etm7172 power & bw budget

7/24/2019 ETM7172 Power & BW Budget

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ETM7172 OPTICAL COMMUNICATION SYSTEMS Multimedia University

L5

Optical Fiber Linkand LAN e!i"n


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Table of content

Transmission Type

Elements in Network Design

Factors for Evaluating Fiber Optic System Design

Link Budget onsiderations

!ower Budget

!ower Budget "e#uirement

E$ample % Long&'aul Transmission System

E$ample % L(N


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Table of content )cont*+

Bandwidt' Budget

System "ise Time

E$ample on ST,&-. ST,&/0 and ST,&0-

Budget Summary

Sensitivity (nalysis

Eye Diagrams

Signal to Noise "atio )SN"+

ost1 !erformance onsiderations

Summary


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Transmission Types

Two types of transmissions:

1. Link (point to point)

2. Network

a. point to multipoint

b. Meshc. Rin


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Elements of Link1 Network Design

Transmitter %

Operating wavelengt' (). Linewidt' ( ).

"ise time. Bit&rate. Line format. !ower level

Fiber %

S,F1,,F. Fiber type 2 S,F34. DSF. etc.

able loss. Spool lengt'"$ %

!SEN. !S(T. "ise time


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Elements of Link1 Network Design )cont*+

onnection%

No* of splice. Splice loss

No* of connectors. onnector Loss

5n Line Devices%

Splitter. Filter. (ttenuator. (mplifier

5nsertion loss. 6ain


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The Main Problems

(ttenuation andLoss

Dispersion

The Main Question

5n Digital System

& Data "ate

& Bit Error "ate

5n (nalog System

& Bandwidt'

& Signal to Noise

"atios


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System Factor onsi!erations

Mo!ulation o!e "M# FM# PM or Digital

$it Error %ate ($E%)

(Digital Systems Only)

&'

#&'&*

Typical

Signal to +oise %atio Specifie! in !ecibels (!$)+umber of onnectors ,oss increases -ith the number of

connectors

+umber of Splices,oss is ,oss increases -ith the

number of splices

Environmental

%e.uirements

/umi!ity# Temperature#

E0posure to sunlight

Mechanical %e.uirements Flammability# 1n!oor2Out!oor

"pplication


(cont3)


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Optical Transmitter2 Sources

LEDs

Output !ower

,odulation

Bandwidt'

enter 7avelengt'

Spectral 7idt'

Source Si8e

Far&Field !attern

Laser Diodes

9 Output !ower

9 ,odulation

Bandwidt'9 enter 7avelengt'.

Number of ,odes

9 'irp. Linewidt'

9 ,ode Field of t'e6aussian beam


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Optical Fiber

,ultimode Fiber

(ttenuation

,ultimode

Dispersion

'romatic

Dispertion

Numerical (perture

ore Diameter

Single&,ode Fiber

9 (ttenuation

9 'romatic

Dispersion

9 utoff 7avelengt'

9 Spot Si8e


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Optical %eceiver2 Photo!io!e

9 "isetime1Bandwidt'

9 "esponse 7avelengt' "ange

9 Saturation Level

9 ,inimum Detection Level


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Si)ple Link

T* +*

Medium and Devices

OA

OA


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Link Budget Considerations

T'ree types of budgets%

)/+ !ower Budget)3+ Bandwidt' or "ise Time Budget

):+ ;


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!O7E" B


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!ower Budget "e#uirements%

!B % !"=> !,5N

!"=? "eceived !ower!,5N? ,inimum !ower at a certain BE"

!"= ? !T=2 Total Losses @ Total 6ain & !,("65N

!T=? Transmitted !ower

!,("65NA 0 dB


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Requirements Contd:

Loss.L ? L5L@ Lfiber@ Lconn*@ Lnon&linearL5L ? 5nsertion Loss

Lfiber ? Fiber Loss

Lconn*? onnector LossLnon&linear? Non&linear Loss

6ain.6 ? 6ainamp@ 6non&linear

6ainamp? (mplifier 6ain

6non&linear? Non&linear 6ain


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dB. dBm. m7

dB ? / log )!/1!3+

dBm Calue of / m7 !ower (pplication

* / /* m7 Typical laser !eak

Output

&/:* *7 Typical !5N

"eceiver

Sensitivity

&:* */ /*7 Typical (!D"eceiver

Sensitivity

&-* */ /*7 Typical LED !eak

Output


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!$ Po-er Out as a 4

of Po-er 1n

4 of Po-er

,ost

%emar5s

/ G 3/ &

3 0: : &

: H t'e power

- - 0 &

:3 04

0 3 I t'e power

3 4 /1 t'e power

4 /0 4- /10 t'e power

G /3 44 /14 t'e power

/ / G /1/ t'e power

Decibel to Po-er onversion


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!$ Po-er Out as a 4

of Po-er 1n

4 of Po-er

,ost

%emar5s

3E B*:D GG*FD /1:BB t'e power

:B B*/D GG*GD /1/BBB t'e power

-B B*B/D GG*GGD /1/B.BBB t'e power

EB B*BB/D GG*GGGD /1/BB.BBB t'e power

Decibel to Po-er onversion


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IS THIS

SYSTEMGOOD

E!amp"e#$o%er Budget Measurement &or Long

Hau" Transmission

PT, - ( d.)

