Uvavanyo lokudibanisa inethiwekhi ye-EPON, i-GPON broadband kunye ne-OLT, i-ODN, kunye ne-ONU triple network

I-EPON（Inethiwekhi ye-Ethernet Passive Optical）

Inethiwekhi ye-Ethernet passive optical yiteknoloji ye-PON esekelwe kwi-Ethernet. Isebenzisa isakhiwo se-point ukuya kwi-multipoint kunye ne-passive fiber optic transmission, inika iinkonzo ezininzi nge-Ethernet. Iteknoloji ye-EPON imiselwe yi-IEEE802.3 EFM working group. NgoJuni 2004, iqela elisebenzayo le-IEEE802.3EFM likhuphe umgangatho we-EPON - IEEE802.3ah (wadibaniswa nomgangatho we-IEEE802.3-2005 ngo-2005).
Kulo mgangatho, ubuchwepheshe be-Ethernet kunye ne-PON zidityanisiwe, kunye neteknoloji ye-PON esetyenziswa kwi-physical layer kunye ne-Ethernet protocol esetyenziswa kwi-data link layer, kusetyenziswa i-topology ye-PON ukufikelela kwi-Ethernet. Ke ngoko, idibanisa iingenelo zobuchwepheshe be-PON kunye ne-Ethernet technology: ixabiso eliphantsi, i-bandwidth ephezulu, i-scalability enamandla, ukuhambelana ne-Ethernet ekhoyo, ulawulo olulula, njl.

I-GPON (i-PON ekwaziyo iGigabit)

Le teknoloji sisizukulwana samva nje somgangatho wokufikelela odibeneyo we-broadband passive optical osekelwe kwi-ITU-TG.984. x standard, enezibonelelo ezininzi ezifana ne-bandwidth ephezulu, ukusebenza kakuhle, indawo enkulu yokugubungela, kunye neendawo ezixineneyo zomsebenzisi. Ithathwa ngabaninzi babaqhubi njengeteknoloji efanelekileyo yokufezekisa i-broadband kunye notshintsho olupheleleyo lweenkonzo zenethiwekhi yokufikelela. I-GPON yaqala ukucetywa yi-FSAN umbutho ngoSeptemba 2002. Ngokusekelwe koku, i-ITU-T yagqiba uphuhliso lwe-ITU-T G.984.1 kunye ne-G.984.2 ngoMatshi 2003, kwaye i-G.984.3 eqhelekileyo ngoFebruwari nangoJuni 2004. Ngoko ke, usapho oluqhelekileyo lwe-GPON lwasekwa ekugqibeleni.

Itekhnoloji ye-GPON yavela kumgangatho wetekhnoloji ye-ATPON owasekwa kancinci kancinci ngo-1995, kwaye i-PON imele "i-Passive Optical Network" ngesiNgesi. I-GPON (i-Gigabit Capable Passive Optical Network) yacetywa okokuqala yintlangano ye-FSAN ngoSeptemba 2002. Ngokusekelwe koku, i-ITU-T yagqiba uphuhliso lwe-ITU-T G.984.1 kunye ne-G.984.2 ngoMatshi 2003, yaza yamiselwa i-G.984.3 ngoFebruwari nangoJuni 2004. Ngoko ke, usapho oluqhelekileyo lwe-GPON lwagqitywa ekugqibeleni. Ulwakhiwo olusisiseko lwezixhobo olusekelwe kubuchwepheshe be-GPON lufana ne-PON ekhoyo, equka i-OLT (i-Optical Line Terminal) kwiofisi ephakathi, i-ONT/ONU (i-Optical Network Terminal okanye i-Optical Network Unit) ekupheleni komsebenzisi, i-ODN (i-Optical Distribution Network) eyenziwe yi-single-mode fiber (i-SM fiber) kunye ne-passive splitter, kunye nenkqubo yolawulo lwenethiwekhi edibanisa izixhobo ezimbini zokuqala.

