Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement.
High Speed Optical Networks for
Global Telecom Carriers
Tiejun J. Xia, PhD & CREOL Graduate (94’)
Verizon
3/13/2015 For Industrial Affiliates Symposium, CREOL, UCF
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 2
Global Telecom Carriers’ Networks
Local Network
Local
Convergence
Cabinet
Business
Customers
Residential
Customers
Local Central
Office
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 3
Transport (move data packages physically)
- Construct signal channels to carry data
packages around (e.g. SONET, OTN, ROADM)
Two main networking functions
Access
Network
Access
Network
Metro Core
Network
National Long Haul Network
Switch (decide where a data package goes)
- Data packet routing (e.g. IP router)
- Data frame switching (e.g. MPLS, Ethernet)
Metro Core
Network
- Transport network is the focus in this talk
IP - Internet Protocol
MPLS - Multi-protocol labeled switch
SONET – Synchronous optical networking; OTN – Optical transport
networking; ROADM – Reconfigurable optical add/drop multiplexing
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 4
Driving Force for Network Growth – Fast
Internet Protocol (IP) Traffic Growth
Sources: Cisco
1.00E-08
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
1.00E+00
1.00E+01
1.00E+02
1.00E+03
1980 1985 1990 1995 2000 2005 2010 2015 2020
Glo
bal
IP T
raff
ic (
EB/m
on
th)
1 hour YouTube per day
Global IP Traffic
10 orders of magnitude increase in 30 years
• Averaged annual
growth >100%
• 22% in 2014
Almost all network traffic are IP now
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 5
Switch Port Speed vs Transport Channel
Speed
Transport channel speed must support data port speed
0.01
0.1
1
10
100
1000
10000
1985 1990 1995 2000 2005 2010 2015 2020 2025
Ch
ann
el R
ate
(Gb
/s)
Optical channel
capacity
155M
622M
2.5G
10G
40G
100G
0.01
0.1
1
10
100
1000
10000
1985 1990 1995 2000 2005 2010 2015 2020 2025
Ch
ann
el R
ate
(Gb
/s)
10Base-T
100Base-T
GbE
10GbE
40GbE
100GbE
Data equipment
port speed
Industry Standards
400G Transport Channel
Speed
Switch Port
Speedy
Switch (Router)
Transport (Transponder)
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 6
Fiber Capacity = channel speed x # of channels
O E S C L
Notes: O – Original, E – Extended, S – Short, C – Conventional, L - Long
Optical bands
1. 250 Gb/s (2.5 Gb/s x 100 ch)
2. 1 Tb/s (10 Gb/s x 100 ch)
3. 10 Tb/s (100 Gb/s x 100 ch)
50-GHz Grid
1530 nm
(196 THz)
1569 nm
(191 THz)
Channel
Spacing
Optical Band Used
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 7
Direct Detection vs Coherent Detection
Laser
Data
generator
Data
processing
Data Mapping,
Encoding, DACLaser
Phase modulator
Laser
p/2
p/2
AD
C, E
qualiz
ation,
De
codin
g,
De
mappin
g
90 hybrid
Direct Detection Transmitter
Direct Detection Receiver
Non-Return-to-Zero (NRZ)
Non-Return-to-Zero (NRZ)
Coherent Detection Transmitter
Polarization Multiplexed Quadrature Phase Shift Keying
Polarization Multiplexed Quadrature Phase Shift Keying
Coherent Detection Receiver
For 10 Gb/s or below For 100 Gb/s or above
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 8
1 0 1 1 0 0 1 0
Snap shot of an optical signal
Electrical field (amplitude and phase)
Envelop
Fiber Link
Why Coherent?
(Correcting dispersion caused distortion as an example)
At Transmitter At Receiver
Different frequencies in an optical signal walk off due to dispersion
Direct detection
- Only the intensity is detected.
- Phase information is lost.
- Original signal cannot be fully recovered
Coherent detection with DSP (Digital signal processing)
- Full electrical field (amplitude & phase) is detected
- Original signal is fully recovered in linear region
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 9
Verizon has driven high speed and high
capacity transport in the industry
-40
-30
-20
-10
0
186.5 187 187.5 188 188.5 189
Frequency (THz)
Re
lati
ve
In
ten
sit
y (
dB
)
100G 10G
Video signal fed to
LambdaXtreme® at Tampa
Video signal displayed at Miami
First 100G transmission with live video traffic (Verizon & Bell Labs in 2007)
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 10
Verizon holds records of the highest fiber
capacity in field in the industry
• Multiple super-channels with amp/phase modulation and polarization multiplexing (PM)
• 41 Tb/s for 1,822 km (Long haul distance, PM-8QAM, each super-channel ~ 1Tb/s).
