I roto i te punaha EPON, ka hono te OLT ki te maha o nga ONU (waahanga whatunga whatu) na roto i te POS (whakawehe whatu hāngū).Ka rite ki te matua o EPON, OLT kōwae whatu ka pā tika te mahi o te pūnaha 10G EPON katoa.
1.Introduction ki 10G EPON hangarite OLT kōwae whatu
Ko te 10G EPON symmetrical OLT optical module e whakamahi ana i te urunga pakaru o te hono me te whakaheke i nga tikanga tuku tonu, e whakamahia ana mo te hurihanga whatu / hiko i roto i nga punaha 10G EPON.
Ko te waahanga whiwhi ko te TIA (whakakaha whakawhiti), he APD (Avalanche Photodiode) i te 1270 / 1310nm, me nga LA e rua (whakaiti whakakaha) i te 1.25 me te 10.3125 Gbit / s reiti.
Ko te mutunga tuku he mea tito he 10G EML (hikohiko-absorption modulation laser) me te 1.25 Gbit / s DFB (taiaho urupare tohatoha), a ko ona roangaru tuku he 1577 me te 1490nm, ia.
Kei roto i te ara iahiko taraiwa he hikohiko APC (Automatic Optical Power Control) me te arahiko TEC (Temperature Compensation) mo te pupuri i te roangaru 10G laser tukunga.Ko te tuku me te tango i te aro turuki ka whakatinanahia e te miihini miihini maramara kotahi e ai ki te kawa SFF-8077iv4.5.
Na te mea ka whakamahia e te mutunga whiwhi o te OLT orohiko te urunga powhiri, he mea nui te wa tatūnga.Mena he roa te wa whakatau o te pohiri, ka tino pa ki te tairongo, ka kore pea e pai te mahi o te powhiri pakaru.E ai ki nga whakaritenga o te kawa IEEE 802.3av, ko te wa whakatuu o te 1.25Gbit / s te urunga pakaru me <400 ns, me te tairongo o te tango pakaru kia <-29.78 dBm me te iti o te hapa hapa o te 10-12;me te 10.3125 Gbit / s Ko te wa tatūnga powhiringa pakaru me <800ns, me te tairongo o te poki kia <-28.0 dBm me te reiti hapa hapa o te 10-3.
2.10G EPON hangarite OLT hoahoa kōwae whatu
2.1 Kaupapa hoahoa
Ko te 10G EPON symmetrical OLT optical module is composed of a triplexer (kotahi-fiber three-way module), te tuku, te whiwhi, me te aroturuki.Kei roto i te triplexer e rua nga taiaho me te kaitoi.Ko te marama tuku me te marama kua riro ka whakauruhia ki roto i te taputapu whatu na roto i te WDM (Wavelength Division Multiplexer) ki te whakatutuki i te tuku-a-roopu kotahi.Ko tona hanganga e whakaatuhia ana i te Whakaahua 1.
Ko te waahanga whakawhiti e rua nga laser, ko tana mahi matua ko te huri i nga tohu hiko 1G me te 10G ki nga tohu tohu, ia, me te pupuri i te kaha o te mana whatu i roto i te ahua kati ma te hikohiko APC mamati.I te wa ano, ko te miihini miihini kotahi-marama te whakahaere i te nui o te huringa whakarereke kia whiwhi i te ōwehenga ngaro e hiahiatia ana e te punaha.Ka taapirihia te arahiko TEC ki te 10G whakawhiti iahiko, e tino whakapumau ana i te roangaru whakaputa o te laser 10G.Ko te wahanga whiwhi e whakamahi ana i te APD ki te huri i te tohu whatu pakaru i kitea hei tohu hiko, ka whakaputa i muri i te whakakaha me te hanga.Kia taea ai e te tairongo te tae ki te awhe pai, he mea tika ki te whakarato i te pehanga teitei pumau ki te APD i nga rereke rereke.Ko te rorohiko maramara kotahi ka tutuki tenei whainga ma te whakahaere i te ara iahiko ngaohiko teitei APD.
