84081989-Ch°ng-2 okkk

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Chng 2. QUY TRNH O KIM HA MNG THIT B U CUI QUANG NG-SDH 2.1. o kim tra lp vt l 2.1.1. Php o th 1: o kim tra cng sut pht quang 2.1.1.1. Thit b o - My o cng sut quang. - Cc dy ni quang tng ng. - Trc khi o cn lm sch cc u ni quang, tuyt i khng c lm chy xc v khuyt tt trn mt si. 2.1.1.2. Cu hnh o Hnh 2.1. Cu hnh o kim tra cng sut pht quang. 2.1.1.3.Cc bc thc hin 1. u ni thit b SDH/NG-SDH cn o (DUT) v my o nh trong hnh 2.1. 2. iu chnh my o cng sut quang lm vic bc song ca u pht ca thit b cn o kim tra. 3. Lm mt kh nng hot ng ca b phn chuyn mch bo v laser bng cch t chuyn mch bo v trng thi ngt. 4. o cng sut quang: Gi tr cng sut quang o c hin trn my o chnh l cng sut quang pht ra c tnh ti suy hao b ni quang. 5. t chuyn mch bo v tr v trng thi ban u ( chc nng hot ng bnh thng). 6. ng thi dng phn mm kim tra cng sut pht quang. Kt qu kim tra cng sut pht quang c hin trn mn hnh my tnh iu khin ngoi. So snh hai kt qu trn. 7. Sau khi o xong card chnh, lp li qu trnh o i vi card d phng. 8. Thc hin kim tra ch ngt laser (shutdown) xem xt vic hot ng ca h thng c bnh thng hay khng. Lu : - Trong qu trnh o khng c ngun pht laser chiu vo mt.

Gi tr cng sut o c phi tha mn cc ch tiu quy nh trong khuyn ngh ITU-T G.957, G.691, hoc tiu chun nghnh TCN 68-173. Cc ch tiu ny c tm tt trong ph lc A. 2.1.2. Php o th 2: o di ng ca b thu quang v nhy thu quang 2.1.2.1. Thit b o - Thit b o SDH c chc nng pht tn hiu xung chun v o li bit. - B suy hao quang c iu chnh. - Thit b o cng sut quang. - Cc dy ni quang tng ng. 2.1.2.2. Cu hnh o Hnh 2.2. Cu hnh o di ng v nhy ca b thu quang. 2.1.2.3. Cc bc thc hin 1. Thc hin u ni thit b theo Hnh 2.2.a. 2. Thit lp my pht tn hiu mu chun khng c Jitter ph hp vi giao din ca card nhnh c cp tn hiu (nh trn Bng 2-1). 3. t gi tr ca b suy hoa quang bin i mc 10dB (hoc mc ln nht c th). 4. Thay i gi tr suy hao c c cc gi tr suy hoa min v max tng ng vi mc tn hiu quang quang n u thu ln nht v nh nht v vn duy tr BER = 10 -12 hoc 10-10 ( ty thuc vo loi giao din quang). 5. Ghi li cc gi tr suy hoa min v max tng ng. 6. Thc hin u ni thit b theo hnh 2.2-b: Tho u dy ni quang u thu ca thit b c o kim tra. Ni u dy ny vo my o cng sut quang. 7. o cc gi tr cng sut quang tng ng vi cc gi tr suy hao trn. 8. t cc gi tr suy hao gi tr max ( t BER = 10 -12 hoc 10-10 ty theo loi giao din quang). o cng sut quang gi tr ny v c gi tr cng sut quang Pmin. - t gi tr suy hao gi tr min ( t BER = 10-12 hoc 10-10), o cng sut quang gi tr ny v c gi tr cng sut quang Pmax. 9. nhy thu chnh l gi tr Pmin o c trn.