• 54 Tb/s for 634 km (metro distance, PM-16QAM, each super-channel ~ 1.3 Tb/s)
Highest fiber capacity in field experiment (Verizon & NEC/USA, 2013)
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 11
Spectral Efficiency
(b/s/Hz)
5
10
15
20
2
4
6
8
1
2
3
4
LP01 LP11 LP21
O E S C L
How to Further Increase Fiber Capacity?
Optical Bandwidth
(THz)
SDM Level
(Spatial division
multiplexing)
Commercial 100G system
Wider optical band
More waveguides
Higher level modulation
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 12
Increase fiber capacity is just one story
Enhance network efficiency is another focus
Sources: Money, Cisco
Verizon
AT&T
Revenue Growth: 1% - 4%/Yr
Capacity need be added: 30% - 10%/Yr
30%
10%
How to release the pressure? Make network more efficient!
Increase flexibility is key to enhance network efficiency
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 13
ROADM (Reconfigurable Optical Add/Drop Multiplexer)
is critical enabler for network flexibility
N
S
E W T
Rx
TR
x
TR
x
TR
x
TR
x
TR
x
Add/drop
Express Core
Next Generation ROADM:
- Lambda tunable
- Channel can go any direction
- Unified add/drop modules serve
all directions
Next Generation ROADM can provide full flexibility
Network Node with ROADM
“DCD-F ROADM”
- Colorless
- Directionless
- Contentionless
- Flexible grid
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 14
Optical Node Design with Next Generation
ROADM and Full Flexibility
PM-16QAM
PM-QPSK
PM-QPSK
PM-QPSK Map to
super-
channel 400 Gb/s
Superchannel
PM-QPSK
PM-QPSK
Map to
super-
channel
PM-16QAM
PM-16QAM
PM-16QAM 600 Gb/s
Superchannel
North
South
East
Colorless,
Directionless,
Contentionless
and Flexible
Grid (CDC-F)
Add/Drop
10GbE
40GbE
100GbE
100GbE
400GbE
OTU3
OTU4
OTU4
Clients
OTU2
Switch Fabric Line Optical Carriers and Channels Flexible CDC ROADM
100 Gb/s Channel
200 Gb/s Channel
Data content and protocols, forward error correction (FEC) overhead, modulation
format, data rate, wavelength and destination of an optical channel can be
remotely controlled by operators in Network Operation Center (NOC) or even by
software
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 15
Example of Flexible Network Benefits Optical channel restoration during fiber outage
C
A B
D E
F G
Switch/Router
Optical Node
Router/Switch
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 16
Advancement in Network Management
From multiple control systems to unified software control
Forwarding / switching and control planes
Network
Management
Systems
Present
Applications /
Services
Forwarding / switching planes
Future
Applications /
Services
Network Controller
Network abstraction
Control plane
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 17
• New fiber
– Multi-core / multi-mode fiber for long distance transmission, photonic crystal
fiber for new spectral windows with low attenuation
• Low noise optical amplification
– Low noise amplifier, phase sensitive amplifier (PSA)
• Nonlinear impairments mitigation
• Fast optical path set up
• Low latency in data transmission
• Large optical bandwidth for transmission
• Highly integrated photonic circuits
• Advanced modulation formats
Challenges and Opportunities Ahead
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 18
• Global telecom carriers provide end-to-end networking services to
customers. Network will continue to grow to serve emerging applications
• Network growth is driven by high Internet Protocol (IP) data traffic growth
(80% for consumers and 20% for businesses), video traffic is the number
one bandwidth hog, and mobile traffic has the fastest growth
• 100 Gb/s per channel is main stream in backbone networks and
commercial 100-Gb/s systems can provide 10 Tb/s per fiber. 30-40 Tb/s
per fiber is feasible in near future
• Next generation optical node have full flexibility in channel configuration
and optical path control
• Network management will be advanced to be unified and able to be
controlled by software
• Technical challenges and opportunities continue to attract talents in
academic world and industry R&D to generate new solutions
Summary
Confidential and proprietary materials for authorized Verizon personnel and outside agencies only. Use, disclosure or distribution of this material is not permitted to any unauthorized persons or third parties except by written agreement. 19
Tiejun (TJ) Xia, PhD
Global Optical Transport Planning
Phone: 214-563-2619
Email: [email protected]