Okwu mmalite nke usoro PON dị iche iche
1. APON teknụzụ
N'ime afọ 1990, ụfọdụ ndị na-ahụ maka netwọkụ na-arụ ọrụ hibere Full Service Access Network Alliance (FSAN), nke ebumnuche ya bụ imepụta ụkpụrụ ejikọtara ọnụ maka akụrụngwa PON ka ndị na-emepụta akụrụngwa na ndị na-arụ ọrụ wee nwee ike ịbanye n'ahịa akụrụngwa PON wee sonye ọnụ. Nsonaazụ mbụ bụ nkọwapụta nke ọkọlọtọ sistemụ 155Mbit / s PON na usoro ndụmọdụ ITU-T G.983. N'ihi na a na-eji ATM eme ihe dịka protocol bearer, a na-akpọ usoro a APON usoro, a na-aghọtahiekarị ya dị ka naanị inye ọrụ ATM. Ya mere, a na-akpọgharị ya Broadband Passive Optical Network (BPON) usoro iji gosi na usoro a nwere ike ịnye ọrụ Ethernet Broadband dị ka ịnweta netwọk, nkesa vidiyo, na ahịrị mgbazinye ọsọ ọsọ. Agbanyeghị, maka ọgbọ a nke sistemụ FSAN, aha a na-ejikarị bụ APON. Mgbe e mesịrị, a kwalitere ọkọlọtọ APON, wee malite ịkwado ọnụ ala 622 Mbit / s, yana atụmatụ ọhụrụ agbakwunyere na ụzọ nchebe, oke bandwidth ike (DBA), na akụkụ ndị ọzọ.
APON na-eji ATM dị ka ụkpụrụ na-ebu ibu. Nfefe na-agbada bụ iyi ATM na-aga n'ihu nke nwere ntakịrị ọnụego 155.52Mbit / s ma ọ bụ 622.08Mbit / s. A na-etinye cell oyi akwa pụrụ iche njikwa na mmezi (PLOAM) n'ime data iyi. Nfefe dị n'elu bụ mkpụrụ ndụ ATM n'ụdị gbawara agbawa. Iji nweta mbufe na nnabata, a na-agbakwunye ihe karịrị 3-byte n'ihu cell 53-byte ọ bụla. N'ihi na a isi ọnụego nke 155.52 Mbit / s, nnyefe protocol dabeere a downlink etiti nwere 56 ATM cell (53 bytes kwa cell); Mgbe ọnụọgụ ọnụọgụ na-abawanye na 622.08 Mbit / s, a na-agbatị etiti downlink na 224 Cell. Na isi ọnụego nke 155.52 Mbit / s, usoro nke uplink frame bụ 53 cell, nke ọ bụla cell bụ 56 bytes (53 ATM cell bytes gbakwunyere 3 bytes n'elu). Na mgbakwunye na sel data 54 dị na etiti downlink, enwere sel PLOAM abụọ, otu na mmalite nke etiti na nke ọzọ n'etiti etiti ahụ. Mkpụrụ ndụ PLOAM ọ bụla nwere ikike nnyefe uplink maka mkpụrụ ndụ akọwapụtara na etiti elu (53 Upstream frame cell nwere onyinye 53 nke etinyere n'ime sel PLOAM) yana ozi OAM & P. APON na-enye ọrụ OAM bara ụba na zuru oke, gụnyere nleba anya ọnụego mperi mperi, ihe na-atụ egwu, nchọpụta akpaka na nchọ akpaaka. Dị ka usoro nchekwa, ọ nwere ike mebie ma zoo data downlink.
Site n'echiche nhazi data, na APON, a ga-ebufe data onye ọrụ n'okpuru ntụgharị protocol (AAL1/2 maka TDM na AAL5 maka nnyefe data ngwugwu). Ntughari a siri ike imeghari na bandwidth dị elu, na ngwá ọrụ na-arụ ọrụ a gụnyere ụfọdụ ngwa enyemaka ndị metụtara ya, dị ka ebe nchekwa cell, Glue Logic, wdg, nke na-agbakwụnyekwa ọtụtụ ihe na-efu usoro.
