Njengendlela yonxibelelwano esebenzayo esoloko isetyenziswa.I-EPON isetyenziswe ngabasebenzisi ukuxhuma kwinethiwekhi yokufikelela.Kulo phepha, iteknoloji ephambili ye-EPON ichazwe ngokufutshane, kwaye ukusetyenziswa kwe-EPON kunxibelelwano lwe-optical kwaziswa ngokubanzi, kwaye umgaqo wayo wobugcisa uhlalutywa.
1.Iiintshayeleloye EPON
I-PON yi-contraction ye-Passive Optical Network, eyi-teknoloji yokufikelela kwi-optical eyenzelwe ukuxhasa i-point-to-multipoint applications.I-PON iqukethe i-Optical Line Terminal (OLT), i-Optical Network Unit (ONU) kunye ne-Optical Distribution Network (ODN) .Its uphawu olubalulekileyo kukuba iODN yonke yenziwe ngezixhobo zokwenziwa, kwaye umqondiso usasazwe ukusuka kwifayibha ebonakalayo ekwabelwana ngayo kumsebenzisi ngamnye ngokuqhekeza.Le nkqubo ibizwa ngokuba yiNethiwekhi yePassive Optical kuba yahlukile kunxibelelwano lwemveli phakathi Iofisi kunye nomxhasi, kunye nomthombo izixhobo zombane ziphakathi kolu fikelelo lwenethiwekhi.Ukongezelela kwiingenelo zokugcina izibonelelo zefayibha, i-PON ingenza lula kakhulu ukusebenza kunye nokugcinwa kwenkqubo yenethiwekhi, esebenza kakhulu ekunciphiseni iindleko zokwakha nokusebenza.Ngaphezu koko , Isakhiwo seendaba ezicocekileyo ze-optical media kunye ne-transparent optical fiber broadband network iqinisekisa ukhuseleko lobugcisa bokwandiswa kweshishini elizayo.
Iteknoloji ye-EPON idibanisa iteknoloji ye-Ethernet kunye neteknoloji ye-PON ukuqonda i-point-to-multipoint high-speed Ethernet fiber access ngendlela elula.I-point-to-multipoint topology yindlela yesakhiwo esamkelwe yi-EPON, ngelixa imodi yosasazo isetyenziselwa i-downlink. kunye nemowudi ye-TDMA isetyenziselwa umgca, onokuqonda ukuhanjiswa kwedatha ngeendlela ezimbini.
2.Ukwenziwa kweEPON
Njengobuchwepheshe bokufikelela kwi-fiber point-to-multipoint, i-Passive Optical Network (i-PON) iqulethe i-Optical Line Terminal (OLT), i-Unit-side Optical Network Unit (ONU) kunye ne-Optical Distribution Network (ODN).
2.1 OLT
Amaxesha amaninzi, iOLT ibekwe kwigumbi eliphakathi koomatshini.Ibonelela nge-fiber optical excuse ye-passive optical network kwicala elisezantsi, i-GE, i-10baes-t, i-100base-t, i-10gbase-x kunye nolunye ujongano oluya phezulu, kwaye i-OLT ixhasa ujongano lwe-EI ukuqonda ukufikelela kwelizwi le-TDM.
2.2 ONU/ONT
I-ONU/ONT ibekwe kwisiphelo somsebenzisi, ikakhulu isebenzisa i-Ethernet protocol ukuqonda ukudluliselwa okucacileyo kwedatha yomsebenzisi.Idatha ingathunyelwa phakathi kweOLT kunye ne-ONU.
2.3 ODN
Njengesebe lefiber ye-passive, i-ODN idibanisa izixhobo ze-OLT kunye ne-ONU.Umsebenzi oyintloko we-ODN kukusabalalisa idatha ye-downlink kunye ne-centralise data ye-uplink.Ngenxa yokuba i-passive operation, i-passive splitter deployment iguquguquka kakhulu kwaye ifanelekile kwiindawo ezininzi.Ngokwengqiqo eqhelekileyo, i-POS nganye inezinga lokuhlukana kwe-8, i-16, i-32 okanye 64, kwaye inokudityaniswa kumanqanaba amaninzi.
