Taw qhia txog ntau yam PON systems
1. APON tshuab
Nyob rau hauv nruab nrab-1990s, qee tus tswv lag luam loj tau tsim kom muaj Kev Pabcuam Kev Sib Txuas Sib Txuas Sib Txuas (FSAN), uas nws lub hom phiaj yog los tsim cov qauv sib koom ua ke rau cov khoom siv PON kom cov tuam txhab tsim khoom thiab cov neeg ua haujlwm tuaj yeem nkag mus rau PON cov khoom lag luam thiab sib tw ua ke. Thawj qhov tshwm sim yog qhov tshwj xeeb ntawm 155Mbit / s PON system tus qauv hauv ITU-T G.983 series ntawm cov lus pom zoo. Vim tias ATM siv raws li tus neeg tuav txoj cai, qhov system no hu ua APON system, thiab nws feem ntau nkag siab yuam kev tsuas yog muab kev pabcuam ATM xwb. Yog li ntawd, nws yog renamed Broadband Passive Optical Network (BPON) system los qhia tias qhov system no muaj peev xwm muab Ethernet Broadband cov kev pab cuam xws li kev siv network, kev faib tawm video, thiab high-ceev cov kab xauj tsev. Txawm li cas los xij, rau tiam no ntawm FSAN systems, feem ntau siv lub npe yog APON. Tom qab ntawd, APON tus qauv tau txhim kho, thiab nws tau pib txhawb downlink 622 Mbit / s tus nqi, thiab cov yam ntxwv tshiab tau ntxiv rau hauv txoj kev tiv thaiv, kev faib tawm dynamic bandwidth (DBA), thiab lwm yam.
APON siv ATM raws li tus neeg nqa khoom raws tu qauv. Downstream kis tau tus mob yog ib tug nruam ATM kwj nrog me ntsis tus nqi ntawm 155.52Mbit / s los yog 622.08Mbit / s. Ib txheej txheej tshwj xeeb ntawm lub cev kev tswj hwm thiab kev saib xyuas (PLOAM) ntawm tes tau muab tso rau hauv cov ntaub ntawv kwj dej.Upstream kis tau tus mob yog ATM hlwb hauv daim ntawv tawg. Txhawm rau ua tiav kev sib kis thiab txais tos, 3-byte lub cev nyiaj siv ua haujlwm tau ntxiv rau pem hauv ntej ntawm txhua 53-byte cell. Rau ib qho yooj yim tus nqi ntawm 155.52 Mbit / s, kev sib kis raws tu qauv yog raws li ib tug downlink ncej uas muaj 56 ATM hlwb (53 bytes ib cell); thaum tus nqi me ntsis nce mus rau 622.08 Mbit / s, tus ncej downlink tau nthuav dav mus rau 224 Cell. Ntawm qhov pib tus nqi ntawm 155.52 Mbit / s, hom ntawv ntawm cov ncej uplink yog 53 hlwb, txhua lub xov tooj yog 56 bytes (53 ATM cell bytes ntxiv rau 3 bytes nyiaj siv ua haujlwm). Ntxiv nrog rau 54 cov ntaub ntawv xov tooj hauv lub downlink ncej, muaj ob lub PLOAM hlwb, ib qho pib ntawm tus ncej thiab lwm qhov hauv nruab nrab ntawm tus ncej. Txhua lub xov tooj ntawm PLOAM muaj cov ntawv tso cai xa mus rau qhov tshwj xeeb ntawm lub xov tooj ntawm tes (53 Upstream thav duab cell muaj 53 qhov nyiaj pab cuam mapped rau hauv PLOAM hlwb) thiab OAM & P cov ntaub ntawv. APON muab kev nplua nuj thiab ua tiav OAM ua haujlwm, suav nrog kev soj ntsuam me ntsis yuam kev, ceeb toom, nrhiav tsis siv neeg, thiab tshawb nrhiav tsis siv neeg. Raws li kev ruaj ntseg mechanism, nws muaj peev xwm scramble thiab encrypt downlink cov ntaub ntawv.