2.2 Te whakatinanatanga o te powhiri pakaru-rua
Ko te waahanga whiwhi o te 10G EPON hangarite OLT kōwae whatu e whakamahi ana i te tikanga tango pakaru.Me whiwhi tohu pakaru o nga reeti rereke e rua o te 1.25 me te 10.3125 Gbit / s, e hiahia ana te waahanga whiwhi kia kaha ki te wehewehe i nga tohu whatu o enei reeti rereke e rua kia pai ai te whiwhi tohu hiko whakaputa.E rua nga kaupapa mo te whakatinana i te reeti-rua i te urunga pakaru o nga kowae whatu OLT e whakaarohia ana i konei.
Na te mea ka whakamahia e te tohu whatu urunga te hangarau TDMA (Waiwhanga Waa Whakaaetanga Maha), kotahi noa te reiti o te rama pakaru i te wa ano.Ka taea te wehe i te tohu whakauru i roto i te rohe whatu i roto i te 1: 2 wehewehe whatu, penei i Whakaatuhia i te Whakaahua 2. Ka whakamahi ranei i te kaitirotiro tere tere ki te huri i nga tohu tohu 1G me 10G ki nga tohu hiko ngoikore, ka wehe i nga tohu hiko e rua. nga tohu he rereke nga reiti na roto i te TIA bandwidth nui ake, penei i te Whakaahua 3.
Ko te kaupapa tuatahi e whakaatuhia ana i te Whakaahua 2 ka kawea mai he mate whakaurunga ka pahemo te marama i roto i te 1: 2 whakawehe whatu, me whakanui i te tohu whatu whakauru, na reira ka whakauruhia he whakahiato whatu ki mua o te wehenga whatu.Ko nga tohu whatu kua wehea ka tukuna ki te hurihanga whatu / hiko e nga kaitirotiro o nga reiti rereke, ka mutu e rua nga momo whakaputanga tohu hiko pumau.Ko te kino nui rawa atu o tenei otinga ko te whakamahi i te whakahiato mata me te 1: 2 wehewehe whatu, a ka hiahiatia kia rua nga kaitirotiro hei huri i te tohu tohu, ka piki ake te uaua o te whakatinanatanga me te whakanui ake i te utu.
I te kaupapa tuarua e whakaatuhia ana i te FIG.3, ko te tohu tohu whakaurunga me haere noa i roto i te kaitirotiro me te TIA ki te whakatutuki i te wehenga i roto i te rohe hiko.Ko te kaupapa matua o tenei otinga kei roto i te kowhiringa o te TIA, e kii ana kia whai a TIA he bandwidth 1 ~ 10Gbit / s, me te wa ano he tere te whakautu a TIA i roto i tenei bandwidth.Anake ma te tawhā o nāianei o TIA taea te tiki i te uara whakautu tere, te tairongo whiwhi e taea te pai taurangi.Ko tenei otinga ka tino whakaiti i te uaua o te whakatinanatanga me te pupuri i nga utu i raro i te mana whakahaere.I roto i te hoahoa tonu, ko taatau te tikanga ka whiriwhiri i te kaupapa tuarua hei whakatutuki i te urunga pakaru-rua.
2.3 Te hoahoa o te ara iahiko taputapu i te pito whiwhi
Ko te whakaahua 4 te ara iahiko taputapu o te wahanga pakaru.I te wa ka pakaru te urunga whatu, ka huri te APD i te tohu whatu ki te tohu hiko ngoikore ka tukuna ki te TIA.Ka whakanuia te tohu e te TIA ki te tohu hiko 10G, 1G ranei.Ko te tohu hiko 10G he whakauru ki te 10G LA na roto i te hononga pai o te TIA, a ko te tohu hiko 1G te whakauru ki te 1G LA na roto i te hononga kino o te TIA.Ko nga puritanga C2 me C3 he pūnga hono e whakamahia ana hei whakatutuki i te putanga 10G me te 1G AC-honohono.I whiriwhiria te tikanga hono-AC na te mea he maamaa ake i te tikanga hono-DC.
Engari, ko te hononga AC te utu me te tukunga o te puri, a, ko te tere o te whakautu ki te tohu e pa ana ki te utu me te wa tuku, ara, kaore e taea te whakautu i te tohu i te wa.Ko tenei ahuatanga ka ngaro etahi wa whakatau, no reira he mea nui ki te whiriwhiri me pehea te rahi o te punga hononga AC.Mena ka tohua he punga hononga hono iti ake, ka taea te whakapoto i te wa whakatau, ka taea te whiwhi katoa te tohu e tukuna ana e te ONU i ia mokamoka me te kore e pa ki te paanga o te powhiri na te mea he roa rawa te waa whakatau me te taenga mai o te wa e whai ake nei. mokamoka.
