Download - He Thong Truyen Dan SDH

Chng 9 H thng truyn dn SDHon v tuynCu hnh h thng Cu hnh nodeTn hiu qun l v bo dngng b mngCc tham s nh gi cht lng h thng

Ghp knh PDH & SDH -- Chng 9- H thng truyn dn SDH --

on v tuynon (Section)Trong h thng truyn dn c 2 loi on:on lp on ghp

on lp: L khong truyn dn gia 2 b lp gn nhau nht hoc gia b lp vb ghp (ngha l on c cha trm lp)on ghp: L khong truyn dn gia: 2 thit b u cui, gia 2 thit b xen r, gia thit b u cui n thit b xen rTE: Terminal Equipment: Thit b ghp u cuiREG: Regenerator: Thit b lp


Tuyn (Path)Khi lu thng trn mng, VC c ng gi (assembly) v m gi (dissembly) mt ln duy nht ti node ngun v node ch. Khong cch t ngun n ch y gi l mt Tuyn.Tuyn l khong cch ni logic gia mt im ti VC-n c ng gi v mt im khc ti VC-n c kt cui.Mt tuyn c th xem nh mt ng dn i ngang qua mt s on ghp v ni trc tip gia 2 im truyn d liu.Khong ni gia 2 VC-1X hoc VC-2: Tuyn bc thpKhong ni gia 2 VC-3 hoc VC-4: Tuyn bc cao


Cu hnh h thngim ni im: Hai thit b u cui kt ni vi nhau qua cc trm lp.


Cu hnh h thng (tt)Mng ng trc-Trong mng ny ,thit b c s dng theo ch ghp knh u cui ti 2 trm u cui mng. Gia hai trm u cui, thit b c s dng theo ch ADM (rt/xen) v REG (lp li).


Cu hnh h thng (tt)Mng hnh sao (HUB)Trong mng ny, thit b c s dng theo ch ghp knh u cui (TRM) hay ch rt/xen knh (ADM) ti trm lung trung tm.


Cu hnh h thng (tt)Mng mc li : Trong mng ny, thit b c s dng theo ch ADM c kt ni cho


Cu hnh h thng (tt)Mng vng :Mng bao gm cc trm thit b c ni vi nhau theo mt vng khp kn . Cc thit b ny c s dng theo ch ADM . Kh nng bo v trong mng ny rt cao.


Cu hnh node

Cu hnh NE u cuiThit b u cui ghp cc lung nhnh thnh tn hiu STM-N (N=1, 4, 16, 64) v ngc li tch tn hiu STM-N thnh cc lung nhnh.


Cu hnh node (tt)Cu hnh NE xen rTn hiu nhn c t hng X s c x l con tr, c kt ni n hng Y v hng lung cc mc VC-12 ,VC-3 , VC-4 ty theo thng tin yu cu .


Cu hnh node (tt)Cu hnh NE lpTn hiu t pha X (Y) c x l con tr v a n pha Y (X) trn cng mt khe thi gian.


Cu hnh node (tt)Cu hnh NE ni cho s Tn hiu vo t hng X , Y hoc hng giao tip lung s c x l con tr ; sau , chng c th c kt ni n X ,Y hoc hng lung cc mc VC-12 ,VC-3 , VC-4 ty theo thng tin yu cu .


Tn hiu qun l v bo dngSOH: Cha tn hiu nghip v qun l , bo dng v gim st trn cc on lp v on ghp knh .POH: Cha tn hiu nghip v qun l ,bo dng v gim st cc on cc lung nhnh.

Cu trc SOH trong khung STM-N- STM-1: SOH gm 8 dng 9 ct : 3 dng 9 ct : RSOH 5 dng 9 ct : MSOH

Cu trc chi tit ca cc byte trong SOH nh sau :


