Kuyambitsa machitidwe osiyanasiyana a PON
1. ukadaulo wa APON
M'katikati mwa zaka za m'ma 1990, ogwiritsira ntchito maukonde akuluakulu adakhazikitsa Full Service Access Network Alliance (FSAN), omwe cholinga chake ndi kupanga muyezo wogwirizana wa zida za PON kuti opanga zida ndi ogwira ntchito athe kulowa mumsika wa zida za PON ndikupikisana limodzi. Chotsatira choyamba ndi ndondomeko ya 155Mbit / s PON system muyezo mu ITU-T G.983 mndandanda wa malangizo. Chifukwa ATM imagwiritsidwa ntchito ngati protocol yonyamula, dongosololi limatchedwa dongosolo la APON, ndipo nthawi zambiri silimvetsetseka ngati limapereka ntchito za ATM zokha. Choncho, imatchedwanso Broadband Passive Optical Network (BPON) dongosolo kusonyeza kuti dongosololi likhoza kupereka mautumiki a Ethernet Broadband monga kupeza maukonde, kugawa mavidiyo, ndi mizere yothamanga kwambiri. Komabe, m'badwo uno wa machitidwe a FSAN, dzina lomwe limagwiritsidwa ntchito kwambiri ndi APON. Kenako, APON muyezo anali kumatheka, ndipo anayamba kuthandiza downlink 622 Mbit / s mitengo, ndi zinthu zatsopano anawonjezera njira chitetezo, mphamvu bandwidth allocation (DBA), ndi mbali zina.
APON imagwiritsa ntchito ATM ngati protocol yonyamula. Kutumiza kwapansi ndi mtsinje wa ATM wosalekeza wokhala ndi 155.52Mbit / s kapena 622.08Mbit / s. Selo lapadera loyang'anira ntchito ndi kukonza (PLOAM) cell imalowetsedwa mumtsinje wa data.Kutumiza kwapamwamba ndi maselo a ATM mu mawonekedwe ophulika. Kuti mukwaniritse kufalikira ndi kulandilidwa, 3-byte yakuthupi imawonjezeredwa kutsogolo kwa selo lililonse la 53-byte. Kwa mlingo wofunikira wa 155.52 Mbit / s, ndondomeko yotumizira imakhazikitsidwa pazithunzi zochepetsera zomwe zili ndi maselo 56 a ATM (53 bytes pa selo); pamene pang'ono mlingo wawonjezeka kwa 622.08 Mbit / s, ndi downlink chimango kukodzedwa kwa 224 Cell. Pamlingo woyambira wa 155.52 Mbit / s, mawonekedwe a uplink chimango ndi ma cell 53, selo lililonse ndi 56 byte (53 ATM cell byte kuphatikiza 3 mabayiti pamwamba). Kuphatikiza pa ma cell a data 54 mu chimango cha downlink, pali ma cell awiri a PLOAM, amodzi kumayambiriro kwa chimango ndi china pakati pa chimango. Selo lililonse la PLOAM lili ndi chilolezo chotumizira ma uplink cha cell yeniyeni yomwe ili pamtunda wakumtunda (ma cell 53 Upstream frame ali ndi ma grants 53 omwe amajambulidwa m'maselo a PLOAM) ndi chidziwitso cha OAM & P. APON imapereka ntchito za OAM zolemera kwambiri komanso zathunthu, kuphatikiza kuwunikira zolakwika pang'ono, zowopsa, zodziwikiratu, ndikusaka zokha. Monga njira yachitetezo, imatha kusanthula ndi kubisa deta yotsitsa.
Kuchokera pamalingaliro akusintha kwa data, mu APON, deta ya ogwiritsa ntchito iyenera kutumizidwa pansi pa kutembenuka kwa protocol (AAL1 / 2 ya TDM ndi AAL5 pakupatsira paketi ya data). Kutembenuka kumeneku kumakhala kovuta kuti agwirizane ndi bandwidth yapamwamba, ndipo zida zomwe zimagwira ntchitoyi zimaphatikizapo zida zina zothandizira, monga kukumbukira kwa selo, Glue Logic, ndi zina zotero, zomwe zimawonjezeranso ndalama zambiri pa dongosolo.
