MC LCI, M uTrang 2II, Tng quan v ghp knh quang theo bc sng mt cao DWDMTrang 3III, Cc phng php bo v v phc hi trong mng DWDMTrang 4IV, Nghin cu, phn tch cc gii php bo v v phchi da trn mt s kch bn sai hng trong mt s cu trc mng DWDM.Trang 5V, M phng h thng bng phn mm Optisystem Trang 10VI, Kt lunTrang 12

M UTrong nhng nm gn y, cng ngh thng tin quang t c nhng thnh tu rt to ln trong phi k n k thut ghp knh quang, n thc hin vic ghp cc tn hiu nh sng truyn trn si quang nhm tng dung lng knh truyn v to ra cc tuyn thng tin c tc caoi vi h thng dung lng thp, cng ngh TDM thng c s dng tng dung lng truyn dn ca mt knh cp quang n ln 10Gbps, thm ch l 40Gbps nng cao tc truyn dn v khc phc c nhng hn ch m cch mch in hin ti ch khc phc c, cng ngh ghp knh quang theo bc sng mt cao DWDM ra i, vi nhng u im vt tri ca h thng DWDM v bng thng ln, tc cao, dung lng ln nn c ng dng rt nhiu trong vic xy dng cc h thng truyn dn thng tin trong thc t v tnh lin tc ca mng ngy cng tr ln cp thit, gii quyt vn ny cn ti k thut bo v v phc hi.

I, Tng quan v ghp knh quang theo bc sng mt cao DWDM1, Cu trc h thng DWDMGhp knh theo bc sng mt cao DWDM (Dense Wavelength Division Multiplexing ) l cng ngh trong mt si quang ng thi truyn dn nhiu bc sng tn hiu quang. u pht, nhiu tn hiu quang c bc sng khc nhau c t hp li (ghp knh) truyn i trn mt si quang. u thu tn hiu t hp c phn gii ra (tch knh), khi phc li cc tn hiu gc ri a vo cc u cui khc nhau. Cu trc h thng DWDM v c bn gm ba phn chnh:khi pht quang, khi thu quang v phn truyn dn.2, Cc khi chc nng ca h thng DWDMCu trc c bn ca h thng DWDM gm cc thnh phn chnh sau: -Khi pht p quang OTU. -Khi tch/ ghp knh quang MUX/DEMUX. -Khi khuch i quang si EDFA. -Khi r/xen quang OADM. -Khi b tn sc. -Khi kt ni cho quang OXC. -Khi ng truyn.3, Cc thng s nh hng n h thng DWDMCc thng s nh hng n h thng DWDM l: -Suy hao. -S knh bc sng. - rng ph ca ngun pht. -Qu cng sut. -Tn sc. -Hiu ng phi tuyn. -Di bc sng lm vic ca h thng.II, Cc phng php bo v v phc hi trong mng DWDM1, Khi nim bo v v phc hi mngBo v (protection): l mt phng thc hi phc mng s dng cc ti nguyn bo v c cp pht trc truyn lu lng ti hot ng trn knh b nh hng bi s c nhm m bo kh nng duy tr ca mng. Phc hi (recovery): l mt phng thc hi phc mng s dng cc ti nguyn d phng kh dng nh tuyn li lu lng c gi nh sau khi xy ra s c theo tnh trng hin ti ca mng2, Kho st k thut bo v v phc hi mng DWDMCc k thut bo v quang s dng cc chuyn mch quang v b chia cng sut quang k tha nguyn l ca cc k thut bo v SONET/SDH truyn thng ng thi to hiu qu tng tc hi phc, gim mc phc tp v chi ph qun l cho mng.Tu theo gc xem xt m mi nhm nghin cu c phng php khc nhau phn lp cc k thut hi phc quang, nhng tng ng nhauTheo kin trc chc nng ngi ta c th phn lp cc k thut bo v quang thnh hai kin trc: bo v lung (trail protection), bo v kt ni mng con (SNC protection). - Phng thc phc hi tng quang: Phng thc phc hi on ghp knh quang yu cu tm kim cc b mt tuyn tm thi kh dng vng qua on b s c. phng thc ny c thc thi ti cc nt u cui on b s c, s dng mt thut ton phn b tm tuyn thay th tm thi. - Phng thc bo v tng quang: bo v tng quang c mt s k thut bo v nh Bo v ring (1+1 hoc 1:1), Bo v chia s (1:N), Bo v tuyn ring(DPP 1+1), Bo v on ring(DLP), Ring chuyn mch bo v tuyn n hng OUPSR, Ring chuyn mch bo v on n hng OULSR, Bo v tuyn chia s(SPP 1:N), Bo v on chia s (SLP 1:N), Ring chuyn mch bo v tuyn hai hng OBPSR, Ring chuyn mch bo v on n hng OBLSR2 si hoc 4 si.III, Nghin cu, phn tch cc gii php bo v v phc hi da trn mt s kch bn sai hng trong mt s cu trc mng DWDM1, Phn lp cc phng thc bo v theo cu hnh mngTrc tin chng ta s nghin cu cc gii bo v v phc hi vi mng DWDM c cu hnh c bn nh ng thng, vng ring, li nhng tp trung vo hai cu hnh vng ring v li. Hai loi cu hnh ny hin ang thu ht c s quan tm ch yu ca cc nh thit k. Hnh 1 l cc gii php bo v kh dng cho hai cu hnh vng ring v li : Hnh 1: cc gii php bo v kh dng cho 2 cu hnh ring v li2, Gii php v kch bn bo v mng DWDM cu hnh im imi vi cu hnh ng thng c th p dng trc tip cc k thut bo v tuyn ring/chia s nn khng cn phn tch nhiu. Bo v quang 1+1 tng t nh phng thc bo v 1+1 SDH. Pha pht s dng b chia chia cng sut quang v pht trn c hai tuyn hot ng v d phng; pha thu s dng mt chuyn mch quang c chc nng nh mt b la chn v chuyn mch ln tuyn bo v khi tuyn hot ng tng ng c s c.

