quỹ công suất

1-

1- Qu cng sut:

Phng trnh cn bng :

Ps +Gi Pr = L+ Pc + Pm

Trong :

Ps : Cng sut pht [dBm]

Gi: khuch i ca cc b khuch i trn tuyn [dB]

Pr : nhy my thu [dBm]

L : C ly truyn dn

: H s suy hao ca si [dB/km]

Pc: Suy hao th ng trn tuyn bao gm:

Suy hao do cc mi hn

Suy hao do u ni connector

Suy hao xen r ca cc b b tn sc

Suy hao do cc b xen r bc sng trn ng truyn

Pm: Lng cng sut cn tnh d ra b li s thit thi v cng sut pht sinh trong qu trnh lm vic ca tuyn hoc s suy gim cht lng ca cc thnh phn trong h thng.

Bng gi tr d phng khi thit k tuyn WDM theo phng php truyn thng:

STT

i tng d phng

d tr suy hao (dB)

Ghi ch

1

Cng sut d phng cho thit b pht

4.95

B li s gim m mu mt do s gi ha v s khng hon thin ca thit b.

2

Cng sut d phng cho thit b thu

2.1

B li s gim m mu mt do s gi ha, do hin tng nhy my thu phu thuc phn cc, nhy my thu ph thuc bc sng v do c tnh khng hon thin ca thit b.

3

D phng cho thit b MUX/DEMUX

2.2

B li s gim m mu mt do s gi ha, c tnh khng hon thin gy nn xuyn knh, do ph thuc phn ccca thit b.

4

Cng sut d phng cho si quang:

4.1

Cho s gi ha ca si quang v cc mi hn trn tuyn

3.2

B li s suy hao trn si v cc mi hn.

4.2

Cho nh hng ca tn sc si (CD&PMD)

1.8

B li s thit thi v cng sut gy ra do tn sc ca si quang.

4.3

Cho cc b b tn sc

1.0

B li s thit thi v cng sut gy ra do c tnh b khng hon ho ca cc b b tn sc.

4.4

Cho nh hng ca cc hiu ng phi thuyn

2

B li s thit thi v cng sut do cc hiu ng phi thuyn SPM, XPM, FWM, SRS, SBS

4.5

Cho hin tng suy hao ph thuc vo phn cc trong si quang

0.2

B li s thit thi v cng sut do hin tng suy hao ph thuc vo phn cc trong si quang.

5

Cng sut d phng cho cc b khuch i quang

5.1

Cho nh hng ca c tuyn khuch i khng bng phng ca b khuch i khng bng phng

3.0

Ph thuc vo bng phng ca ph khuch i

5.2

Cho hin tng khuch i ph thuc phn cc ca b khuch i quang

1.0

B li s suy gim m mu mt do hin tng khuch i ph thuc vo phn cc ca b khuch i quang

5.3

Cho s gi ha ca b khuch i quang

1.0

Tng cng

22

2- Qu tn sc:

D= d - DCM + d phng

Trong : D l tn sc tng

DCM : b tn sc

d: Khong cch ca chng

d phng 10km

Ch : D