Tsopano, kaya ndi mtunda wautali wapaintaneti kapena malo olumikizirana ma network a metropolitan area, ukadaulo wolumikizana ndi digito wasintha pang'onopang'ono kuchoka ku ATM-centric kupita ku IP-based kuti apereke mavidiyo, ma audio, ndi ma data. Chifukwa chake, mawonekedwe a netiweki okhawo omwe angagwirizane ndi mwayi wopezekapo komanso matekinoloje amtsogolo apaintaneti omwe angapangitse tsogolo la IP-optical network kukhala zenizeni.
APON yasiya msika pang'onopang'ono chifukwa chazovuta zake komanso kutsika kwapa data.
2. EPON
Pafupifupi nthawi yomweyo monga dongosolo la APON, IEEE inakhazikitsanso gulu lofufuza la Ethernet (EFM) loyamba la mailosi (EFM) kuti likhazikitse EPON (Ethernet Passive Optical Network) yochokera ku Ethernet (Ethernet Passive Optical Network) ponena za maukonde ofikira fiber, kusonyeza chiyembekezo chabwino cha msika. Gulu lophunzirira ndi la gulu la IEEE 802.3 lomwe linapanga muyezo wa Ethernet. Momwemonso, kuchuluka kwa kafukufuku wake kumangokhala ndi kamangidwe kake, ndipo kuyenera kugwirizana ndi ntchito zomwe zilipo 802.3 media access control (MAC). Mu Epulo 2004, gulu lofufuza lidayambitsa mulingo wa IEEE 802.3ah wa EPON, wokhala ndi uplink ndi downlink rate wa 1 Gbit / s (pogwiritsa ntchito 8B / 10B coding, ndi mzere wa 1.25 Gbit / s), kutha kwa opanga EPON ' kugwiritsa ntchito ma protocol achinsinsi kuti apange zida zoyenera.
EPON ndi njira yofikira pa burodibandi yozikidwa paukadaulo wa Ethernet. Imagwiritsa ntchito PON topology kukhazikitsa mwayi wofikira pa Ethernet. Matekinoloje ofunikira a gawo lolumikizana ndi data makamaka ndi awa: Multiple Access Control Protocol (MPCP) ya uplink channel, plug and play vuto laONU, ndondomeko zamalipiro oyambira ndi kuchedwetsa aOLT, ndi zovuta zogwirizana ndi protocol.
Zosanjikiza zakuthupi za IEEE 802.3ah zimaphatikizanso ma point-to-point (P2P) olumikizidwa ndi ulusi wamaso ndi mawaya amkuwa, komanso mawonekedwe a PON network point-to-multipoint (P2MP). Pofuna kuwongolera magwiridwe antchito ndi kukonza zolakwika, njira ya OAM imaphatikizidwanso. Kwa P2MP network topology, EPON imachokera pa makina otchedwa Multipoint Control Protocol (MPCP), yomwe ndi ntchito mkati mwa MAC sublayer. MPCP imagwiritsa ntchito mauthenga, makina a boma, ndi zowerengera nthawi kuti ziwongolere kupeza kwa P2MP network topology. Gawo lililonse la Optical network (ONU) mu P2MP network topology ili ndi gulu la protocol la MPCP lomwe limalumikizana ndi gulu la protocol la MPCP muOLT. .
Maziko a EPON / MPCP protocol ndi gawo-to-point simulation sublayer, yomwe imapangitsa kuti P2MP network iwoneke ngati gulu la P2P kumagulu apamwamba a protocol.
