Transcript 40G System Integration Testing

OPTICAL ENGINEERING 2014
ORT Hermelin College
Wednesday, February 26, 2014 "
,'
" ,
Enabling Technologies and
Challenges in Coherent
Transport Networks
David Dahan, Ph.D.
ECI Telecom Ltd.
Drivers and Impact for Optical
Networking Ecosystem
Shifting to the Cloud…
Video and more Video….
Internet streaming
Enterprise and personal IT are moving to
the cloud computing
Service Providers become
“All Play” providers…
Dynamic Traffic
Networks
Slow Revenue
Growth
IP Video
Traffic
Other IP
Traffic
90%
2013 - IP at 5x 2008 levels with 90% Video
Exponential Traffic
Growth
Technology challenges
Need more optical
channel capacity :
100G/400G/1T
Improve service provisioning,
time and resource utilization :
SDT/ROADM/SDN
Business challenges
Reduce cost
/bit/switch/transport
Confidential , not for distribution
2
Optical Network Evolution
History and roadmap
2012
2015-
2011
400G/1T
2008
40G/100G
40G
2006
80 Channels
10G
40 Channels
2.5G

CWDM, DWDM






SDH / Sonet
Networks
Increase capacity
Point-to-point
CWDM/DWDM
Up to 40 channels
2.5/10G channels





SDH / Sonet / EoS
services support
Ring topology
East/west protection
Reconfigurable
OADM
WDM over OTN
10G channels






IP over WDM
Mesh topology
ASON GMPLS-based
ODU basednetworks
10G/40G channels,
ready for 100G
coherent
Plug and play
Coherent




100G Coherent
networks support
DCFless networks
Colorless /
directionless /
contentionless
WSON GMPLSbased
Superchannel
 Bandwidth on
Demand
 N:M ROADM
configuration
 Gridless ROADM
 400G/1T
transceivers
 Fully automated
network
Continued demand for bandwidth from all applications
Confidential , not for distribution
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From Direct Detection to
Coherent Detection
Up to 10G (SE = 0.2 b/s/Hz)
40G/100G/200G coherent solution
(SE > 2 b/s/Hz)
Intradyne Coherent detection



40G non coherent solution (SE = 0.8 b/s/Hz)
Phase and polarization diverse receiver
Frequency Locked Lasers (<+/- 2 GHz)
Digital Signal Processing at TX/RX
TX
RX
Confidential , not for distribution
4
Current 100G Coherent Transceiver
architecture
Modulation format : DP-QPSK
(Symbol Rate is ¼ Bit Rate : 2bit/s symbol x 2pol)
Integrated PDM QPSK
MZM LiNBO3
Modulator
Integrated Coherent receiver
40 nm CMOS ASIC
with 4 (8 bit resolution)
x63 Gsamples/s ADC
* Nelson et al, “A Robust Real-Time 100G Transceiver With Soft-Decision Forward Error Correction” J. OPT. COMMUN. NETW,
vol 4, no. 11,2012
Confidential , not for distribution 5
Current 100G Coherent Transceiver
architecture
DSP block
Coh. Rx
PMD>30 ps
D>60000 ps/nm
SD- FEC decoder
j
Soft Symbol
estimation
j
Frequency & phase
recovery
LO
Qx
90°
Hybrid
I
& Detector y
Qy
Slicing
S
Resampling
Ix
Clock recovery
&Interpolation
ADCs
OTU4
112G
120G
6-8 bits
Gen
Type
Code
FEC
Over
head
Pre-FEC BER TH.
For post FEC<10-15
Coding
gain [dB]
1st
HD
BCH (Bose-Chaudhuri-Hocquenghem)
and RS (Reed-Solomon) codes
7%
~10-4
6-7 dB
2nd
HD
Concatenation of RS codes, Viterbi
convolutional codes and BCH codes
(CBCH)
7%
~1x10-3
(EFEC)
8.5-10 dB
3rd
SD
BCT (Block Turbo code) or Turbo
Product Code (TPC) and LDPC (Low
Density Parity Check) codes
15%20%
~2x10-2
10.5-11.5
dB
1 bit
+reliability bit
info
Confidential , not for distribution
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100G submarine Field trial over
4600 km
The 100G trial was carried out over Bezeq International’s live operational submarine fiber, in
conjunction with the TeraSanta Consortium : demonstration of advanced capabilities of ECI 100G
transmission system and technologies in compensating for non-linear channel impairments and
chromatic dispersion utilizing advanced SD-FEC algorithms.
DMUX
100G
Apollo
Platform
100G
MUX
Confidential , not for distribution
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Next Generation of Coherent Transceiver :
: Software Defined Transceiver (SDT)
28 or 20 nm CMOS ASIC with
DAC/ADC and DSP capabilities in
both TX/RX