Ugbu a, ma ọ bụ netwọk mgbasa ozi dị anya ma ọ bụ mpaghara mepere emepe ịnweta netwọk mmekọrịta, teknụzụ nzikọrịta ozi dijitalụ ejirila nke nta nke nta gbanwee site na ATM-centric gaa na IP dabere iji nye vidiyo, ọdịyo, na nkwukọrịta data. Ya mere, ọ bụ naanị nhazi netwọk ịnweta nke nwere ike ime mgbanwe maka ohere dị ugbu a na teknụzụ isi netwọk n'ọdịnihu nwere ike ime ka netwọk IP niile na-ahụ anya dị n'ọdịnihu.
APON ejirila nwayọọ nwayọọ na-apụ n'ahịa n'ihi mgbagwoju anya ya na obere ọrụ nnyefe data.
2. EPON
Ihe fọrọ nke nta ka ọ bụrụ n'otu oge ahụ dị ka usoro APON, IEEE guzobekwara otu nyocha nke mbụ Ethernet (EFM) iji malite EPON dabeere na Ethernet (Ethernet Passive Optical Network) n'ihe gbasara netwọk ịnweta eriri, na-egosi ezigbo atụmanya ahịa. Otu ọmụmụ ihe bụ nke IEEE 802.3 otu mepụtara ụkpụrụ Ethernet. N'otu aka ahụ, oke nyocha ya nwekwara oke na ụkpụrụ ụlọ, ma ọ ga-agbasorịrị ọrụ oyi akwa 802.3 media access control (MAC). N'April 2004, otu nyocha ahụ webatara ọkọlọtọ IEEE 802.3ah maka EPON, yana ọnụego uplink na downlink nke 1 Gbit / s (iji koodu 8B / 10B, yana ọnụego akara nke 1.25 Gbit / s), na-akwụsị ndị nrụpụta EPON. iji usoro iwu nkeonwe iji wulite ọkwa akụrụngwa.
EPON bụ usoro ịnweta brọdband dabere na teknụzụ Ethernet. Ọ na-eji PON topology mejuputa ohere Ethernet. Teknụzụ igodo nke oyi akwa njikọ data gụnyere: Multiple Access Control Protocol (MPCP) maka ọwa uplink, plọg na nsogbu egwuregwu.ONU, usoro nkwụghachi ụgwọ nke nso na igbu oge nkeOLT, na okwu ndakọrịta protocol.
Okpokoro anụ ahụ nke IEEE 802.3ah gụnyere ma isi-na-isi (P2P) ejikọrọ eriri anya na waya ọla kọpa, yana ọnọdụ netwọk PON maka point-to-multipoint (P2MP). Iji mee ka ọrụ netwọk dị mfe na nrụzi mmejọ, a na-etinyekwa usoro OAM. Maka topology netwọk P2MP, EPON dabere na usoro a na-akpọ Multipoint Control Protocol (MPCP), nke bụ ọrụ n'ime Mac sublayer. MPCP na-eji ozi, igwe steeti, na ngụ oge jikwaa ịnweta topology netwọkụ P2MP. Ngalaba netwọkụ anya ọ bụla (ONU) na P2MP network topology nwere ụlọ ọrụ protocol MPCP nke na-ekwurịta okwu na ụlọ ọrụ protocol MPCP naOLT. .
Ndabere nke usoro EPON / MPCP bụ sublayer simulation nke na-eme ka netwọọdụ P2MP dị ka nchịkọta P2P njikọ na ọkwa protocol dị elu.
Iji belata ego nkeONU, isi teknụzụ nke oyi akwa anụ ahụ EPON na-elekwasị anya naOLT, gụnyere ngwa ngwa mmekọrịta nke mgbawa mgbawa, netwọk mmekọrịta, ike njikwa nke modul transceiver anya, na nnabata nnabata.