10. Di ng ca b thu quang l di cng sut quang gia 2 gi tr Pmin v Pmax o c trn. 11. o cng sut thu quang, ch cn tho u si ti b ni quang connector pha u thu quang v o gi tr cng sut quang pht ra t u xa. 12. Lp li qu trnh o i vi card d phng. Bng 2.1. Tn hiu gi ngu nhin (ITU-T O.151). Tc bit (Mbit/s) Mu xung chun 2,048 215 1 34,358 223 1 139,266 223 1 155,520 223 1 Yu cu: Gi tr cng sut o c phi tha mn cc ch tiu qui nh trong khuyn ngh ITU-T G.957, G.691, hoc tiu chun nghnh TCN 68-173. Cc ch tiu ny c tm tt trong ph lc B. 2.1.3. Php o th 3: o cc tham s bc sng Mc ch: Xc inh cc tham s bc sng DUT s dng trong cc h thng WDM kiu tch hp. 2.1.3.1. Thit b o - Thit b pht xung chun - Thit b o bc sng vi chnh xc bc sng 0.001 nm. - Thit b phn tch ph vi chnh xc bc sng 0.001 nm. 2.1.3.2. Cu hnh o Hnh 2.3. Cu hnh o cc tham s ca bc sng. 2.1.3.3. Cc bc thc hin 1. Thc hin u ni thit b nh hnh 2.3. - Thit b pht chui tn hiu chun PRBS c ni vi card nhnh ca thit b cn o. - u ra ca DUT c ni vi my phn tch ph hoc my o bc sng. 2. Thit lp my pht tn hiu mu chun khng c jitter ph hp vi giao din ca card nhnh c cp tn hiu (nh trn Bng 2-1). 3. o v ghi li cc gi tr sau:

- Tn s trung tm. - lch tn s trung tm. - rng ph. Yu cu: Cc tham s bc sng o c phi ph hp vi cc gi tr qui nh trong ITU-T G.692. 2.1.4. Php o th 4: o kim tra dng xung tn hiu Mc ch: Kim tr xem dng xung ca tn hiu c tun theo cc tiu chun ca ITU-T hay khng. 2.1.4.1. Thit b o - My phn tch PDH/SDH - Osciloscope 2.1.4.2. Cu hnh o Hnh 2.4. Cu hnh o mt n xung ca tn hiu ti cc giao din ra 2.1.4.3.Cc bc thc hin 1. Thc hin u ni thit b nh Hnh 2-4 2. Thit lp my phn tch PDH/SDH pht tn hiu ph hp vi lung cn o 3. Quan st trn my hin sng. So snh dng xung tn hiu o c vi cc gii hn xung chun quy nh ca ITU-T 4. Thc hin bc 2, 3 i vi tt c cc lung ti giao din ra ca thit b SDH Yu cu: Dng xung thu c phi tun theo ITU-TG.703 hoc tiu chun ngnh TCN 68-175 i vi cc tn hiu ra in (2, 34, 155 Mbit/s v STM-1e) v tun theo ITU-T G.957, G691 hoc tiu chun ngnh TCN 68-173 vi cc tn hiu ra quang 2.1.5.Php o th 5: Kim tra cc hot ng cnh bo ca thit b Mc ch:Kim tra kh nng gim st cnh bo ca thit b bng cch gi tn hiu m phng cnh bo t thit b phn tch PDH/SDH n thit b 2.1.5.1.Thit b o - Thit b phn tch PDH/SDH c kh nng m phng cc tn hiu cnh bo