Tn hiu qun l v bo dng (tt)Cc byte RSOH c s dng cho cng vic gim st , iu khin trn on lp . Cc byte ny c x l ti cc trm lp v nu cn th c th c chuyn i tip n cc trm khc . Do , ngay c trm lp cng phi c ng b vi mng .Cc byte MSOH ch c tc dng gia cc trm xen r vi nhau m khng c tc dng vi cc trm lp ( ngha l c chuyn tip qua cc trm lp ).Trong trng hp ghp khung STM-N th SOH gm cc byte SOH c ghp xen k t cc byte SOH ca cc STM-1 ring l .STM-4: SOH gm (8 36) byte , trong :- Cha 12 byte A1, 12 byte A2, 12 byte B2, 12 byte J0/C1 (nu dng C1).- Nhng byte khc ch xut hin 1 ln trong STM-1 #1STM-16: SOH gm (8144)byte, trong :- Cha 48 byte A1, 48 byte A2, 48 byte B2,48 byte J0/C1(nu dng)- Nhng byte khc ch xut hin 1 ln trong STM-1 #1STM-64: SOH gm (8576)byte, trong :- Cha 192 byte A1, 192 byte A2, 192 byte B2, 192byte J0/C1(nu dng)Nhng byte khc ch xut hin 1 ln trong STM-1 #1


Tn hiu qun l v bo dng (tt)STM-4: SOH gm (8 36) byte , trong :- Cha 12 byte A1, 12 byte A2, 12 byte B2, 12 byte J0/C1 (nu dng C1).- Nhng byte khc ch xut hin 1 ln trong STM-1 #1


Tn hiu qun l v bo dng (tt)STM-16: SOH gm (8144) byte, trong :- Cha 48 byte A1, 48 byte A2, 48 byte B2, 48 byte J0/C1 (nu dng)- Nhng byte khc ch xut hin 1 ln trong STM-1 #1


Tn hiu qun l v bo dng (tt)* Xc nh v tr mi byte SOH ca STM-1 # n (n=1 n N)V tr mi byte c c trng bi 2 thng s : (a,b)a = 1 n 3 v 5 n 9: S th t dng trong STM-1b = ch s ct ca byte ang xt thuc STM-1 # n trong khung STM-Nb = N (i-1) + n (*)trong : i: ch s ct ca byte SOH ang xt trong khung STM-1(i=1 n 9)n: th t ca khung STM-1 cha byte ang xt trong khung STM-N Biu thc (*) dng xc nh ta cc byte SOH trong khung STM-4,STM-16, STM-64.V d: Xc nh v tr byte D2 trong khung STM-4 v STM-16a=3STM-4: b= 4(4-1) +1=13STM-16: b=16(4-1) + 1=49Ch : Biu thc (*) khng p dng cho byte M1 v byte M1 cv tr c nh trong dng 9 v cch ct th D11 mt ct v pha bn phi


Tn hiu qun l v bo dng (tt)Tn hiu qun l v bo dng on lp (RSOH)RSOH 3 hng u ca SOH c chc nng :-Gim st iu khin trn on lp-c x l ti cc trm lp v c th chuyn n cc trm lp khc.Chc nng cc byte nh sau: A1, A2:- 6 byte u tin ca SOH c dnh cho cc thng tin ng b khung. 6 byte nyc cu trc : A1 A1 A1 A2 A2 A2 , trong :A1 = 1 1 1 1 0 1 1 0 = F6 (hexa)A2 = 0 0 1 0 1 0 0 0 = 28(hexa)- Cc mu ny c cha trong mi tn hiu STM-1 trong STM-N v khng b ngu nhin ha .- Tng t s c 4 6 =24 byte ng b trong mt khung STM-4, 16 6 = 96byte ng b c ghp trong mt khung STM-16 , 64 6 =384 byte ng bc ghp trong mt khung STM-64.- C 2 mc li ca ng b khung l li v ng b khung OOF (out of frame)v mt ng b khung LOF (loss of frame )


Tn hiu qun l v bo dng (tt)


Tn hiu qun l v bo dng (tt)J0 :(trc y l C1)C1: Nhn dng tng STM-1 ring l trong STM-N Mi mt STM-1 u c mt s nhn dng ID (Identification) xc nh v kim tra v tr ca tng STM-1 ring ltrong STM-N khi ghp hoc phn knh . S nhn dng ny c cha trong byte C1 ca t mo SOH trong mi STM-1 . V d: trong khung STM-16 STM-1#1: C1 = 0000 0001STM-1#16: C1 = 0001 0000J0: nh tuyn on lp (G.783) J0 c tryn trong 16 khung lin tip to thng t m nhn dng im truy nhp my thu chuyn thng tin n ng my pht nh.Cu trc J0 trong da khung 16 khung nh sau:


Tn hiu qun l v bo dng (tt)Cu trc J0 trong a khung 16 khung nh sau:


Tn hiu qun l v bo dng (tt) Z1,Z2: byte d tr dnh cho tiu chun ha trong tng lai

B1: BIP-8 (bit interleaved parity) - Kim tra li on lp.c thc hin trn cc trm lp v truyn thng sut qua cc trm ghp. - BIP-8 (t m kim tra chn xen bit) l phng php kim tra li tn hiu.Vic kim tra ny c tin hnh trn ton b khung STM-1 th n sau khi c ngu nhin ha . Kt qu ca t m BIP-8 ny s c t vo byte B1 ca khung STM-1 k tip (n+1)trc khi n c ngu nhin ha . - i vi khung STM-N , ch c byte B1 ca STM-1 u tin c s dng . - Mi trm lp kim tra tt c cc bit ca cc byte trong khung STM-1 th n v cng thm cc bit tng ng ca B1 trong khung th (n+1). Nu tng s l l th b m li tng 1. Kt qu li khi pha thu c chuyn v trm gim st h thng.


Tn hiu qun l v bo dng (tt)-Trn hng pht, t m n bit c to ra trn mi dng bit vi di tun theo giao thc m c nh . - hng thu, dng bit cng c m ha theo qui lut trn. T m mi ny c so snh vi t m m hng pht gi qua . Bt k s khc bit no gia cc t m mi v c ch ra li bit trong truyn dn


Tn hiu qun l v bo dng (tt)Hnh- BIP-N .


Tn hiu qun l v bo dng (tt)E1:Cung cp knh thoi nghip v (EOW-Engineering Order Wire) - Byte ny to ra knh nghip v ni b gia cc trm lp v cc trm khc trong qu trnh qun l, gim st v bo dng. - E1 c truy nhp ti cc trm lp v trm ghp l ni c gn b CODEC-PCM. F1 : - Cung cp mt knh thoi hoc truyn s liu tm thi cho vic bo dng h thng khi c s c h hng. - Cch s dng byte ny cha c chun ha v ngi ta thng dng byte ny nhn bit on ng truyn c s c trong mt s cc on lp . Khi mt trm lp pht hin c s c trong on lp ca n th n s xen vo byte ny mt chui 6 bit xc nh tn trm lp c s c , 2 bit cn li l tn ca s c .D1, D2, D3 : Knh truyn s liu on lp RS-DCC - Cc knh thng tin d liu cho b lp DCCR t D1 D3 , c tc tng cng l 192 Kbit/s . - Cc knh DCCR c nhim v chuyn lnh iu khin t mt node qun l mng n trm lp hoc chuyn n cc node cc d liu gim st c ti cc trm lp thng qua cc cng GNE (Gate Network Element )


Tn hiu qun l v bo dng (tt)RF: Dng cho vi ba s, gm 3 byte RF1, RF2, RF3RF1: - 4 bit FFK dng nhn bit tng chn trong tuyn nhm m bo cho b gii iu ch lm vic vi ng tn hiu pht i t b iu ch tng ng.- MSI: ch th mt tn hiu bng gc ti b iu ch DM: dng choiu khin cng sut pht t ng

RF2:-PAR: Bit kim tra chn gim st li ca byte RF2-LFI: Ch th li ng truyn , v tr cc bit LFI ghp cc bit li do b sa li trc pht hin nhng cha c sa li. RF3:Dng cho chuyn mch bo v Cc byte RF d tr cho vic pht trin dch v v tuyn


Tn hiu qun l v bo dng (tt)Tn hiu qun l v bo dng on ghp (MSOH)Cc byte ny c truy nhp v kt cui ti cc trm ghp v truyn thng sut qua cc trm lp . B2 : BIP-N24 - 3 byte ( 3 B2 ) trong mi STM-1 dng kim tra li bit trong phn ghp knh ca cc trm u cui hay xen r . -Trong tn hiu STM-N , tt c cc byte B2 ca STM-1 u c s dng (N 3 B2 ). -Th tc kim tra BIP-N24 to ra t m N 24 bit (3byte ) v a vo v tr byte B2 trong khung STM-N. Phn chia khung STM-N thnh tng khi , mi khi N24bit. C ch hot ng ging nh BIP-8.