Kuti muchepetse mtengo waONU, matekinoloje ofunikira a EPON wosanjikiza amakhazikika paOLT, kuphatikizapo kulunzanitsa kwachangu kwa zizindikiro zophulika, kugwirizanitsa maukonde, kulamulira mphamvu kwa ma modules optical transceiver, ndi kulandirira kosinthika.
EPON imaphatikiza zabwino za PON ndi Ethernet data product kupanga zabwino zambiri zapadera. Dongosolo la EPON limatha kupereka ma uplink ndi downlink bandwidths mpaka 1 Gbit / s, omwe angakwaniritse zosowa za ogwiritsa ntchito mtsogolo kwa nthawi yayitali. EPON imagwiritsa ntchito ukadaulo wochulukirachulukira kuthandiza ogwiritsa ntchito ambiri, ndipo wogwiritsa ntchito aliyense amatha kusangalala ndi bandwidth yayikulu. Dongosolo la EPON siligwiritsa ntchito zida za ATM zamtengo wapatali ndi zida za SONET, ndipo zimagwirizana ndi Ethernet yomwe ilipo, imathandizira kwambiri dongosolo la dongosolo, zotsika mtengo, komanso zosavuta kukweza. Chifukwa cha moyo wautali wa zida za passive optical, ndalama zosamalira mizere yakunja zimachepetsedwa kwambiri. Nthawi yomweyo, mawonekedwe amtundu wa Ethernet amatha kutenga mwayi pazida zotsika mtengo za Ethernet ndikusunga ndalama. Kapangidwe ka PON kokha kamatsimikizira kuti maukonde ndi owopsa kwambiri. Malingana ngati zida zowonongeka zisinthidwa, maukonde amatha kusinthidwa kukhala 10 Gbit / s kapena apamwamba. EPON sichingaphatikizepo ma TV omwe alipo kale, deta ndi mautumiki a mawu, komanso kuti agwirizane ndi mautumiki amtsogolo monga TV ya digito, VoIP, msonkhano wamavidiyo ndi VOD, ndi zina zotero, kuti akwaniritse mwayi wogwirizanitsa ntchito.
Kugwiritsa ntchito mokwanira kwa onyamula EPON ndi matekinoloje ena ofikira kumawonjezeranso njira zothetsera ukadaulo wa Broadband.
Kugwiritsa ntchito EPON kungapangitse DSL kuthetsa malire a mtunda wachikhalidwe ndikukulitsa kufalikira. Pamene aONUimaphatikizidwa mu Digital Subscriber Line Access Multiplexer (DSLAM), mtundu wofikirika wa DSL ndipo gulu lake la ogwiritsa ntchito lidzawonjezeka kwambiri.
Momwemonso, pophatikiza CMTS (Cable Modem Termination System) yaONU, EPON ikhoza kupereka bandiwifi kumalumikizidwe a Ma Cable omwe alipo kale, ndikulola ogwiritsa ntchito ma chingwe kuti agwiritse ntchito njira zolumikizirana pomwe akuchepetsa ndalama zomanga ndi zoyendetsera.
Muzochitika zonsezi, ogwiritsira ntchito amatha kuonjezera ogwiritsa ntchito awo potengera momwe alili pa intaneti komanso ndalama zawo. EPON imathanso kukulitsa MSPP (Multiple Services Provisioning Platform) ndi IP / Ethernet.
Kuphatikiza apo, ukadaulo wa EPON ungagwiritsidwenso ntchito kuthana ndi vuto la data ya uplink ya siteshoni yoyambira muukadaulo wopanda zingwe wophatikizidwa ku netiweki yapakati.