3.Iintshayeleloof key tubugcisaof EPON
3.1Dbasfor dngamandlabnobubanziaulwabiwo
Ixesha langempela (ms/us magnitude) litshintsha i-uplinking bandwidth mechanism ye-OUN nganye kwi-EPON, eyaziwa ngokuba yi-algorithm yolwabiwo lwe-bandwidth.Kwi-EPON, ukuba i-bandwidth yabelwe ngokwezibalo, ngoko ke inkonzo yesantya sothumelo lonxibelelwano lwedatha ayifanelekanga kakhulu. i-bandwidth yabelwe i-statically kwi-peak speed, yonke i-bandwidth yenkqubo iya kuphelelwa ngexesha elifutshane.Izinga le-W bandwidth aliphezulu, ngakolunye uhlangothi, ulwabiwo lwe-bandwidth oluguquguqukayo luya kuphucula ukusetyenziswa kwe-bandwidth yenkqubo.Iimfuno zenkonzo ngokukhawuleza ze-ONU inokuphunyezwa yi-DBA.Ukulungelelaniswa kwe-bandwidth ye-Dynamic phakathi kwe-ONU inokuphucula ukusebenza kakuhle kwe-PON yomgca we-bandwidth.Ngenxa yokuphuculwa kwe-bandwidth yokusetyenziswa kwe-bandwidth, abasebenzisi abaninzi be-W banokongezwa kwi-PON ekhoyo, kunye nexabiso lencopho ye-bandwidth abasebenzisi be-W abanokufikelela kuyo inokuthelekiswa okanye nokuba. ugqithise umda wendlela yokwabiwa kweyunifomu yesiNtu.
Ulawulo oluphakathi yindlela yolwabiwo lwebhanwidth eguquguqukayo.Le ndlela yeyonke imiyalezo ye-ONU ye-uplink, isetyenziswe kwi-OLT ye-bandwidth, ngoko i-OLT ngokwesicelo sogunyaziso lwe-ONU ngokuhambelana ne-algorithm efanelekileyo ye-broadband ebalwe kwi-W.The Ingcamango esisiseko ye-algorithm yeendlela zolwabiwo kukuba i-ONU lee uplink nganye inokwahlula ixesha lokusasazwa kokufika kweseli kunye nokucela i-bandwidth.Ngokuvumelana nesicelo se-ONU nganye, i-OLT yabela i-bandwidth ngokufanelekileyo nangengqiqo, kwaye iphatha ukugqithiswa kokusebenza, ikhowudi yempazamo yolwazi, iseli. ilahleko, njl.
3.2Phinda usebenzise itekhnoloji yesitishi se-uplink
Okwangoku, ukuphunyezwa okuphambili kuluhlu lwexesha lokuphindaphinda ukufikelela kwi-multiplexing (TDMA), enokusetyenziswa ngexesha elifanayo le-slot time division multiplexing, i-statistical time division multiplexing access multiplexing, access random and so on.Nangona kunjalo, M - ixesha - ixesha le-slot. - i-multiplexing yokwahlula inezinye iintsilelo.Ngokomzekelo, xa ezinye zezithuba zexesha zingasetyenziswanga, zihlala kwi-bandwidth ethile, ukwenzela ukuba ukulungelelaniswa kwenkonzo yokuqhuma okuphezulu akunamandla ngokwaneleyo.I-ONU idinga ukuvumelanisa kunye nezinye iindlela zokufikelela ngokungaqhelekanga ngaphandle ixesha elithile lokufikelela.Ngoko ke, ulwahlulo lwexesha lezibalo ubuninzi bokufikelela kwi-multiplexing ngokuqhelekileyo kusetyenziswa emva kokuthelekisa ukunqongophala kwezinto ezimbini.Xa isignali ye-uplink idluliswa, isakhelo se-Ethernet sithunyelwa kwixesha lexesha apho i-ONU yabelwe khona, kunye nobukhulu idatha enikezelwe yi-statistical multiplexing isetyenziselwa ukutshintsha ubungakanani bexesha eliqingqiweyo.
3.3 Itekhnoloji yembuyekezo ye-OLT esukela kunye nokulibaziseka kunye ne-ONU plug-and-play technology
Ngenxa yokuba umjelo onyukayo we-EPON USEBENZISA i-TDMA, ukufikelela kwamanqaku amaninzi kwenza ukulibaziseka kwesakhelo sedatha ye-ONU nganye yahluke, ngoko ke itekhnoloji yembuyekezo esukela kunye nokulibaziseka yaziswa ukunqanda ukungqubana kwedatha kwisizinda sexesha.Ukuze ugweme ukungqubana kwexesha. idatha yesizinda, umlinganiselo womgama kunye nexesha leteknoloji yembuyekezo yokulibaziseka kufuneka isetyenziswe ukuvumelanisa yonke i-gap yexesha lomnatha.Ngale ndlela, iipakethi zifika kwixesha elichaziweyo ngokuhambelana ne-algorithm ye-DBA kunye neplagi yenkxaso kunye nokudlala kwi-ONU.Ukulinganisa umgama ukusuka kwindawo nganye. I-ONU ukuya kwi-OLT ngokuchanekileyo kunye nokulungelelanisa ukulibaziseka kokuthunyelwa kwe-ONU ngokuchanekileyo kunokunciphisa ixesha phakathi kokuthumela iWindows ye-ONU, ukuphucula ukusetyenziswa kweshaneli ye-uplink kunye nokunciphisa ukulibaziseka.Uluhlu lwe-EPON luqalisiwe kwaye lugqitywe ngexesha elifanayo ukuba i-OLT idlula, ukuphawula kwangelo xesha linye ukuba iplagi kunye nomdlalo we-ONU ufunyenwe.