Hnh 2: bo v quang 1+1Bo v quang 1:1 tng t nh phng thc bo v 1:1 trong SDH. Khc vi bo v 1+1, dch v khng c ni cu ln c hai si hot ng v lm vic m s dng chuyn mch c hai u. Ban u chuyn mch t ln si hot ng, khi pht hin s c th chuyn mch lu lng ln si bo v

Hnh 3: bo v quang 1:13, Gii php v kch bn bo v phc hi mng DWDM cu hnh vng RING 3.1, Bo v knh quang (Bo v tuyn) Bo v knh quang c mt s gii php bo v sau: - Gii php vng RING bo v ring knh quang (OCh-DPRING) - Gii php vng RING bo v chia s knh quang (OCh-SPRING) 3.2, Bo v on ghp knh quang Bo v on ghp knh quang c mt s gii bo v php sau: - Gii php vng RING bo v ring on ghp knh quang (OMSDPRING)- Gii php vng RING bo v chia s on ghp knh quang (OMSSPRING)4, Gii php v kch bn bo v phc hi mng DWDM cu hnh li 4.1, Bo v v phc hi tuyn knh quang Bo v v phc hi tuyn knh quang bao gm mt s phng php bo v sau: - Bo v tuyn ring - Bo v chia s tuyn 4.2, Hi phc on ghp knh quang trong mng li DWDM Trong hi phc on, tt c cc kt ni i qua on b s c c nh tuyn li i vng qua on . Qu trnh chuyn mch bo v on c thc thi trong sut i vi cc nt ngun v ch. i vi bo v on, trong sut qu trnh thit lp phin lin lc, cc ng v bc sng d phng c dnh trc vng qua mi on ca ng ban u. Cn trong phc hi on, cc nt k cn ca on b s c tm mt chuyn ng vng qua on cho mi bc sng i qua on b s c .4.3, Gii php phc hi trong kin trc mng lin kt gia cc min quang4.3.1,Lin kt gia cc mng con v vn bo v Trong gii php ny c 2 k thut bo v l: - Bo v vi kin trc RING o: Kin trc ring o ban u c th ch c ng dng cho OC-DPRing. Phng thc nh tuyn v bo v s dng cc nt lin kt chuyn tip vin (border) gia cc vng ring ti cng bc sng. - Cc kin trc RING o ci tin: Mc ch y l s dng mi bc sng truyn mt na s kt ni tng client nn v mt nguyn l th yu cu ti nguyn ging nh trng hp ca VRA trn OCh-DPRing (hoc tt hn tng ng vi OMS-SPRing). Mi mng con (SSN v d mt ring) khng ch phc hi mt s c nt n hoc s c on n, m c th cho php chng li c trng hp nhiu xy ra s c (mi s c trn mt ring) gia nt A v B. Nhng c hai kin trc ny u km hn kin trc s dngVRA trn OCh-DPRing ti cc nt lin kt: ch phc hi mt na s kt ni tng client khi xy ra s c ti v tr lin kt. Nu thc thi bo v cc b 1:N 8 cc knh quang lin kt gia I1 v I3, gia I2 v I4 vt qua im yu ny th gii php ny cng kh hiu qu v mt chi ph. 4.3.2, Bo v vi kin trc tch v chuyn tip Trong gii php ny c 3 k thut bo v l: - Kin trc OMS-SPRING hai mc: Kin trc OMS-SPRing hai mc gm mt OMS-SPRing mc trn vi nt u cui v hai OMS-SPRing mc di vi cc nt u cui lin kt vi nhau thng qua cc nt kp thc thi lin kt v nh tuyn min quang.