3.GPON
Mu 2001, FSAN idayambitsa kuyesetsa kwatsopano kuti ma network a PON agwire ntchito pamwamba pa 1 Gbit / s. Kuwonjezera pa kuthandizira mitengo yapamwamba, ndondomeko yonse yakhala yotseguka kuti aganizirenso ndikupeza njira yabwino komanso yothandiza kwambiri pothandizira mautumiki ambiri, ntchito za OAM & P ndi scalability. Monga gawo la ntchito ya GPON, FSAN poyamba inasonkhanitsa zofunikira za mamembala ake onse (kuphatikizapo akuluakulu ogwira ntchito padziko lonse lapansi), ndiye potengera izi, analemba chikalata chotchedwa Gigabit Service Requirements (GSR) ndipo adachipanga kukhala ndondomeko yovomerezeka ( G.GON. GSR) kupita ku ITU-T. Zofunikira zazikulu za GPON zofotokozedwa mufayilo ya GSR ndi izi.
l Imathandizira ntchito zonse, kuphatikiza mawu (TDM, SONET / SDH), Efaneti (10/100 Base-T), ATM, mizere yobwereketsa, ndi zina zambiri.
l Mtunda wakuthupi wophimbidwa ndi osachepera 20km, ndipo mtunda womveka umangokhala 60km.
l Imathandizira mitengo yosiyanasiyana yogwiritsira ntchito ndondomeko yomweyi, kuphatikizapo symmetrical 622 Mbit / s, symmetrical 1.25 Gbit / s, kumunsi kwa 2.5 Gbit / s ndi kumtunda kwa 1.25 Gbit / s, ndi mitengo ina.
l OAM & P ntchito zamphamvu zomwe zimatha kupereka kasamalidwe komaliza mpaka kumapeto.
l Chifukwa cha mawonekedwe owulutsa a PON, chitetezo cha ma downlink services chiyenera kutsimikiziridwa pamlingo wa protocol.
FSAN inanena kuti mapangidwe a GPON akuyenera kukwaniritsa zolinga zotsatirazi.
l Mapangidwe a chimango amatha kukulitsidwa kuchokera ku 622Mbit / s mpaka 2.5Gbit / s, ndipo amathandizira asymmetric bit rate.
l Kutsimikizira kugwiritsidwa ntchito kwa bandwidth kwakukulu komanso kuchita bwino pabizinesi iliyonse.
l Gwirizanitsani ntchito iliyonse (TDM ndi paketi) mu chimango cha 125ms kudzera pa GFP.
l Kutumiza koyenera komanso kopanda mtengo kwa ntchito zoyera za TDM.
l Kugawa kwamphamvu kwa bandwidth kwa aliyenseONUkudzera pa bandwidth pointer.
Popeza GPON inaganiziranso ntchito ndi zofunikira za PON kuchokera pansi mpaka pansi, idayala maziko a yankho latsopano ndipo salinso zochokera muyeso yapitayi ya APON, kotero opanga ena amachitcha PON yachibadwidwe (mawonekedwe achilengedwe PON). Kumbali imodzi, GPON imasunga ntchito zambiri zomwe sizikugwirizana mwachindunji ndi PON, monga mauthenga a OAM, DBA, ndi zina zotero. Komano, GPON imachokera ku TC (transmission convergence) yatsopano. GFP (general framing procedure) yosankhidwa ndi FSAN ndi ndondomeko yokhazikitsidwa ndi chimango yomwe imasintha zambiri zautumiki kuchokera kwa makasitomala apamwamba amtundu wa zoyendera kupyolera mu makina ambiri. Maukonde oyendetsa amatha kukhala amtundu uliwonse wa netiweki, monga SONET / SDH ndi ITU-T G.709 (OTN), etc. Zambiri zamakasitomala zitha kukhala zotengera paketi (monga IP / PPP, mwachitsanzo IP / Point to Point protocal , kapena Efaneti MAC mafelemu, etc. ), Ikhozanso kukhala mtsinje wokhazikika wokhazikika kapena mitundu ina yazambiri zamabizinesi. GFP yakhazikitsidwa mwalamulo ngati muyeso wa ITU-T G.7041. Chifukwa GFP imapereka njira yabwino komanso yosavuta yotumizira mautumiki osiyanasiyana pa intaneti yotumizirana ma synchronous, ndi bwino kuigwiritsa ntchito ngati maziko a GPON TC wosanjikiza. Kuphatikiza apo, mukamagwiritsa ntchito GFP, GPON TC imakhala yolumikizana ndipo imagwiritsa ntchito mafelemu a SONET / SDH 8kHz (125ms), zomwe zimathandiza GPON kuthandizira mwachindunji ntchito za TDM. Mu muyezo wotulutsidwa wa G.984.3, malingaliro a FSAN pa GFP monga ukadaulo wosinthira wosanjikiza wa TC adatengera, ndipo kukonza kosavuta kudachitika, komwe kudatchedwa GPON encapsulation method (GEM, GPONEncapsulationMethod).
