Segment nyiaj siv ua haujlwm

1. Regenerator Section Nyiaj siv ua haujlwm

(1) Ncej Alignment Bytes A1, A2A1 thiab A2 yog siv los txheeb xyuas txoj haujlwm pib ntawm STM-N ncej. A1 yog 11110110 (F6), thiab A2 yog 00101000 (28).

(2) Regenerator Section Trace Byte J0The J0 byte rov xa ib qho cim sawv cev rau qhov chaw nkag, ua kom tau txais qhov kawg ntawm tshooj regenerator kom paub meej tias nws puas muaj kev sib txuas txuas ntxiv nrog rau qhov kawg xa tawm. J0 bytes nyob rau hauv 16 sib law liag thav duab tsim ib 16-byte thav duab kom xa cov nkag mus rau point identifier. Tsis pub dhau lub network ntawm tib tus neeg teb xov tooj, cov byte no tuaj yeem ua tus cim; Txawm li cas los xij, ntawm thaj tsam ntawm lub network ntawm cov neeg ua haujlwm sib txawv, J0 bytes ntawm ob qho tib si tau txais thiab xa khoom kawg ntawm cov khoom siv yuav tsum yog tib yam. Cov neeg khiav dej num tuaj yeem tshawb xyuas thiab daws qhov ua yuam kev ua ntej thiab txo lub sijhawm rov qab los ntawm lub network los ntawm J0 byte.

(3) STM-1 Tus Cwj Pwm C1Nyob rau hauv thawj qhov kev pom zoo CCITT, C1 byte tau teem rau hauv txoj haujlwm ntawm J0, uas yog siv los qhia txoj haujlwm ntawm STM-1 hauv qhov kev txiav txim siab dua STM-N. Thaum cov cuab yeej qub siv C1 byte cuam tshuam nrog lub cuab yeej tshiab siv J0 byte, lub cuab yeej tshiab tau teeb tsa J0 rau "00000001" los qhia "regenerator seem kab tsis tau teev tseg."

(4) Regenerator Section Yuam Kev Saib Xyuas Byte B1The B1 byte yog siv rau kev saib xyuas kev ua yuam kev hauv online ntawm ntu regenerator. Nws txais yuav txawm tias -parity ntsis-interleaved parity 8-ntsis code (hu ua BIP-8). BIP-8 faib cov kev soj ntsuam mus rau hauv pawg ntawm 8 cov khoom, tom qab ntawd suav cov parity (kawg lossis txawm) ntawm tus lej ntawm "1" cov khoom hauv txhua kab. Yog tias tus lej yog khib, qhov sib thooj me ntsis hauv BIP-8 yog teem rau "1"; yog tias txawm, nws yog teem rau "0". Ntawd yog, tom qab ntxiv BIP-8 cov khoom, tus naj npawb ntawm "1" cov khoom hauv txhua kab yuav txawm tias. Piv txwv li, rau qhov luv luv "1101010001110011101010101010111010", BIP-8 suav nrog hauv qab no:

Hauv STM-N thav duab, BIP-8 kev ua haujlwm tau ua tiav ntawm txhua qhov ntawm STM-N thav duab dhau los tom qab sib tsoo, thiab cov txiaj ntsig tau muab tso rau hauv B1 txoj haujlwm ntawm tus ncej tam sim no ua ntej scrambling. Qhov kawg tau txais kev sib piv BIP-8 tus nqi xam los ntawm tag nrho cov khoom ntawm tus ncej dhau los ua ntej descrambling nrog B1 ntawm tus ncej tam sim no tom qab descrambling. Yog tias ib qho me ntsis tsis sib haum, nws qhia tau tias "thaiv" uas tau saib xyuas los ntawm BIP-8 no muaj qhov yuam kev thaum lub sijhawm sib kis. Los ntawm kev txheeb xyuas tus naj npawb ntawm qhov tsis sib xws ntawm BIP-8 suav los ntawm qhov kawg tau txais thiab B1 tau txais, tus naj npawb ntawm qhov yuam kev "blocks" (piv txwv li, tus naj npawb ntawm cov khoom yuam kev) tuaj yeem tau txais thaum lub teeb liab kis tau tus mob, yog li paub txog kev ua yuam kev hauv online ntawm kev saib xyuas ntawm ntu regenerator.

(5) Regenerator Section Service Communication Byte E1E1 yog siv rau regenerator seem kev pabcuam kev sib txuas lus, muab 64 kbit / s txoj kev, uas tuaj yeem nkag mus lossis poob ntawm qhov rov ua dua.

(6) Tus neeg siv Channel Byte F1Nws muab txoj hauv kev 64 kbit / s rau cov tswv lag luam network, ua haujlwm ib ntus cov ntaub ntawv / suab channel rau kev saib xyuas tshwj xeeb.

(7) Regenerator Section Data Communication Channel Bytes (D1, D2, D3) D1, D2, thiab D3 yog siv los xa cov ntaub ntawv kev ua haujlwm, kev tswj hwm, thiab kev saib xyuas (OAM) cov ntaub ntawv ntawm lub tshuab hluav taws xob hauv seem regenerator, muab cov channel nrog tus nqi txog li 192 kbit / s (3 × 64 kbit / s).