EPON na-ejikọta uru nke ngwaahịa data PON na Ethernet iji mepụta ọtụtụ uru pụrụ iche. Sistemụ EPON nwere ike ịnye bandwidth uplink na downlinks ruru 1 Gbit / s, nke nwere ike gboo mkpa ndị ọrụ n'ọdịniihu ogologo oge. EPON na-eji teknụzụ multiplexing iji kwado ọtụtụ ndị ọrụ, na onye ọrụ ọ bụla nwere ike ịnụ ụtọ bandwidth ka ukwuu. Sistemu EPON anaghị eji ngwa ATM dị oke ọnụ na ngwa SONET, yana dakọtara na Ethernet dị adị, na-eme ka usoro sistemụ dị mfe, ọnụ ala dị ala, yana dị mfe ịkwalite. N'ihi ogologo ndụ nke ngwa ngwa anya ngwa anya, ụgwọ mmezi nke ahịrị dị n'èzí na-ebelata nke ukwuu. N'otu oge ahụ, ọkọlọtọ Ethernet interfaces nwere ike iji ohere nke ngwa Ethernet dị ọnụ ala ma chekwaa ego. Usoro PON n'onwe ya na-ekpebi na netwọk ahụ nwere ike ịgbatị nke ukwuu. Ọ bụrụhaala na edochiri akụrụngwa ọdụ, enwere ike ịkwalite netwọkụ ahụ na 10 Gbit / s ma ọ bụ karịa. EPON nwere ike ọ bụghị naanị ijikọ eriri USB dị ugbu a, data na ọrụ olu, kamakwa ọ dakọtara na ọrụ n'ọdịnihu dị ka TV dijitalụ, VoIP, conferencing video na VOD, wdg, iji nweta ọrụ ntinye aka.
Ojiji zuru oke nke onye na-ebu EPON na teknụzụ ohere ndị ọzọ na-eme ka ụzọ teknụzụ nweta brọdband na-abawanye.
Iji EPON nwere ike ime ka DSL mebie mmachi anya ọdịnala wee gbasaa mkpuchi. MgbeONUetinyere n'ime Digital Subscriber Line Access Multiplexer (DSLAM), nso nso nke DSL na ndị nwere ike iji ya ga-abawanye nke ukwuu.
N'otu aka ahụ, site na ijikọ CMTS (Cable Modem Termination System) nkeONU, EPON nwere ike inye bandwit na njikọ USB dị ugbu a, ma kwe ka ndị na-arụ ọrụ USB mejuputa ọrụ mmekọrịta n'ezie na-ebelata ihe owuwu na ụgwọ ọrụ.
N'okwu abụọ ahụ, ndị na-arụ ọrụ nwere ike ịbawanye ntọala ndị ọrụ ha dabere na nhazi netwọk ha dị na ntinye ego. EPON nwekwara ike ịgbatị isi-na-isi MSPP (Multiple Services Provisioning Platform) na IP / Ethernet.
Na mgbakwunye, enwere ike iji teknụzụ EPON dozie nsogbu nke data uplink nke ọdụ ọdụ na teknụzụ ohere ikuku jikọtara na netwọkụ isi.
3.GPON
N'afọ 2001, FSAN malitere mbọ ọhụrụ iji hazie netwọk PON na-arụ ọrụ karịa 1 Gbit / s. Na mgbakwunye na ịkwado ọnụ ọgụgụ dị elu, usoro dum emeghewo iji chegharịa ma chọta ngwọta kachasị mma na nke kachasị dị irè n'ịkwado ọtụtụ ọrụ, ọrụ OAM & P na scalability. Dịka akụkụ nke ọrụ GPON, FSAN buru ụzọ chịkọta ihe niile ndị otu ya chọrọ (gụnyere ndị isi ọrụ gburugburu ụwa), wee dabere na nke a, depụtara akwụkwọ akpọrọ Gigabit Service Requirements (GSR) wee mee ka ọ bụrụ nkwanye ugwu (G.GON. GSR) na ITU-T. Isi ihe GPON chọrọ akọwara na faịlụ GSR bụ ndị a.