Umahluko phakathi kwe-EPON kunye ne-GPON

I-GPON isebenzisa iteknoloji ye-wavelength division multiplexing (WDM) ukuze ikwazi ukulayisha nokukhuphela ngaxeshanye. Ngokwesiqhelo, kusetyenziswa i-optical carrier ye-1490nm xa ikhutshelwa, ngelixa i-optical carrier ye-1310nm ikhethwa xa ikhutshelwa. Ukuba iimpawu zeTV kufuneka zidluliselwe, kuya kusetyenziswa ne-optical carrier ye-1550nm. Nangona i-ONU nganye inokufikelela kwisantya sokukhuphela se-2.488 Gbits/s, i-GPON ikwasebenzisa i-Time Division Multiple Access (TDMA) ukwabela ixesha elithile lomsebenzisi ngamnye kwisignali yexesha.

Izinga eliphezulu lokukhuphela le-XGPON lifikelela kwi-10Gbits/s, kwaye izinga lokulayisha nalo liyi-2.5Gbit/s. Ikwasebenzisa itekhnoloji ye-WDM, kwaye ubude bamaza ee-optical carriers ezisezantsi neziphezulu ziyi-1270nm kunye ne-1577nm, ngokwahlukeneyo.

Ngenxa yokwanda kwesantya sokudluliselwa, ii-ONU ezininzi zinokuhlulwa ngokwefomathi yedatha efanayo, kunye nomgama ophezulu wokugubungela ukuya kuthi ga kwi-20km. Nangona i-XGPON ingekasetyenziswa ngokubanzi okwangoku, ibonelela ngendlela elungileyo yokuphucula abaqhubi bonxibelelwano lwe-optical.

I-EPON ihambelana ngokupheleleyo neminye imigangatho ye-Ethernet, ngoko ke akukho mfuneko yokuguqulwa okanye ukufakwa kwee-capsulation xa iqhagamshelwe kwiinethiwekhi ezisekelwe kwi-Ethernet, kunye nomthwalo ophezulu we-1518 bytes. I-EPON ayifuni indlela yokufikelela kwi-CSMA/CD kwiinguqulelo ezithile ze-Ethernet. Ukongeza, njengoko ukudluliselwa kwe-Ethernet kuyindlela ephambili yokudluliselwa kwenethiwekhi yendawo, akukho mfuneko yokuguqulwa kweprotocol yenethiwekhi ngexesha lokuphuculwa kwinethiwekhi yendawo yedolophu.

Kukwakho nenguqulelo ye-Ethernet ye-10 Gbit/s ebizwa ngokuba yi-802.3av. Isantya sokwenyani somgca yi-10.3125 Gbits/s. Imo ephambili yi-uplink ye-10 Gbits/s kunye ne-downlink rate, ezinye zisebenzisa i-downlink ye-10 Gbits/s kunye ne-uplink ye-1 Gbit/s.

Inguqulelo ye-Gbit/s isebenzisa ubude be-optical obahlukeneyo kwifayibha, kunye nobude be-downstream obuyi-1575-1580nm kunye nobude be-upstream obuyi-1260-1280nm. Ke ngoko, inkqubo ye-10 Gbit/s kunye nenkqubo eqhelekileyo ye-1Gbit/s zinokudityaniswa ubude be-wavelength kwifayibha efanayo.

Ukudibanisa imidlalo emithathu

Ukudibana kweenethiwekhi ezintathu kuthetha ukuba kwinkqubo yokuvela kwinethiwekhi yonxibelelwano, inethiwekhi yerediyo nomabonwakude, kunye ne-intanethi ukuya kwinethiwekhi yonxibelelwano ye-broadband, inethiwekhi yethelevishini yedijithali, kunye ne-intanethi yesizukulwana esilandelayo, ezi nethiwekhi zintathu, ngokuguqulwa kobugcisa, zihlala zinemisebenzi yobugcisa efanayo, ububanzi beshishini elifanayo, unxibelelwano lwenethiwekhi, ukwabelana ngezixhobo, kwaye zinokubonelela abasebenzisi ngelizwi, idatha, irediyo nomabonwakude kunye nezinye iinkonzo. Ukudibana kathathu akuthethi ukuhlanganiswa okubonakalayo kweenethiwekhi ezintathu ezinkulu, kodwa ikakhulu kubhekisa ekudibaneni kwezicelo zoshishino eziphezulu.

