Sistemụ EPON nwere ọtụtụ ngalaba netwọkụ anya.ONU), ọdụ ụgbọ mmiri anya (OLT), na otu netwọkụ anya ma ọ bụ karịa (lee foto 1). N'ebe ndọtị ahụ, mgbama zitere site naOLTna-agbasa ozi niileONU. 8h Gbanwee usoro etiti, kọwapụta akụkụ ihu, wee tinye oge na njirimara ezi uche (LLID)). LLID na-achọpụta nke ọ bụlaONUna usoro PON, na LLID akọwapụtara n'oge usoro nchọpụta.
(1) Na-agba ọsọ
Na usoro EPON, anya anụ ahụ n'etiti nke ọ bụlaONUna nkeOLTn'usoro mgbasa ozi nke elu adịghị nhata. Usoro EPON izugbe na-akọwa na ogologo kacha ogologo n'etitiONUnaOLTbụ 20km, ebe kacha nso bụ 0km. Ọdịiche dị anya a ga-eme ka igbu oge dị iche n'etiti 0 na 200 anyị. Ọ bụrụ na enweghi oghere dịpụrụ adịpụ zuru oke, akara si dị iche icheONUnwere ike iru na-anata ọgwụgwụ nkeOLTn'otu oge ahụ, nke ga-ebute esemokwu nke mgbama elu. Esemokwu ahụ ga-eme ka ọnụ ọgụgụ dị ukwuu nke njehie na nkwụsị mmekọrịta, wdg, na-eme ka usoro ahụ ghara ịrụ ọrụ nke ọma. Iji usoro nsonye, buru ụzọ tụọ anya nke anụ ahụ, wee mezie ihe niileONUna otu ezi uche anya dị kaOLT, wee rụọ usoro TDMA iji nweta mgbanarị esemokwu. Ka ọ dị ugbu a, usoro ndị a na-eji eme ihe na-agụnye ịgbasa-dị iche iche nkewa, nke na-apụ apụ na windo imeghe n'ime band. Dịka ọmụmaatụ, a na-eji usoro akara mkpado oge na-ebu ụzọ tụọ oge igbu oge nke ọ bụla site na nke ọ bụlaONUkaOLT, wee fanye kpọmkwem nha nhata Td uru maka nke ọ bụlaONU, nke mere na loop na-egbu oge oge niileONUmgbe itinye Td (A na-akpọ equalization loop delay value Tequ) hà nhata, nsonaazụ ya yiri nke ọ bụlaONUa na-akwaga n'otu ebe ezi uche dị na yaOLT, na mgbe ahụ enwere ike izipu etiti ahụ nke ọma dịka teknụzụ TDMA na-enweghị esemokwu. .
(2) Usoro nchọpụta
NkeOLTna-achọpụta naONUna sistemụ PON na-eziga ozi MPCP Gate kwa oge. Mgbe enwetara ozi Gate, ndị edebanyeghị ahaONUga-echere oge enweghị usoro (iji zere ndebanye aha nke otutu n'otu ogeONU), wee zipu ozi ndekọ naOLT. Mgbe ịga nke ọma ndebanye aha, naOLTna-ekenye LLID naONU.
(3) Ethernet OAM
MgbeONUedebanyela aha naOLT, Ethernet OAM naONUna-amalite usoro nchọta wee guzobe njikọ naOLT. A na-eji Ethernet OAM eme iheONU/OLTnjikọ ịchọta mperi ndị dịpụrụ adịpụ, kpalite loopbacks dịpụrụ adịpụ, yana chọpụta ogo njikọ. Agbanyeghị, Ethernet OAM na-enye nkwado maka OAM PDU ahaziri ahazi, nkeji ozi na akụkọ oge. ỌtụtụONU/OLTndị na-emepụta na-eji OAM extensions ka ịtọ ọrụ pụrụ iche nkeONU. Ngwa a na-ahụkarị bụ ijikwa bandwit nke ndị ọrụ njedebe na ụdị bandwit nhazi gbasaa n'imeONU. Ngwa a na-abụghị ọkọlọtọ bụ igodo maka ule ahụ wee bụrụ ihe mgbochi na mmekọrịta n'etitiONUnaOLT.
(4) Ọgbara mgbada
MgbeOLTnwere okporo ụzọ izipuONU, ọ ga-ebu ozi LLID nke ebe a na-agaONUna okporo ụzọ. N'ihi njirimara mgbasa ozi nke PON, data zitereOLTa ga-agbasa ozi nye mmadụ niileONU. Anyị ga-atụlerịrị ọnọdụ ebe okporo ụzọ mgbada na-ebufe iyi ọrụ vidiyo. N'ihi ọdịdị mgbasa ozi nke usoro EPON, mgbe onye ọrụ na-ahazi mmemme vidiyo, a ga-agbasa ya na ndị ọrụ niile, nke na-eri bandwidth ala nke ukwuu.OLTna-akwado IGMP Snooping. Ọ nwere ike snoop IGMP Join Request ozi ma ziga data multicast na ndị ọrụ metụtara otu a kama ịgbasa ozi nye ndị ọrụ niile, na-ebelata okporo ụzọ n'ụzọ dị otú a.