l Na-akwado ọrụ zuru oke, gụnyere olu (TDM, SONET / SDH), Ethernet (10/100 Base-T), ATM, ahịrị mgbazinye, wdg.
l Ogologo anụ ahụ kpuchiri ma ọ dịkarịa ala 20km, ebe ezi uche dị na ya bụ naanị 60km.
l Na-akwado ọnụego bit dị iche iche site na iji otu ụkpụrụ, gụnyere symmetrical 622 Mbit / s, symmetrical 1.25 Gbit / s, mgbada 2.5 Gbit / s na elu 1.25 Gbit / s, na ọnụego bit ndị ọzọ.
l OAM & P ọrụ dị ike nke nwere ike inye njikwa ọrụ njedebe na njedebe.
l N'ihi njirimara mgbasa ozi nke PON, nchekwa nke ọrụ downlink ga-enwerịrị nkwenye na ọkwa protocol.
FSAN tụrụ aro ka imepụta ụkpụrụ GPON kwesịrị iru ebumnuche ndị a.
l Enwere ike ịgbasa usoro etiti ahụ site na 622Mbit / s ruo 2.5Gbit / s, ma na-akwado ọnụego bit asymmetric.
l na-ekwe nkwa ojiji bandwidth dị elu yana arụmọrụ dị elu maka azụmaahịa ọ bụla.
l Tinye ọrụ ọ bụla (TDM na ngwugwu) n'ime etiti 125ms site na GFP.
l Nbufe ọrụ TDM dị ọcha na enweghị ọnụ ahịa.
l ike bandwidth nke ọ bụlaONUsite na pointer bandwit.
Ebe GPON tụgharịrị uche ngwa na ihe PON chọrọ site na ala elu, ọ tọrọ ntọala maka ngwọta ọhụrụ ahụ na ọ dịghịzi adabere na ọkọlọtọ APON gara aga, ya mere ụfọdụ ndị na-emepụta na-akpọ ya PON (natural mode PON). N'aka nke ọzọ, GPON na-ejigide ọtụtụ ọrụ ndị na-enweghị njikọ PON ozugbo, dị ka ozi OAM, DBA, wdg. N'aka nke ọzọ, GPON dabeere na oyi akwa TC (transmission convergence) ọhụrụ. GFP (usoro nhazi izugbe) nke FSAN họpụtara bụ ụkpụrụ dabere na etiti nke na-eme ka ozi ọrụ sitere n'aka ndị ahịa dị elu nke netwọk njem site na usoro izugbe. Netwọk njem nwere ike ịbụ ụdị netwọkụ ọ bụla, dị ka SONET / SDH na ITU-T G.709 (OTN), wdg. Ozi ndị ahịa nwere ike dabere na ngwugwu (dị ka IP / PPP, ntụgharị IP / Point to Point Protocal). , ma ọ bụ Ethernet MAC okpokolo agba, wdg), nwekwara ike ịbụ a mgbe niile bit ọnụego iyi ma ọ bụ ndị ọzọ ụdị azụmahịa ozi. A haziri GFP n'ihu ọha dịka ọkọlọtọ ITU-T G.7041. N'ihi na GFP na-enye ụzọ dị mma ma dị mfe iji nyefee ọrụ dị iche iche na netwọk mgbasa ozi mmekọrịta, ọ dị mma iji ya dịka ndabere nke oyi akwa GPON TC. Na mgbakwunye, mgbe ị na-eji GFP, GPON TC na-emekọrịta ihe na-eji ọkọlọtọ SONET/SDH 8kHz (125ms), nke na-enyere GPON aka ịkwado ọrụ TDM ozugbo. Na ọkọlọtọ G.984.3 ewepụtara n'ihu ọha, atụmatụ FSAN na GFP ka a nakweere teknụzụ ngbanwe oyi akwa TC, wee mee nhazi ọzọ dị mfe, nke aha ya bụ GPON encapsulation method (GEM, GPONEncapsulationMethod).