Kugwiritsa ntchito dongosolo la EPON
EPON, monga teknoloji yatsopano yopezera burodibandi, ndi njira yoperekera ntchito zonse zomwe zingathe kuthandizira mautumiki a deta komanso mautumiki a nthawi yeniyeni monga mawu ndi kanema.
Mapangidwe anjira ya EPON amatha kugwiritsa ntchito mafunde atatu. Ngati simuganizira kuthandizira ntchito za CATV kapena DWDM, mafunde awiri amagwiritsidwa ntchito nthawi zambiri. Mukamagwiritsa ntchito mafunde atatu, kutalika kwa mtunda ndi 1310nm, kutsika kwamtunda ndi 1490nm, ndipo mawonekedwe owonjezera a 1550nm amawonjezeredwa. Kuwonjezeka kwa 1550nm wavelength kumagwiritsidwa ntchito kutumiza mwachindunji ma siginecha a analogi. Chifukwa chakuti chizindikiro chamakono chamakono cha analogi chikadali cholamulidwa ndi mautumiki a wailesi ndi wailesi yakanema, akuyerekezedwa kuti sichidzasinthidwa kwathunthu ndi mavidiyo a digito mpaka 2015. Choncho, dongosolo la EPON lopangidwa panopa liyenera kuthandizira mavidiyo onse a digito ndi mavidiyo a analogi. 1490nm yoyambirira imanyamulabe data yotsika, makanema apa digito ndi mautumiki a mawu, ndipo 1310nm imatumiza ma sign a mawu a uplink, kanema wa digito pakufunika (VOD), ndikupempha zambiri pakutsitsa deta.
Zizindikiro zamawu zimakhala ndi zofunika kwambiri pakuchedwa ndi jitter, ndipo Ethernet sapereka kuchedwa kwa paketi yomaliza, kutayika kwa paketi, ndi mphamvu zowongolera bandwidth. Chifukwa chake, momwe mungatsimikizire mtundu wautumiki pamene EPON ikuwongolera ma siginecha a mawu ndizovuta zomwe ziyenera kuthetsedwa.
1. TDM bizinesi
Pakadali pano, kuthekera kokayikitsa kwa EPON kwamitundu ingapo ndikutha kutumiza ntchito zachikhalidwe za TDM.
Ntchito za TDM zomwe zatchulidwa apa zikuphatikiza mitundu iwiri ya mautumiki amawu (POTS, Popular Old Telephone Service) ndi ntchito zamadera (T1 / El, N'64kbit / s mizere yobwereketsa).
Pamene makina a EPON ali ndi ma data operekedwa (2048kbit / s kapena 13'64kbit / s data services), TDM over Ethernet ikulimbikitsidwa. Dongosolo la EPON limatha kutengera kusintha kwa dera kapena VolP mukanyamula mau.