- Kin trc hai mc OMS-SPRING/Li quang: Kin trc hai mc OMSSPRing/li quang bao gm cc li quang vi cc nt u cui v mt OMSSPRing mc trn vi nt u cui (thc thi lin kt v nh tuyn min quang). Lin kt gia cc nt u cui s dng bc sng a, lin kt gia cc nt u cui s dng bc sng b.-Kin trc hai mc li quang/ OMS-SPRING: Kin trc hai mc li quang/OMS_SPRing bao gm hai OMS-SPRing mc di lin kt vi mt li quang mc trn thng qua nt lin kt kp (thc thi lin kt v nh tuyn min quang).

IV, M phng bng phn mm OptisystemH thng DWDM gm 3 khi chc nng chnh: khi pht, khi thu v khi truyn tn hiu.1,Khi pht(Transmitter)

(Hnh nh chp t m phng trn my tnh)

Khi pht l khi c vai tr quan trng nht trong h thng truyn thng tin quang. N bao gm ngun quang,b to xung in t v b iu chnh.Tn hiu t b pht c a qua 1 b WDM Mux( ng vai tr l b ghp knh) truyn nhiu tn hiu trong 1 si quang

2, Khi truyn

(Hnh nh chp t phn mm Optisystem)

ng truyn SMF kh dng cho truyn tn hiu quang vi dung lng ln, tc cao v bng thng rng. Trong si quang, sau khi truyn mt qung ng di, cng tn hiu b suy yu i ng k v vy cn c mt b tip thm tn hiu quang vic truyn tn hiu c tip tc. Hin nay cng ngh EDFA c p dng cho vic ny, n s tip thm tn hiu quang c sau mi 50m truyn b cho tn hiu b mt

3, Khi thu

(Hnh nh chp t phn mm Optisystem)Trc khi c a vo khi thu i ra cc thit b u cui khc nhau, tn hiu s c a qua 1 b WDM Demux, b ny c nhim v tch knh khi phc tn hiu ng tn hiu t pha pht.

KT LUNDWDM vi nhng u th v mt cng ngh tr thnh mt phng tin ti u v k thut cng nh kinh t m rng dung lng si quang mt cch nhanh chng v qun l hiu qu h thng. DWDM p ng c hon ton cc dch v bng rng trn mng v l tin xy dng mng ton quang trong tng lai. Cc c ch bo v v khi phc d liu trn h thng DWDM ch yu da trn nn tng WDM. Nhng trong thc t khng phi thit b trn h thng DWDM cng ging hon ton vi thit b trn h thng WDM, do vy ta phi ch trong qu trnh xy dng cc c ch bo v v khi phc d liu trn h thng DWDM.

Cui cng, em xin cm n c Hong Phng Chi gip chng em hon thnh ti ny!

Ti liu tham kho: T cc website:www.academypublisher.comwww.optiwave.com

8