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 kis tau tus mob 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.
a. 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
a. 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 lubONUtau 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
a. Sib piv daim ntawv teev npe LLID ua ntejOLTtxais cov ntaub ntawv.
b. TxhuaONUxa cov ntaub ntawv ncej nyob rau hauv lub sij hawm slot uniformly faib los ntawm lub chaw ua hauj lwm cov khoom.
c. Lub sijhawm faib lub sijhawm them nyiaj rau qhov kev ncua deb ntawm qhovONUsthiab zam kev sib tsoo ntawm covONUs.
(5) Cov txheej txheem ua haujlwm ntawm EPON system
OLTkev ua haujlwm
a. 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. TswjONUsau npe.
ONUkev ua haujlwm
a. CovONUsynchronizes nrog covOLTlos ntawm lub sij hawm stamp ntawm downstream tswj ncej.
b. ONUtos rau kev tshawb pom ncej.
c. ONUua cov txheej txheem tshawb pom, suav nrog: ntau yam, qhia lub cev ID thiab bandwidth.
d. ONUtos kev tso cai,ONUtuaj 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
a. Lub realization ntawm EPON network tswj system suav nrog kev ua tiav ntawm kev tswj 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 tham 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 kis tau tus mob hom yog tsim los ntawmOLT(optical kab davhlau ya nyob twg), ODN (optical distribution network), thiabONU(optical network unit).
ODN muab optical kis tau tus mob txhais tau tias rauOLTthiabONU. Nws muaj passive optical splitter thiab passive optical combiner. Nws yog ib tug passive ntaus ntawv uas txuasOLTthiabONU.
(3) GPON txoj cai-kwv yees
a. Kev xa tawm ntawm cov ntaub ntawv upstream yog uniformly tswj los ntawm lubOLT.
b. CovONUxa cov neeg siv cov ntaub ntawv raws li lub sij hawm qhov chaw faib los ntawm lubOLTkom tsis txhob kis cov ntaub ntawv tsis sib haum xeeb tsim los ntawm covONU.
c. CovONUinserts uplink cov ntaub ntawv nyob rau hauv nws tus kheej lub sij hawm qhov chaw raws li lub sij hawm qhov chaw faib thav duab, paub txog kev sib koom ntawm uplink channel bandwidth ntawm ntau yam.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 cov neeg sivONU. IbONUtsuas 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 qhoONU, thiab txhua tus neeg nyob hauv qis 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.