M'zaka zingapo zikubwerazi, chifukwa kufunikira kwa msika kwa ntchito zoyendera dera kukadali kwakukulu, dongosolo la EPON likuyenera kunyamula mapaketi onse awiri-kusinthantchito ndi dera-kusinthantchito. Kodi EFM imanyamula bwanji TDM pa EPON komanso momwe mungawonetsere kuti ntchito za TDM zili bwino. Palibe zofunikira zenizeni muukadaulo, koma ziyenera kugwirizana ndi mawonekedwe a Ethernet frame. Multi-service EPON (MS-EPON) imagwiritsa ntchito ukadaulo wa E1 Over Ethernet, womwe umathetsa bwino vuto lakusintha kwa ntchito za TDM pamafelemu a Efaneti, ndikupangitsa EPON kuzindikira kutumizirana kwamautumiki ambiri ndi mwayi. Pa nthawi yomweyo, MS-EPON amagonjetsa kusiyana pakatiOLTndiONU. Chochitika chamkangano cha bandwidth chogawana chimapatsa ogwiritsa ntchito Ethernet chitsimikizo chotsimikizika cha bandwidth.
Njira ya encapsulation ya Ethernet imapangitsa teknoloji ya EPON kukhala yoyenera kunyamula mautumiki a IP, koma imakhalanso ndi vuto lalikulu-ndizovuta kunyamula mautumiki a TDM monga deta ya mawu kapena dera. EPON ndi Ethernet-based asynchronous transmission network. Ilibe wotchi yolondola kwambiri yolumikizidwa pa netiweki yonse, ndipo ndizovuta kukwaniritsa zofunikira zanthawi ndi kulunzanitsa kwa ntchito za TDM. Kuti tithane ndi vuto la kulunzanitsa nthawi kwa ntchito za TDM ndikuwonetsetsa zovuta zaukadaulo monga QoS ya mautumiki a TDM, sitiyenera kuwongolera kamangidwe ka EPON yokha, komanso tifunika kutengera matekinoloje ena.
Mlozera wa magwiridwe antchito a derakusinthamautumiki amawu amasonyeza kuti pamene dongosolo la EPON limagwiritsa ntchito derakusinthaNjira yonyamula mautumiki a mawu, iyenera kukwaniritsa zofunikira za YDN 065-1997 "General Technical Specification for Telephone switching Equipment of the Ministry of Posts and Telecommunications" ndi YD / T 1128-2001 "General Telephone Switching Equipment" Specifications Technical (Supplement 1 ) "Zofunikira pamayendedwe abwinokusinthakhalidwe la mawu. Chifukwa chake, EPON pakadali pano ili ndi zovuta zotsatirazi ndi ntchito za TDM.
① Chitsimikizo cha TDM cha QoS: Ngakhale bandwidth yomwe ntchito ya TDM ndi yaying'ono, ili ndi zofunika kwambiri pazizindikiro monga kuchedwa, jitter, drift, ndi kulakwitsa pang'ono. Izi zimafuna osati kungoganizira momwe mungachepetsere kuchedwa ndi kugwedezeka kwa ntchito ya TDM panthawi ya uplink dynamic bandwidth allocation, komanso kuonetsetsa kuti ntchito ya TDM imayendetsa mosamalitsa kuchedwa ndi jitter mu downlink bandwidth control strategy.
② Nthawi ndi kuyanjanitsa kwa ntchito za TDM: Ntchito za TDM zili ndi zofunika kwambiri pa nthawi ndi kuyanjanitsa. EPON kwenikweni ndi netiweki yopatsirana yosasinthika yotengera ukadaulo wa Ethernet. Palibe wotchi yolondola kwambiri yamatelefoni yolumikizidwa pa netiweki yonse. Kulondola kwa wotchi komwe kumatanthauzidwa ndi Ethernet ndi ± 100'10 ndipo kulondola kwa wotchi komwe kumafunikira ndi ntchito zachikhalidwe za TDM ndi ± 50'10. Kuphatikiza apo, popereka wotchi yamatelefoni yolumikizidwa pa netiweki yonse, deta ya TDM iyenera kutumizidwa nthawi ndi nthawi kuti ikwaniritse zofunikira zake.
