System commissioning

1.Optical power adjustment

2.commissioning skills

Optical power adjustment

• Master signal flow

• Familiar with some reference points

• Classification of Attenuator

• Power adjustment

Signal Flow (1)

M

16

D

16

TWC

TWC

RWC

RWC

S

C

A

SCC

OHP

SC1

WBA

WPA

RWC

TWC

OTM

Signal Flow (2)

OLA

S

C

A

SCC

OHP

SC2

WBA WPA

S

C

A

WPA WBA

Important reference point

M16

OTU

OTU

OTU

SCA

SCC

OHP

SC1

WBA

WPA M16

D16

OTU

OTU

OTU

OTU

OTU

SCA

SCC

OHP

SC1

WBA

WPASCC

OHP

SC2

WPA WBA

SCA

SCA

OTU

O L A O T M

M16

D16

OTU

OTU

OTU

OTU

OTU

OTU

SCA

SCC

OHP

SC1

WBA

WPA M16

D16

OTU

OTU

OTU

OTU

OTU

SCA

SCC

OHP

SC1

WBA

WPASCC

OHP

SC2

WBA WPA

WPA WBA

SCA

SCA

OTU

O T M O L A O T M

• Transmission SideSDH——TWC(LWC)

M16(IN)

M16 ——WBA

• Receiving SideSCA ——WPA

D16 ——RWC(LWC)

Important section

• OLA SideSCA——WPA(WLA)

WPA ——WBA

Classification of Attenuator

1,Fixed optical attenuator

5dB 10dB 15dB

2,Variable optical attenuator

1.5~30dB

Power adjustment

OTM

TO

RI

TWC

RWC

D16

M16

WBA

WPA

SC1

S

C

A

TM

RM

MON

MON

MON

SDH Tx

SDH Rx

RO

TI1

2

3

4

1,2

Fixed attenuator

3,4

Variable Attenuator

Power adjustment(1)

1 Adjustment of fixed attenuator

It depends on the following factors

a.mean launched power of SDH transmitter

b.receiver type of OTU(TWC/LWC)

c. mean launched power of OTU(RWC/LWC) transmitter

d.type of SDH receiver unit

2 Installation of fixed attenuator

a.ODF frame provided by customer indirectly

b.upper ODF of DWDM equipment(seldom)

Installation in middle(lower) ODF is forbidden

Power adjustment(1)

Power adjustment(2)

1,Adjustment of variable attenuator

a.installed before OA to adjust optical power

b.location of variable attenuator(corresponding to OAs)

c.adjust optical power according to :

WBA01 ： -18+10*lg(N)(dBm)

WPA01 ： -28+10*lg(N)(dBm)

N:number of channels

2,Notice items during commissioning

a.perform system commissioning with one channel ：

input of WBA01:-18dBm WPA01:-28dBm

b.forbidden to increase optical power(OSNR) too much,or else it will be difficult to upgrade

Power adjustment(2)

Min.Input power(1 channel)

Max.Input power(1 channel)

Gain(dB)

WBA01 -20dBm -6dBm 23

WBA03 -17dBm -3dBm 23

WPA01 -28dBm -13dBm 23

WLA05 -28dBm -13dBm 30/33

Power Types of OA

Power adjustment(3)

commissioning of M16 input port

a.balance of each channel power(usually it’s not necessary)

b. Be careful about :

output power of TWC(LWC)(common value:-1.5dBm~-2dBm, regardless open or integrated system

Esp.in integrated system,adjust SDH output power with attenuator to -2dBm nearly.

Keep the balance of optical power before M16

Similarly:

a.adjust the balance before the input of M16

b.adjust optical power to:

-18dBm+10*lg(N) WBA01

-28dBm+10*lg(N) WPA01

commissioning of OLA /OADM/REG

Power adjustment(4)

Look for “optical power” in DWDM system

a.with ouput optical power of TWC/LWC

b.with ouput optical power of SC1/2

Keep fibre and connector clear please

commissioning skills

At transmission side,power of noise can be neglected .

But in practical network,noise will be accumulated and amplified,So at receiver side,power of noise cannot be neglected.

In system commissioning,in some corresponding points(eg. WLA/WPA),it should reserve redundance(adjust with optical power meter and NMS)

NOTE:consider 1dB about 1 WPA/WLA,and OSA is recommended in system commissioning

commissioning skills

1.Directly connect MON ports of M16/M32 、 D16/

D32 、 WBA 、 WPA to IN port of MS1/2 for on-line

optical spectral monitoring.2.In DWDM system,we mainly consider OSNR at receiver side instead of transmitter side.

Receiver side :OSNR>20dB

Connection of MS1/2

Extend ECC communication

It also can implemented by Ethernet connection.

A£ BB£

remote side

receive or transmit

n

n£¬wavelength NO.n

1 At client side(eg.SDH service)

ABB

remote side

receive or transmit

2 At fibre line side

Fibre identifier

WPA WBA

OTU OTU

M

R

2

M

R

2

MO

MI

1 2

Variable attenuators(1&2) are flexibly installed to meet the requirement of system power flatness.

At dropping direction,fixed attenuator is installed,at adding direction,variable attenuator is installed.

commissioning of MR2

NM monitoring principle:

Connect all Ethernet ports of sub-racks to a

HUB,or connect all BNC ports with a cascading

cable(concatenation).

The common HUB has 8 ports 。

WBA

RX

TX

RX

TX

WPA

RX

TX

RX

TX

WBA

WPA

AB

Protection pair between WBA&WPA of A and B.if the fibre form A to B is broken, WBA of B will shut off the laser(after detecting of R-LOS on WPA),so WPA of A will occur R － LOS, WBA of A will shut off the laser.

APR function-for security

Thanks

Very much ！

Troubleshooting