Heoi, he iti rawa te kaha o te kaha ka pa ki te hononga hono me te tino whakaiti i te pumau o te powhiri.Ka taea e te kaha nui ake te whakaiti i te jitter o te punaha me te whakapai ake i te maarama o te pito whiwhi.No reira, kia whai whakaaro ki te wa whakatau i te pohiri me te tairongo o te powhiri, me whiriwhiri nga puritanga honohono tika C2 me C3.I tua atu, hei whakarite i te pumau o te tohu hiko whakauru, ka honoa he puri hononga me tetahi parenga 50Ω ki te tauranga kino o LA.
LVPECL (Ngaohiko Iti Pai Emitter Coupling Logic) ara iahiko i hangaia he parenga R4 me R5 (R6 me R7) me te puna ngaohiko 2.0 V DC na roto i te putanga tohu rereke na 10G (1G) LA.tohu hiko.
2.4 Wāhanga whakarewa
Ko te waahanga tuku o te 10G EPON symmetric OLT optical module ka wehea ki nga waahanga e rua o te 1.25 me te 10G te tuku, ka tukuna nga tohu me te roangaru o te 1490 me te 1577 nm ki te hono.Ka mau i te waahanga tuku 10G hei tauira, ka uru te rua o nga tohu rerekee 10G ki roto i te maramara CDR (Clock Shaping), he AC-honoa ki te maramara taraiwa 10G, ka mutu ka uru rereke ki te taiaho 10G.No te mea ka nui te awe o te huringa o te pāmahana i runga i te roangaru tukunga laser, hei whakapumau i te roangaru ki te taumata e hiahiatia ana e te kawa (e hiahia ana te kawa ki te 1575 ~ 1580nm), me whakatika te waa mahi o te iahiko TEC, na reira. kia pai te whakahaere i te roangaru whakaputa.
3. Nga hua whakamatautau me te tātari
Ko nga tohu whakamatautau matua o te 10G EPON symmetric OLT kōwae whatu ko te wa tatūnga kaiwhiwhi, te aro o te kaiwhiwhi, me te tuku hoahoa kanohi.Ko nga whakamatautau motuhake e whai ake nei:
(1) Whiwhi wa tatūnga
I raro i te taiao mahi noa o te mana whatu pakaru uplink o -24.0 dBm, ko te tohu whatu e tukuna ana e te puna marama pakaru ka whakamahia hei timatanga inenga, a ka whiwhi te kōwae me te whakatu i tetahi tohu hiko katoa hei tohu mutunga ine, kare e aro ki te wa roa o te marama i roto i te muka whakamātautau.Ko te 1G ine te wa tatūnga powhiri pakaru he 76.7 ns, e tutuki ana ki te paerewa o te ao <400 ns;ko te 10G te wa tatūnga powhiri he 241.8 ns, e tutuki ana hoki ki te paerewa o te ao <800 ns.
3. Nga hua whakamatautau me te tātari
Ko nga tohu whakamatautau matua o te 10G EPON symmetric OLT kōwae whatu ko te wa tatūnga kaiwhiwhi, te aro o te kaiwhiwhi, me te tuku hoahoa kanohi.Ko nga whakamatautau motuhake e whai ake nei:
(1) Whiwhi wa tatūnga
I raro i te taiao mahi noa o te mana whatu pakaru uplink o -24.0 dBm, ko te tohu whatu e tukuna ana e te puna marama pakaru ka whakamahia hei timatanga inenga, a ka whiwhi te kōwae me te whakatu i tetahi tohu hiko katoa hei tohu mutunga ine, kare e aro ki te te roa o te marama i roto i te muka whakamatautau.Ko te 76.7 ns te ine i te wa tatūnga powhiri pakaru 1G, e tutuki ana ki te paerewa o te ao <400 ns;ko te 10G te wa tatūnga powhiri he 241.8 ns, e tutuki ana hoki ki te paerewa o te ao <800 ns.