③ Kupulumuka kwa EPON: Ntchito ya TDM imafunanso kuti netiweki yonyamulayo ikhale ndi moyo wabwino. Pamene kulephera kwakukulu kumachitika, ntchitoyo ikhoza kukhala yodalirikakusinthamunthawi yochepa kwambiri. Chifukwa EPON imagwiritsidwa ntchito kwambiri pomanga ma netiweki, ili pafupi ndi ogwiritsa ntchito, ndipo machitidwe osiyanasiyana ndi malo ogwiritsira ntchito ndizovuta. Zimakhudzidwa mosavuta ndi zinthu zosadziwika monga kumanga tawuni, zomwe zimayambitsa ngozi monga kusokonezeka kwa maulalo. Chifukwa chake, dongosolo la EPON likufunika mwachangu kuti lipereke njira yotetezedwa yotsika mtengo.
2. Ntchito za IP
EPON imatumiza mapaketi a data a IP popanda kutembenuzidwa kwa protocol ndipo imakhala yogwira ntchito kwambiri, yomwe ili yoyenera kwambiri pa ntchito za data.
Ukadaulo wa VolP, monga ukadaulo wotentha pakukula, wakwaniritsa ntchito zina m'zaka zaposachedwa, ndipo ndi njira yabwino yonyamula mautumiki amawu pamanetiweki a IP. Mu dongosolo la EPON, ndizothekanso kukhazikitsa mwayi wopeza ma foni achikhalidwe powonjezera zida kapena ntchito zina za VoIP. Pogwiritsa ntchito ukadaulo wa VoIP, bola ngati kuchedwa ndi mawonekedwe a jitter a EPON voice service ndi otsimikizika, ntchito zina zimasiyidwa ku chipangizo cholumikizira chophatikizika cha ogwiritsa (IAD, Integrated Access Device) ndi chida chapakati cholowera pachipata kuti agwiritse ntchito mawu. Kutumiza. Njirayi ndiyosavuta kugwiritsa ntchito ndipo imatha kunyamula matekinoloje omwe alipo, koma imafunikira zida zotsika mtengo zapakati paofesi yapakhomo, zokwera mtengo zomanga maukonde, ndipo zimachepetsedwa ndi zolephera zaukadaulo wa VoIP womwe. Kuphatikiza apo, ma data a E1 ndi N'64kbit / s sangathe kuperekedwa.
Dongosolo la EPON likamagwiritsa ntchito VoIP kunyamula mautumiki a mawu, liyenera kukwaniritsa zizindikiro zotsatirazi za mautumiki a VoIP.
① Nthawi yosinthira yosinthira mawu ndi yochepera 60ms.
② Iyenera kukhala ndi 80ms buffer yosungirako kuti iwonetsetse kuti palibe zoletsa zolankhula ndi jitters zikuchitika.
③ Kuwunika kwalingaliro la mawu: Pamene maukonde ali abwino, mtengo wapakati wa PSQM ndi wochepera 1.5; pamene maukonde ali osauka (packet loss rate = 1%, jitter = 20ms, kuchedwa = 100ms), mtengo wapakati wa PSQM ndi <1.8; Zinthu zikafika poipa (packet loss rate = 5%, jitter = 60ms, delay = 400ms), pafupifupi PSQM imakhala yochepera 2.0.
④ Kuwunika kwachiyankhulidwe: Pamene maukonde ali abwino, pafupifupi mtengo wa MOS ndi> 4.0; pamene maukonde ali osauka (packet loss rate = 1%, jitter = 20ms, kuchedwa = 100ms), pafupifupi mtengo wa MOS ndi <3.5; network Pamene mikhalidwe ili yoipa (packet loss rate = 5%, jitter = 60ms, kuchedwa = 400ms), mtengo wapakati wa MOS <3.0.
⑤ Mlingo wa encoding: G.711, encoding rate = 64kbit / s. Kwa G.729a, mtengo wofunikira ndi <18kbit / s. Kwa G.723.1, G.723.1 (5.3) kuchuluka kwa ma code ndi <18kbit / s, ndipo G.723.1 (6.3) kuchuluka kwa ma code ndi <15kbit / s.