Ngwa nke EPON usoro
EPON, dị ka teknụzụ ịnweta brọdband ọhụrụ, bụ ikpo okwu na-enye ọrụ zuru oke nke nwere ike ịkwado ọrụ data yana ọrụ oge dị ka olu na vidiyo.
Nhazi ụzọ anya nke EPON nwere ike iji 3 wavelengths. Ọ bụrụ na ị naghị atụle ịkwado CATV ma ọ bụ ọrụ DWDM, a na-ejikarị ogologo wavelength abụọ eme ihe. Mgbe ị na-eji 3 wavelength, ebili mmiri dị elu bụ 1310nm, ogologo ikuku nke ala bụ 1490nm, yana mgbakwunye 1550nm ọzọ. A na-eji ogologo ikuku 1550nm na-abawanye na-ebufe akara vidiyo analog ozugbo. N'ihi na akara ngosi vidiyo analog dị ugbu a ka ọrụ redio na telivishọn na-achịkwa, a na-eme atụmatụ na ọ gaghị edochi ya kpamkpam site na ọrụ vidiyo dijitalụ ruo 2015. Ya mere, usoro EPON a haziri ugbu a kwesịrị ịkwado ma ọrụ vidiyo dijitalụ na ọrụ vidiyo analog. 1490nm mbụ ka na-ebu data downlink, vidiyo dijitalụ na ọrụ olu, yana 1310nm na-ebufe akara olu onye ọrụ uplink, vidiyo dijitalụ na-achọ (VOD), na ịrịọ ozi maka nbudata data.
Mgbama olu nwere ihe siri ike chọrọ na igbu oge na jitter, na Ethernet anaghị enye nkwụsị njedebe njedebe na njedebe, ọnụego mfu ngwugwu, yana ikike njikwa bandwit. Ya mere, otu esi achọpụta ogo ọrụ mgbe EPON na-ebuli mgbama olu bụ nsogbu dị ngwa a ga-edozi.
1. TDM azụmahịa
Ka ọ dị ugbu a, ikike ọtụtụ ọrụ EPON a na-enyo enyo bụ ikike ya ibufe ọrụ TDM ọdịnala.
Ọrụ TDM a kpọtụrụ aha ebe a gụnyere ụdị ọrụ olu abụọ (POTS, Ọrụ ekwentị ochie ama ama) yana ọrụ sekit (T1 / El, N'64kbit / s ahịrị mgbazinye).
Mgbe sistemụ EPON na-ebu ọrụ ahịrị data raara onwe ya nye (2048kbit / s ma ọ bụ 13′64kbit / s ọrụ data), TDM over Ethernet ka akwadoro. Sistemu EPON nwere ike ịnwe mgbanwe sekit ma ọ bụ VolP mgbe ọ na-ebu ọrụ olu.
N'ime afọ ole na ole sochirinụ, n'ihi na ahịa ahịa maka ọrụ sekit ka dị ukwuu, a chọrọ usoro EPON ka ọ buru ngwugwu abụọ ahụ-gbanweeọrụ na sekit-gbanweeọrụ. Kedu ka EFM si ebu TDM na EPON yana otu esi achọpụta ogo ọrụ TDM. Enweghị usoro a kapịrị ọnụ na teknụzụ, mana ha ga-adabarịrị na usoro etiti Ethernet. Multi-service EPON (MS-EPON) na-anabata teknụzụ E1 Over Ethernet, nke na-edozi nke ọma nsogbu nke mmegharị nke ọrụ TDM na okpokolo agba Ethernet, na-enyere EPON aka ịghọta nnyefe na ịnweta ọtụtụ ọrụ. N'otu oge ahụ, MS-EPON na-emeri ọdịiche dị n'etitiOLTnaONU. Esemokwu esemokwu bandwit na-ekekọrịta na-enye ndị ọrụ Ethernet ikike bandwit ejiri n'aka.