K1 v K2: Cc knh t ng chuyn mch bo v (APS) : -2 byte dng cho vic t ng chuyn mch bo v l K1 v K2 , c chc nng nh sau : -Byte K1 , K2 ch c b tr trong STM-1 th nht ca khung STM-N


Tn hiu qun l v bo dng (tt) D4 n D12: Cc knh thng tin d liu ghp knh DCCM t D4 D12 , c tc 576Kbit/s . Cc knh ny cho php chuyn cc thng tin d liu gia cc GNE v cc b tch / ghp lung . Cc knh data ny ch c trang b trong STM-1 th nht ca mi STM-N .

S1: Trng thi ng b

Vng SSM (Synchronization Status Messages) truyn ch th cho bit cc mc cht lng ca ng h trm ny truyn ti trm khc.

1 2 3 4 5 6 7 8


Tn hiu qun l v bo dng (tt)Bng- Cc mc cht lng ca ng h


Tn hiu qun l v bo dng (tt) M1: Ch th li u xa on ghp MS-REI (hoc section FEBE-far end block error )-Byte ny cha s cc khi b li c pht hin bi BIP-24 (3 byte B2 ) . Cc gi tr t 0 24 (cho STM-1 ) v t 0 N24 (cho STM-N ) l cc gi tr hp l .-Tt c cc gi tr trn c biu th bi 8 bit ca byte M1 .

E2: Cung cp knh thoi nghip v (EOW-Engineering Order Wire)-Byte ny to ra knh thoi ni b gia cc trm ghp.-Cc trm lp khng truy nhp c cc byte ny.


Tn hiu qun l v bo dng (tt)Tn hiu qun l v bo dng tuyn (POH) VC-1X v VC2:C 4 byte POH trong a khung 500 s ca VC-1X v VC-2 . POH ca LVC gm V5, J2, N2, K4Hnh- POH ca VC-1X v VC-2


Tn hiu qun l v bo dng (tt) V5


Tn hiu qun l v bo dng (tt)- Cc chc nng ca byte V5 gm : Gim st li . Cha nhn tn hiu . Ch nh trng thi ng dn ca VC- 1X hay VC-2 .Chc nng cc bit trong V5 : BIP-2 : Dnh cho vic gim st li bit trn ng dn VC-1X hay VC-2 .Tt c cc bit trong a khung u c tc ng n BIP-2 ngoi tr cc byte con tr TU-1X v TU-2 .Tuy nhin , trong trng hp ng chnh m con tr , byte con tr V3 s c tc ng n t m BIP-2 . REI :ch th li u xa (trc y l FEBE Far End Block Error ). Nu c li c pht hin bi BIP-2 , bit th 3 s c t ln "1" ; ngc li , bit th 3 s c t v "0" .Bit ny s c truyn v ni bt u ca ng dn VC-1X hay VC-2 . RFI: Ch th mt tn hiu thu VC-1X v VC-2 u xa. Bit ny c gi t u xa v trm gc. Nhn tn hiu: Cc bit t 5 7 ch th cc trng thi ca LVC. RDI: ch th cnh bo u xa. Trong c 2 trng hp nhn c tn hiu AIS hoc b mt lung tn hiu , bit ny s c t ln "1" v s c truyn ngc v trm gc


Tn hiu qun l v bo dng (tt) J2 : nh tuyn-Byte J2 dng truyn m nhn dng im truy nhp tuyn bc thp my thu nhn bit v tip tc chuyn thng tin n my pht c ch nh trc. M nhn dng c truyn lin tip trong 16 khung VC-1X/VC-2 N2: iu hnh mng-Byte ny gim st ni chuyn tip (TCM-Tandem Connection Monitoring) mc VC-1X v VC-2.