- Cc b suy hao quang c s dng ni gia giao din quang ca my o v DUT 2.1.5.2.Cu hnh o Hnh 2-5: Cu hnh o kim tra cc hot ng cnh bo ca thit b 2.1.5.3.Cc bc thc hin 1. Thc hin u ni thit b nh Hnh 2-5. Thit b o c th l SDH hay PDH ph thuc vo giao din ca DUT. Cc thit b ny c kh nng m phng chnh xc cc cnh bo v thi gian cnh bo 2. S dng cc thit b o, ch ng to ra cc iu kin gy cnh bo (v d nh LOF, LOS,) bng cch vo phn POH v SOH thay cc m mc nh bng cc m cnh bo 3. Quan st trn PC v thit b o xem c xut hin cc cnh bo khng. Phn tch cc hot ng cnh bo sau: - Tn hiu tr ngc tr li( upstream) - Cc tn hiu i tip (downstream) - Cc hin th cnh bo ni b (nu c) ca thit b - Cc bn tin pht ti h thng qun l phn nht k cnh bo t h thng qun l s x l. Yu cu: Hot ng cnh bo ca thit b phi tun theo s nh trong Hnh 2-6 di y Hnh 2-6: Cc tn hiu v hot ng cnh bo 2.1.6. Php o th 6: Kim tra qu trnh sp xp (mapping) ca thit b Mc ch: Php o ny xc nh ch lm vic v cht lng ghp cc lung nhnh PDH vo trong khung SDH ca DUT. 2.1.6.1.Thit b o - My pht tn hiu - My phn tch - B suy hao quang 2.1.6.2.Cu hnh o

Hnh 2-7: Cu hnh o qu trnh sp xp tn hiu 2.1.6.3.Cc bc thc hin 1. Thc hin u ni thit b nh hnh 2-7. Ty theo card nhnh ca thit b SDH l 2,34 hay 140 Mbit/s m thit lp tc ca lung tn hiu th cho ph hp 2. Thay i dung sai tc ca lung tn hiu th ti u vo thit b SDH t ti gi tr dung sai cc i trong Bng 2-2 3. S dng thit b phn tch SDH kim tra xem tn hiu PDH c c sp xp ng trong cc container ca khung SDH hay khng 4. Thc hin o BER (o trong khong thi gian ngn ) trn tng lung tn hiu Bng 2-2: Dung sai tc cho php i vi cc lung tn hiu ti u vo nhnh STT 1 2 3 Yu cu: -Tn hiu PDH phi c sp xp ng trong khung SDH - Kt qu o BER l khng c li 2.1.7.Php o th 7: Kim tra qu trnh gii sp xp ca thit b (Demapping) Mc ch: Kim tra chc nng gii sp xp ca thit b SDH 2.1.7.1.Thit b o - Thit bi o SDH c kh nng pht cu trc tn hiu th ph hp - B suy hao quang - Thit b o BER 2.1.7.2.Cu hnh o Hnh 2-8: Cu hnh o chc nng gii sp xp ca thit b SDH 2.1.7.3.Cc bc thc hin 1. Thc hin u ni thit b nh Hnh 2-8 Tc 2Mbit/s 34Mbit/s 140Mbit/s Dung sai max (ppm) 50 20 15

2. Thit lp thit b o SDH pht ra chui tn hiu th ph hp vi lung cn kim tra: - i vi lung 2 Mbit/s, s dng cu trc TSS8 - i vi lung 34Mbit/s, s dng cu trc TSS6 hoc TSS7 ty theo thit b SDH s dng cu trc AU-3 hay AU-4 - i vi lung 140Mbits/s, s dng cu trc TSS5 3. To dung sai tc trn lung tn hiu th cn o t ti gi tr max nh quy nh trn bng 2-2 4. Thc hin o BER trn lung tn hiu c gii sp xp ( o trong khong thi gian ngn) 5. Thc hin gim st cc s kin trong qu trnh o nh m t trong Bng 2-3 6. Thc hin cc bc 2, 3,4, 5i vi tt c cc lung m DUT cung cp Bng 2-3: Cc s kin cn gim st trong qu trnh o chc nng sp xp Cu trc tn hiu th