Los ntawm qhov kev xav ntawm kev ua cov ntaub ntawv, hauv APON, cov neeg siv cov ntaub ntawv yuav tsum raug xa mus raws li kev hloov pauv raws tu qauv (AAL1 / 2 rau TDM thiab AAL5 rau cov ntaub ntawv xa mus). Qhov kev hloov dua siab tshiab no yog qhov nyuaj rau kev hloov pauv mus rau qhov siab bandwidth, thiab cov cuab yeej siv ua haujlwm no suav nrog qee cov khoom siv cuam tshuam, xws li lub cim xeeb ntawm tes, Glue Logic, thiab lwm yam, uas tseem ntxiv ntau rau cov nqi system.
Tam sim no, txawm hais tias nws yog qhov txuas txuas mus ntev lossis thaj chaw hauv nroog nkag mus rau cov txheej txheem sib koom ua ke, cov thev naus laus zis kev sib txuas lus tau maj mam hloov ntawm ATM-centric mus rau IP-raws li muab kev sib txuas lus video, suab, thiab cov ntaub ntawv. Yog li ntawd, tsuas yog cov qauv nkag mus rau hauv lub network uas tuaj yeem hloov mus rau ob qho tib si tam sim no thiab yav tom ntej network core technologies tuaj yeem ua rau yav tom ntej tag nrho-optical IP network muaj tseeb.
APON tau maj mam thim tawm ntawm kev ua lag luam vim nws qhov nyuaj thiab cov ntaub ntawv tsis tshua muaj kev sib kis tau zoo.
2. EPON
Yuav luag tib lub sijhawm raws li APON system, IEEE kuj tau tsim thawj mais Ethernet (EFM) pawg tshawb fawb los tsim Ethernet-based EPON (Ethernet Passive Optical Network) hais txog kev siv fiber ntau, qhia txog kev lag luam zoo. Cov pab pawg kawm yog nyob rau IEEE 802.3 pawg uas tsim Ethernet tus qauv. Ib yam li ntawd, nws txoj kev tshawb fawb tseem txwv rau cov qauv tsim, thiab nws yuav tsum ua raws li 802.3 media access control (MAC) txheej txheej uas twb muaj lawm. Thaum lub Plaub Hlis 2004, pab pawg tshawb fawb tau qhia txog IEEE 802.3ah tus qauv rau EPON, nrog rau qhov nce thiab nqis ntawm 1 Gbit / s (siv 8B / 10B coding, thiab kab nqi ntawm 1.25 Gbit / s), xaus rau EPON manufacturers ' siv cov kev cai ntiag tug los tsim cov txheej txheem txheej txheem.
EPON yog ib qho kev siv dav dav raws li Ethernet thev naus laus zis. Nws siv PON topology los siv Ethernet nkag. Cov thev naus laus zis tseem ceeb ntawm cov ntaub ntawv txuas txheej feem ntau suav nrog: Ntau Yam Kev Tswj Xyuas Kev Tswj Xyuas Txheej Txheem (MPCP) rau uplink channel, ntsaws thiab ua si teeb meem ntawm covONU, qhov sib txawv thiab ncua sij hawm them nyiaj raws tu qauv ntawm lubOLT, thiab raws tu qauv compatibility teeb meem.
Lub cev txheej ntawm IEEE 802.3ah suav nrog ob qho tib si point-to-point (P2P) txuas kho qhov muag fibers thiab tooj liab xov hlau, nrog rau PON network scenarios rau point-to-multipoint (P2MP). Txhawm rau pab txhawb kev lag luam network thiab kho qhov yuam kev, OAM mechanism kuj suav nrog. Rau P2MP network topology, EPON yog ua raws li lub tshuab hu ua Multipoint Control Protocol (MPCP), uas yog ib qho haujlwm nyob rau hauv MAC sublayer. MPCP siv cov lus, lub xeev cov tshuab, thiab timers los tswj kev nkag mus rau P2MP network topology. Txhua chav tsev optical network (ONU) hauv P2MP network topology muaj MPCP raws tu qauv uas sib txuas lus nrog MPCP raws tu qauv chaw nyob rau hauvOLT. .
Lub hauv paus ntawm EPON / MPCP raws tu qauv yog point-to-point simulation sublayer, uas ua rau ib tug P2MP network zoo li ib tug sau ntawm P2P txuas mus rau cov txheej txheem ntau dua.