(5) Ọgbara n'elu
Naanị onyeONUnwere ike izipu okporo ụzọ n'otu oge. NkeONUnwere otutu ụzọ kwụ n'ahịrị (nke ọ bụla kwụ n'ahịrị kwekọrọ na a QoS larịị. TheONUna-ezigara ozi mkpesaOLTịrịọ ohere izipu, na-akọwa ọnọdụ kwụ n'ahịrị ọ bụla. NkeOLTna-eziga ozi Gate na nzaghachiONU, na-agwa ndịONUmmalite oge nke ọzọ nnyefe TheOLTga-enwe ike ijikwa bandwit chọrọ maka mmadụ niileONU, ma ga-ebuterịrị ikike nnyefe ụzọ. Dị ka mkpa nke kwụ n'ahịrị na itule arịrịọ nke otutuONU, nkeOLTga-enwe ike ijikwa bandwidth chọrọ maka mmadụ niileONU. Oke oke nke bandwit elu iyi (ya bụ DBA algọridim).
2.2 Dabere na njirimara teknụzụ nke usoro EPON, ihe ịma aka ule chere usoro EPON chere ihu.
(1) N'ịtụle ọnụ ọgụgụ nke usoro EPON
Ọ bụ ezie na IEEE802.3ah adịghị akọwapụta ọnụọgụ kachasị na sistemụ EPON, ọnụọgụ kachasị nke usoro EPON na-akwado bụ site na 16 ruo 128. Onye ọ bụla.ONUịbanye na usoro EPON chọrọ oge MPCP na nnọkọ OAM. Ka ọtụtụ saịtị na-esonyere EPON, ihe ize ndụ nke njehie sistemụ ga-abawanye. Dịka ọmụmaatụ, nke ọ bụlaONUkwesịrị ịchọpụtaghachi usoro, usoro nbanye wee malite nnọkọ OAM. Ya mere, oge mgbake nke usoro dum ga-abawanye na ọnụ ọgụgụ nkeONU.
(2) Nsogbu nke nkwurịta okwu nke akụrụngwa
A na-atụle akụkụ ndị a maka njikọta nke akụrụngwa:
●Algorithm bandwit ike (DBA) nke ndị nrụpụta dị iche iche nyere dị iche iche.
● Ụfọdụ ndị na-emepụta ihe na-eji "OrganizaTion Specific Elements" nke OAM iji tọọ àgwà ụfọdụ.
● Ma mmepe nke MPCP protocol bụ kpamkpam agbanwe agbanwe.
● Ma usoro nha anya nke ndị nrụpụta dị iche iche mepụtara kwekọrọ na nhazi elekere.
(3) Ihe egwu ezoro ezo na nnyefe nke ọrụ egwuregwu atọ na sistemụ EPON
N'ihi njirimara nnyefe nke EPON, a ga-ewebata ụfọdụ ihe egwu zoro ezo mgbe ị na-ebufe ọrụ egwuregwu atọ:
● Downstream na-emebi ọtụtụ bandwit: usoro EPON na-eji ọnọdụ mgbasa ozi mgbasa ozi na ala ala: nke ọ bụlaONUga-enweta nnukwu ego nke okporo ụzọ ezigara ndị ọzọONU, na-emefusị ọtụtụ bandwidth ala ala.
●Nkwụsị oge dị elu dị oke ibu: MgbeONUna-eziga data naOLT, ọ ga-echere ohere nnyefe ekenyelaOLT. Ya mere, ndịONUga-echekwa oke okporo ụzọ dị elu, nke ga-ebute igbu oge, nhụsianya na mfu ngwugwu.
3 EPON ule teknụzụ
Nnwale nke EPON gụnyere ọtụtụ akụkụ dị ka nnwale interoperability, ule protocol, ule arụmọrụ nnyefe sistemụ, ọrụ na nkwenye ọrụ. E gosipụtara topology ule ọkọlọtọ na eserese 2. Ngwaahịa IxN2X nke IXIA na-enye kaadị nnwale EPON raara onwe ya nye, ihe nyocha EPON, nwere ike ijide ma nyochaa usoro MPCP na OAM, nwere ike izipu okporo ụzọ EPON, nye mmemme nnwale akpaka, ma nwee ike inyere ndị ọrụ aka ịnwale. DBA algọridim.
