EPON system muaj ntau qhov chaw kho qhov muag (ONU), ib qho chaw kho qhov muag (OLT), thiab ib lossis ntau qhov chaw kho qhov muag (saib daim duab 1).Hauv kev taw qhia txuas ntxiv, lub teeb liab xa los ntawm OLT tau tshaj tawm rau txhua ONUs.8h Hloov kho cov qauv qauv, rov txhais lub hauv ntej, thiab ntxiv lub sijhawm thiab kev txheeb xyuas qhov tseeb (LLID)).LLID txheeb xyuas txhua ONU hauv PON system, thiab LLID tau teev tseg thaum lub sijhawm tshawb nrhiav.
(1) Kev sib tw
Hauv EPON system, qhov kev ncua deb ntawm lub cev ntawm txhua ONU thiab OLT nyob rau hauv cov ntaub ntawv xa mus rau cov kev taw qhia tsis sib npaug.Cov txheej txheem EPON dav dav qhia tias qhov ntev tshaj plaws ntawm ONU thiab OLT yog 20km, thiab qhov luv tshaj plaws yog 0km.Qhov kev ncua deb no yuav ua rau ncua sij hawm sib txawv ntawm 0 thiab 200 peb.Yog tias tsis muaj qhov sib txawv txaus, cov teeb liab los ntawm ONUs sib txawv tuaj yeem ncav cuag qhov kawg ntawm OLT tib lub sijhawm, uas yuav ua rau muaj kev tsis sib haum xeeb ntawm cov teeb liab ntws.Qhov kev tsis sib haum xeeb yuav ua rau muaj ntau qhov yuam kev thiab synchronization poob, thiab lwm yam, ua rau lub kaw lus tsis ua haujlwm li qub.Siv cov txheej txheem sib txawv, ua ntej ntsuas lub cev nyob deb, thiab tom qab ntawd kho tag nrho ONUs mus rau tib lub laj thawj nyob deb li OLT, thiab tom qab ntawd ua cov txheej txheem TDMA kom ua tiav qhov tsis sib haum xeeb.Tam sim no, cov kev siv ntau yam siv suav nrog kev sib kis-spectrum sib txawv, tawm-ntawm-band ntau thiab hauv-band qhov rais-qhib ntau.Piv txwv li, lub sij hawm sib piv txoj kev yog siv los ntsuas thawj lub teeb liab voj ncua sij hawm los ntawm txhua ONU mus rau OLT, thiab tom qab ntawd ntxig ib qho kev sib npaug tshwj xeeb ncua Td tus nqi rau txhua ONU, kom lub voj ncua sij hawm ntawm tag nrho ONUs tom qab ntxig Td. (hu ua vaj huam sib luag voj ncua nqi Tequ) yog sib npaug, qhov tshwm sim zoo ib yam li txhua ONU raug txav mus rau tib lub laj thawj nyob deb li OLT, thiab tom qab ntawd cov ncej tuaj yeem raug xa mus raws li TDMA thev naus laus zis yam tsis muaj teeb meem..
(2) Kev Tshawb Fawb
OLT pom tias ONU hauv PON system xa Gate MPCP cov lus tsis tu ncua.Thaum tau txais cov lus Gate, ONU tsis tau sau npe yuav tos lub sijhawm random (kom tsis txhob tso npe ib txhij ntawm ntau ONU), thiab tom qab ntawd xa cov lus Sau npe rau OLT.Tom qab kev tso npe ua tiav, OLT muab LLID rau ONU.
(3) Ethernet OAM
Tom qab ONU tau sau npe nrog OLT, Ethernet OAM ntawm ONU pib txoj kev tshawb pom thiab tsim kev sib txuas nrog OLT.Ethernet OAM yog siv rau ntawm ONU/OLT txuas mus nrhiav tej thaj chaw deb tsis raug, ua rau tej thaj chaw deb loopbacks, thiab xyuas qhov link zoo.Txawm li cas los xij, Ethernet OAM muab kev txhawb nqa rau OAM PDUs, cov ntaub ntawv qhia thiab cov ntawv ceeb toom sijhawm.Ntau ONU / OLT cov tuam txhab siv OAM txuas ntxiv los teeb tsa cov haujlwm tshwj xeeb ntawm ONUs.Ib daim ntawv thov raug yog los tswj cov bandwidth ntawm cov neeg siv kawg nrog cov qauv teeb tsa bandwidth nthuav dav hauv ONU.Daim ntawv thov tsis yog tus qauv no yog tus yuam sij rau qhov kev xeem thiab dhau los ua qhov cuam tshuam rau kev sib txuas lus ntawm ONU thiab OLT.
