Transcript NEPTUNE Alternate System Design

NEPTUNE
Alternate System Design
Peter Phibbs
7-8 January 2003
Page 1
Outline
• What is the Alternate System Design?
• Communications System
• Power System
• Reliability Implications
• Commercial Implications
• Current Status
• Next Steps
• Conclusions
Page 2
What is the Alternate System Design?
• Backbone Built to Commercial Submarine Telecommunications Standards
– Leverages Industry Experience
– Consists of Cable, Optically Amplified Repeaters, and Branching Units
– Delivers Extremely High Reliability
• Science Nodes Built to Meet NEPTUNE Project Needs
– Include Power Converters, Gigabit Ethernet Transponders, and Ethernet
Switches
– Use of Terrestrial Grade Equipment Trades-off Reliability for Function
• A Philosophy of Minimizing and Simplifying Underwater Equipment
Page 3
Alternate System Design
North Shore
Terminal
South Shore
Terminal
Comms Link
(Internet)
Branching
Unit
Repeater
Node
Page 4
Alternate System Design Features
• Topology Driven by Power, Not Comms
• Cable Run is Linear from Station to Station; No Branching
• Each Node Communicates with Both Cable Stations for Diversity
• Each Node Uses a Unique Wavelength on a Fiber Pair
• Data Does Not Pass Through Other Nodes on Way to Shore Station
Page 5
ASD Communications Node Configuration
Node Branching Unit
Optical Couplers
Node
Optical Filter
Optical Filter
GigE
Transponder
GigE
Transponder
Ethernet Switch
Ethernet Switch
10/100 Base-T
To Instruments
Page 6
ASD Communications Node Configuration
Optical Coupler Drops All
Waves from North Terminal
and Adds Wave to South
Terminal
Node Branching Unit
Optical Coupler Drops All
Waves from South Terminal
and Adds Wave to North
Terminal
To/From North
Shore Station
To/From South
Shore Station
Comms to/from Other Nodes
Pass Through Branching Unit
Node
Optical Filters
Select Desired
Wavelength
GigE
Transponder
GigE
Transponder
Ethernet Switch
Ethernet Switch
10/100 Base-T
To Instruments
Page 7
ASD Power
Page 8
Reliability Implications
• Nodes Do Not Rely on Other Nodes
• Node Failures Are Extremely Unlikely to Affect Other Nodes
– Only exception are certain laser faults which
cause interactions on the optical line
• Baseline Design Relies on Mesh to Route Around Failed Nodes
– This is Effective for Certain Combinations of Failures
• The Alternate Design Relies on Multiple Rings
– In General, Rings are a Less Effective Topology Than a Mesh
– Because Each Node Uses a Unique Wavelength,
Each Node is an Independent Ring
– Multiple, Overlaid Rings Enhance Reliability
• Preliminary Reliability Calculations Indicate Alternate
Design Compares Favorably to Baseline
• Alternate Design Copes With Unpredictable Failures
– Cable Break + Node Failure
– Catastrophic Node Failure
Page 9
Shore
Station
Shore
Station
Baseline Design
Page 10
Shore
Station
Shore
Station
Baseline Design
Page 11
Shore
Station
Shore
Station
Baseline Design
Page 12
Shore
Station
Shore
Station
Baseline Design
Page 13
Shore
Station
Shore
Station
Alternate System Design
Page 14
Commercial Implications
• Backbone Provided Under Supply Contract
• Supplier Assumes Performance Risk
• Service and Support for Minimum of 15 Years
• Costs Still to Be Assessed; Both Baseline and
Alternate are Moving Targets
Page 15
Status of Alternate System Design
• Alternate System Design Preliminary Study Released November 2002
• Alcatel Testing Indicates Optical Design is Feasible
• Support from Alcatel Has Been Adequate, But Alcatel
Need to Generate Business/Revenues to Continue
• Study from Power Group Anticipated Shortly
• Interim Report Released in February
Page 16
Next Steps
• Digest Implications of Power System Design Update
• Further Demonstration of Gigabit Ethernet Transponder
• Optical Line Design
– Repeater Spacing
– Spur Cable Length
– Number of Nodes Supported
• Network Management Design Analysis:
– Is Network Management System Required to Ensure Reliability?
• Timing Distribution
• Detailed Cost Estimate
• Complete Reliability Analysis
• Interim Report Anticipated in February
Page 17
Summary
• Key Feature of Alternate Design is High Reliability Backbone
• Alternate System Design Is Worthy of Consideration
• Alternate Comms and Alternate Power Are Synergistic
• Reliability and Commercial Implications Differentiate Alternate Design
• Technical Challenges Remain
• Study and Evaluation of Alternate Design Is Ongoing
Page 18