Usoro ntinye nke Ethernet na-eme ka nkà na ụzụ EPON dị mma maka ibu ọrụ IP, ma ọ na-echekwa nnukwu nsogbu ihu-ọ na-esiri ike iburu ọrụ TDM dị ka ụda olu ma ọ bụ data sekit. EPON bụ netwọk nnyefe asynchronous dabere na Ethernet. Ọ nweghị elekere dị elu nke emekọrịtara n'ofe netwọkụ, ọ na-esikwa ike izute oge na mmekọrịta chọrọ nke ọrụ TDM. Iji dozie nsogbu nke imekọrịta oge nke ọrụ TDM ka ị na-ahụ maka ihe isi ike teknụzụ dị ka QoS nke ọrụ TDM, anyị agaghị emeziwanye nhazi nke usoro EPON n'onwe ya, mana ọ dịkwa mkpa ịnakwere ụfọdụ teknụzụ akọwapụtara.
Ndekọ arụmọrụ nke sekitgbanweeọrụ olu na-egosi na mgbe usoro EPON na-eji sekitgbanweeusoro iji na-ebu ọrụ olu, ọ kwesịrị izute ihe ndị chọrọ YDN 065-1997 "General Technical Specification for Telephone Switching Equipment of the Ministry of Posts and Telecommunications" na YD / T 1128-2001 "General Telephone Switching Equipment" Nka na ụzụ nkọwa (Mgbakwunye 1). ) “Ihe achọrọ maka sekit dị ọchagbanweeogo olu. Ya mere, EPON nwere nsogbu ndị a ugbu a na ọrụ TDM.
① Ọrụ TDM QoS nkwa: Ọ bụ ezie na bandwit nke ọrụ TDM ji dị obere, ọ nwere ihe dị elu chọrọ na egosi dị ka igbu oge, jitter, drift, na bit njehie. Nke a na-achọ ọ bụghị naanị ịtụle otu esi ebelata oge nnyefe na jitter nke ọrụ TDM n'oge oke bandwidth ike dị elu, kamakwa iji hụ na ọrụ TDM na-achịkwa nke ọma igbu oge na jitter na atụmatụ njikwa bandwidth downlink.
② Oge na mmekọrịta nke ọrụ TDM: Ọrụ TDM nwere ihe siri ike chọrọ maka oge na mmekọrịta. EPON bụ n'ezie netwọk mgbasa ozi asynchronous dabere na teknụzụ Ethernet. Enweghị elekere ekwentị dị elu nke emekọrịtara na netwọkụ niile. Izi ezi elekere nke Ethernet kọwapụtara bụ ± 100′10 yana izi ezi elekere nke ọrụ TDM ọdịnala chọrọ bụ ± 50′10. Na mgbakwunye, ka ị na-enye elekere nkwukọrịta ka emekọrịtara ọnụ na netwọkụ niile, data TDM ga-ebunye ya kwa oge ka o kwere mee iji zute ihe ndị chọrọ ya na njehie.
③ Ịlanarị EPON: Ọrụ TDM na-achọkwa ka netwọk ndị na-ebu ga-enwe ezigbo ndụ. Mgbe nnukwu ọdịda mere, ọrụ ahụ nwere ike ịdabere na ntụkwasị obigbanween'ime obere oge enwere ike. N'ihi na a na-ejikarị EPON eme ihe maka ịmepụta netwọkụ, ọ dị nso ndị ọrụ, yana ngwa dị iche iche na gburugburu ebe eji eme ihe dị mgbagwoju anya. A na-emetụta ya ngwa ngwa site na ihe ndị a na-amaghị dị ka iwu obodo, na-akpata ihe mberede dịka nkwụsị njikọ. Ya mere, usoro EPON chọrọ ngwa ngwa iji nye usoro nchebe usoro dị ọnụ ahịa.
