Kuunzwa kweakasiyana maPON masisitimu
1. APON teknolojia
Pakati pemakore ekuma1990, mamwe makuru evashandisi venetiweki akatanga iyo Full Service Access Network Alliance (FSAN), ine chinangwa chekugadzira chiyero chakabatana chePON michina kuitira kuti vagadziri vemidziyo nevashandisi vapinde mumusika wePON wemidziyo uye vakwikwidze pamwechete. Mhedzisiro yekutanga ndeyekutsanangurwa kweiyo 155Mbit / s PON system standard muITU-T G.983 yakatevedzana yekurudziro. Nekuti ATM inoshandiswa semutakuri weprotocol, iyi system inodaidzwa kuti APON system, uye inowanzosanzwisiswa sekupa masevhisi eATM chete. Naizvozvo, inotumidzwa zita rekuti Broadband Passive Optical Network (BPON) system kuratidza kuti iyi sisitimu inogona kupa Ethernet Broadband masevhisi akadai setiweki kuwana, kugovera mavhidhiyo, uye mitsara yekumhanya-mhanya. Zvakadaro, kuchizvarwa chino cheFSAN masisitimu, zita rinonyanya kushandiswa ndi APON. Gare gare, iyo APON chiyero chakawedzerwa, uye chakatanga kutsigira downlink 622 Mbit / s mazinga, uye maficha matsva akawedzerwa munzira dzekudzivirira, dynamic bandwidth allocation (DBA), uye zvimwe zvinhu.
APON inoshandisa ATM semutakuri protocol. Kuyerera kwekudzika kunogara ATM rukova ine chiyero chidiki che155.52Mbit / s kana 622.08Mbit / s. A special body layer operation management and maintenance (PLOAM) sero inopinzwa mudhata stream.Upstream transmission is ATM cells in burst form. Kuti uwane kuputika kwekufambisa uye kugamuchira, 3-byte yemuviri wepamusoro inowedzerwa pamberi pesero 53-byte yega yega. Nokuda kwechiyero chekutanga che 155.52 Mbit / s, transmission protocol inobva pane downlink frame ine 56 ATM masero (53 bytes per cell); kana iyo bit rate yakawedzera kusvika 622.08 Mbit / s, iyo downlink furemu inowedzerwa kusvika ku224 Cell. Pachiyero chekutanga che 155.52 Mbit / s, chimiro cheuplink furemu masero makumi mashanu nematatu, sero rega rega 56 bytes (53 ATM cell bytes pamwe ne3 bytes pamusoro). Pamusoro pemaseru makumi mashanu nemana edata ari mudownlink frame, kune maviri PLOAM maseru, rimwe riri pakutanga kwefuremu uye rimwe riri pakati pefuremu. Sero rega rega rePLOAM rine mvumo yekufambiswa kweuplink kune chaiyo sero murukova furemu (53 Kumusoro furemu maseru ane 53 magrants akamepurwa muPLOAM maseru) uye OAM & P ruzivo. APON inopa akapfuma uye akazara maOAM mabasa, anosanganisira bit kukanganisa mwero wekutarisa, zvinotyisa, kuwanikwa otomatiki, uye otomatiki kutsvaga. Senzira yekuchengetedza, inogona kukwenya uye encrypt downlink data.
Kubva pamaonero ekugadzirisa data, muAPON, data remushandisi rinofanira kuendeswa pasi peprotocol conversion (AAL1 / 2 yeTDM uye AAL5 yekufambisa data packet). Uku kutendeuka kwakaoma kuchinjika kune yakakwira bandwidth, uye midziyo inoita basa iri inosanganisira zvimwe zvine chekuita nemidziyo yekubatsira, senge cell memory, Glue Logic, nezvimwe, izvo zvinowedzerawo zvakawanda kumari yehurongwa.
Ikozvino, ingave iri kure-kure core transmission network kana metropolitan area access network convergence layer, tekinoroji yedhijitari yachinja zvishoma nezvishoma kubva kuATM-centric kuenda kuIP-based kuti ipe vhidhiyo, odhiyo, uye data kutaurirana. Naizvozvo, iyo chete yekuwana network dhizaini inogona kuchinjika kune ese azvino kuwana uye remangwana network core tekinoroji anogona kuita remangwana rese-optical IP network ive yechokwadi.