b1b2b3b4b5b6b7b8BIP-21AIS nTC-REIOEI TC-APId, TC-RDI,ODI, d tr


Tn hiu qun l v bo dng (tt)-Bit 1 v 2 to thnh t m kim tra chn c 2 bit (BIP-2) cho VC ni chuyn tip.-Bit 3: Pht c nh 1 nhm m bo cho N2 khng pht i mt dy cc bit 0.-Bit 4: hot ng nh b ch th AIS n-Bit 5: ch th cc khi b li do ni chuyn tip-Bit 6: ch th cc khi b li trong lung ra VC-n-Bit 7 v bit 8: hot ng trong a khung 76 khung :.Nhn dng im truy nhp ca ni chuyn tip, thng bo TC-APId nhn dng truy nhp ni chuyn tip ) c truyn i..Ch th trong tn hiu ni chuyn tip u gn c s c v thng bo TC-RDI c chuyn ti u xa..Ch th TU-AIS xen vo trong lung ni chuyn tip trc hoc trong khi ni chuyn tip v thng bo ODI c chuyn ti u xa..D tr pht trin cho tng lai.K4: knh chuyn mch bo v t ng -Dng bit 1n 4 truyn bo hiu chuyn mch bo v t ng cc LVC-Bit 5-7 ch th u xa c s c (LP-RDI)-Bit 8 : D tr.


Tn hiu qun l v bo dng (tt)Tn hiu qun l v bo dng tuyn ( POH) ca VC-3/VC-4


Tn hiu qun l v bo dng (tt) J1 :Byte thng bo ng dn-Byte ny c s dng truyn thng bo ng dn . Thc cht y l mt knh data c tc 64 Kbit/s thng bo ng m d liu s c truyn .-Mu tin ng dn di 64 bytes v c 1 byte s c mang trong byte J1 ca mi khung tng ng . Mu truyn dn bn tin bt u tr li sau 64 khung . Chui 64 byte gm 4 khung , mi khung c cu trc nh m t trong byte J0 B3: Byte gim st li ng dn dng BIP-8-Byte BIP-8 (B3) dng kim tra li khi tuyn bc cao . Nguyn tc ny c m t phn trc. Phm vi cc bit c kim tra l VC-3 v VC-4.-Vic kim tra s ng ng c tin hnh trn ton b ccbyte ca VC .. Sau kt qu kim tra c lu li truyn trn byte B3 ca VC k tip . C2 : Byte nhn tn hiu-Byte C2 dng thng bo kiu "mapping " (b tr ) c s dng trong VC-3 v VC-4, hoc ch th cc trng thi bo dng ca VC bc cao.-Byte C2 c cc gi tr sau :


Tn hiu qun l v bo dng (tt)Bng: Chc nng ca byte C2DQDB :Distributed Queue Dual Bus


Tn hiu qun l v bo dng (tt) G1: Byte ch trng thi ng dn-Byte G1 dng bo ngc v cho trm xut pht bit tnh trng li ca ng dn v n lun c ci trong t mo tuyn POH ca tuyn ngc v .- Byte ny mang 2 loi thng tin nh sau : REI (trc y l FEBE -Far End Block Error ): Cc bit t 1 4 ca byte G1 s cha s li c pht hin bi BIP-8 (byte B3 ) trm xa .REI c gi tr t 0 8 , cc gi tr cn li ch th khng c li. RDI(trc y l FERF-Far End Receive Failure ): Bit 5-7 ca byte G1 c dng bo v trm gc l trm xa pht hin mt s c nghim trng nh : Nhn AIS . Li tn hiu . ng kt ni khng hon thnh .


Tn hiu qun l v bo dng (tt)Bng 5.4:Cu trc RDI ca byte G1 F2, F3: Knh nghip v- Dng lin lc gia cc trm ca tuyn phc v cho bo dng. H4: Ch th a khung- Byte H4 trong VC-3 v VC-4 c lin qian n cc lung nhnh bc thp khi ghp cc lung ny vo VC3 hoc VC-4. - 2 bit cui ca byte H4 ch th v tr cc byte con tr TU-1X v TU-2 trong a khung VC-3 v VC-4


Tn hiu qun l v bo dng (tt) K3 : Knh chuyn mch bo v t ng (APS)-Dng bit 1-4 truyn bo hiu APS mc VC-3/VC-4, cc bit cn li l d tr. N1: iu hnh mng-C chc nng gim st ni chuyn tip (TCM) cc HVC. Chc nng cc bit c th nh sau:TC-REI

TC-APId,TC-RDI, ODI, d trOEI

- bit 1-4 : m li n (IEC) trong t m BIP-8 (B3). M ho 4 bit ca EIC nh sau:IEC

b1b2b3b4b5b6b7b8


Tn hiu qun l v bo dng (tt)-bit 5: ch th cc li khi khi ni chuyn tip(TC-REI)-bit 6: ch th cc khi b li trong lung ra VC-n.-bit 7 v 8: ch th im truy nhp ca lung ni chuyn tip (TC-APId), ch thu gn c s c trong ni chuyn tip v thng bo TC-RDI chyun ti u xa.Cu trc 2 bit ny ging hon ton byte N2.


