1.PON Taw Qhia

(1)PON yog dab tsi

PON (passive optical network) thev naus laus zis (xws li EPON, GPON) yog lub ntsiab siv thev naus laus zis rau kev txhim kho FTTx (fiber rau hauv tsev).Nws tuaj yeem txuag cov pob txha pob txha fiber ntau thiab qib network, thiab tuaj yeem muab ob txoj hauv kev siab bandwidth peev xwm nyob rau hauv kev sib kis mus ntev.Muaj ntau hom kev pabcuam nkag, thiab nws cov peev txheej tswj xyuas chaw taws teeb thiab cov qauv siv hluav taws xob tsis zoo tuaj yeem txo cov nqi khiav lag luam thiab kev saib xyuas, thiab tuaj yeem pab txhawb ntau yam kev thov.

(2) PON technology txhim kho

Txij li thaum PON tshwm sim, nws tau tsim muaj ntau xyoo, tsim cov ntsiab lus, kev qhia tshwj xeeb thiab cov khoom lag luam xws li APON, BPON, EPON, thiab GPON.

APON (ATMPON)

ATM yog lub xov tooj ntawm tes raws li kev sib kis.155Mb/s PON system technical specifications, ITU-TG.983 series qauv;

BPON (BroadbandPON)

APON tus qauv tom qab tau ntxiv dag zog los txhawb kev sib kis tus nqi ntawm 622Mb / s, thaum ntxiv kev ua haujlwm xws li kev faib tawm thiab kev tiv thaiv dynamic bandwidth.

EPON (Ethernet PON)

GPON (GigabitPON)

(3) Optical fiber nkag tshuab

2.EPON kev taw qhia

(1) EPON yog dab tsi?

EPON (Ethernet Passive Optical Network) yog ib hom taw tes-rau-multipoint network qauv, passive optical fiber ntau kis txoj kev, raws li high-ceev Ethernet platform thiab TDM (lub sij hawm division multiplexing) sij hawm faib MAC media access control method, muab ntau yam An integrated service broadband access technology.

EPON system siv WDM thev naus laus zis kom paub txog ib leeg-fiber bidirectional kis tau tus mob.

(2) Txoj Cai ntawm EPON

Txhawm rau cais cov khoom nkag thiab tawm ntawm ntau tus neeg siv ua khub ntawm tib lub fiber ntau, ob txoj kev sib tw hauv qab no tau siv.

ib.Cov ntaub ntawv downstream kwj siv siv tshuab tshaj tawm.

b.Cov ntaub ntawv ntws ntws los siv TDMA thev naus laus zis.

(3)Lub hauv paus ntsiab lus ntawm EPON-kawg

ib.Muab ib qho LLID tshwj xeeb tom qabONUtau sau npe ua tiav.

b.Ntxiv ib qho LLID ua ntej pib ntawm txhua pob ntawv los hloov qhov kawg ob bytes ntawm Ethernet preamble.

c.Sib piv daim ntawv teev npe LLID thaum lubOLTtxais cov ntaub ntawv.Thaum ONU tau txais cov ntaub ntawv, nws tsuas yog tau txais thav duab lossis tshaj tawm cov thav ntawv uas phim nws tus kheej LLID.

(4) Txoj Cai ntawm EPON-Uplink

ib.Sib piv daim ntawv teev npe LLID ua ntej OLT tau txais cov ntaub ntawv.

b.Txhua ONU xa cov ntaub ntawv thav duab hauv lub sijhawm sib koom ua ke los ntawm cov khoom siv hauv chaw ua haujlwm.

c.Lub sijhawm teem sijhawm them nyiaj rau qhov kev ncua deb ntawm ONUs thiab zam kev sib tsoo ntawm ONUs.

(5) Cov txheej txheem ua haujlwm ntawm EPON system

OLT kev ua haujlwm

ib.Tsim cov ntawv teev sijhawm rau lub sijhawm siv lub sijhawm.

b.Muab cov bandwidth los ntawm MPCP ntas.3. Ua haujlwm ntau yam.

c.Tswj ONU sau npe.

ONU kev ua haujlwm

ib.ONU synchronizes nrog OLT los ntawm lub sij hawm thwj ntawm downstream tswj ncej.

b.ONU tos rau kev tshawb pom tus ncej.

c.ONU ua cov txheej txheem tshawb pom, suav nrog: sib piv, qhia lub cev ID thiab bandwidth.

d.ONU tos rau kev tso cai, ONU tsuas tuaj yeem xa cov ntaub ntawv thaum lub sijhawm tso cai.

(6) Tsim ntawm EPON network tswj system

Lub EPON network tswj qhov system tau muab faib ua plaub lub modules raws li kev tswj hwm lub network: kev tswj xyuas kev teeb tsa, kev tswj xyuas kev ua haujlwm, kev tswj tsis raug thiab kev tswj xyuas kev nyab xeeb.

(7) Kev lees paub ntawm EPON network tswj qhov system

ib.Lub realization ntawm EPON network tswj system suav nrog kev paub txog kev tswj hwm chaw nres tsheb network tswj software thiab kev ua tiav ntawm tus neeg sawv cev chaw nres tsheb software.

b.Kev tswj hwm chaw nres tsheb network tswj qhov system yog lub chaw tswj hwm uas muab cov neeg siv nrog tus phooj ywg sib tham sib cuam tshuam thiab siv SNMP raws tu qauv los tswj cov txheej txheem tus neeg sawv cev.

c.Kev ua tiav ntawm SNMP hauv chaw nres tsheb tus neeg sawv cev feem ntau suav nrog kev ua tiav ntawm tus neeg sawv cev txheej txheem software thiab tsim thiab koom haum ntawm MIB.