APON yakabuda zvishoma nezvishoma kubva pamusika nekuda kwekuoma kwayo uye kushomeka kwekufambisa data.
2. EPON
Inenge panguva imwe chete neAPON system, IEEE yakagadzirawo boka rekutsvakurudza remaira eEthernet (EFM) kutanga Ethernet-based EPON (Ethernet Passive Optical Network) maererano nefiber access network, ichiratidza tarisiro yakanaka yemusika. Boka rekudzidza ndereboka reIEEE 802.3 rakagadzira chiyero cheEthernet. Saizvozvo, chiyero chayo chekutsvagisa chinongogumira kune chivakwa, uye chinofanira kuenderana neiyo iripo 802.3 midhiya yekuwana control (MAC) layer mabasa. Muna Kubvumbi 2004, boka rekutsvagisa rakaunza iyo IEEE 802.3ah chiyero cheEPON, ine uplink uye downlink rate ye1 Gbit / s (ichishandisa 8B / 10B coding, uye mutsara chiyero che1.25 Gbit / s), ichipedzisa EPON vagadziri '. kushandiswa kwezvibvumirano zvepachivande kugadzira mamiriro emidziyo.
EPON ibroadband access system yakavakirwa paEthernet tekinoroji. Inoshandisa iyo PON topology kushandisa Ethernet kuwana. Iwo akakosha matekinoroji eiyo data link layer anonyanya kusanganisira: Multiple Access Control Protocol (MPCP) yeiyo uplink chiteshi, plug uye play dambudziko reiyo.ONU, kuverengera uye kunonoka muripo mapuroteni eOLT, uye nyaya dzekuenderana kweprotocol.
Iyo yemuviri layer yeIEEE 802.3ah inosanganisira ese ari maviri point-to-point (P2P) yakabatana optical fibers uye waya dzemhangura, pamwe nePON network scenarios for point-to-multipoint (P2MP). Kuti ufambise kushanda kwetiweki uye kugadzirisa kukanganisa, iyo OAM michina inosanganisirwa zvakare. PaP2MP network topology, EPON inobva pane imwe nzira inonzi Multipoint Control Protocol (MPCP), inova basa mukati meMAC sublayer. MPCP inoshandisa mameseji, michina yenyika, uye nguva kudzora kupinda kune P2MP network topology. Imwe neimwe optical network unit (ONU) muP2MP network topology ine MPCP protocol entity inotaurirana neMPCP protocol entity muOLT. .
Hwaro hweEPON / MPCP protocol inzvimbo-ku-point simulation sublayer, inoita kuti P2MP network itaridzike senge muunganidzwa weP2P zvinongedzo kune yakakwirira protocol layer.
Kuti uderedze mutengo weONU, iyo yakakosha tekinoroji yeEPON yemuviri layer yakatarisana neiyoOLT, kusanganisira kukurumidza kuwiriranisa kwezviratidzo zvinoputika, network synchronization, simba rekudzora optical transceiver modules, uye adaptive kugamuchira.
EPON inosanganisa zvakanakira zvePON uye Ethernet data zvigadzirwa kugadzira akawanda akasiyana mabhenefiti. Iyo EPON system inogona kupa uplink uye downlink bandwidths anosvika 1 Gbit / s, iyo inogona kusangana nezvinodiwa nevashandisi mune ramangwana kwenguva yakareba. EPON inoshandisa tekinoroji yemultiplexing kutsigira vashandisi vakawanda, uye mushandisi wega wega anogona kunakidzwa nebandwidth yakakura. Iyo EPON sisitimu haishandisi inodhura michina yeATM uye SONET midziyo, uye inowirirana neiyo iripo Ethernet, inorerutsa zvakanyanya magadzirirwo ehurongwa, mutengo wakaderera, uye nyore kusimudzira. Nekuda kwehupenyu hurefu hwepassive optical zvishandiso, mari yekuchengetedza yemitsara yekunze yakaderedzwa zvakanyanya. Panguva imwecheteyo, yakajairwa Ethernet interfaces inogona kutora mukana weiyo iripo yakaderera-mutengo weEthernet michina uye kuchengetedza mutengo. Iyo PON chimiro pachayo inosarudza kuti network yakanyanya scalable. Chero bedzi mudziyo wekupedzisira uchitsiviwa, network inogona kukwidziridzwa kusvika ku10 Gbit / s kana kupfuura. EPON haingogone kubatanidza tambo yeTV iripo, data uye masevhisi ezwi, asi zvakare kuenderana nemasevhisi emangwana akadai sedhijitari TV, VoIP, vhidhiyo musangano uye VOD, nezvimwewo, kuti uwane yakasanganiswa sevhisi kuwana.