Yuav kom txo tau tus nqi ntawm covONU, cov thev naus laus zis tseem ceeb ntawm EPON lub cev txheej txheej yog tsom rau ntawmOLT, suav nrog ceev synchronization ntawm cov teeb liab tawg, network synchronization, tswj fais fab ntawm optical transceiver modules, thiab txais kev txais tos zoo.
EPON muab cov txiaj ntsig zoo ntawm PON thiab Ethernet cov khoom lag luam los tsim ntau yam zoo. Lub EPON system tuaj yeem muab cov uplink thiab downlink bandwidths txog li 1 Gbit / s, uas tuaj yeem ua tau raws li cov kev xav tau ntawm cov neeg siv yav tom ntej rau lub sijhawm ntev. EPON siv multiplexing thev naus laus zis los txhawb cov neeg siv ntau dua, thiab txhua tus neeg siv tuaj yeem txaus siab rau bandwidth ntau dua. EPON system tsis siv cov cuab yeej ATM kim thiab cov khoom siv SONET, thiab tau sib xws nrog Ethernet uas twb muaj lawm, ua kom yooj yim rau cov qauv tsim, tus nqi qis, thiab yooj yim rau kev txhim kho. Vim lub neej ntev ntawm cov khoom siv kho qhov muag tsis pom kev, cov nqi kho mob ntawm cov kab sab nraum zoov tau txo qis heev. Tib lub sijhawm, tus qauv Ethernet interfaces tuaj yeem ua kom zoo dua ntawm cov khoom siv Ethernet uas twb muaj lawm thiab txuag nqi. Tus qauv PON nws tus kheej txiav txim siab tias lub network yog qhov ua tau zoo heev. Ntev npaum li cov khoom siv davhlau ya nyob twg hloov, lub network tuaj yeem hloov kho mus rau 10 Gbit / s lossis siab dua. EPON tsis tuaj yeem koom ua ke nrog cov cable TV uas twb muaj lawm, cov ntaub ntawv thiab cov kev pabcuam suab, tab sis kuj tseem siv tau nrog cov kev pabcuam yav tom ntej xws li digital TV, VoIP, video conferencing thiab VOD, thiab lwm yam, kom ua tiav kev pabcuam kev sib koom ua ke.
Kev siv dav dav ntawm EPON bearer thiab lwm yam kev siv thev naus laus zis ntxiv ua kom muaj txiaj ntsig zoo rau kev siv thev naus laus zis thev naus laus zis.
Kev siv EPON tuaj yeem ua rau DSL rhuav tshem cov kev txwv ib txwm nyob thiab nthuav dav. Thaum lubONUyog kev koom ua ke rau hauv Digital Subscriber Line Access Multiplexer (DSLAM), qhov ncav cuag ntau yam ntawm DSL thiab nws pab pawg neeg siv tau yuav nce siab heev.
Ib yam li ntawd, los ntawm kev sib koom ua ke ntawm CMTS (Cable Modem Termination System) ntawmONU, EPON tuaj yeem muab bandwidth rau cov kev sib txuas Cable uas twb muaj lawm, thiab tso cai rau cov neeg siv cable los siv cov kev pabcuam sib tham tiag tiag thaum txo kev tsim kho thiab kev khiav haujlwm.
Nyob rau hauv ob qho tib si, cov neeg ua haujlwm tuaj yeem nce lawv cov neeg siv khoom raws li lawv cov qauv network uas twb muaj lawm thiab kev nqis peev. EPON tseem tuaj yeem txuas ntxiv qhov point-to-point MSPP (Multiple Services Provisioning Platform) thiab IP / Ethernet.
Tsis tas li ntawd, EPON thev naus laus zis kuj tuaj yeem siv los daws qhov teeb meem ntawm cov ntaub ntawv uplink ntawm lub hauv paus chaw nres tsheb hauv kev siv wireless nkag mus rau hauv cov tub ntxhais network.
