Physical Layer Components, Architectures and Trends for Agile Photonic Layer Mesh NetworkingBrandon C. Collings
JDSU Optical Networks Research LabRobbinsville, NJ 08691 USA
ECOC, Sept. 23, 2009
Paper 6.7.2
© 2009 JDSU. All rights reserved. 2
Outline
Advantages of “Static” ROADM Optical Mesh Networks
The WSS and Current “Static” Mesh Node Architectures
Applications of “Dynamic” Optical Mesh Networks
Node Architectures for “Dynamic” Mesh Networks– Colorless ports
– Directionless ports
© 2009 JDSU. All rights reserved. 3
Advantages of Static ROADM Optical Mesh Networks
Eliminate OEO at network junctions– Considerable cost, complexity and maintenance savings
Flexible wavelength topology enables efficient capacity growth– Most efficient routes can be selected
– Extends lifetime of system
Add new connectivity via unused degrees as needed– Parallel spans, spurs, extensions, ring interconnects
– Maintains in-situ HW and management
© 2009 JDSU. All rights reserved. 4
The Wavelength Selective Switch (WSS)1xN port device
Independently routes each channel to one of N ports
Attenuate and block channels independently
Optically bi-directional
wavelengthWavelength
SelectiveSwitch(WSS) N
ports
© 2009 JDSU. All rights reserved. 5
WEST
Typical Reconfigurable Ring Node Architecture
WSS selects outbound wavelength traffic
AWG’s used to multiplex and demultiplex locally added and dropped channels – “Colored” add/drop ports
Tx Tx Tx Tx
AWG
Tx
WSS
Power
Splitter
Rx
Rx
Rx
Rx
AWG
Rx
TxTxTxTx
AWG
Tx
WSS
Pow
er
Split
ter
Rx
Rx
Rx
Rx
AWG
Rx
EAST
© 2009 JDSU. All rights reserved. 6
WEST
Typical Reconfigurable Mesh Node Architecture
Tx Tx Tx TxAWG
Tx
WSS
Power
Splitter
Rx
Rx
Rx
Rx
AWG
Rx
TxTxTxTxA
WG
Tx
WSSPower Splitter
RxRxRxRx A
WG
Rx
TxTxTxTx
AWG
Tx
WSS
Pow
er
Split
ter
Rx
Rx
Rx
Rx
AWG
Rx
TxTxTxTx
AW
G
Tx
WSSPower SplitterRx
RxRxRx
AW
G
Rx
NORTH
SOUTH
EAST
© 2009 JDSU. All rights reserved. 7
Dynamic Optical Mesh Network ApplicationsPhotonic layer restoration
– Restoration complements higher layer protection to increase overall availability
– Relaxes urgency to repair fiber (OpEx argument and reliability increase)• Some locations have limited access (disaster zone, subways, remote locations, undersea
festoons)
– Reduces excess capacity allocated for protection contingencies (CapEx argument)
Load Balancing– Move existing traffic to relieve emerging bottlenecks
Maintenance switching– In-service wavelength bridge-and-roll around planned maintenance
© 2009 JDSU. All rights reserved. 8
Dynamic Optical Mesh Network ApplicationsPhotonic layer restoration
– Restoration complements higher layer protection to increase overall availability
– Relaxes urgency to repair fiber (OpEx argument and reliability increase)• Some locations have limited access (disaster zone, subways, remote locations, undersea
festoons)
– Reduces excess capacity allocated for protection contingencies (CapEx argument)
Load Balancing– Move existing traffic to relieve emerging bottlenecks
Maintenance switching– In-service wavelength bridge-and-roll around planned maintenance
© 2009 JDSU. All rights reserved. 9
Dynamic Optical Mesh Network ApplicationsPhotonic layer restoration
– Restoration complements higher layer protection to increase overall availability
– Relaxes urgency to repair fiber (OpEx argument and reliability increase)• Some locations have limited access (disaster zone, subways, remote locations, undersea
festoons)
– Reduces excess capacity allocated for protection contingencies (CapEx argument)
Load Balancing– Move existing traffic to relieve emerging bottlenecks
Maintenance switching– Move traffic away from area of planned maintenance
© 2009 JDSU. All rights reserved. 10
Dynamic Optical Mesh Switching Requires…
Optical network level features:– Colorless add/drop ports
– Directionless add/drop ports
© 2009 JDSU. All rights reserved. 11
WEST
Colorless Add/Drop Ports
Replace mux/demux AWGs with WSS’s– Wavelength assigned to each port is provisionable
Applications– Fewer physical ports present simplifying faceplate
– Operating wavelength can be remotely modified
Tx Tx Tx Tx
WSS
Tx
WSS
Power
Splitter
Rx
Rx
Rx
Rx
WSS
Rx
TxTxTxTx
WSS
Tx
WSS
Pow
er
Split
ter
Rx
Rx
Rx
Rx
WSS
Rx
EAST
© 2009 JDSU. All rights reserved. 12
Directionless Add/Drop Ports
Rx
Rx
Rx
WS
S
WE
ST
PS
WS
S
NO
RTHP
S
WSSPS
WSSPS
Tx Tx Tx Rx
Rx
Rx
WSSPS
WSSPS
Tx Tx Tx
WS
S
SO
UTH
PS
WS
S EA
STP
S
Add/Drop Bank 1
Add/Drop Bank 2
1xN
1xM
© 2009 JDSU. All rights reserved. 13
Directionless Add/Drop Ports: NxM WSS
WS
S
WE
ST
PS
WS
S
NO
RTHP
SW
SS
SO
UTH
PS
WS
S EA
STP
S
WSS WSS
Add/Drop Bank 1
Add/Drop Bank 2
NxMWSS WSS
Rx
Rx
Rx
Tx Tx Tx Rx
Rx
Rx
Tx Tx Tx
© 2009 JDSU. All rights reserved. 14
Summary
Past and Present– Optical mesh networks currently being deployed for efficient
operations and capacity growth
Present– Applications leveraging the dynamic capabilities of the mesh
network are emerging
Future– Mesh networks with colorless and directionless add/drop ports
– Network optimization must become multi-layer • Leveraging the strengths of each layer
– Develop multi-layer management systems which can execute this optimization automatically and seamlessly