⑥ Delay index (kuchedwa kwa loopback): Kuchedwa kwa VoIP kumaphatikizapo kuchedwa kwa codec, kuchedwa kwa bafa polandira, komanso kuchedwa kwa mzere wamkati. G.729a encoding ikagwiritsidwa ntchito, kuchedwa kwa loopback ndi <150ms. G.723.1 encoding ikagwiritsidwa ntchito, kuchedwa kwa loopback ndi <200ms.
3.CATV bizinesi
Kwa mautumiki a analogi a CATV, EPON ingathenso kunyamulidwa mofanana ndi GPON: kuwonjezera kutalika kwa kutalika (kwenikweni iyi ndi teknoloji ya WDM ndipo ilibe kanthu kochita ndi EPON ndi GPON yokha).
Tekinoloje ya PON ndiyo njira yabwino kwambiri yopezera mwayi wofikira ku BTTx. EPON ndiukadaulo watsopano wolumikizira netiweki wopangidwa pophatikiza ukadaulo wa Ethernet ndi ukadaulo wa PON. Itha kugwiritsidwa ntchito potumiza mau, data ndi makanema ndipo imagwirizana. Pazinthu zina zatsopano m'tsogolomu, EPON idzakhala ukadaulo wapamwamba kwambiri wogwiritsa ntchito mawonekedwe a Broadband Optical ndi maubwino ake onse monga bandwidth yayikulu, kuchita bwino kwambiri, komanso kukulitsa kosavuta.
Chitetezo cha dongosolo la PON
Pofuna kupititsa patsogolo kudalirika kwa maukonde ndi kupulumuka, njira yosinthira fiber chitetezo ingagwiritsidwe ntchito mu dongosolo la PON. Makina osinthira opangira ma fiber owoneka bwino amatha kuchitidwa m'njira ziwiri: ① kusintha kodziwikiratu, komwe kumayambitsa kuzindikira zolakwika; ② kusintha kokakamiza, koyambitsidwa ndi zochitika zowongolera.
Pali mitundu itatu ikuluikulu yachitetezo cha CHIKWANGWANI: chitetezo cha backbone fiber redundancy,OLTChitetezo cha PON port redundancy, ndi chitetezo chokwanira, monga zikuwonekera pa Chithunzi 1.16.
Chitetezo cha backbone fiber redundancy (Chithunzi 1.16 (a)): kugwiritsa ntchito doko limodzi la PON lopangidwa ndi 1'2 OpticalkusinthakuOLTPON doko; pogwiritsa ntchito 2: Palibe choboola chowonekera; ndiOLTimazindikira mawonekedwe a mzere; Palibe zofunikira zapadera zaONU.
OLTChitetezo cha PON port redundancy (Chithunzi 1.16 (b)): Doko la PON loyimilira lili pamalo ozizira, pogwiritsa ntchito 2: N splitter ya kuwala; ndiOLTimazindikira mawonekedwe a mzere, ndipo kusintha kumachitidwa ndiOLT, popanda zofunikira zapadera zaONU.
Chitetezo chokwanira (Chithunzi 1.16 (c)): madoko onse akuluakulu ndi osunga zobwezeretsera a PON akugwira ntchito; awiri 2: No optical splitters amagwiritsidwa ntchito; ndi kuwalakusinthaimamangidwa kutsogolo kwaONUPON port, ndiONUimazindikira momwe mzere uliri ndikusankha kugwiritsa ntchito kwakukulu Mizere ndikusintha kumachitika ndiONU.
Njira yosinthira chitetezo ya PON system imatha kuthandizira kubwerera basi kapena kubwereranso pamanja kwa ntchito zotetezedwa. Kwa njira yobwerera yokha, mutatha kuthetsa kulephera kwa kusintha, pambuyo pa nthawi yodikira yobwerera, ntchito yotetezedwa iyenera kubwereranso ku njira yoyamba yogwirira ntchito. Nthawi yodikira yobwerera ikhoza kukhazikitsidwa.