Kushandiswa kwakadzama kwemutakuri weEPON uye humwe matekinoroji ekuwana zvinowedzera kupfumisa mhinduro dzetekinoroji yebroadband.
Kushandisa EPON kunogona kuita kuti DSL iparadze chinhambwe chetsika uye kuwedzera kuvharika. Apo iyoONUinosanganiswa muDigital Subscriber Line Access Multiplexer (DSLAM), iyo inosvikika yeDSL uye boka rayo rekushandisa richawedzera zvikuru.
Saizvozvo, nekubatanidza iyo CMTS (Cable Modem Termination System) yeONU, EPON inogona kupa bandwidth kune iripo Cable connections, uye inobvumira macable operators kuti aite masevhisi anopindirana zvechokwadi achideredza mari yekuvaka nekushandisa.
Muzviitiko zvese izvi, vashandisi vanogona kuwedzera mushandisi wavo kubva pane yavo iripo network chimiro uye kudyara. EPON inogona zvakare kuwedzera iyo point-to-point MSPP (Multiple Services Provisioning Platform) uye IP / Ethernet.
Pamusoro pezvo, tekinoroji yeEPON inogona zvakare kushandiswa kugadzirisa dambudziko reuplink data ye base station mune isina waya yekuwana tekinoroji yakabatanidzwa kune yakakosha network.
3.GPON
Muna 2001, FSAN yakatanga nhamburiko nyowani yekumisikidza PON network inoshanda pamusoro pe1 Gbit / s. Pamusoro pekutsigira mitengo yakakwira, iyo protocol yakavhurika kuitira kuti ufunge zvakare uye uwane yakanakisa uye inoshanda mhinduro maererano nekutsigira akawanda-sevhisi, OAM & P mabasa uye scalability. Sechikamu chebasa reGPON, FSAN yakatanga kuunganidza zvinodiwa nenhengo dzayo dzose (kusanganisira vashandi vakuru munyika yose), zvino zvichibva pane izvi, yakanyora gwaro rainzi Gigabit Service Requirements (GSR) uye rakaita kuti rive kurudziro yepamutemo ( G.GON. GSR) kuenda kuITU-T. Izvo zvinodikanwa zvikuru zveGPON zvinotsanangurwa mufaira reGSR ndezvinotevera.
l Inotsigira masevhisi akazara, anosanganisira izwi (TDM, SONET / SDH), Ethernet (10/100 Base-T), ATM, mitsara yakabhadharwa, nezvimwe.
l Chinhambwe chemuviri chakavharwa chingangoita 20km, uye nhambwe inonzwisisika inogumira ku60km.
l Inotsigira zvakasiyana-siyana bit rates uchishandisa imwecheteyo protocol, kusanganisira symmetrical 622 Mbit / s, symmetrical 1.25 Gbit / s, yakadzika 2.5 Gbit / s uye kumusoro 1.25 Gbit / s, uye mamwe mabhiti mareti.
l OAM & P mabasa ane simba anogona kupa kupera-kusvika-kumagumo masevhisi manejimendi.
l Nekuda kwekutepfenyura maitiro ePON, chengetedzo yedownlink masevhisi inofanirwa kuvimbiswa padanho reprotocol.
FSAN yakaronga kuti dhizaini yeGPON chiyero inofanira kuzadzisa zvinangwa zvinotevera.
l Chimiro chechimiro chinogona kuwedzerwa kubva pa622Mbit / s kusvika ku2.5Gbit / s, uye inotsigira asymmetric bit rate.
l Guarantee yakakwirira bandwidth kushandiswa uye kushanda kwakanyanya kune chero bhizinesi.
l Encapsulate chero sevhisi (TDM uye packet) mune 125ms furemu kuburikidza neGFP.
l Inoshanda uye inodhura-yemahara kutapurirana kweakachena TDM masevhisi.
l Dynamic bandwidth kugoverwa kune yega yegaONUkuburikidza ne bandwidth pointer.