1&5 k)

PSEN - /2&d.)

Sp"ice

Atten0atin Cecient3 - (425 d.k)

i!per!in Cecient3 - 1& p!n)/k)

N0)ber 6 Splice - $%

Splice L!! - (41 d.

PMar"in- % d.

Cnnectr L!! - (42 d.

Connector


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CO'CL(SIO'# B)D

SYSTEM**

Si)ple Calc0latin4

Fiber L!! - (425 d.k) * 1&5 k)

- $%4# d.

Splice L!! - (41 d. * $% - $4% d.

PMar"in- % d.

Ttal L!!e! - $%4# 8 $4% 8(4$ - 514# d.

Po-er $u!get# P%67 PSE+ 88

P+* - /574#

d.

P+* - PT*9 Ttal L!!e! 9PMar"in - ( 9 514# 9 %

Cnnectr L!! - (42 d. * 2

- (4$ d.


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:; TSler

.0t ?@at i! t@e "ain


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Fir!t ;e calc0late t@e a)pli>er! "ain44

Bain PSEN/ P+*

Bain /2& 9 /574#D

Bain 2'4# d.

T )ake it ea!3Bain #( d.

N;?@ere t p0t t@ea)pli>er=


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T@ree c@ice! aer 9 At t@e tran!)itter

Prea)pli>er 9 At t@e recei


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Let 0! c@eck ne b ne

P;er A)pli>er PT*8 Bain -POUT ( 8 #( - #(

d.).0t i! t@ere an p;er a)pli>er ;it@ #( d.)

POUT= NO3 T:E+E ISNT

:ence


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?@at ab0t Prea)pli>er=

POUTreceier ;it@ #( d. a


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Let us c+eck In Line )mp"i,ers

#( d. "ain a)pli>er a


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?@ere i! t@e 9#( d.) pint=

PT*9 L!! At T@at Pint - ( d.) 9 #(d.

L!! At T@at Pint - /#( d.)

#( - , Len"t@ 6 T@atPint+e)e)ber - (4253

Pint Len"t@ - #((425

- 12( k)

.0t 12( k) 6r) T,3N4 6 !plice - 12($

- #(

A!!0)e Ot@er L!! - (3 L!! At T@at Pint - Fiber L!!3

Splice L!! - (41 d. , #( - # d.


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Al! re)e)ber cnnectr l!! at a)pli>er and T,

2 cnnectr!

Cnnectr L!! - (42 d. , # - (4% d.

Ttal L!!e! - Fiber L!! 8 Splice L!! 8 Cnnectr L!

Act0all3 at 12( k)3

- #( 8 # 8 (4% - ##4% d.

##4% d. G #( d.HH NOT BOOHN;3 ?e @a


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Let 0! cn>r) t@e an!;erAt 1(54% k) 6r) T,3

Fiber L!! - (425 , 1(54% - 2%4$ d.

N4 6 Splice at 1(54% k) - 1(54%$ -2%4$ - 27

Splice L!! - (41 , 27 - 247 d.

Ttal L!!e! - 2%4$ 8 247 - 2'41 d.

2'41 d. #( d. HH

CO'-I.M/01234 5M IS ) GOOD LOC)TIO'**

PT, - ( d.)

1&5 k)

PSEN - /2& d.)Sp"ice Connector

1(54%JM


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IS THIS

SYSTEMGOOD

PT, - /15 d.)

5(( )

U!in"

&5(n) PSEN - /25d.)Atten0atin Cecient3 - $45 d.k)

i!per!in Cecient3 - 1& p!n)/k)

N0)ber 6 Splice - (

Splice L!! - ( d.

PMar"in- 2 d.

Cnnectr L!! - (45 d.

Server A Server B

E!amp"e#$o%er Budget Measurement &or L)'


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.AN?IT:.UBET


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Calc0late t@e ttal ri!e ti)e!

T,3 Fiber3 +,

Calc0late Fiber ri!e ti)e3 TFiber

T>ber- ,

, L - i!per!in Cecient- Line;idt@L - Fiber Len"t@

T, +i!e Ti)e3 TT*- nr)all "i


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Ttal +i!e ti)e3 T!!

T!!-141TT*28T+*28T>ber2D12


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.and;idt@ .0d"et

T* +*

Medium and Devices

T

9: ; T< T

T

OA

OA


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7'at is a good "ise time;

Fr a "d receptin 6 !i"nalT!E! (47 , P0l!e ?idt@ P?D

P? - 1.it+ate 6r N+K

12.it+ate 6r +K


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E!amp"e#.ise Time Budget Measurement

&or Long Hau" )pp"ication

T, ri!e ti)e3 TT*- (41

n!+, ri!e ti)e3 T+*- (45

n!Line;idt@D - (415 n)

i!per!in Cecient3 - 1& p!n)/k)Fiber len"t@ - 15(k)

.it +ate - %22Mbp!Fr)at - +K


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Fiber ri!e ti)e3 TF-Len"t@ , ,

Line;idt@D - 15( k) , 1& , (415 n)

- (4$ n!