Tn hiu qun l v bo dng (tt)6. S truyn tn hiu bo dngCc nh ngha v cc s kin v cnh bo trong SDHRegenerator sectionon lpLOSLoss of signalMt tn hiu OOFOut of frameLi khung(ngoi khung)LOFLoss of frameMt ng b khungB1RegeneratorLi BIP on lpRS-TIMRegenerator section traceLi khi nhn dng du identifier mismatch on lpMultiplex Sectionon ghp knhB2Multiplex section BIP errorLi BIP on ghp knhMS-AISMultiplex section AISAIS on ghp knhMS-RDIMultiplex section remoteCh th h hng u xa defect indicationon ghp knhMS-REIMultiplex section remoteCh th li u xa error indication on ghp knh


Tn hiu qun l v bo dng (tt)Higher order path (HP)ng dn cp caoAU-LOPLoss of AU-pointer-Mt con tr AUAU-NDFAU pointer new data flagC d liu mi ca con tr AUAU-AISAU poiter justification eventS kin hiu chnh con tr AUB3HP BIP errorLi BIP ng dn cp caoHP-UNEQHP unequippedng dn cp cao khng c cung cpHP-RDIHP remote defect indicationCh th h hng u xa ng dn cp caoHP-REIHP remote error indicationCh th li u xa HP-TIMHP trace identifier mismatchLi (khng khp) khi nhn dng du ng dn cp caoHP-PLMHP payload label mismatchLi (khng khp) khi nhn dng nhn ti tin ng dn cp cao


Tn hiu qun l v bo dng (tt)Lower order path (LP)ng dn cp thpTU-LOPLoss of TU-pointerMt con tr TUTU-NDFTU pointer new data flagC d liu mi ca con trTUTU-AISTU alarm indication signal Tn hiu ch th cnh bo con tr TUTU-LOMTU loss of multiframeMt a khung TUBIP-2/ B3LP BIP errorLi BIP ng dn cp thpLP-UNEQLP unequippedng dn cp thp khng c cung cpLP-RDILP remote defect indicationCh th h hng u xa ng dn cpthpLP-REILP remote error indicationCh th li u xa LP-RFILP remote failure indicationCh th h hng u xa ng dn cpthpLP-TIMLP trace identifier mismatchLi (khng khp) khi nhn dng du ng dn cp thpLP-PLMLP payload label mismatchLi (khng khp) khi nhn dng nhn ti tin ng dn cp thp(


Tn hiu qun l v bo dng (tt)Trong cc on ghp, cc on lp v trong cc tuyn u c cc tn hiu bo dng v cc cnh bo tng ng. Cc cnh bo c phn lm 2 nhm:Nhm th nht truyn cng hng.Nhm th hai truyn ngc hng (hay cnh bo xa)Cc tn hiu bo dng l cc tn hiu thng bo v ch th trng thi ca ng truyn. Trong trng hp ng truyn c s c hoc b li th cnh bo ph hp c pht iTn hiu bo dng on lp v on ghpLOSLOFREIMS-AIS


Tn hiu qun l v bo dng (tt)LOS: Mt tn hiuKhi mt tn hiu on no th on y pht AIS cng hng v pht RDI ngc hng.V d: u vo STM-1 mt tn hiu th: Khi STM-1 ci t 3 bit cui ca byte K2 bng 110 v truyn ngc hng ngc tr li cho STM-1 gc. ng thi, ci t AIS vo cc bit b5,b6,b7 ca byte G1 bng 111 truyn cng hng n VC-n pha sau.LOF: Mt ng b khungNu 625s tri qua m khng thu ng cc byte A1 v A2 th xc nhn mt ng b khung. V d: Khi trm u xa mt ng b khung th:Ci t cc bit b6,b7,b8 ca bye K2 bng 110 v truyn ngc li cho trm gcng thi, ci t AIS (111) vo cc bit b5,b6,b7 ca byte G1 truyn cng hng n VC-n pha sau


Tn hiu qun l v bo dng (tt)REI (FEBE): Ch th li khi u xaKhi kim tra t m BIP-24 (byte B2) pht hin c li th ci t REI vo byte M1 v truyn ngc v trm gc.

