okudlulisa e-OLT adingeka kakhulu.Ukuze kuqinisekiswe ukuthi amandla ngamunye afinyelela ku-ONU angaphezulu kokuzwela okutholayo futhi anomkhawulo othile, isabelomali kufanele sisekelwe enanini langempela kanye nokusatshalaliswa kwendawo.
Inethiwekhi yokusabalalisa ye-3.Optical
Inethiwekhi yokusabalalisa okubonakalayo (i-ODN) iyindlela yokuhlinzeka ngokudluliswa kwe-optical phakathi kwe-OLT ne-ONU.Umsebenzi wayo oyinhloko ukuqedela ukudluliswa kolwazi nokusabalalisa phakathi kwe-OLT ne-ONU, nokusungula isiteshi sokudlulisa ulwazi esisuka ekupheleni siye ekupheleni phakathi kwe-ONU ne-OLT.
Ukucushwa kwe-ODN kuvame ukuba yi-point-to-multipoint, okungukuthi, ama-ONU amaningi axhunywe ku-OLT eyodwa nge-ODN eyodwa, ukuze ama-ONU amaningi akwazi ukwabelana ngendlela yokudlulisela optical phakathi kwe-OLT ne-ODN kanye nedivayisi ye-optoelectronic ye-OLT. .
(1) Ukwakhiwa kwe-ODN
Izingxenye eziyinhloko ze-passive ezakha i-ODN yilezi: intambo ye-fiber enemodi eyodwa kanye nentambo ye-fiber optic, izixhumi, izihlukanisi ze-passive optical (OBD), izixhumi ze-passive optical, nezixhumi ze-fiber optic.
(2) Isakhiwo se-Topological se-ODN
I-topology yenethiwekhi ye-ODN ngokuvamile iyisakhiwo se-point-to-multipoint, esingahlukaniswa sibe yinkanyezi, isihlahla, ibhasi, nendandatho.
Isakhiwo senethiwekhi ye-ODN
(3) Izilungiselelo zokuvikela okusebenzayo nokubekwe eceleni
Isethingi yokuvikela esebenzayo/ebekwe eceleni yenethiwekhi ye-ODN iwukumisa amashaneli amabili okudlulisa amehlo kumasignali okubona asakazwa yinethiwekhi ye-ODN.Uma isiteshi esiyinhloko sihluleka, singashintshela kwesinye isiteshi ngokuzenzakalelayo ukuze sidlulise amasignali okubona, okuhlanganisa ama-optical fibers, ama-OLT, ama-ONU, kanye nezilungiselelo zokuvikela eziyisisekelo neziyisipele zefayibha yokudlulisela.
Imicu yokudlulisa eyinhloko nebekwe eceleni ingaba kukhebula yokubona efanayo noma kumakhebula okubona ahlukene.Izintambo ezibonakalayo neziyisipele zingafakwa kumapayipi ahlukene, ukuze ukusebenza kokuvikela kube ngcono.
(4) Izici zokudlulisa amehlo ze-ODN
Izici zokuklama ze-ODN kufanele ziqinisekise ukuthi noma iyiphi isevisi ebonwayo okwamanje inganikezwa ngaphandle kwezinguquko ezinkulu, imfuneko enomthelela omkhulu ezicini zezingxenye ezihlukahlukene zokungenzi lutho.Izidingo ezingase zithinte ngokuqondile izici ze-optical ze-ODN zimi kanje.
l Ukubonakala kwe-Optical wavelength: Izingxenye ezihlukahlukene ze-optical passive akufanele zithinte ukucaca kwesiginali ye-optical edlulisiwe.Isignali yokubona edingwa inethiwekhi ye-optical eklanyelwe kufanele idluliselwe ngokusobala, ngaleyo ndlela inikeze izinhlelo zokusebenza zesistimu ye-WDM yesikhathi esizayo.Isisekelo.
l Ukubuyisela emuva: Uma okukhiphayo nokokufaka kwenethiwekhi ye-ODN kushintshaniswa, izici zokudlulisela zenethiwekhi ye-ODN akufanele zishintshe kakhulu, okungukuthi, ukuguqulwa komkhawulokudonsa wokudlulisela kanye nezici zokulahlekelwa kwe-optical kufanele kube kuncane.Lokhu kwenza idizayini yenethiwekhi ibe lula.
l Ukuvumelana kokusebenza kwenethiwekhi: Inethiwekhi ye-ODN kufanele igcine amasiginali abonakalayo angashintshi.Izici zokudlulisela zenethiwekhi ye-ODN kufanele zihambisane nayo yonke i-OFSAN nayo yonke inethiwekhi yokuxhumana.Umkhawulokudonsa wokudlulisa kanye nezici zokulahleka kokubona kufanele zilungele yonke i-OFSAN.