Ttal +i!e ti)e3 TSYS- 141TLS28 TP28

TF2

- 141(4(1 8 (425 8 (41%

Si)ple Calc0latin4

TSYS- (477 n!


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Let !a3.it +ate - STM $ - %22 Mbp!Fr)at - +K

T!! (47 , P0l!e ?idt@ P?D

P0l!e ?idt@ P?D - 1%22,1(%D

- 14% n!

(477 n! (47 , 14%n!

(477 n! 141 n! HH

Bd +i!e Ti)e .0d"etHH


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Let !a3.it +ate - STM 1% - 245 Bbp!Fr)at - +K

T!! (47 , P0l!e ?idt@ P?D

P0l!e ?idt@ P?D - 1245,1('D

- (4$ n!

(477 n! (47 , (4$n!

(477 n! (42& n! HH

.ad +i!e Ti)e .0d"etHH


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!u"et #ummary Option Po-er

$u!get

$an!-i!th

$u!getFinancial

" Source (,ED vs3 ,D)

9=

4nm ,ediocre Bad 'eap

/:/nm 6ood 6ood Less

e$pensive

/nm Cery good Cery good E$pensive

Mo!ulation

$an!-i!th

LED N( Bad 'eap

LD N( 6ood E$pensive

Output Po-er LED ,ediocre N( 'eap

LD 6ood N( E$pensive

%a!iation pattern LED )far&field pattern+

N( Bad 'eap

LD )6aussian

beam+

N( 6ood E$pensive


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!u"et #ummary

$ Fiber Option $o%erBudget

$an!-i!th

$u!getFinancial

(ttenuation ,, ,ediocre ,ediocre 'eap

S, 6ood 6ood E$pensive

Dispersion ,, ,ediocre ,ediocre 'eap


Numerical (perture

)N(+

,, ,ediocre ,ediocre 'eap


ore Diameter ,, ,ediocre ,ediocre 'eap



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!u"et #ummary

%eceiver (P1+ vs3

"PD)

Option $o%erBudget

$an!-i!th

$u!get

Financial

"ise time1

Bandwidt'

!5N ,ediocre ,ediocre 'eap

(!D 6ood 6ood E$pensive

"esponse

wavelengt' range



Saturation Level !5N ,ediocre ,ediocre 'eap


,inimum detectionlevel




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$5


Sensitivity (nalysis

,inimum optical power t'at must

be present at t'e receiver in order

to ac'ieve t'e performance level

re#uired for a given system*


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$%


Factors will affect t'is analysis

/* Source 5ntensity Noise & "efers to noise generated by t'eLED or Laser

!'ase Noise & t'e difference in t'e p'ases of two

optical wavetrains separated by time. cut out of t'e

optical wave(mplitude Noise & caused by t'e laser emission

process*

3* Fiber Noise

"elates to modal partition noise

:* "eceiver Noise

!'otodiode. conversion resistor


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-* Time Jitter and 5ntersymbol 5nterference

Time Jitter & s'ort term variation or instability in t'e

duration of a specified interval

5ntersymbol 5nterferenceresult of ot'er bits interfering wit' t'e bit of interest

inversely proportional to t'e bandwidt'

Eye diagrams & to see t'e effects of time Kitter and

intersymbol interference


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$&


* Bit error rate & main #uality criterion for a digital

transmission system

BE" ? M5,5N31 )- 3N3 $)

w'ere %

N ? Noise power spectral density )(318+

5,5N ? ,inimum effective signal amplitude )(mps+

B ? Bandwidt'

)$+ ? umulative distribution function )6aussian distribution+


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Eye Diagrams


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Signal to Noise "atio

SN" ? S1NS & represents t'e information to be transmitted

N & integration of all noise factors over t'e full system bandwidt'

SN" )dB+ ? / log/B)S1N+


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ost1!erformance onsiderations

omponents considerations suc' as %

Lig't Emitter Type

Emitter 7avelengt'

onnector Type

Fiber TypeDetector Type


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Summary

T'e key factors t'at determine 'ow far one can

transmit over fiber are transmitter optical output

power. operating wavelengt'. fiber attenuation.

fiber bandwidt' and receiver optical sensitivity*

T'e decibel )dB+ is a convenient means of

comparing two power levels*

T'e optical link loss budget analy8es a link toensure t'at sufficient power is available to meet

t'e demands of a given application*


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Summary

"ise and fall times determine t'e overall responsetime and t'e resulting bandwidt'*

( sensitivity analysis determines t'e amount ofoptical power t'at must be received for a system to

perform properly*

Bit errors may be caused by source intensity noise.fiber noise. receiver noise. time Kitter and

intersymbol interference*T'e five c'aracteristics of a pulse are rise time.

period. fall time. widt' and amplitude*


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T


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T'ank Pou

etm7172 power & bw budget

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