(4) Cov dej ntws hauv qab
Thaum OLT muaj tsheb thauj mus los xa ONU, nws yuav nqa cov ntaub ntawv LLID ntawm qhov chaw ONU hauv kev tsheb.Vim tias cov yam ntxwv tshaj tawm ntawm PON, cov ntaub ntawv xa los ntawm OLT yuav tshaj tawm rau txhua ONUs.Peb yuav tsum tshwj xeeb yog xav txog qhov xwm txheej uas cov tsheb thauj mus los hauv qab xa cov kev pabcuam video.Vim qhov kev tshaj tawm ntawm EPON system, thaum tus neeg siv kho qhov kev pab cuam video, nws yuav tshaj tawm rau txhua tus neeg siv, uas siv cov bandwidth qis heev.OLT feem ntau txhawb IGMP Snooping.Nws tuaj yeem snoop IGMP Koom Nrog Thov cov lus thiab xa cov ntaub ntawv multicast rau cov neeg siv cuam tshuam nrog pab pawg no es tsis txhob tshaj tawm rau txhua tus neeg siv, txo cov tsheb khiav hauv txoj kev no.
(5) Cov dej ntws ntws
Tsuas yog ib qho ONU tuaj yeem xa cov tsheb khiav ntawm lub sijhawm.ONU muaj ntau qhov tseem ceeb hauv kab (txhua kab ntawv sib raug rau qib QoS. ONU xa ib tsab ntawv ceeb toom rau OLT kom thov lub sijhawm xa, piav qhia txog qhov xwm txheej ntawm txhua kab. OLT xa Gate lus teb rau ONU, qhia ONU lub sijhawm pib ntawm kev sib kis tom ntej OLT yuav tsum muaj peev xwm tswj hwm cov kev cai bandwidth rau tag nrho ONUs, thiab yuav tsum ua qhov tseem ceeb ntawm kev tso cai kis tau tus mob. tswj cov kev cai bandwidth rau tag nrho ONUs. Dynamic faib ntawm upstream bandwidth (ie DBA algorithm).
2.2 Raws li cov yam ntxwv ntawm EPON system, kev sim cov teeb meem ntsib los ntawm EPON system
(1) Xav txog qhov ntsuas ntawm EPON system
Txawm hais tias IEEE802.3ah tsis txhais tus lej siab tshaj plaws hauv EPON system, tus lej siab tshaj plaws txhawb nqa los ntawm EPON system yog los ntawm 16 txog 128. Txhua ONU koom nrog EPON system yuav tsum muaj kev sib tham MPCP thiab OAM kev sib kho.Raws li ntau qhov chaw koom nrog EPON, qhov kev pheej hmoo ntawm kev ua yuam kev yuav nce ntxiv.Piv txwv li, txhua ONU yuav tsum rov tshawb nrhiav cov txheej txheem, nkag mus rau hauv txheej txheem thiab pib OAM kev sib kho.Yog li ntawd, lub sij hawm rov qab los ntawm tag nrho cov kab ke yuav nce nrog tus naj npawb ntawm ONUs.
(2) Qhov teeb meem ntawm kev sib txuas lus ntawm cov khoom siv
Cov nram qab no feem ntau yog txiav txim siab rau kev sib txuas lus ntawm cov khoom siv:
● Cov dynamic bandwidth algorithm (DBA) muab los ntawm cov tuam ntxhab sib txawv txawv.
●Qee lub tuam txhab siv OAM's "OrganizaTion Specific Elements" los teeb tsa tus cwj pwm tshwj xeeb.
● Txawm hais tias kev txhim kho MPCP raws tu qauv zoo ib yam.
● Txawm hais tias txoj kev ntsuas qhov deb tau tsim los ntawm cov tuam txhab sib txawv yog ua raws li lub moos ua.
(3) Tsis muaj kev phom sij hauv kev sib kis ntawm kev ua si triple hauv EPON system
Vim yog cov yam ntxwv kis tau tus mob ntawm EPON, qee qhov kev phom sij zais yuav raug qhia thaum kis peb qhov kev ua si:
● Downstream khib nyiab ntau ntawm bandwidth: EPON system siv cov kev tshaj tawm hauv xov tooj cua hauv qab: txhua ONU yuav tau txais ntau cov tsheb thauj mus los rau lwm ONUs, nkim ntau qhov downstream bandwidth.
● Qhov kev ncua sij hawm ntws tawm yog qhov loj: Thaum ONU xa cov ntaub ntawv mus rau OLT, nws yuav tsum tau tos rau lub sijhawm xa mus los ntawm OLT.Yog li ntawd, ONU yuav tsum tsis txhob muaj cov tsheb thauj mus los loj heev, uas yuav ua rau ncua sij hawm, ntxhov siab, thiab pob ntawv poob.
3 EPON xeem tshuab
Kev ntsuam xyuas ntawm EPON feem ntau suav nrog ntau yam xws li kev sib koom ua haujlwm sib koom ua ke, kev sim raws tu qauv, kev ntsuas kev sib kis, kev pabcuam thiab kev ua haujlwm pov thawj.Cov txheej txheem kuaj topology yog pom nyob rau hauv daim duab 2. IXIA's IxN2X cov khoom muab EPON kev xeem daim npav tshwj xeeb, EPON xeem interface, tuaj yeem ntes thiab txheeb xyuas MPCP thiab OAM raws tu qauv, tuaj yeem xa EPON kev khiav tsheb, muab qhov kev xeem tsis siv neeg, thiab tuaj yeem pab cov neeg siv kuaj. DBA algorithms.