2. Ọrụ IP
EPON na-ebufe ngwugwu data IP na-enweghị ntụgharị protocol ma nwee arụmọrụ dị elu, nke dabara adaba maka ọrụ data.
Teknụzụ VolP, dị ka teknụzụ na-ekpo ọkụ na mmepe, enwetala ụfọdụ ngwa ngwa n'afọ ndị na-adịbeghị anya, ọ bụkwa ụzọ dị irè maka ibu ọrụ olu n'elu netwọk IP. Na usoro EPON, ọ ga-ekwe omume ịmejuputa ohere ịnweta ọrụ ekwentị ọdịnala site na ịgbakwunye ụfọdụ ngwa ma ọ bụ ọrụ VoIP. Iji teknụzụ VoIP, ọ bụrụhaala na ejiri n'aka igbu oge na njirimara jitter nke ọrụ olu EPON, a na-ahapụ ọrụ ndị ọzọ n'akụkụ ngwaọrụ agbakwunyere n'akụkụ onye ọrụ (IAD, Ngwa Nweta Integrated) yana ngwaọrụ oghere etiti iji hazie ọrụ olu. Mbufe. Usoro a dịtụ mfe iji mejuputa na nwere ike ozugbo ọdụ ụgbọ mmiri dị teknụzụ, ma na-achọ oké ọnụ Central ụlọ ọrụ ohere ọnụ ụzọ ámá ngwá, elu netwọk ewu ụgwọ, na-ejedebeghị site adịghị ike nke VoIP technology n'onwe ya. Na mgbakwunye, enweghị ike ịnye ọrụ data E1 na N'64kbit / s.
Mgbe usoro EPON na-eji VoIP ebu ọrụ olu, ọ kwesịrị izute ihe ngosi arụmọrụ ndị a maka ọrụ olu VoIP.
① Oge ngbanwe dị ike nke ngbanwe olu erughị 60ms.
② O kwesịrị inwe ikike nchekwa nchekwa 80ms iji hụ na enweghị nkwụsị okwu na jitters mere.
③ Ebumnuche ebumnuche nke olu: Mgbe ọnọdụ netwọk dị mma, nkezi uru PSQM erughị 1.5; mgbe ọnọdụ netwọk adịghị njọ (ọnụego mfu ngwugwu = 1%, jitter = 20ms, igbu oge = 100ms), nkezi uru PSQM bụ <1.8; Mgbe ọnọdụ ahụ dị njọ (ọnụego mfu ngwugwu = 5%, jitter = 60ms, igbu oge = 400ms), nkezi PSQM erughị 2.0.
④ Ntụle isiokwu nke okwu: Mgbe ọnọdụ netwọk dị mma, nkezi uru MOS bụ> 4.0; mgbe ọnọdụ netwọk adịghị njọ (ọnụego ọnwụ ngwugwu = 1%, jitter = 20ms, igbu oge = 100ms), nkezi uru MOS bụ <3.5; netwọk Mgbe ọnọdụ dị njọ (ọnụego ọnwụ ngwugwu = 5%, jitter = 60ms, igbu oge = 400ms), nkezi uru nke MOS <3.0.
⑤ Ọnụego ntinye: G.711, ọnụọgụ koodu = 64kbit / s. Maka G.729a, ọnụọgụ koodu achọrọ bụ <18kbit / s. Maka G.723.1, ọnụọgụ koodu G.723.1 (5.3) bụ <18kbit / s, yana G.723.1 (6.3) ọnụọgụ koodu bụ <15kbit / s.