Power reduction
Higher computational strength
Adapt modulation format/Symbol
rate
Technol.
Gate
ADC
(8bits)
DAC
(8bits)
28 nm
150200M
110-130
GS/s
1.7W
110-130
GS/s
0.7W
2013
20 nm
200250M
110-130
GS/s
1.2W
110-130
GS/s
0.5W
2014
Client Data
Rate
100G/150G/200G
/400G/1T
GA
Si Photonics IC with
Electronic and Optical
functionality
FEC
overhead
Modulation
format
0%-30%
BPSK/QPSK/
8-QAM/16QAM
TX
DSP
Pulse Shaping
Optical
Carrier
Flexgrid tunable laser
(C/L band)
Confidential , not for distribution
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New DSP features
■ Nyquist spectral shaping at TX : increases of the spectral
efficiency by reducing the channel bandwidth to ~ symbol rate
4
2
1
0
-1
Raised Cosine FIR filter
-2
-3
-4
1
2
3
4
5
6
7
8
symbol index
0.8
0.6
Tap coeffcient
In phase symbol value
3
0.4
0.2
0
-0.2
0
2
4
6
8
10
Tap index
12
14
16
18
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New DSP features
■ Self diagnostic monitoring features :
■
■
■
■
Accumulated Chromatic Dispersion monitor
PMD monitor
OSNR monitor
ESNR monitor
■ Still missing : Efficient nonlinear compensation technique
■ Current state of the art techniques based on digital back
propagation or Volterra Series are too complex for real time ASIC
implementation
■ Nonlinear optical impairments are the ultimate limitations in optical
network
Confidential , not for distribution
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Transmission Technology options
for 400 Gb/s
4x120G
Modulation
Gbit/s
OSNR min [dB]
DP-QPSK
120
12.5
DP-16QAM
240
18.5
DP-16QAM
480
21.5
DP-256QAM
480
>30
90 Gbaud
f
4 bands with DP-QPSK (30Gbaud)
 No spectral efficiency
improvement over 100G
 Suitable for long haul (>2000 km)
60 Gbaud
Limitations of
DACs/ADC and
electronics
Symbol Rate
30 Gbaud
QPSK 8-QAM
1 bands with DP-16 QAM (60 Gbaud)
 High spectral efficiency
 Reach Limited to Metro (~700 km)
16-QAM 32-QAM
64-QAM
1
Reach Limited
<<100km
2
256-QAM
Constellation
size
3
1x480G
4
2 bands with DP-16 QAM (30 Gbaud)
 High spectral efficiency
 Reach Metro /Long Haul distances
Subcarriers/band
1 bands with DP-256 QAM (30 Gbaud)
 Extremely high spectral efficiency
 Reach Limited (~100 km)
1x480G
2x240G
f
f
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Hybrid Raman Amplifiers
Improving transmission reach
■ Complex Coherent modulation formats like 200G DP-16QAM require for 6-8 dB
■
OSNR improvement with respect with current 100G DP-QPSK modulation
format
The use of hybrid Raman-EDFA amplification schemes is required to improve
the received OSNR or mitigate the nonlinear penalties by lowering the launched
power into the fiber : can improve the transmission reach by 100%
x N times
ROADM
EDFA
EDFA
L km
ROADM
EDFA
RX
Optical
signal
power
[dBm]
Optical
signal power
power
[dBm]
Optical
signal
[dBm]
TX
1010
55
Non
Non linear
linear impairments
impairments
00
-5-5
-10
-10
-10
With Hybrid
Raman –EDFA
amplification
-15
-15
-15
-20
-20
-20
-25
-25
-25
000
Low OSNR
OSNR
Low
20
20
20
40
60
40
60
40
60
FiberLength
Length [km]
[km]
Fiber
80
80
100
100
Fiber Length [km]
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Superchannels
Improving spectral efficiency beyond 100G
■ Future services of 400Gb/s and 1T will be packed into
super channels, in order to provide optimum flexibility and
reach performance tradeoffs :
■ 400G : 2 channels spaced by 37.5 GHz
■ 1T : 5 channels spaced by 37.5 GHz
■ For optimized spectral efficiency, Super channels use
Nyquist spectral shaping and Flexgrid WSS ROADMs
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Flexgrid Networks
■ To increase spectral efficiency, we move from a fixed channel grid
(50GHz/100GHz) to flexible channel grid management :
■ 6.25 GHz grid
■ 12.5 GHz bandwidth granularity
■ The channel spectral slot is adapted on a per channel basis using :
■
■
■
■
10G/ 40G on 25 GHz slot
100G and 200G on 37.5 GHz slot
400G on 75 GHz slot
1T on 187.5 GHz slot
400G
100G
1T
10G
40G
Fixed
50GHz grid
f
50 GHz
400G
Flex grid
50 GHz
100G
1T
Increase by 25 % the
10G available useable fiber
bandwidth
40G
f
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Flex Grid Technology enablers
■ Very stable tunable lasers compatible with 6.25 GHz grid resolution
■ Flexgrid ROADMs :
■ First generation of WSS allocated a channel on a single MEM based pixel
■ Flexible WSS based on LCoS technology use a flexible matrix based wavelength
switching platform with megapixel matrices allowing programmable channel bandwidth
* EXFO Webinar : “400G Technologies: the new challenges that lie ahead”,04/02/2014
http://www.exfo.com/library/multimedia/webinars/400g-technologies-challenges
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Optical Network Node with Full Flexibility
■ Network node capabilities are enhanced with new
features allowing full flexibility :
■ Flexgrid : any channel/ superchannel can be directed
Flexgrid WSS
towards any other node
■ Colorless
■ Directionless
■ Contentionless
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Optical Network Node with Full Flexibility
■ Network node capabilities are enhanced with new features
allowing full flexibility :
■ Flexgrid
■ Colorless : any wavelength can be added or dropped at any port
■ Directionless
■ Contentionless
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Optical Network Node with Full Flexibility
■ Network node capabilities are enhanced with new
features allowing full flexibility :
■ Flexgrid
■ Colorless
■ Directionless : any wavelength can be directed at any
direction an reach a given port
■ Contentionless
Confidential , not for distribution
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Optical Network Node with Full Flexibility
■ Network node capabilities are enhanced with new
features allowing full flexibility :
■ Flexgrid
■ Colorless
■ Directionless
■ Contentionless : Multiple channels of the same wavelength
can be dropped or added by a single module
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Optimum management of the optical
spectrum resources
 Optimized routing and resource allocation algorithms
for flexible optical networking
 Conventional Routing and Wavelength Assignment (RWA) algorithms can