3.GPON
Nyob rau hauv 2001, FSAN pib ib tug tshiab kev rau siab rau standardize PON tes hauj lwm ua hauj lwm saum toj no 1 Gbit / s. Ntxiv nrog rau kev txhawb nqa tus nqi siab, tag nrho cov txheej txheem tau qhib kom rov xav dua thiab nrhiav cov kev daws teeb meem zoo tshaj plaws thiab muaj txiaj ntsig zoo tshaj plaws ntawm kev txhawb nqa ntau yam kev pabcuam, OAM & P kev ua haujlwm thiab scalability. Raws li ib feem ntawm GPON txoj haujlwm, FSAN thawj zaug tau sau cov kev cai ntawm tag nrho nws cov tswv cuab (nrog rau cov neeg ua haujlwm loj thoob ntiaj teb), tom qab ntawd raws li qhov no, tau sau ib daim ntawv hu ua Gigabit Service Requirements (GSR) thiab ua nws cov lus pom zoo (G.GON. GSR) to ITU-T. Lub ntsiab GPON yuav tsum tau piav qhia hauv GSR cov ntaub ntawv yog raws li hauv qab no.
l Txhawb nqa tag nrho cov kev pabcuam, suav nrog lub suab (TDM, SONET / SDH), Ethernet (10/100 Base-T), ATM, cov kab xauj, thiab lwm yam.
l Qhov kev ncua deb ntawm lub cev yog tsawg kawg yog 20km, thiab qhov kev ncua deb yog txwv rau 60km.
l Txhawb ntau tus nqi me ntsis siv tib txoj cai, suav nrog symmetrical 622 Mbit / s, symmetrical 1.25 Gbit / s, downstream 2.5 Gbit / s thiab upstream 1.25 Gbit / s, thiab lwm yam me ntsis nqi.
l OAM & P muaj zog ua haujlwm uas tuaj yeem muab kev pabcuam kawg-rau-kawg.
l Vim yog cov yam ntxwv tshaj tawm ntawm PON, kev ruaj ntseg ntawm cov kev pabcuam downlink yuav tsum tau lav ntawm qib raws tu qauv.
FSAN tau hais tias kev tsim qauv GPON yuav tsum ua kom tau raws li cov hom phiaj hauv qab no.
l Cov qauv qauv tuaj yeem nthuav tawm ntawm 622Mbit / s mus rau 2.5Gbit / s, thiab txhawb nqa asymmetric ntsis tus nqi.
l Muab kev siv bandwidth siab thiab ua haujlwm siab rau txhua lub lag luam.
l Encapsulate ib qho kev pabcuam (TDM thiab pob ntawv) rau hauv 125ms thav duab los ntawm GFP.
l Kev sib kis tau zoo thiab tsis muaj nqi ntawm cov kev pabcuam TDM ntshiab.
l Dynamic bandwidth faib rau txhua tusONUlos ntawm tus pointer bandwidth.
Txij li thaum GPON rov xav txog daim ntawv thov thiab cov kev xav tau ntawm PON los ntawm hauv qab, nws tau tso lub hauv paus rau cov kev daws teeb meem tshiab thiab tsis ua raws li tus qauv APON yav dhau los, yog li qee cov tuam txhab hu nws haiv neeg PON (natural hom PON). Ntawm qhov tod tes, GPON khaws ntau lub zog uas tsis muaj feem cuam tshuam ncaj qha rau PON, xws li OAM cov lus, DBA, thiab lwm yam. Ntawm qhov tod tes, GPON yog raws li cov txheej txheem TC tshiab (kev sib txuas lus sib txuas). GFP (tus txheej txheem txheej txheem dav dav) xaiv los ntawm FSAN yog cov txheej txheem raws li cov txheej txheem uas hloov kho cov ntaub ntawv kev pabcuam los ntawm cov neeg siv khoom siab ntawm kev thauj mus los los ntawm cov txheej txheem dav dav. Lub network thauj tuaj yeem yog txhua hom kev sib txuas, xws li SONET / SDH thiab ITU-T G.709 (OTN), thiab lwm yam. Cov ntaub ntawv cov neeg siv khoom tuaj yeem ua raws li pob ntawv (xws li IP / PPP, piv txwv li IP / Point to Point protocal. , lossis Ethernet MAC thav duab, thiab lwm yam ), tuaj yeem ua tus nqi me ntsis tas li lossis lwm yam ntaub ntawv lag luam. GFP tau raug cai raws li ITU-T tus qauv G.7041. Vim tias GFP muab txoj hauv kev zoo thiab yooj yim rau kev xa cov kev pabcuam sib txawv ntawm kev sib txuas lus sib txuas, nws yog qhov zoo tshaj plaws los siv nws los ua lub hauv paus ntawm GPON TC txheej. Tsis tas li ntawd, thaum siv GFP, GPON TC yog qhov tseem ceeb synchronous thiab siv tus qauv SONET / SDH 8kHz (125ms) thav duab, uas ua rau GPON ncaj qha txhawb TDM cov kev pabcuam. Nyob rau hauv kev tso tawm G.984.3 tus qauv, FSAN lub tswv yim ntawm GFP raws li TC txheej adaptation tshuab tau txais, thiab ntxiv kev ua kom yooj yim dua, hu ua GPON encapsulation method (GEM, GPONEncapsulationMethod).