Ukuhlanganiswa kwezi nethiwekhi zintathu kusetyenziswa kakhulu kwiinkalo ezahlukeneyo ezifana nothutho olukrelekrele, ukhuseleko lokusingqongileyo, umsebenzi karhulumente, ukhuseleko loluntu, kunye namakhaya akhuselekileyo. Kwixesha elizayo, iifowuni eziphathwayo zinokubukela iTV kwaye zivule i-intanethi, iTV inokwenza iifowuni kwaye ivule i-intanethi, kwaye iikhompyutha zinokwenza iifowuni kwaye zibukele iTV.

Ukuhlanganiswa kweenethiwekhi ezintathu kunokuhlalutywa ngokwengqiqo ukusuka kwiimbono ezahlukeneyo kunye namanqanaba, kubandakanya ukuhlanganiswa kwetekhnoloji, ukuhlanganiswa kweshishini, ukuhlanganiswa kweshishini, ukuhlanganiswa kwesiphelo, kunye nokuhlanganiswa kwenethiwekhi.

Itekhnoloji ye-Broadband

Eyona nto iphambili kwitekhnoloji ye-broadband yitekhnoloji yonxibelelwano lwe-fiber optic. Enye yeenjongo zokudibana kwenethiwekhi kukubonelela ngeenkonzo ezidibeneyo ngenethiwekhi. Ukuze kubonelelwe ngeenkonzo ezidibeneyo, kuyimfuneko ukuba neqonga lenethiwekhi elinokuxhasa ukuhanjiswa kweenkonzo ezahlukeneyo ze-multimedia (iimidiya zokusasaza) ezifana nesandi kunye nevidiyo.

Iimpawu zala mashishini zimfuno ephezulu yeshishini, ubungakanani bedatha enkulu, kunye neemfuno zomgangatho ophezulu wenkonzo, ngoko ke ngokubanzi zifuna i-bandwidth enkulu kakhulu ngexesha lokudlulisa ulwazi. Ngaphezu koko, ngokwembono yezoqoqosho, iindleko akufuneki zibe phezulu kakhulu. Ngale ndlela, ubuchwepheshe bonxibelelwano lwe-fiber optic obunamandla aphezulu kunye noluzinzileyo luye lwaba lolona khetho lubalaseleyo kwimidiya yokudlulisa ulwazi. Uphuhliso lwetekhnoloji ye-broadband, ngakumbi itekhnoloji yonxibelelwano lwe-optical, lubonelela nge-bandwidth efunekayo, umgangatho wokudlulisa ulwazi, kunye neendleko eziphantsi zokudlulisa ulwazi lweshishini olwahlukeneyo.

Njengeteknoloji ephambili kwicandelo lonxibelelwano lwanamhlanje, iteknoloji yonxibelelwano lwe-optical ikhula ngesantya sokukhula okuphindwe kalikhulu rhoqo emva kweminyaka eli-10. Uthumelo lwe-fiber optic olunamandla amakhulu lulona qonga lifanelekileyo lothumelo "lweenethiwekhi ezintathu" kunye nomthwali oyintloko wendlela yolwazi yexesha elizayo. Itekhnoloji yonxibelelwano lwe-fiber optic enomthamo omkhulu isetyenziswa kakhulu kwiinethiwekhi zonxibelelwano, iinethiwekhi zekhompyutha, kunye neenethiwekhi zosasazo kunye nomabonwakude.