Sezvo GPON yakaongororazve mashandisirwo uye zvinodiwa zvePON kubva pasi zvichikwira, yakateya hwaro hwemhinduro itsva uye haichabvi pane yakapfuura APON mwero, saka vamwe vanogadzira vanoidaidza kuti PON (natural mode PON). Kune rumwe rutivi, GPON inochengetedza mabasa akawanda asina hukama zvakananga nePON, semashoko eOAM, DBA, nezvimwewo. Kune rumwe rutivi, GPON inobva pane itsva TC (transmission convergence) layer. Iyo GFP (general framing procedure) yakasarudzwa neFSAN is a frame-based protocol iyo inogadzirisa ruzivo rwebasa kubva kune vatengi vepamusoro-soro yetiweki yekutakura kuburikidza nemaitiro eruzhinji. Iyo network yekutakura inogona kuve chero mhando yetiweki, senge SONET / SDH uye ITU-T G.709 (OTN), nezvimwewo. Ruzivo rwevatengi runogona kuve packet-based (senge IP / PPP, kureva IP / Point to Point protocal. , kana Ethernet MAC mafuremu, zvichingodaro), Inogona zvakare kuve inogara iine bit rate stream kana mamwe marudzi ebhizinesi ruzivo. GFP yakamisikidzwa zviri pamutemo seITU-T chiyero cheG.7041. Nekuti GFP inopa inoshanda uye yakapusa nzira yekufambisa masevhisi akasiyana pane iyo synchronous transmission network, yakanakira kuishandisa sehwaro hweGPON TC layer. Pamusoro pezvo, kana uchishandisa GFP, iyo GPON TC inowirirana uye inoshandisa yakajairwa SONET / SDH 8kHz (125ms) mafuremu, ayo anogonesa GPON kutsigira zvakananga TDM masevhisi. Mune yakaburitswa zviri pamutemo G.984.3 chiyero, chirevo cheFSAN paGFP sezvo tekinoroji yekuchinjisa yeTC yakagamuchirwa, uyezve kugadzirwa kwakareruka kwakaitwa, yakanzi GPON encapsulation method (GEM, GPONEncapsulationMethod).
Kushandiswa kweEPON system
EPON, se tekinoroji nyowani yekuwana Broadband, ipuratifomu yekupa-sevhisi-yakazara inogona kutsigira masevhisi edata pamwe chete nemasevhisi enguva chaiyo akadai sezwi nevhidhiyo.
Iyo yekuona nzira dhizaini yeEPON inogona kushandisa 3 wavelengths. Kana iwe usingafungi kutsigira CATV kana DWDM masevhisi, mawavelength maviri anowanzo shandiswa. Paunenge uchishandisa 3 wavelengths, iyo yavelength yekumusoro i1310nm, iyo yakadzika wavelength i1490nm, uye imwezve 1550nm wavelength inowedzerwa. Iyo yakawedzera 1550nm wavelength inoshandiswa kufambisa zvakananga analog vhidhiyo masaini. Nemhaka yekuti ikozvino analogi yevhidhiyo yechiratidzo ichiri kutungamirirwa neredhiyo neterevhizheni, inofungidzirwa kuti haizotsiviwa zvachose nemavhidhiyo edhijitari masevhisi kusvika 2015. Naizvozvo, iyo ikozvino yakagadzirirwa EPON system inofanirwa kutsigira ese edhijitari vhidhiyo masevhisi uye analog vhidhiyo masevhisi. Iyo yekutanga 1490nm ichiri kutakura downlink data, dhijitari vhidhiyo uye izwi masevhisi, uye 1310nm inotumira uplink mushandisi izwi masaini, vhidhiyo yedhijitari painodiwa (VOD), uye kukumbira ruzivo rwekudhawunirodha data.
