1. Amplification, ROADM
and Optical Networking
activities at CPqD
Miquel Garrich Alabarce, PhD.
Senior Researcher – Optical Technologies Division
WTON – Campinas – May 28th 2015

2. 2/23
Outline
Optical Technologies Division
• Optical networks team
Amplification
• Automated amplifier characterizer
• Field calibration procedure for distributed Raman amplifiers
Reconfigurable Optical Add/Drop Multiplexer (ROADM)
• Transient response issues in cascaded WSS-based ROADMs
SDN-based dual-optimization application
• Adaptive EDFA algorithm
• Global WSS equalization algorithm
Collaboration activities with UTD
• Estimating EDFA Output Power with an Efficient Numerical Modeling Framework
• Network-wide signal power control strategies in WDM networks

3. 3/23
Optical Technologies Division at CPqD
Technological Trends
Transmission
and Networks
Product
Technologies
Microelectronics
Integrated
Photonics
Transmission
DSP
Access
Amplification
ROADM
Networks
Hardware
Software
Firmware
Tests
Mechanics
Requirements
Front End
Back End
Design
Alignment
Packaging
Systems
S
Y
S
T
E
M
S
D
E
V
I
C
E
STransport
Optical networks team

4. 4/23
Optical networks team
1 - Alexandre Daoud de Andrade
2 - Anderson Bravalheri
3 - Benjamin Sarti
4 - Camila de Araujo Souto Diniz
5 - Heitor Silva Carvalho
6 - João Carlos Sampaio Januário
7 - Leonardo Fagundes Luz Serrano
8 - Matheus Smythe Svolenski
9 - Miquel Garrich Alabarce
10 - Uiara Celine de Moura

5. 5/23
Motivation
Bandwidth variable
transponders (BVTs)
Reconfigurable optical add-drop
multiplexers (ROADMs)
Wavelength selective switches (WSSs)
Elastic optical networking (EON)
Inputs
1
2
3
Drops Adds
Outputs
1
2
3
EDFA
Splitter
WSS

6. 6/23
Input power
Outputpower
Measuredparam.
Power mask
Aux
Amp
Variable Att
WSS
Splitter
50/50
Optical
switch
OSA
40-CW
laser bank
Serial GPIB
GPIB
USB
Ethernet
Amplifier
Automated amplifier characterizer

7. 7/23
Field calibration procedure for distributed
Raman amplifiers
Distributed counter-propagated Raman amplifier
Sumbitted to International Microwave and Optoelectronics Conference (IMOC) 2015

8. 8/23
ROADM activities
Rx
Tx
Reconfigurable optical add-drop
multiplexer (ROADM)
• Wavelength selective switch (WSS)
• Optical channel monitor (OCM)

9. 9/23
Transient response issues in cascaded ROADMs
Higher threshold
Lower threshold
Target
power
Transient
Failure Convergence
Failure
Iteration:
• Get information
• Calculation
• Application
Operation:
• Simultaneous
• Independent

10. 10/23
Transient response feedback control mechanism
Three analyzed controllers
1. Integrative (I)
2. Proportional, integrative and derivative (PID)
3. Proportional double integrative (PII)
Techniques to enhance the performance of the controllers
1. Threshold levels
2. Standard deviation (STD)
• trigger the actuation on WSS
𝐶I 𝑠 =
𝑘𝑖
𝑠
𝑢[z+1]=𝑢[z]+𝑘1∙𝑒[z]
𝐶PID 𝑠 = 𝑘 𝑝 +
𝑘𝑖
𝑠
+ 𝑘 𝑑 ∙ 𝑠
𝑢[z+1]=𝑢[z]+𝑘1∙𝑒[z]+
𝑘2∙𝑒[z−1]+𝑘3∙𝑒[z−2]
𝐶PII 𝑠 = 𝑘 𝑝 +
𝑘𝑖1
𝑠
+
𝑘𝑖2
𝑠 + 𝛼
𝑢[z+1]=𝑘1∙𝑢[z]+𝑘2∙𝑢[z−1]+𝑘3∙𝑒[z]+
𝑘4∙𝑒[z−1]+𝑘5∙𝑒[z−2]

11. 11/23
Node
Transient response simulation analysis
Exhaustive approach:
Full analysis with all controllers and the enhanced techniques
Node
IterationsTransient[dB]
Number of controllers
analyzed:
1. I: 70
2. PID: 4096
3. PII: 4096
1 2 3 4 5 6 7 8
0
2
4
6
1 2 3 4 5 6 7 8
0
3
6
9
12
15
17
I
PID
PII
ISTD
PIDSTD
PIISTD
I
PID
PII
ISTD
PIDSTD
PIISTD
Iteration:
• Get information
• Calculation
• Application

12. 12/23
Experimental setup
• 100km links
• Two EDFA per link and per direction
• 80 continuous wave lasers
• 128Gb/s DP-QPSK channels (at 50GHz)
Node 1
Node 2
Node 3
Node 4
Node 5
WSS cardsKEY:
EDFA cards
SOM/SOD cards
Eth. switches 100-km SMF spans
ROADM node
• SDN controller
• EDFA gain configuration
• lightpath establishment
• NETCONF protocol

13. 13/23
Iterations
Transient response experimental results
Demonstration the overshoot problem for an I controller (ki = 0.4)
without STD enhance technique
5 10 15 20 25 30
-6
-2
2
6
I (sim) I (exp)
5 10 15 20 25 30
-6
-1
4
9
12
I (sim) I (exp)
Iterations
Node4Node8
Power[dBm]Power[dBm]