STT

Php o

Cc s kin cn gim st

1

Sp xp lung nhnh vo C-4 bc cao

TSS5

OOF, li B3, HP-REI, TSE, LOS, LOF, MS-AIS, MS-RDI, AU-LOP, AU-AIS, HP-RDI, HP-TIM, HPLOM, HPTC-TIM, HPTC RDI, HPTC-TC-RDI, HPTC-LTC, LSS OOF, li B3, HP-REI, TSE, LOS, LOF, MS-AIS, MS-RDI, AU-LOP, AU-AIS, HP-RDI, HP-TIM, HPLOM, HPTC-TIM, HPTC RDI, HPTC-RDI, HPTC-LTC, LSS OOF, li B3, HP-REI, TSE, LOS, LOF, MS-AIS, MS-RDI, AU-LOP, AU-AIS, HP-RDI, HP-TIM, HPLOM, HPTC-TIM, HPTC RDI, HPTC-LTC, LP-RDI, TU-LOP, TUAIS, LP-TIM, LPTC-TIM, LPTC

2

Sp xp lung nhnh vo C-3 bc cao TSS6 Sp xp lung nhnh vo C-3 bc thp TSS7

3

RDI, LPTC-LTC, LSS OOF, li BIP-2, LP-REI, TSE, LOS, LOF, MS-AIS, MS-RDI, AU-LOP, AU-AIS, HP-RDI, HP-TIM, HPLOM, HPTC-TIM, HPTC-RDI, HPTC-LTC, LP-RDI, TU-LOP, TUAIS, TU-LOM, LP-TIM, LPTC-TIM, LPTC-RDI, LPTC-LTC, LSS

4

Sp xp lung vo nhnh cc container bc thp(C-11/C12/C-2)

TSS8

Yu cu: -Khng c li bit trn lung tn hiu c o. - Khng c bt c cnh bo no ca s kin c gim st. Ghi ch: C th thc hin php o ny ng thi vi php o jitter gii sp xp. 2.1.8. Php o th 8: Kim tra kh nng gim st c tnh li ca thit b Mc ch: Kim tra kh nng gim st li thong bng cch s dng thit b o SDH chn cc loi li khc nhau ln tn hiu SDH. 2.1.8.1. Thit b o - Thit b o PDH/SDH c kh nng to v o li bit. - B suy hao quang ( s dng trong trng hp kt ni gia thit b o v DUT qua giao din quang). 2.1.8.2. Cu hnh o Hnh 2.9. Cu hnh o kim tra kh nng gim st li. 2.1.8.3. Cc bc thc hin 1. Thc hin u ni thit b nh hnh 2.9 - Thit b o SDH to ra tn hiu STM-N c cha cc tn hiu PDH 2/34/140 Mbit/s c sp xp trong cc VC ca khung SDH tng ng vi cc u ra PDH cn o ca DUT. Thit b o SDH ny phi c kh nng chn cc loi li khc nhau ln tn hiu SDH kim tra kh nng pht hin li v x l cc li nhn c ca thit b. - i vi lung nhnh, s dng thit b o PDH thc hin o BER trn mu tn hiu th c gii sp xp. 2. Thc hin chn cc li vo trong lung tn hiu th sau:

- i vi cc lp on, cc li c chn ln tt c cc byte ca tn hiu c truyn hoc trc tip ln cc byte BIP (B1, B2) m c cc lien quan ti on . - i vi vic kim tra lp lung th cc li c chn vo cc byte ca VC cn kim tra hoc l cc BIP tng ng (BIP-8 cho lung bc cao, BIP-2 cho lung bc thp). 3. o v ghi li gi tr li bit. So snh vi kt qu gim st li bit ca thit b 4. Gi nhm cc li xc nh kim tra ngng t SES ca thit b. 5. Thc hin cc bc trn cho hng truyn lu lng theo chiu ngc li ca thit b. Yu cu: Kt qu gim st li ca thit b phi ph hp vi kt qu o li bit ca thit b o. Ti bc 4 c xut hin cnh bo REI ti thit b o SDH. Khng c s thay