Masaini ezwi ane zvakaomesesa zvinodiwa pakunonoka uye jitter, uye Ethernet haipe kupera-kusvika-kumagumo kunonoka kwepaketi, chiyero chekurasikirwa kwepaketi, uye bandwidth yekudzora masimba. Naizvozvo, maitiro ekuona sevhisi yemhando yepamusoro kana EPON yakasimudza masaini ezwi idambudziko rekukasika kugadziriswa.
1. TDM bhizinesi
Parizvino, iyo inonyanya kukahadzika EPON yakawanda-sevhisi kugona kugona kwayo kufambisa echinyakare TDM masevhisi.
Iwo masevhisi eTDM ataurwa pano anosanganisira marudzi maviri emasevhisi ezwi (POTS, Yakakurumbira Old Telephone Service) uye masevhisi edunhu (T1 / El, N'64kbit / s mitsara yakarejeswa).
Kana masisitimu eEPON aine data yakatsaurirwa mitsara masevhisi (2048kbit / s kana 13'64kbit / s data masevhisi), TDM pamusoro peEthernet inokurudzirwa. EPON system inogona kutora seti inochinja kana VolP kana yakatakura masevhisi ezwi.
Mumakore mashoma anotevera, nekuti kudiwa kwemusika kwemasevhisi edunhu kuchiri kwakakura, EPON system inodiwa kutakura ese packet-switchedmasevhisi uye dunhu-switchedmasevhisi. EFM inotakura sei TDM paEPON uye maitiro ekuona kunaka kweTDM masevhisi. Iko hakuna kurongeka kwakanangana nehunyanzvi, asi inofanirwa kuenderana neEthernet furemu fomati. Multi-service EPON (MS-EPON) inotora tekinoroji yeE1 Pamusoro peEthernet, iyo inogadzirisa zvinobudirira dambudziko rekuchinjisa masevhisi eTDM paEthernet mafuremu, zvichiita kuti EPON ione kutapurirana kwesevhisi yakawanda uye kuwana. Panguva imwecheteyo, MS-EPON inokunda mukaha uripo pakatiOLTuyeONU. Iyo yakagovaniswa bandwidth gakava chiitiko chinopa vashandisi veEthernet neyakavimbiswa bandwidth garandi.
Iyo encapsulation nzira yeEthernet inoita kuti EPON tekinoroji inyatsokodzera kutakura IP masevhisi, asi inotarisanawo nedambudziko guru-zvakaoma kutakura masevhisi eTDM akadai sezwi kana redunhu data. EPON iEthernet-based asynchronous transmission network. Iyo haina yakakwirira-chaiyo wachi yakawiriraniswa panetiweki, uye zvakaoma kuzadzisa iyo nguva uye kuwiriranisa zvinodiwa zveTDM masevhisi. Kugadzirisa dambudziko rekuwiriranisa nguva kweTDM masevhisi tichiona matambudziko ehunyanzvi akadai seQoS yeTDM masevhisi, hatifanire kungovandudza dhizaini yeEPON system pachayo, asi zvakare tinoda kutora mamwe matekinoroji chaiwo.
The performance index of the circuitswitchedvoice service inoratidza kuti kana EPON system inoshandisa dunhuswitchednzira yekutakura masevhisi ezwi, inofanirwa kusangana nezvinodiwa zveYDN 065-1997 "General Tekinoroji Yekutsanangurwa Kwefoni Switch Equipment yeMinistry yePosts neTerecommunications" uye YD / T 1128-2001 "General Telephone Switching Equipment" technical Specifications (Supplement 1 ) “zvinodiwa zvedunhu rakachenaswitchedinzwi remhando. Naizvozvo, EPON parizvino ine anotevera matambudziko neTDM masevhisi.
① TDM sevhisi QoS vimbiso: Kunyangwe iyo bandwidth inogarwa neTDM sevhisi idiki, ine zvakakwirira zvinodikanwa pane zviratidzi senge kunonoka, jitter, kudhiraivha, uye bit kukanganisa mwero. Izvi zvinoda kwete kungofunga nzira yekudzikisa kunonoka kwekufambisa uye jitter yeTDM sevhisi panguva yeuplink dynamic bandwidth kugoverwa, asi zvakare kuve nechokwadi chekuti sevhisi yeTDM inonyatso kudzora kunonoka uye jitter mune yedownlink bandwidth control strategy.
