The Evolution of Optical Transport
Networks
Rod C. Alferness
Chief Technology Officer - Optical Networking Group
Lucent Technologies
SPARTAN Symposium - 5/20/98
Page 1
Network Architecture Dynamics
... in a dramatically changing landscape
Explosive Growth of Data
• fueled by Internet & Intranets
Demand for Low
Cost Bandwidth ($/Mb)
• fueled by competition
Need for Reliable,
Predictable Bandwidth
• VPNs, Intranets
• Internet Commerce
Market Forces
Network Architecture Evolution
• parallel service layer networks (IP, ATM, PSTN, etc.)
• unifying transport layer of DWDM & STM (SONET/SDH)
• DWDM expands from core toward edge
• restoration at the optical layer
Technology Drivers
Optical Networking Technology
• number of wavelengths
• total capacity
• wavelength management
Page 2
Router Technology
• throughput
• QoS mechanisms
IncreasingTransmission Capacity
in Wavelength and Time Domains
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Page 3
Ultra-Wideband EDFA
30
G a in ( d B )
40.8 nm
43.5 nm
20
Total 3dB Bandwidth = 84.3 nm
10
10
Noise ≤ 6.5 dB
Output Power ≅ 24.5 dBm
0
1525
1550
5
1575
W a v el e n gt h ( n m )
Page 4
15
1600
N o is e F ig u re ( d B )
L-Band
C-Band
1 Tb/s Experiment: Channel Spectrum
Page 5
40Gb/s Waveform After 85km
TrueWave Fiber @1554.5nm
10ps/Div.
Page 6
30 Wavelength Spectra
Transmitter Output
Page 7
Receiver Input
Flexibility, Efficiency, & Reliability
Selective Layered Bandwidth
Management
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Broadband
Circuit
Wideband
Circuit
Frame
Relay
Cell
Relay
IP/ATM
IP over
SONET/SDH
AAL 5
IP
ATM
PPP/HDLC
IP over
WDM
SDL
Next Big
Thing?
NBT
?
STM
Optical
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WRPDWFKVHUYLFHPL[DQGQHWZRUNQHHGV
Page 8
Selective Layered
Bandwidth Management
Today
Wideband &
Broadband
Circuit
ServiceOptimized
Virtual
Backbones
Unified
Transport
Infrastructure
Frame Relay
Native LAN
Cell Relay
IP: VPN
IP: Best Effort
IP
ATM
PPP/HDLC
STM
DWDM
• Rapid expansion of core capacity via DWDM
• Overlaid with circuit, ATM, & IP virtual backbones
Page 9
Network Example - IP Transport
Today
IP/ATM/SONET/ON
connection
IP/ATM/SONET connection
ATM
ATM
ATM
IP/SONET/ON
connection
ATM
ATM
ATM
ATM
Service Layer
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
SONET Layer
λ
λ
IP end-to-end thread
logical connection
λ
λ
λ
λ
λ
λ
Optical Networking Layer
Access
Page 10
Metro
Core
Selective Layered
Bandwidth Management
Mid Term
Wideband &
Broadband
Circuit
ServiceOptimized
Virtual
Backbones
Unified
Transport
Infrastructure
•
Page 11
Wideband Circuit
Frame Relay
Native LAN
Cell Relay
IP: Best Effort &
Differentiated Services
IP
ATM
SDL
STM
Optical Networking
DWDM with restoration, OAM&P, and flexible
bandwidth management becomes Optical Networking
layer,
layer expands into Metro IOF
Network Example - IP Transport
Mid Term
IP/ATM/SONET connection
ATM
ATM
ATM
IP/SONET/ON
connection
IP/ON connection
ATM
ATM
ATM
ATM
ATM
ATM
Service Layer
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
SONET Layer
λ
λ
IP end-to-end thread
logical connection
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
wavelength add/drop
Optical Networking Layer
Access
Page 12
Metro
Core
Selective Layered
Bandwidth Management
Long Term
Wideband Circuit
Frame Relay
Native LAN
Cell Relay
BB circuit
ServiceOptimized
Virtual
Backbones
Unified
Transport
Infrastructure
•
•
Page 13
IP (all classes)
Clear channel
λ
IP
ATM
SDL
STM
Optical Networking
Optical Networking layer expands into access
Optical Cross-connects support clear channel λ
services, mesh restoration, & efficient λ expressing
Network Example - IP Transport
Long Term
ATM
ATM
ATM
ATM
ATM
IP/ON connection
IP/ON connection
IP/SONET/ON connection
ATM
ATM
ATM
ATM
Service Layer
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
STM
SONET Layer
λ XC
λ
λ
λ XC
λ
λ XC
λ
λ XC
λ XC
λ XC
λ
λ
Optical Networking Layer
IP end-to-end thread
backup optical paths
logical connection
λ
Page 14
wavelength add/drop
Access
Metro
Core