14. 14/23
Iterations
Transient response experimental results
Dynamic power response of the PII controller (kp= 0.05; ki1= 0.1;
ki2=0.05) with STD enhance technique for overshoot suppression
5 10 15 20 25 30
-6
-4
-2
0
2
PIISTD
(sim) PIISTD
(exp)
5 10 15 20 25 30
-6
-4
-2
0
2
PIISTD
(sim) PIISTD
(exp)
Node4Node8
Power[dBm]Power[dBm]
Iterations
Optical Fiber Communication Conference (OFC) March 2015

15. 15/23
Adaptive EDFA algorithm
Input power
Outputpower
Measuredparam.
Power mask
Dual-optimization application
Tx
add
ROADM 1 ROADM 3
drop
Rx
Pin Measurment
Gain Search
Given: SDN control
Apply Gain
ROADM 4ROADM 2

16. 16/23
Local equalization algorithm
Dual-optimization application
Tx
add
ROADM 1 ROADM 3
drop
Rx
ROADM 4ROADM 2
1.53 1.5351.54 1.5451.55 1.5551.56-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.53 1.535 1.54 1.545 1.55 1.555 1.56-60
-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.531.5351.541.5451.55 1.5551.56-60
-50
-40
-30
-20
-10
0
10
Wavelength
Power
‘
1.53 1.5351.54 1.5451.55 1.5551.56-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.53 1.5351.54 1.5451.55 1.5551.56-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.53 1.5351.54 1.5451.55 1.5551.56-50
-40
-30
-20
-10
0
10
Wavelength
Power

17. 17/23
Global equalization algorithm
Dual-optimization application
Tx
add
ROADM 1 ROADM 3
drop
Rx
ROADM 4ROADM 2
1.53 1.5351.54 1.5451.55 1.5551.56-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.53 1.535 1.54 1.545 1.55 1.555 1.56-60
-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.531.5351.541.5451.55 1.5551.56-60
-50
-40
-30
-20
-10
0
10
Wavelength
Power
1.53 1.5351.54 1.5451.55 1.5551.56-50
-40
-30
-20
-10
0
10
Wavelength
Power




1
2
TOTAL
N
i
i TAA
][minTOTAL wAA TOTAL
w

Apply Γ
T ≤ allowed tilt?
End
Yes
No
Given: N ≥ 2, W, A{1, …, N - 1} , T

18. 18/23
Dual-optimization application
Adaptive EDFA algorithm Global equalization algorithm




1
2
TOTAL
N
i
i TAA
][minTOTAL wAA TOTAL
w

Apply Γ
T ≤ allowed tilt?
End
Yes
No
Given: N ≥ 2, W, A{1, …, N - 1} , T
Input power
Outputpower
Measuredparam.
Power mask
Pin Measurment
Gain Search
Given: SDN control
Apply Gain
Tx
add
ROADM 1 ROADM 3
drop
Rx
ROADM 4ROADM 2

19. 19/23
Test-bed description (SDN controller)
• Sub Controler
• NETCONF-modeling language
YANG models ROADM building
blocks and its interconnections
(ROADM-plugin)
• Application Server
• Node abstraction model
ApplicationServer
SDK-C++
SubController
NETCONF / REST
REST
REST
Adaptive EDFA Global WSS Equalization
Dual-optimization application
SDN
controller
Node
Properties
Interfaces
Property 1
Property 2
Property N
Interface 1 Interface N
Property 1
Property 2
Property N
...
...
Property 1
Property 2
Property N
...
...
Lightpath with:
Λ1 = 20
Λ2 = 40
Λ3 = 80

20. 20/23
1530 1535 1540 1545 1550 1555 1560
10
15
20
25
30
1530 1535 1540 1545 1550 1555 1560
0
10
20
30
40
Local
Local + EDFA
Global
Global + EDFA
Dual-optimization application (experimental results)
OSNR(dB)
Wavelength (nm)
Attenuation(dB)
0 20 40 60 80 100
0
5
10
15
20
25
Local
Local + EDFA
Global
Global + EDFA
Number of channels
Lightpaths (Λ) 20 40 80
Local 13,7 12,9 11,83
Local+EDFA 19,4 16,58 13,86
Global 19,43 21,52 16,43
Global+EDFA 23,3 23,79 20
Mean OSNR (dB)
Wavelength (nm)
Optical Fiber Communication Conference (OFC) March 2015

21. 21/23
International Conference on Communications (ICC) June 2015
Collaboration activities with UTD
Estimating EDFA Output Power with an Efficient
Numerical Modeling Framework
Input power
Outputpower
Measuredparam.
Power mask
Module 1: Finer
Spectrum Granularity
Module 2: Continuous
Input Power Values

22. 22/23
One of top three scored papers in Optical Network Design and Modeling (ONDM) May 2015
Collaboration activities with UTD
Network-wide signal power control strategies in WDM networks
• EDFA gain control
• Ideal gain
• Fixed gain
• Noise Figure (NF)-based gain
• WSS power equalization control
• Flat output power (FP)
• Linear tilted output power (LTP)
• Flat OSNR (FOSNR)
• Wavelength assignment algorithm
• WA: High-to-low frequency First Fit
• WA: Low-to-high frequency First Fit
Lightpath average OSNR versus offered load
WSS: Flat Power equalization,
EDFA: Fixed Gain and NF-based gain control.
with NF gain control
fixed gain

23. 23/23
Outline / Summary
Amplification
• Automated amplifier characterizer
• Field calibration procedure for distributed Raman amplifiers
Reconfigurable Optical Add/Drop Multiplexer (ROADM)
• Transient response issues in cascaded WSS-based ROADMs
SDN-based dual-optimization application
• Adaptive EDFA algorithm
• Global WSS equalization algorithm
Collaboration activities with UTD
• Estimating EDFA Output Power with an Efficient Numerical Modeling Framework
• Network-wide signal power control strategies in WDM networks

24. Thank You!
miquel@cpqd.com.br
www.cpqd.com.br