⑥ Ndekọ igbu oge (nkwụghachi azụ azụ): igbu oge VoIP gụnyere igbu oge codec, igbu oge ntinye ntinye na njedebe nnata, na igbu oge n'ahịrị n'ime. Mgbe ejiri koodu G.729a mee ihe, igbu oge loopback bụ <150ms. Mgbe ejiri koodu G.723.1 mee ihe, igbu oge loopback bụ <200ms.
3.CATV azụmahịa
Maka ọrụ CATV analog, a pụkwara iburu EPON n'otu ụzọ ahụ dị ka GPON: tinye ogologo ogologo ogologo (n'ezie nke a bụ nkà na ụzụ WDM na ọ nweghị ihe jikọrọ ya na EPON na GPON n'onwe ya).
Teknụzụ PON bụ ụzọ kachasị mma iji nweta ohere brọdband FTTx. EPON bụ teknụzụ netwọk nweta ngwa anya ọhụrụ emepụtara site na ijikọ teknụzụ Ethernet na teknụzụ PON. Enwere ike iji ya bufee olu, data na ọrụ vidiyo yana dakọtara. Maka ụfọdụ ọrụ ọhụrụ n'ọdịnihu, EPON ga-abụ teknụzụ kachasị maka ịnweta ngwa anya brọdband na-arụ ọrụ zuru oke yana uru ya zuru oke dị ka bandwit dị elu, arụmọrụ dị elu, na mgbasawanye dị mfe.
Atụmatụ nchekwa nke sistemu PON
Iji meziwanye ntụkwasị obi netwọkụ yana ịlanarị, enwere ike iji usoro ngbanwe nchekwa fiber na sistemụ PON. Enwere ike ịmegharị usoro ngbanwe ihe nchekwa eriri anya n'ụzọ abụọ: ① ngbanwe akpaka, kpalitere site na nchọpụta mmejọ; ② mmanye ngbanwe, nke mmemme njikwa kpalitere.
E nwere isi ihe atọ dị iche iche nke nchekwa eriri: nchekwa nchekwa eriri azụ azụ,OLTNchekwa mgbapụta mgbapụta PON, yana nchekwa zuru oke, dịka egosiri na eserese 1.16.
Nchekwa eriri azụ azụ azụ (Nyocha 1.16 (a)): iji otu ọdụ ụgbọ mmiri PON nke nwere ngwa anya 1'2 wuru.ịgbanweenaOLTọdụ ụgbọ mmiri PON; iji 2: N optical splitter; nkeOLTna-achọpụta ọnọdụ ahịrị; Enweghị ihe pụrụ iche chọrọ maka ndịONU.
OLTNchekwa redundancy ọdụ ụgbọ mmiri PON (Njirimara 1.16 (b)): Ọdụ ụgbọ mmiri PON na-echere dị na ọnọdụ njikere oyi, na-eji 2: N nkesa anya anya; nkeOLTna-achọpụta ọnọdụ ahịrị, na mgbanwe na-eme site naOLT, na-enweghị ihe pụrụ iche chọrọ makaONU.
Nchedo zuru oke (Nyocha 1.16 (c)): ma isi na ọdụ ụgbọ mmiri PON na-arụ ọrụ; abuo 2: N optical splitters na-eji; ihe anyaịgbanweena-ewu n'ihuONUPON ọdụ ụgbọ mmiri, naONUna-achọpụta ọnọdụ ahịrị ma chọpụta isi ojiji Lines na ịgbanwee na-eme site naONU.
Usoro ngbanwe nchedo nke sistemu PON nwere ike ịkwado nloghachi akpaka ma ọ bụ nkwụghachi aka nke ọrụ echekwara. Maka ọnọdụ nlọghachi akpaka, mgbe ewepụsịrị ọdịda ngbanwe, mgbe oge nchere ụfọdụ gachara, ọrụ echedoro kwesịrị ịlaghachi na ụzọ ọrụ mbụ. Enwere ike ịtọ oge nchere nloghachi.