Kev siv ntawm EPON system
EPON, raws li kev siv thev naus laus zis tshiab, yog qhov kev pabcuam puv ntoob uas tuaj yeem txhawb nqa cov ntaub ntawv pabcuam nrog rau cov kev pabcuam hauv lub sijhawm xws li lub suab thiab video.
Txoj kev kho qhov muag ntawm EPON tuaj yeem siv 3 wavelengths. Yog tias koj tsis xav txog kev txhawb nqa CATV lossis DWDM cov kev pabcuam, feem ntau siv ob lub wavelengths. Thaum siv 3 wavelengths, qhov nruab nrab wavelength yog 1310nm, downstream wavelength yog 1490nm, thiab ntxiv 1550nm wavelength ntxiv. Qhov nce 1550nm wavelength yog siv los xa ncaj qha analog video signals. Vim hais tias tam sim no analog video teeb liab tseem nyob rau hauv xov tooj cua thiab TV cov kev pab cuam, nws yog kwv yees hais tias nws yuav tsis tau hloov tag nrho los ntawm cov kev pab cuam video mus txog rau thaum 2015. Yog li ntawd, tam sim no EPON system tsim yuav tsum txhawb ob qho tib si digital video kev pab cuam thiab analog video kev pab cuam. Tus thawj 1490nm tseem nqa cov ntaub ntawv downlink, cov yees duab digital thiab cov kev pabcuam suab, thiab 1310nm xa cov neeg siv lub suab xa tawm, cov yees duab digital ntawm kev thov (VOD), thiab thov cov ntaub ntawv rub tawm cov ntaub ntawv.
Lub suab teeb liab muaj qhov yuav tsum tau nruj ntawm kev ncua thiab jitter, thiab Ethernet tsis muab qhov kawg-rau-kawg pob ntawv ncua, pob ntawv poob tus nqi, thiab bandwidth tswj peev xwm. Yog li ntawd, yuav ua li cas los xyuas kom meej cov kev pab cuam zoo thaum EPON superimposes suab signals yog ib qho teeb meem ceev yuav tsum tau daws.
1. TDM kev lag luam
Tam sim no, cov lus nug ntau tshaj plaws EPON muaj peev xwm ua haujlwm ntau yog nws lub peev xwm los xa cov kev pabcuam TDM ib txwm muaj.
Cov kev pabcuam TDM tau hais ntawm no suav nrog ob hom kev pabcuam suab (POTS, Kev Pabcuam Xovtooj nrov nrov) thiab cov kev pabcuam hauv Circuit Court (T1 / El, N´64kbit / s leased kab).
Thaum EPON tshuab nqa cov ntaub ntawv tshwj xeeb cov kev pabcuam (2048kbit / s lossis 13´64kbit / s cov ntaub ntawv pabcuam), TDM hla Ethernet tau pom zoo. EPON system tuaj yeem txais kev hloov pauv lossis VolP thaum nqa cov kev pabcuam suab.
Hauv ob peb xyoos tom ntej no, vim tias kev lag luam xav tau rau cov kev pabcuam hauv Circuit Court tseem loj heev, EPON system yuav tsum nqa ob pob ntawv-hloovkev pabcuam thiab circuit-hloovkev pabcuam. EFM nqa TDM ntawm EPON li cas thiab yuav ua li cas kom ntseeg tau qhov zoo ntawm TDM cov kev pabcuam. Tsis muaj cov kev cai tshwj xeeb hauv thev naus laus zis, tab sis lawv yuav tsum sib haum nrog Ethernet thav duab hom. Multi-service EPON (MS-EPON) txais yuav E1 Tshaj Ethernet thev naus laus zis, uas daws tau qhov teeb meem ntawm kev hloov pauv ntawm TDM cov kev pabcuam ntawm Ethernet thav duab, ua rau EPON paub txog ntau qhov kev pabcuam xa mus thiab nkag mus. Tib lub sijhawm, MS-EPON kov yeej qhov sib txawv ntawmOLTthiabONU. Kev sib koom bandwidth tshwm sim muab Ethernet cov neeg siv nrog kev lav bandwidth lav.
