Inkqubo yeEPON iqulathe iiyunithi ezininzi zothungelwano olubonayo (I-ONU), i-terminal yomgca wokukhanya (OLT), kunye nenethiwekhi enye okanye ngaphezulu ye-optical (jonga umfanekiso 1). Kwindlela yolwandiso, uphawu oluthunyelwe yiOLTisasazwa kubo bonkeIi-ONU. 8h Guqula ifomathi yesakhelo, chaza kwakhona inxalenye yangaphambili, kwaye wongeze ixesha kunye nokuchonga okusengqiqweni (LLID)). I-LLID ichonga nganyeI-ONUkwinkqubo yePON, kwaye iLLID icacisiwe ngexesha lenkqubo yobhaqo.
(1) Ukutshintsha
Kwinkqubo ye-EPON, umgama womzimba phakathi kwendawo nganyeI-ONUkwaye iOLTkwindlela yokuhanjiswa kolwazi enyukayo ayilingani. Inkqubo ye-EPON ngokubanzi imisela owona mgama mde phakathiI-ONUkwayeOLTyi-20km, kwaye owona mgama umfutshane yi-0km. Lo mahluko womgama uya kubangela ukulibaziseka kwahluka phakathi kwe-0 kunye ne-200 yethu. Ukuba akukho msantsa waneleyo wokuzihlukanisa, imiqondiso evela ngokwahlukileyoIi-ONUinokufikelela kwisiphelo sokufumana iOLTkwangaxeshanye, nto leyo eya kubangela ukungqubana kweempawu zomlambo. Ingxabano iya kubangela inani elikhulu leempazamo kunye nelahleko yokuvumelanisa, njl., kubangela ukuba inkqubo ingaphumeleli ukusebenza ngokuqhelekileyo. Usebenzisa indlela yokulinganisa, qala ulinganise umgama womzimba, kwaye emva koko ulungelelanise yonke intoIi-ONUkumgama ofanayo onengqiqo njengeOLT, kwaye emva koko wenze indlela ye-TDMA ukuphumeza uthintelo longquzulwano. Okwangoku, iindlela ezisetyenzisiweyo ezisetyenzisiweyo ziquka ukusasazeka kwe-spectrum, ukuphuma kwe-band kunye ne-band-in-band-opening range. Umzekelo, indlela yethegi yexesha isetyenziselwa ukulinganisa kuqala ixesha lokulibaziseka kwe-loop ukusuka kwindawo nganyeI-ONUkwiOLT, kwaye emva koko faka ulibaziseko oluthile lokulinganisa ixabiso le-Td kwinto nganyeI-ONU, ukuze ixesha lokulibaziseka kwe-loop kubo bonkeIi-ONUemva kokufaka i-Td ( Ebizwa ngokuba yi-equalization loop delay value Tequ) ziyalingana, iziphumo ziyafana naleyo nganyeI-ONUisiwa kumgama ofanayo nengqiqoOLT, kwaye ke isakhelo sinokuthunyelwa ngokuchanekileyo ngokweteknoloji ye-TDMA ngaphandle kongquzulwano. .
(2) Inkqubo yokufumanisa
IOLTufumanisa ukuba iI-ONUkwinkqubo yePON ithumela imiyalezo yeSango MPCP ngamaxesha athile. Ekufumaneni umyalezo weSango, ongabhaliswangaI-ONUiya kulinda ixesha elingenamkhethe (ukunqanda ukubhaliswa ngaxeshanye kokuphindaphindaIi-ONU), kwaye ke uthumele umyalezo Bhalisa kwiOLT. Emva kobhaliso oluyimpumelelo, iOLTyabela iLLID kwiI-ONU.
(3) I-Ethernet OAM
Emva kweI-ONUubhalise neOLT, i-Ethernet OAM kwiI-ONUiqala inkqubo yokufumanisa kwaye iseke uqhagamshelwano neOLT. I-Ethernet OAM isetyenziswa kwiI-ONU/OLTamakhonkco okufumana iimpazamo ezikude, qalisa i-loopbacks ekude, kwaye ubone umgangatho wekhonkco. Nangona kunjalo, i-Ethernet OAM inikezela ngenkxaso yee-PDU ze-OAM ezenziwe ngokwezifiso, iiyunithi zolwazi kunye neengxelo zexesha. AbaninziI-ONU/OLTabavelisi basebenzisa izandiso ze-OAM ukuseta imisebenzi ekhethekileyo yeIi-ONU. Isicelo esiqhelekileyo kukulawula i-bandwidth yabasebenzisi bokugqibela kunye nemodeli yoqwalaselo yoqwalaselo eyandisiweyo kwiI-ONU. Esi sicelo non-standard isitshixo uvavanyo kwaye iba ngumqobo intercommunication phakathiI-ONUkwayeOLT.