(5) Imingcele yokusebenza kwe-ODN
Amapharamitha anquma ukusebenza kokulahleka kwesiteshi esibonakalayo sayo yonke isistimu ikakhulukazi alandelayo.
l Ukulahleka kwesiteshi esibonakalayo se-ODN: umehluko phakathi kwamandla amancane okudlulisela kanye nokuzwela okuphezulu kakhulu kokuthola.
l Ubukhulu bokulahlekelwa kwesiteshi okuvunyelwe: umehluko phakathi kwamandla okudlulisa aphezulu kanye nokuzwela kokwamukela okuphezulu kakhulu.
l Isilinganiso esincane esivunyelwe sokulahlekelwa kwesiteshi: umehluko phakathi kwamandla amancane okudlulisela kanye nokuzwela okuphansi kokuthola (iphoyinti lokugcwala).
(6) Ukubonakaliswa kwe-ODN
Ukubonakaliswa kwe-ODN kuncike ekubuyiselweni kokulahlekelwa kwezingxenye ezihlukahlukene ezakha i-ODN nanoma yimaphi amaphuzu okubonisa esiteshini sokukhanya.Ngokuvamile, yonke imidwebo ehlukene kufanele ibe ngcono kunaleyo−35 dB, kanye nokuboniswa okuphezulu okuhlukene kokufinyelela kwefayibha kufanele kube ngcono kuno−50db.
4. Iyunithi yenethiwekhi ye-Optical (ONU)
Iyunithi yenethiwekhi yokubona (i-ONU) itholakala phakathi kwe-ODN nempahla yomsebenzisi, futhi inikeza isixhumi esibonakalayo esibonakalayo phakathi komsebenzisi ne-ODN kanye nesixhumi esibonakalayo sikagesi esinohlangothi lomsebenzisi ukuze kusetshenziswe ukuphathwa nokugcinwa kokugcinwa kwezimpawu ezihlukahlukene zikagesi.I-ONU yakhiwe isendlalelo esiyinhloko, isendlalelo sesevisi, kanye nesendlalelo somphakathi.Isendlalelo sesevisi ngokuyinhloko sibhekisela kumachweba wabasebenzisi;isendlalelo esiyinhloko sihlinzeka nge-multiplexing kanye ne-optical interfaces;kanye nesendlalelo somphakathi sihlinzeka ngokuphakelwa kukagesi kanye nokuphathwa kokulungisa.
5. Imodi yesicelo se-PON
Ukucaca kwebhizinisi le-PON kuhle, futhi ngokomthetho kungasetshenziswa kunoma iyiphi isignali esezingeni kanye nesilinganiso.Uma kuqhathaniswa ne-point-to-point amanethiwekhi optical asebenzayo, ubuchwepheshe be-PON bubonakala ngokulungiswa okulula, izindleko eziphansi (ukugcina i-fiber ne-optical interfaces), umkhawulokudonsa ophezulu wokudlulisa kanye nenani eliphezulu lentengo yokusebenza.Lezi zici zizoyenza igcine inzuzo yokuncintisana isikhathi eside, futhi i-PON ibilokhu ithathwa njengesiqondiso sokuthuthukiswa kwesikhathi esizayo senethiwekhi yokufinyelela.
Isicelo esifaneleke kakhulu se-PON yilesi: ingxenye yenethiwekhi yokufinyelela eduze nokuphela kwekhasimende;ikhasimende lensizakalo ye-ONU aligcizeleli isidingo sokuchithwa kabusha noma ukuvikelwa kokudlula;i-OLT ingasethwa endaweni esebenza kahle yokusinda (isibonelo, i-node enokuvikelwa kokuzungeza).Indawo lapho abasebenzisi bagxile khona ngokwendawo.I-PON ikakhulukazi inezinhlobo ezintathu zohlelo lokusebenza.
(1) Shintshanisa inethiwekhi yokuhlanganisa enezendlalelo ezimbili ekhona: I-PON ingangena esikhundleni seswishi ye-Layer 2 ekhona kakade kanye ne-optical transceiver, futhi iqondise inethiwekhi yokufinyelela ye-LAN kunethiwekhi yendawo yedolobha elikhulu lase-IP, njengoba kuboniswe esithombeni:
I-PON ingena esikhundleni senethiwekhi Yesendlalelo sesi-2 esikhona
(2) Shintshanisa ikhebula yokungena yendima efanele: Isistimu ye-PON ingangena esikhundleni sengxenye ekhona yekhebula yokubona kanye nemishini yokushintsha i-optical, ngaleyo ndlela ilondoloze intambo yokufinyelela yendima efanele, njengoba kubonisiwe:
I-PON ithatha indawo yamasegimenti afanelekile ukuze ufinyelele ikhebuli yokubona
(3) Imodi yokufinyelela yezinsizakalo eziningi (ukusebenzisa i-FTTH): Uhlelo lwe-PON lunganikeza ukufinyelela kwezinsizakalo eziningi kanye nezilinganiso eziningi ezihlangabezana nezimfuneko ezihlukene ze-QoS, futhi lingakwazi ukuzivumelanisa nokuhlukahluka kwabasebenzisi kanye nokungaqiniseki kokuthuthukiswa kwebhizinisi, njengoba kuboniswe ku- umfanekiso olandelayo:
Ukufinyelela kwezinsiza eziningi