Txoj kev encapsulation ntawm Ethernet ua rau EPON thev naus laus zis tsim nyog rau nqa cov kev pabcuam IP, tab sis nws kuj ntsib teeb meem loj - nws nyuaj rau nqa TDM cov kev pabcuam xws li lub suab lossis cov ntaub ntawv hauv Circuit Court. EPON yog Ethernet-based asynchronous kis tau tus mob network. Nws tsis muaj lub sijhawm ua haujlwm siab ua haujlwm sib koom ua ke thoob plaws lub network, thiab nws nyuaj rau ua kom tau raws li lub sijhawm thiab synchronization xav tau ntawm TDM cov kev pabcuam. Txhawm rau daws qhov teeb meem ntawm lub sijhawm synchronization ntawm TDM cov kev pabcuam thaum ua kom muaj kev nyuaj siab xws li QoS ntawm TDM cov kev pabcuam, peb yuav tsum tsis tsuas yog txhim kho tus qauv tsim ntawm EPON system nws tus kheej, tab sis kuj yuav tsum tau txais qee cov thev naus laus zis tshwj xeeb.
Qhov Performance index ntawm Circuit CourthloovKev pabcuam lub suab qhia tau hais tias thaum EPON system siv lub voj vooghloovTxoj kev los nqa cov kev pabcuam suab, nws yuav tsum ua kom tau raws li qhov yuav tsum tau ua ntawm YDN 065-1997 "General Technical Specification for Telephone Switching Equipment of Ministry of Posts thiab Telecommunications" thiab YD / T 1128-2001 "General Telephone Switching Equipment" Technical Specifications (Ntxiv 1 ) "yuav tsum tau rau lub voj voog dawb huvhloovsuab zoo. Yog li, EPON tam sim no muaj cov teeb meem hauv qab no nrog TDM cov kev pabcuam.
① TDM kev pabcuam QoS lav: Txawm hais tias qhov bandwidth nyob los ntawm TDM kev pabcuam me me, nws muaj cov kev xav tau siab ntawm cov ntsuas xws li qeeb, jitter, drift, thiab me ntsis yuam kev. Qhov no yuav tsum tsis tsuas yog xav txog yuav ua li cas kom txo tau qhov kev ncua sij hawm thiab jitter ntawm TDM kev pab cuam thaum lub sij hawm uplink dynamic bandwidth faib, tab sis kuj yuav tsum xyuas kom meej tias cov kev pab cuam TDM nruj me ntsis tswj qhov ncua sij hawm thiab jitter nyob rau hauv lub downlink bandwidth tswj lub tswv yim.
② Sijhawm thiab synchronization ntawm TDM cov kev pabcuam: TDM cov kev pabcuam muaj cov kev cai nruj tshwj xeeb ntawm lub sijhawm thiab synchronization. EPON yog qhov tseem ceeb ntawm kev sib kis asynchronous raws li Ethernet thev naus laus zis. Tsis muaj kev sib txuas lus ceev ceev synchronized thoob plaws hauv lub network. Lub moos raug txhais los ntawm Ethernet yog ± 100´10 thiab lub moos raug xav tau los ntawm cov kev pabcuam TDM yog ± 50´10. Tsis tas li ntawd, thaum muab kev sib txuas lus moos synchronized thoob plaws hauv lub network, TDM cov ntaub ntawv yuav tsum raug xa mus raws sij hawm raws li qhov ua tau kom tau raws li nws qhov kev xav tau thiab qhov yuam kev.