MS-AIS : Tn hiu ch th cnh bo on ghpMS-AIS xut hin trong cc trng hp sau y:Hng thu thit b ADM b mt tn hiu (LOS)Hng thu thit b ADM b mt ng b khung (LOF)Lc , thit b s: Ci t bit b6, b7, b8 ca byte K2 bng 111 v truyn cng hng ti trm sauCc byte con tr ti thi im cng c ci t ln 1 v truyn cng hng ti trm sau


Tn hiu qun l v bo dng (tt)Tn hiu bo dng tuyn VC-3 v VC-4REILOPVC-AISRDI

REI (FEBE): Ch th khi li u xaCc trm ghp kim tra t m BIP-8 (byte B3) trong VC-3 POH hoc VC-4 POH, nu pht hin li th ci t cnh bo trong cc bit b1,b2,b3,b4 ca byte G1 v truyn v trm gc.LOP: Ch th con tr TU-3, AU-3 hoc AU-4Ti pha pht, nu con tr no b mt th chuyn i tt c cc bit trong con tr y bng 1 v truyn ti trm xaTrm u xa nhn bit s ci t 100 vo cc bit b5,b6,b7 ca byte G1 v truyn ngc hng v trm gc.. ng thi, ci t VC-AIS vo byte C2 truyn cng hng


Tn hiu qun l v bo dng (tt)VC-AIS: Ch th cnh bo tuyn bc caoVC-AIS xy ra khi lung nhnh 34368 Mbps hoc 139264 Mbps ca b ghp b mt. Lc :AIS ca b ghp y c ci t bng cch gn cc bit con tr v cc bit trong VC-3 hoc VC-4 ca lung nhnh mt bng 1 v truyn cng hng.Khi VC-3 v VC-4 tip theo nhn c AIS hoc LOP th ci t AIS v truyn cng hng.RDI (FERF): Ch th mt tn hiu thu VC-3/ VC-4 u xaTrong trng hp u xa nhn VC-AIS, LOP, LOS th ci t RDI (101) vo cc bit b5,b6,b7 ca G1 v truyn cng hng


Tn hiu qun l v bo dng (tt)Tn hiu bo dng tuyn VC-3 v VC-4REI (FEBE)LOPVC-AISRDI (FERF)

REI (FEBE): CH th li khi u xaVC-n bc thp kim tra kim tra t m BIP-2 ca byte V5, nu pht hin c li th ci t bit th 4 bng 1 v truyn ngc hng.LOP: Mt mt trong cc con tr TU-2, TU-12, TU-11Khi pha thu nhn c cc bit trong cc con tr TU bng 1 th: ci t bit th 8 ca byte V5 bng 1 v truyn ngc v trm gc.ng thi, ci t VC-AIS vo cc bit ca con tr v cc bit ca a khung VC-n bc thp truyn cng hng.


Tn hiu qun l v bo dng (tt)VC-AIS: Tn hiu ch th cnh bo tuyn bc thpKhi trm u xa nhn c cnh bo LOP, LOS, AIS trong tuyn bc thp th ci t AIS tuyn bc thp v truyn cng hng.

RDI (FERF): Ch th mt tn hiu thu VC-n bc thp u xaKhi trm u xa nhn c mt trong cc cnh bo trong lung tn hiu bc thp nh LOP, LOS, VC-AIS th ci t cnh bo RDI trong byte G1 ca VC-n bc thp v truyn ngc v trm gc.


ng b mngS cn thit ca ng bng b: L cc phng thc gi cho tt c cc thit b s trn mng vin thng hot ng theo cng mt tc trung bnh.C 3 cp ng b: bit, khe thi gian, khungng b bit lin quan n thit b. Cc u cui pht v thu ca mt kt ni phi hot ng theo cng mt tc cho cc bit khng c c sai.ng b khe thi gian ng chnh my pht v my thu sao cho cc khe thi gian c th c nhn bit trong qu trnh khi phc d liu. (Bng cch s dng khun kh khung c nh phn chia cc byte. Cc vn chnh ca ng b khe thi gian l thi gian nh li khung v pht hin) mt khung.ng b khung lin quan n vic my pht v my thu c cn bng v pha sao cho c th nhn bit s bt u ca mt khung. (Khung ca T-1 hay E1 gm c 24 byte hay 30 byte tng ng v mt xung ng b khung, thi gian ca mt khung l 125s )