(4) Ukuhamba komlambo
Xa iOLTunetrafikhi yokuthumela iI-ONU, iyakuthwala ulwazi lwe-LLID yendawo ekuyiwa kuyoI-ONUkwitrafikhi. Ngenxa yeempawu zosasazo zePON, idatha ethunyelwe yiOLTiya kusasazwa kubo bonkeIi-ONU. Kufuneka siqwalasele ngokukodwa imeko apho i-traffic traffic esezantsi ihambisa imijelo yenkonzo yevidiyo. Ngenxa yobume bokusasazwa kwenkqubo ye-EPON, xa umsebenzisi elungiselela inkqubo yevidiyo, iya kusasazwa kubo bonke abasebenzisi, edla i-bandwidth esezantsi kakhulu.OLTihlala ixhasa i-IGMP Snooping. Iyakwazi ukukhangela i-IGMP Joyina imiyalezo yesicelo kwaye ithumele idatha ye-multicast kubasebenzisi abanxulumene neli qela endaweni yokusasaza kubo bonke abasebenzisi, ukunciphisa i-traffic ngale ndlela.
(5) Ukuhamba komlambo
Mnye kuphelaI-ONUinokuthumela itrafikhi ngexesha elithile. II-ONUinemigca ephambili emininzi (umgca ngamnye uhambelana nenqanaba leQoSI-ONUithumela umyalezo weNgxelo kwiOLTukucela ithuba lokuthumela, echaza imeko yomgca ngamnye. IOLTithumela umyalezo weSango ukuphendula kwiI-ONU, uxelela iI-ONUixesha lokuqala losasazo olulandelayoOLTkufuneka ikwazi ukulawula iimfuno zebandwidth kubo bonkeIi-ONU, kwaye kufuneka ibeke phambili imvume yothumelo. Ngokokubaluleka komgca kunye nokulinganisela izicelo zokuphindaphindaIi-ONU, iOLTkufuneka ikwazi ukulawula iimfuno zebandwidth kubo bonkeIi-ONU. Ulwabiwo oluguquguqukayo lwebhanwidth enyukayo (okt i-algorithm ye-DBA).
2.2 Ngokweempawu zobugcisa zenkqubo ye-EPON, imingeni yovavanyo ejongene nenkqubo ye-EPON
(1) Ukuqwalasela umlinganiselo wenkqubo ye-EPON
Nangona i-IEEE802.3ah ingachazi inani eliphezulu kwinkqubo ye-EPON, inani eliphezulu elixhaswa yinkqubo ye-EPON lisuka kwi-16 ukuya kwi-128.I-ONUukujoyina inkqubo ye-EPON kufuna iseshoni yeMPCP kunye neseshoni ye-OAM. Njengoko iisayithi ezininzi zijoyina i-EPON, umngcipheko weempazamo zenkqubo uya kwanda. Umzekelo, ngamnyeI-ONUifuna ukufumanisa inkqubo, inkqubo yokungena kwaye uqale iseshoni ye-OAM. Ngoko ke, ixesha lokubuyisela inkqubo yonke liya kwanda ngenaniIi-ONU.
(2) Ingxaki yokunxibelelana kwezixhobo
Le miba ilandelayo iqwalaselwa ikakhulu kunxibelelwano lwezixhobo:
● I-algorithm ye-dynamic bandwidth (DBA) enikezelwa ngabavelisi abahlukeneyo yahlukile.
●Abanye abavelisi basebenzisa i-OAM's “Organization Specific Elements” ukuseta iindlela zokuziphatha ezithile.
●Ukuba ngaba uphuhliso lomthetho weMPCP luyahambelana ngokupheleleyo.
●Ingaba iindlela zokulinganisa umgama eziphuhliswe ngabavelisi abohlukeneyo ziyangqinelana nokusetyenzwa kwewotshi.
(3) Iingozi ezifihliweyo ekuhanjisweni kweenkonzo zokudlala kathathu kwinkqubo ye-EPON
Ngenxa yeempawu zothumelo lwe-EPON, ezinye iingozi ezifihlakeleyo ziya kwaziswa xa kuhanjiswa iinkonzo zokudlala kathathu:
● I-Downstream ichitha i-bandwidth eninzi: Inkqubo ye-EPON isebenzisa imodi yokusasazwa kokusasazwa kwi-downstream: nganyeI-ONUuya kufumana isixa esikhulu setrafikhi esithunyelwa kwabanyeIi-ONU, ukuchitha i-bandwidth eninzi ezantsi.
●Ulibaziseko olunyukayo luninzi kakhulu: Xa iI-ONUithumela idatha kwiOLT, kufuneka ilinde ithuba lothumelo elinikezelwe nguOLT. Ngoko ke, iI-ONUKufuneka ikhusele isixa esikhulu setrafikhi enyukayo, nto leyo eya kubangela ukulibaziseka, ijitter, kunye nokulahleka kwepakethi.
3 iteknoloji yovavanyo lweEPON
Uvavanyo lwe-EPON ikakhulu lubandakanya imiba emininzi efana novavanyo lokusebenzisana, uvavanyo lweprotocol, uvavanyo lwenkqubo yokuhanjiswa kwenkqubo, inkonzo kunye nokuqinisekiswa komsebenzi. Umgangatho wovavanyo we-topology uboniswe kuMfanekiso 2. Iimveliso ze-IXIA ze-IxN2X zibonelela ngekhadi lovavanyo le-EPON elizinikeleyo, ujongano lovavanyo lwe-EPON, lunokuthi lubambe kwaye luhlalutye iiprothokholi zeMPCP kunye ne-OAM, zinokuthumela i-EPON traffic, ibonelela ngenkqubo yovavanyo oluzenzekelayo, kwaye inokunceda abasebenzisi bavavanye. DBA algorithms.