③ EPON survivability: TDM kev pab cuam kuj xav kom cov neeg nqa khoom network yuav tsum muaj kev ciaj sia zoo. Thaum muaj qhov ua tsis tiav loj, kev pabcuam tuaj yeem ntseeg tauhloovhauv lub sijhawm luv tshaj plaws. Vim tias EPON feem ntau yog siv rau kev nkag mus siv network, nws kuj nyob ze rau cov neeg siv, thiab ntau yam kev siv thiab kev siv ib puag ncig yog nyuaj. Nws yooj yim cuam tshuam los ntawm cov yam tsis paub xws li kev tsim kho hauv nroog, ua rau muaj kev sib tsoo xws li kev cuam tshuam kev sib txuas. Yog li, EPON system yog qhov yuav tsum tau ceev nrooj los muab kev tiv thaiv kev tiv thaiv tus nqi.
2. Cov kev pabcuam IP
EPON xa IP cov ntaub ntawv pob ntawv yam tsis muaj kev hloov pauv raws tu qauv thiab muaj kev ua haujlwm siab, uas tsim nyog rau cov ntaub ntawv kev pabcuam.
VolP thev naus laus zis, raws li cov thev naus laus zis kub hauv kev txhim kho, tau ua tiav qee qhov kev thov hauv xyoo tas los no, thiab yog ib txoj hauv kev zoo rau kev nqa cov kev pabcuam suab hauv IP network. Hauv EPON system, nws tseem tuaj yeem siv tau rau kev siv xov tooj ib txwm siv los ntawm kev ntxiv qee yam khoom siv VoIP lossis kev ua haujlwm. Siv VoIP thev naus laus zis, tsuav yog qhov ncua sij hawm thiab cov yam ntxwv ntawm lub suab nrov ntawm EPON kev pabcuam tau lees paub, lwm yam haujlwm raug tso tseg rau cov neeg siv sab hauv kev sib koom ua ke (IAD, Integrated Access Device) thiab lub hauv paus nkag mus rau qhov rooj nkag mus rau kev ua haujlwm lub suab. Kev sib kis. Txoj kev no yog qhov yooj yim rau kev siv thiab tuaj yeem ncaj qha chaw nres nkoj cov thev naus laus zis uas twb muaj lawm, tab sis yuav tsum muaj cov khoom siv hauv nruab nrab ntawm cov khoom siv nkag mus rau lub rooj vag, cov nqi tsim kho network ntau dua, thiab raug txwv los ntawm qhov tsis txaus ntawm VoIP thev naus laus zis nws tus kheej. Tsis tas li ntawd, E1 thiab N´64kbit / s cov ntaub ntawv kev pabcuam tsis tuaj yeem muab.
Thaum EPON system siv VoIP los nqa cov kev pabcuam suab, nws yuav tsum ua tau raws li cov lus qhia hauv qab no rau VoIP cov kev pabcuam suab.
① Lub sijhawm hloov pauv hloov pauv ntawm lub suab coding tsawg dua 60ms.
② Nws yuav tsum muaj 80ms tsis muaj peev xwm los xyuas kom meej tias tsis muaj kev hais lus tsis sib xws thiab jitters tshwm sim.
③ Lub hom phiaj kev soj ntsuam lub suab: Thaum lub network tej yam kev mob zoo, qhov nruab nrab tus nqi ntawm PSQM yog tsawg dua 1.5; thaum lub network tsis zoo (pob ntawv poob tus nqi = 1%, jitter = 20ms, ncua = 100ms), tus nqi nruab nrab ntawm PSQM yog <1.8; Thaum cov xwm txheej tsis zoo (pob ntawv poob tus nqi = 5%, jitter = 60ms, ncua = 400ms), qhov nruab nrab PSQM tsawg dua 2.0.
④ Kev ntsuam xyuas cov ntsiab lus ntawm kev hais lus: Thaum lub network tej yam kev mob zoo, qhov nruab nrab tus nqi ntawm MOS yog> 4.0; thaum lub network tsis zoo (pob ntawv poob tus nqi = 1%, jitter = 20ms, ncua = 100ms), tus nqi nruab nrab ntawm MOS yog <3.5; network Thaum cov xwm txheej tsis zoo (pob ntawv poob tus nqi = 5%, jitter = 60ms, ncua = 400ms), tus nqi nruab nrab ntawm MOS <3.0.