② Nguva uye kuwiriranisa kweTDM masevhisi: TDM masevhisi ane zvakanyanya kuomarara zvinodiwa pakuita nguva uye kuwiriranisa. EPON ndeye asynchronous transmission network yakavakirwa paEthernet tekinoroji. Iko hakuna yakakwirira-chaiyo telecommunication wachi yakawiriraniswa mukati metiweki. Kurongeka kwewachi kunotsanangurwa neEthernet ndeye ± 100'10 uye kunyatsoita kwewachi kunodiwa netsika dzeTDM masevhisi ± 50'10. Uye zvakare, tichipa iyo yekufonera wachi yakawiriraniswa mukati metiweki, TDM data inofanirwa kufambiswa nguva nenguva sezvinobvira kuti isangane nejitter uye kukanganisa kwayo zvinodiwa.
③ Kupona kweEPON: Iyo TDM sevhisi inoda zvakare kuti mutakuri network anofanirwa kuve nekupona kwakanaka. Kana kukanganisa kukuru kukaitika, sevhisi inogona kuve yakavimbikaswitchedmunguva pfupi inobvira. Nekuti EPON inonyanya kushandiswa kuwana network kuvaka, iri padyo nevashandisi, uye akasiyana maapplication uye nharaunda dzekushandisa zvakaoma. Inobatwa nyore nyore nezvinhu zvisingazivikanwi zvakadai sekuvaka kwemaguta, zvichikonzera njodzi dzakadai sekukanganiswa kwekubatanidza. Naizvozvo, iyo EPON sisitimu inodiwa nekukurumidza kuti ipe inodhura-inoshanda system yekudzivirira mhinduro.
2. IP masevhisi
EPON inotumira IP data packet pasina kutendeuka kweprotocol uye ine hunyanzvi hwepamusoro, iyo yakakodzera kwazvo masevhisi edata.
Tekinoroji yeVolP, setekinoroji inopisa mukusimudzira, yakawana imwe chiyero chekushandisa mumakore achangopfuura, uye inzira inoshanda yekutakura masevhisi ezwi pamusoro peIP network. Muchirongwa cheEPON, zvinogonekawo kuita kuti vanhu vakwanise kuwana nharembozha dzechinyakare nekuwedzera zvimwe zvekushandisa zveVoIP. Uchishandisa tekinoroji yeVoIP, chero kunonoka uye jitter maitiro eEPON izwi sevhisi akavimbiswa, mamwe mabasa anosiiwa kune mushandisi-parutivi rwakabatanidzwa yekuwana mudziyo (IAD, Integrated Access Device) uye yepakati yekupinda gedhi mudziyo kugadzirisa iyo izwi sevhisi. Transmission. Iyi nzira iri nyore kushandisa uye inokwanisa kutakura zvakananga matekinoroji aripo, asi inoda inodhura yepakati hofisi yekupinda gedhi michina, yakakwirira mari yekuvaka network, uye inogumira nekukanganisa kweiyo VoIP tekinoroji. Uye zvakare, E1 uye N'64kbit / s data masevhisi haigone kupihwa.
Kana iyo EPON ichishandisa VoIP kutakura masevhisi ezwi, inofanirwa kusangana nezviratidzo zvinotevera zveVoIP voice services.
① Iyo inochinja nguva yekuchinja yezwi coding isingasviki 60ms.
② Inofanirwa kunge iine 80ms buffer kuchengetedza kuchengetedza kuti ive nechokwadi chekuti hapana kusaenderera kwekutaura uye jitters zvinoitika.
③ Chinangwa chekuongorora izwi: Kana mamiriro etiweki akanaka, avhareji kukosha kwePSQM iri pasi pe1.5; kana mamiriro etiweki asina kunaka (packet kurasikirwa rate = 1%, jitter = 20ms, kunonoka = 100ms), chiyero chepakati chePSQM chiri <1.8; Kana mamiriro ezvinhu akaipa (packet kurasikirwa rate = 5%, jitter = 60ms, kunonoka = 400ms), avhareji PSQM iri pasi pe2.0.