3. GPON kev taw qhia

(1) GPON yog dab tsi?

GPON (Gigabit-CapablePON Gigabit Passive Optical Network) thev naus laus zis yog cov tiam tshiab broadband passive optical integrated access standard raws li ITU-TG.984.x (International Telecommunication Union TG.984.x) tus qauv, nrog high bandwidth, High efficiency, loj kev pab them nqi, nplua nuj neeg siv interface thiab ntau lwm yam Qhov zoo yog suav tias yog cov neeg ua haujlwm feem ntau yog cov cuab yeej zoo tshaj plaws kom paub txog broadband thiab kev hloov pauv ntawm kev siv cov kev pabcuam hauv network.

(2) GPON txoj cai

GPON downstream-broadcast kis tau tus mob

GPONs upstream-TDMA hom

Lub network topology ntawm passive optical fiber ntau kis tau tus mob yog tsim los ntawm OLT (optical kab davhlau ya nyob twg), ODN (optical distribution network), thiab ONU (optical network unit).

ODN muab kev sib kis tau zoo rau OLT thiab ONU.Nws muaj passive optical splitter thiab passive optical combiner.Nws yog ib qho khoom siv passive uas txuas OLT thiab ONU.

(3) GPON txoj cai-kwv yees

ib.Kev xa tawm ntawm cov ntaub ntawv ntws tawm yog ib txwm tswj hwm los ntawm OLT.

b.ONU xa cov neeg siv cov ntaub ntawv raws li lub sijhawm teem los ntawm OLT kom tsis txhob muaj cov ntaub ntawv xa tawm tsis sib haum xeeb tsim los ntawm ONU.

c.Lub ONU ntxig cov ntaub ntawv uplink hauv nws tus kheej lub sijhawm raws li lub sijhawm sib faib thav duab, paub txog kev sib koom ntawm uplink channel bandwidth ntawm ntau ONUs.

(4) GPON networking hom

GPON feem ntau siv peb hom kev sib txuas: FTTH / O, FTTB + LAN thiab FTTB + DSL.

a.FTTH / O yog fiber ntau rau hauv tsev / chaw ua haujlwm.Tom qab lub optical fiber nkag mus rau hauv lub splitter, nws yog ncaj qha mus rau tus neeg siv ONU.Ib qho ONU tsuas yog siv los ntawm ib tus neeg siv, nrog cov bandwidth siab thiab tus nqi siab, thiab feem ntau yog tsom rau cov neeg siv khoom siab thiab cov neeg siv khoom lag luam.

b.FTTB + LAN siv fiber ntau kom ncav cuag lub tsev, thiab tom qab ntawd txuas cov kev pabcuam sib txawv rau ntau tus neeg siv los ntawm lub peev xwm loj ONU (hu ua MDU).Yog li ntawd, ntau tus neeg siv faib cov peev txheej bandwidth ntawm ib qho ONU, thiab txhua tus neeg siv qis dua bandwidth thiab tus nqi qis dua., Feem ntau rau cov neeg siv khoom lag luam qis thiab qis kawg.

c.FTTB + ADSL siv fiber ntau kom ncav cuag lub tsev, thiab tom qab ntawd siv ADSL los txuas cov kev pabcuam rau ntau tus neeg siv, thiab ntau tus neeg siv sib koom ONU.Cov bandwidth, tus nqi thiab cov neeg siv khoom zoo ib yam li FTTB + LAN.

4. GPON thiab EPON technology sib piv

Raws li kev pom ntawm cov yam ntxwv sib txawv ntawm GPON thiab EPON thev naus laus zis, kev tshuaj xyuas hauv qab no tuaj yeem ua rau ob lub thev naus laus zis no.

(1) GPON txhawb ntau theem ntawm tus nqi, thiab tuaj yeem txhawb nqa asymmetric nce toj thiab nqes dej.GPON muaj ntau dua leeway hauv kev xaiv cov khoom siv kho qhov muag, yog li txo cov nqi.

(2) EPON tsuas yog txhawb nqa ODN qib ntawm Chav Kawm A thiab B, thaum GPON tuaj yeem txhawb Chav Kawm A, B thiab C, yog li GPON tuaj yeem txhawb nqa mus txog 128 qhov sib cais thiab mus txog 20km kis nrug.

(3) Sib piv tsuas yog los ntawm cov txheej txheem, vim tias tus qauv EPON yog raws li 802.3 system qauv, yog li muab piv nrog GPON tus qauv, nws cov txheej txheem txheej txheem yooj yim dua thiab kev siv cov txheej txheem yooj yim dua.

(4) ITU tau ua raws ntau lub tswv yim ntawm APON tus qauv G.983 hauv cov txheej txheem ntawm kev tsim cov qauv GPON, uas ua tiav ntau dua li EPON tus qauv tsim los ntawm EFM.Kev muab cov txheej txheem TC txheej txheem ua tau zoo yuav dhau los ua qhov tseem ceeb rau ITU hauv kev tsim cov qauv GPON.

(5) GPON tus qauv qhia tias TC sublayer tuaj yeem siv ob txoj kev encapsulation, ATM thiab GFP.GFP encapsulation txoj kev yog tsim nyog rau nqa IP / PPP thiab lwm cov pob ntawv raws li cov txheej txheem siab.