⑤ Encoding tus nqi: G.711, encoding tus nqi = 64kbit / s. Rau G.729a, qhov xav tau coding tus nqi yog <18kbit / s. Rau G.723.1, G.723.1 (5.3) coding tus nqi yog <18kbit / s, thiab G.723.1 (6.3) coding tus nqi yog <15kbit / s.
⑥ Ncua qhov Performance index (loopback ncua): VoIP ncua suav nrog codec ncua, cov tswv yim tsis ncua ntawm qhov kawg tau txais, thiab kev ncua hauv kab. Thaum siv G.729a encoding, lub loopback ncua yog <150ms. Thaum siv G.723.1 encoding, lub loopback ncua yog <200ms.
3.CATV business
Rau cov kev pabcuam CATV analog, EPON tuaj yeem nqa tau tib yam li GPON: ntxiv lub wavelength (qhov no yog WDM thev naus laus zis thiab tsis muaj dab tsi ua rau EPON thiab GPON nws tus kheej).
PON thev naus laus zis yog txoj hauv kev zoo tshaj plaws kom ua tiav FTTx broadband nkag. EPON yog ib qho tshiab optical access network technology tsim los ntawm combining Ethernet technology thiab PON technology. Nws tuaj yeem siv los xa cov suab, cov ntaub ntawv thiab cov kev pabcuam video thiab yog sib xws. Rau qee qhov kev pabcuam tshiab yav tom ntej, EPON yuav dhau los ua cov thev naus laus zis tseem ceeb rau kev pabcuam broadband kho qhov muag nrog nws cov txiaj ntsig zoo xws li kev siv bandwidth siab, kev ua haujlwm siab, thiab kev nthuav dav yooj yim.
Kev tiv thaiv txheej txheem ntawm PON system
Txhawm rau txhim kho kev ntseeg tau ntawm lub network thiab kev muaj sia nyob, kev tiv thaiv fiber ntau hloov tshuab tuaj yeem siv rau hauv PON system. Kev tiv thaiv fiber ntau hloov tshuab tuaj yeem ua tau nyob rau hauv ob txoj kev: ① tsis siv neeg hloov, ua los ntawm kev ua txhaum; ② yuam kev hloov, tshwm sim los ntawm kev tswj hwm cov xwm txheej.
Muaj peb hom kev tiv thaiv fiber ntau: nraub qaum fiber ntau tiv thaiv,OLTPON chaw nres nkoj redundancy tiv thaiv, thiab kev tiv thaiv tag nrho, raws li pom hauv daim duab 1.16.
Backbone fiber redundancy tiv thaiv (Daim duab 1.16 (a)): siv ib qho PON chaw nres nkoj nrog ib qho built-in 1'2 opticalhloovntawmOLTPON chaw nres nkoj; siv 2: N optical splitter; tusOLTntes cov kab xwm txheej; Tsis muaj cov cai tshwj xeeb rau covONU.
OLTPON chaw nres nkoj redundancy tiv thaiv (Daim duab 1.16 (b)): Qhov chaw nres nkoj PON nyob rau hauv qhov chaw txias txias, siv 2: N optical splitter; tusOLTntes cov kab xwm txheej, thiab kev hloov pauv yog ua los ntawmOLT, tsis muaj kev tshwj xeeb rau covONU.
Kev tiv thaiv tag nrho (Daim duab 1.16 (c)): ob lub ntsiab thiab thaub qab PON chaw nres nkoj nyob hauv lub xeev ua haujlwm; ob 2: N siv optical splitters; ib opticalhloovyog ua nyob rau hauv pem hauv ntej ntawm lubONUPON chaw nres nkoj, thiab lubONUkuaj cov kab xwm txheej thiab txiav txim siab siv cov kab tseem ceeb thiab kev hloov pauv yog ua los ntawm covONU.
Kev tiv thaiv kev hloov pauv ntawm PON system tuaj yeem txhawb nqa rov qab tsis siv neeg lossis phau ntawv xa rov qab ntawm cov kev pabcuam tiv thaiv. Rau lub tshuab xa rov qab tsis siv neeg, tom qab tshem tawm qhov hloov pauv tsis ua haujlwm, tom qab qee lub sijhawm tos rov qab, cov kev pabcuam tiv thaiv yuav tsum tau rov qab mus rau txoj haujlwm qub. Lub sijhawm tos rov qab tuaj yeem teem sijhawm.