3.4Ukuthumela kunye nokufumana iimpawu ezigqabhukileyo
Ekubeni isignali yokuqhuma kwe-ONU nganye ifunyenwe yi-OLT, i-OLT idinga ukuqonda ukulungelelaniswa kwesigaba kwithuba lexesha kwaye emva koko ifumane idatha.Oku kufuna ukusetyenziswa kwezixhobo ze-optical ezikwazi ukuxhasa iimpawu zokuqhuma kwi-ONU kunye ne-OLT.Izixhobo ezininzi ezibonakalayo azikwazi ukuhlangabezana le mfuneko, kunye nenani elincinci lezixhobo ze-optical mode zokuqhuma zinesantya sokusebenza malunga ne-155M, ethe kratya kwixabiso eliphezulu.Ngoko ke, ukuze kuqatshelwe imo yokuqhuma ngokufanelekileyo, iindlela ezikhethekileyo zisetyenziselwa ukuphela kokufumana.I-optical burst transmission circuit kufuneka ikwazi ukuvala kwaye ivule ngokukhawuleza kwaye imise izibonakaliso ngokukhawuleza.Ngoko ke, imodyuli yokuguqula i-electro-optical yendabuko usebenzisa ulawulo lwamandla oluzenzekelayo kunye nengxelo ayisafanelekanga ukusetyenziswa, kodwa ifuna i-lasers ngempendulo ekhawulezayo. isiphelo sokufumana sifumana isiginali yokukhanya amandla omsebenzisi ngamnye yahlukile kwaye iyaguquguquka ngakumbi.Ngoko ke, kwisekethe yokufumana ukuqhuma, inqanaba lokufumana (umqobo) kufuneka lilungiswe rhoqo xa kufunyanwa isiginali entsha.
4.Ukusetyenziswa konxibelelwano lwefiber optic kwiseli
I-ONU inokumiselwa kwicala lomxhasi (FTTH) okanye kwipaseji (FTTB), kodwa oku kwimeko yofikelelo iiseli.Kwimo ye-FTTH, inani labasebenzisi aliqinisekanga.Kule meko, ukwenzela ukuba kuphuculwe izinga lokusetyenziswa kwezixhobo, ukunciphisa iindleko kunye nokuququzelela ukugcinwa.Ukumiselwa kwe-optical divider kugxininiswe ngokulinganayo, kunye nokusetyenziswa kwenqanaba lokusabalalisa ukukhanya, ukusetwa kwendawo yezinto ezininzi kwikhompyutheni. igumbi loluntu okanye loluntu ngaphakathi kwibhokisi yonikezelo olukhanyayo.Emva kokwakhiwa ngendlela enjalo, kungakhathaliseki ukuba inani labasebenzisi landa okanye liyancipha, ukusetyenziswa kwezixhobo kunokunyuswa.Nangona kunjalo, xa inani labasebenzisi likhulu, imfuno yokufikelela kwi-fiber optical iya kwandisa kakhulu.Ngeli xesha kwimodi ye-FTTB, i-OMU ibekwe kwi-corridor, kwaye i-optical splitter ibekwe ngendlela efanayo ne-FTTH.Le ndlela yokufikelela ngokuqhelekileyo iqhutyelwa kwi-corridor switch.
Ukuqukumbela
Itekhnoloji ye-EPON ineenzuzo ezininzi, ezifana nokugubungela ngokubanzi kwabasebenzisi, isantya esiphezulu sokunyuka nokwehla, iimpawu zokuhanjiswa kwe-optical ezisebenzayo, ukonga izixhobo zefiber ukusuka kwindawo ukuya kwi-multi-point networking njalo njalo.Ngedatha yelizwi, ividiyo eneenkonzo ezininzi kunye nomphathiswa. -Umsebenzi wenqanaba elichongiweyo loyilo lobugcisa, kodwa likwane-passive, akukho ugcino lwamandla emitha ye-electromagnetic kunye neempawu zokhuselo lokusingqongileyo.Njengetekhnoloji yonxibelelwano olubonakalayo, itekhnoloji ye-EPON ibaluleke kakhulu.Njengenye yeetekhnoloji eziphambili kwixesha elizayo, itekhnoloji yeEPON ineempawu ukuguquguquka okuqinileyo kwimeko yokusasazwa, ukuthembeka okuphezulu kunye nokugcinwa ngaphandle kokugcinwa, kuba lolona khetho lungcono kulwakhiwo lwesizukulwana esilandelayo sothungelwano lokufikelela kwibroadband.