be used only for rigid grid networking
New paradigms based on Routing and Spectral allocation Assignment
(RSA) algorithms should be developed for flexible grid networking
Need
to findofoptimum
Physical Impairment awareness and optimal
combination
Software
Defined Transceiver parameters (modulation
format/symbol
rate, FEC
strategies
for spectrum
overhead) will be required
defragmentation
Rigid grid network
Flex grid network
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Software Defined Networking : Why ?
Flexible Multi-layer Networking
■ Bandwidth hungry services (video, mobile data, cloud
services) lead to new traffic characteristics :
■ Rapidly changing traffic patterns
■ High Pic to average traffic ratio
■ Large Data chunk transfers
■ Asymmetric traffic between nodes
■ SDN will turn the networks into programmable virtualized
resource for better efficiency and automation
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Software Defined Networking
Flexible Multi-layer Networking
User I/Fs
Application requirements
Network
Apps
Dynamic connectivity
Bandwidth
QoS
Resiliency
Open APIs
SND Control
Plane
Hardware Abstraction
& Virtualization
SDN Control Plane
Aware of Application requirement
Optimized resource and configuration
OpenFlow
Multi layer network
elements
Multi layer Network
Elements
Ethernet switch/MPLS router
OTN switch
ROADM, SDT
Fiber switch
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Conclusion
■ The future optical transport networking will provide better
■ Capacity : coherent modulation formats, superchannel, better SE
■ Flexibility : software defined transceivers, flexible grid, flexible
CDC ROADMs nodes
■ Resource utilization : impairment aware- RSA algorithms, SDN
■ The future optical transport networking needs to provide :
■ Efficient nonlinear optical impairment compensation techniques
■ Strategies for pro-active and re-active spectrum defragmentation
and fragmentation awareness in service expansion and
contraction policies
■ Energy efficient strategies
■ Capex and Opex reductions
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