ng b mngCc phng thc ng b mng SDHGii m byte trng thi ng b S1S1 c dng chuyn thng tin v cht lng ca tn hiu ng b c trao i gia cc phn t mng. Thm vo , gii m byte S1 gi i bi NE s gip nhanh chng xc nh c ngun ng b cho NE .Khi NE c ng b trc tip t ngun PRC (Primary Reference Clock), bn tin S1 c gii m l G.811. Ngha l: NE nhn c tn hiu ng b t PRC theo khuyn ngh ITU-T G.811.Khi NE c ng b gin tip t ngun PRC (Primary Reference Clock), bn tin S1 c gii m l G.812. Ngha l: NE ang nhn tn hiu ng b t ng h t (slave) ca PRC theo khuyn ngh ITU-T G.812.


ng b mngng b phn t SDHCh ng b ngoi: S dng ngun nh thi c lp vi cc ngun ng h ni, hoc tch t thit b quang hoc t tn hiu nhnh thu c. Ngun ng b ngoi thng l ngun ng h c chnh xc cao nh ng h Stratum.


ng b mngCh b ng b ng truyn (line timimg)Tn hiu ng b c tch t tn hiu quang thu c t mt hng v c dng ng b cho c hai tn hiu quang pht trn c 2 hng v ton b tn hiu nhnh c kt cui bi ADM .


ng b mngng b vng (loop timing)Ch ny c dng cho cc NE u cui. y l mt dng ca ng b ng truyn.Trong tn hiu ng h c s dng ng b tn hiu quang pht cho hng ngc li v cc tn hiu nhnh ca thit b u cui.


ng b mngCh ng b xuyn qua (Through Timing)L mt dng ca ng b ng b ng truyn c p dng cho on lp. Trong tn hiu quang u vo c dng ng b tn hiu quang pht cng hng. S ng b cc tn hiu truyn theo hng ngc li qua trm lp l c lp. V vy mi hng cn c 1 ngun ng b.


ng b mngCh chy t do (Free run)L phng thc ng b bng cch s dng ng h ni. ng h ni thng thuc loi Stratum 3.5 ( 20 ppm). ng h ni b ca thit b cung cp tn hiu nh nhp cho cc tn hiu quang u ra v cc tn hiu nhnh.Nhc im ca phng php ny l tri ca tn hiu ng h ni ln hn nhiu so vi cc loi ng h khc trong mng.


ng b mngCu trc mng ng bHai phmg php c bn ng b cc ng h node mng l:ng b ch tng b tng h (thng dng cho mng mc li, ang nghin cu)Mt mng ng h c bit c thit lp bo m tt c cc phn t trong mng vin thng c ng b vi nhau.Mng c phn b theo hnh thc phn cp:PRC: l mt ngun ng h chun s cp iu khin tt c cc ng h cho cc node mng (SSU) v cc phn t mng (SEC). Cng cn phi quan tm n cc tn hiu cn ng b vo trong mng ng b.


ng b mng


ng b mngPRC: Primary Reference ClockSSU: Synchronous Supply UnitSEC: SDH Equipment Clock

Chui di nht khi u t 1 PRC khng vt qu 10 SSU. Trong :S SEC gia 2 SSU 20Tng SEC 60PRC: l b dao ng Cesium c LORAN-C hay GPS h tr


ng b mng


ng b mngPRC: l mt ng h ch cho mngMt trong nhng loi ng h PRC l ng h Stratum 1(c cht lng cao nht trong mng) Stratum 1: L ng h chy t do, khng s dng tn hiu tham chiu ng b. Thng Stratum 1 l ng h nguyn t Cesium.Mt loi PRC khc l cc ng h da trn h thng nh v ton cu (GPS) v cc ng h LORAN-C. Chng khng c xem l Strtum1 v chng c iu khin. Chng dng b dao ng ni rubidium hay quartz c iu khin bng cc thng tin ng b thu t GPS hay LOEAN-C ( )


ng b mng


ng b mngV d: Stratum 4

chnh xc:


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