2. Multiplex Section Overhead

(1) Multiplex Section Yuam Kev Saib Xyuas Byte B2Nws yog siv rau kev saib xyuas qhov yuam kev hauv online ntawm seem multiplex. Peb B2 bytes tag nrho 24 khoom, ua haujlwm me ntsis -interleaved parity check. Yav dhau los, nws yog BIP-24 kos, thiab tom qab ntawd txhim kho rau 24 × BIP-1. Nws txoj kev suav yog zoo ib yam li BIP-8, tshwj tsis yog tias ntawm no cov khoom tau muab faib ua 24-ntsis pawg.Cov txheej txheem ntawm kev tsim cov B2 byte yog: ua BIP kev ua haujlwm ntawm txhua qhov khoom ntawm cov scrambled STM yav dhau los tshwj tsis yog lub regenerator seem overhead, thiab muab qhov tshwm sim nyob rau hauv B2 byte txoj hauj lwm ntawm tam sim no STM ncej ua ntej scrambling. Qhov kawg tau txais suav cov BIP tus nqi ntawm qhov tau txais cov ncej dhau los, tom qab ntawd XORs nws nrog B2 ntawm tus ncej tam sim no kom tau txais cov lej yuam kev.

(2) Cov ntaub ntawv sib txuas lus Channel Bytes D4-D12Lawv tsim ib qho kev sib txuas lus rau kev ua haujlwm, kev tswj hwm, thiab kev saib xyuas (OAM) cov ntaub ntawv ntawm multiplex seem ntawm kev tswj xyuas network, muab cov channel nrog tus nqi txog li 576 kbit / s (9 × 64 kbit / s).

(3) Multiplex Section Service Communication Byte E2Nws yog siv rau multiplex section service kev sib txuas lus, thiab tsuas yog nkag tau los yog muab tso rau ntawm cov khoom uas muaj cov Multiplex Section Termination (MST) function block, muab ib tug 64 kbit / s txoj kev.

(4) Tsis Siv Neeg Tiv Thaiv Hloov Hloov Channel Bytes K1, K2 (b1-b5)K1 thiab K2 yog siv los xa cov Multiplex Section Protection Switching (APS) raws tu qauv. Lawv xyuas kom muaj kev hloov pauv tsis siv neeg thaum cov cuab yeej tsis ua haujlwm, ua rau lub network tus kheej - kho, uas yog siv rau tus kheej - kho qhov xwm txheej ntawm multiplex seem tiv thaiv switching.Qhov kev faib me ntsis thiab me ntsis - cov txheej txheem taw qhia ntawm ob bytes tau teev tseg hauv Annex A ntawm ITU-T Kev Pom Zoo G.783. K1 (b1-b4) qhia tias yog vim li cas rau qhov kev thov hloov, K1 (b5-b8) qhia tus lej ntawm kev ua haujlwm uas pib qhov kev thov hloov, thiab K2 (b1-b5) qhia tus lej ntawm kev ua haujlwm uas qhov kev tiv thaiv kev hloov pauv hloov mus rau ntawm ntu multiplex tau txais sab txuas.

(5) Multiplex Section Remote Defect Indication Byte K2 (b6-b8) Nws yog siv los xa rov qab cov xwm txheej qhia txog lub teeb liab ntawm qhov tau txais qhov kawg mus rau qhov kawg ntawm kev xa xov ntawm seem multiplex, ceeb toom rau kev xa xov kawg tias qhov kawg tau txais qhov kawg tau kuaj pom qhov ua txhaum loj lossis tau txais Multiplex Section Alarm Indication Signal (MS{10}}AIS). Thaum muaj qhov tsis xws luag, tus lej "110" tau muab tso rau hauv K2 (b6-b8) los qhia Multiplex Section Remote Defect Indication (MS-RDI).

(6) Synchronization Status Byte S1 (b5-b8)Bits b5-b8 ntawm S1 byte yog siv los xa cov ntaub ntawv synchronization xwm txheej, uas yog, cov xwm txheej synchronization ntawm qhov chaw nres tsheb sab saud tau xa mus rau qhov chaw nres tsheb hauv qab los ntawm S1 (b5-b8). Qhov kev npaj ntawm S1 muaj nyob rau hauv Table 1-3.

(7) Multiplex Section Remote Error Indication Byte M1M1 yog siv los xa rov qab tus naj npawb ntawm qhov tsis raug kuaj pom los ntawm qhov tau txais qhov kawg ntawm seem multiplex mus rau qhov kawg xa tawm. Cov ntaub ntawv yuam kev ntawm qhov kawg tau txais (qhov kawg kawg) tau los ntawm kev sib piv 24 × BIP-1 xam los ntawm qhov kawg tau txais nrog B2 tau txais. Tus naj npawb ntawm cov khoom yuam kev sib raug rau tus lej ntawm qhov yuam kev, thiab tom qab ntawd tus lej ntawm qhov yuam kev yog sawv cev hauv binary thiab muab tso rau hauv M1 txoj haujlwm, raws li qhia hauv Table 1-4, Table 1-5, thiab Table 1-6.

(8) Bytes Reserved rau yav tom ntej International StandardsCov dawb paug bytes nyob rau hauv daim duab 1-9 nrog unspecified lub hom phiaj yog tseg rau yav tom ntej thoob ntiaj teb tus qauv siv. Tam sim no, qee qhov ntawm cov bytes no tau tso cai siv rau kev sib txuas lus muaj feem xyuam.

SOH kev ua haujlwm ntawm SDH yog qhov ua tiav, tab sis tsis yog txhua tus bytes yog qhov tseem ceeb hauv txhua kis. Simplifying lub interface raws li cov xwm txheej tiag tiag thiab tshem tawm qee qhov tsis yog -bytes tseem ceeb tuaj yeem txo cov nqi khoom siv. Tsuas yog A1, A2, B2, thiab K2 bytes yog qhov tseem ceeb.

Kev xaiv ntawm SOH bytes rau qhov yooj yim interface yog qhia hauv Table 1-7. Qhov kev sib txuas yooj yim no tsuas yog ib qho kev xaiv muab rau cov tuam txhab tsim khoom thiab cov tswv lag luam network, thiab tuaj yeem siv tau raws li cov xwm txheej tiag tiag hauv kev siv tswv yim.