④ Kuongorora kwekutaura kwekutaura: Kana mamiriro etiweki akanaka, avhareji kukosha kweMOS ndeye> 4.0; kana mamiriro emumbure akashata (packet loss rate = 1%, jitter = 20ms, kunonoka = 100ms), muvhareji wekukosha weMOS ndeye <3.5; network Kana mamiriro ezvinhu akaipa (packet kurasikirwa rate = 5%, jitter = 60ms, kunonoka = 400ms), muvhareji kukosha kweMOS <3.0.
⑤ Encoding rate: G.711, encoding rate = 64kbit / s. PaG.729a, mwero unodiwa wekodha i <18kbit / s. Kune G.723.1, iyo G.723.1 (5.3) chiyero chekodha i <18kbit / s, uye iyo G.723.1 (6.3) chiyero chekodha i <15kbit / s.
⑥ Delay index (loopback delay): Kunonoka kweVoIP kunosanganisira kunonoka kwecodec, kunonoka kwekuisa buffer pamagumo ekugamuchira, uye kunonoka kwemutsetse wemukati. Kana G.729a encoding ikashandiswa, loopback kunonoka i <150ms. Kana G.723.1 encoding ikashandiswa, loopback kunonoka i <200ms.
3.CATV bhizinesi
Kune analog CATV masevhisi, EPON inogonawo kutakurwa nenzira yakafanana neGPON: wedzera wavelength (chaizvoizvo iyi inyanzvi yeWDM uye haina chekuita neEPON neGPON pachayo).
PON tekinoroji ndiyo yakanakisa nzira yekuwana FTTx Broadband kuwana. EPON tekinoroji nyowani yekuwana network yakagadzirwa nekubatanidza tekinoroji yeEthernet nePON tekinoroji. Inogona kushandiswa kufambisa izwi, data uye vhidhiyo masevhisi uye inoenderana. Kune mamwe masevhisi matsva mune ramangwana, EPON inozova iyo tekinoroji yakakura kune yakazara-sevhisi Broadband Optical access ine mabhenefiti ayo akadai seyepamusoro bandwidth, kushanda kwakanyanya, uye kuwedzera kuri nyore.
Dziviriro chirongwa chePON system
Kuti uvandudze kuvimbika kwetiweki uye kupona, fibre kuchengetedza switching mechanism inogona kushandiswa muPON system. Iyo optical fiber kuchengetedza switching mechanism inogona kuitwa nenzira mbiri: ① otomatiki switching, inokonzereswa nekuona kukanganisa; ② kumanikidzwa kuchinjika, kukonzereswa nezviitiko zve manejimendi.
Kune marudzi matatu makuru ekuchengetedza fiber: backbone fiber redundancy kuchengetedza,OLTPON port redundancy kuchengetedzwa, uye kuchengetedzwa kwakazara, sezvakaratidzwa mumufananidzo 1.16.
Backbone fiber redundancy protection (Mufananidzo 1.16 (a)): kushandisa imwe PON port ine yakavakirwa-mukati 1'2 opticalchinjapaOLTPON port; kushandisa 2: N optical splitter; theOLTinoona mamiriro emutsara; Iko hakuna zvakakosha zvinodiwa kune iyoONU.
OLTPON port redundancy protection (Figure 1.16 (b)): Iyo yekumira yePON port iri munzvimbo inotonhora yekumira, uchishandisa 2: N optical splitter; theOLTinoona mamiriro emutsara, uye kuchinja kunoitwa neOLT, pasina zvakakosha zvinodiwa zveONU.
Kudzivirirwa kwakazara (Mufananidzo 1.16 (c)): ese makuru uye backup PON ports ari kushanda; maviri 2: No optical splitters anoshandiswa; an opticalchinjainovakwa pamberi peONUPON port, uye iyoONUinoona mamiriro emutsara uye inosarudza kushandiswa kukuru Mitsetse uye kuchinja kunoitwa neONU.
Iyo yekudzivirira yekuchinja masisitimu yePON system inogona kutsigira otomatiki kudzoka kana bhuku rekudzoka kwemasevhisi akachengetedzwa. Kune iyo otomatiki yekudzoka modhi, mushure mekubvisa kutadza kwekuchinja, mushure meimwe nguva yekumirira yekudzoka, iyo yakachengetedzwa sevhisi inofanirwa kudzokera kune yekutanga nzira yekushanda. Nguva yekumirira yekudzoka inogona kuiswa.