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Overview
• Transmission technologies– 4 technologies
• Long Reach & Ultra Long Reach• With & without Raman
– Varying reaches with fibre different types
• Links– Arbitrary lengths– Arbitrary dB loss
• Solution test all design possibilities even the use of technology ‘patch works’
X
Transmission Technology Choice
2,500 km
Hypothetical data, do not use out of example context
Long Reach (1,000km)
Ultra Long Reach (2,000km)
Long Reach + Raman (1,500km)
Ultra Long Reach + Raman (3,000km)
3R 3R3R 3R3R X3R
Good fit Good fit but includes cost of 2 Regens! Regen Required - high cost! Wastage of reach distance & inclusion of 3R cost Mixture of technologies – Case #1Mixture of technologies – Case #2
X
Transmission Technology Choice
2,500 km
Hypothetical data, do not use out of example context
Long Reach (1,000km)
Ultra Long Reach (2,000km)
Long Reach + Raman (1,500km)
Ultra Long Reach + Raman (3,000km)
X
• Cost of transponders• Cost of regenerators• Cost of Raman amps• Number of wavelengths• Fibre, floor space, …
Which technology gives the least cost fit?
Dependencies:
Transmission Technology Choice
Long Reach (1,000km)
Ultra Long Reach (2,000km)
Long Reach + Raman (1,500km)
Ultra Long Reach + Raman (3,000km)
Long Reach only $24m
Ultra Long Reach only $27m
Long Reach + Raman only $27m
Ultra Long Reach + Raman only $15m
Ultra Long Reach & Long Reach + Raman $22m
Long Reach & Long Reach + Raman $19m
Cheapest because no regenerators are required
However this can all change with varying distances, number of wavelengths and hardware costs!
Hypothetical data, do not use out of example context
• 2500km link• 80km amp spacing• Including dispersion compensation• 40 • Representative costs!
Example: least cost transmission technology
Link Distance (km)
Wav
elen
gth
Lo
adin
g
LRULRULR with RamanLR with Raman
Hypothetical data, do not use out of example context
The plot shows the least cost technology for varying link distances and wavelength loadings. It varies for different relative component costs.
Geography and Topology Constraints
Throughout a real network large span distances and poor fiber can reduce dB loss, thus making the minimal cost solution less straight forward
xxNode A Node Z
Large span distances force the need for regeneration
R
{ {
xxNode A Node Z
Or
Raman pump over these difficult spans
But trade-offs exist!
So each possible design must be tested to gain the minimal cost
Geography and Topology Constraints
Throughout a real network large span distances and poor fiber can reduce dB loss, thus making the minimal cost solution less straight forward
xxNode A Node Z
OADM’s reduce transparency distances
OADM
xxNode A Node Z
So
Raman pump to recover the range
But eventually regeneration is needed!
So again, each possible design must be tested to gain the minimal cost
OADMR
OADM OADM
Integrated transmission & switching
Mux/demux+ grooming
Service interfaces
Patch panelShort reachinterfaces
Trunk interfaces
Mux/demux+ grooming
Service interfaces
Trunk interfaces
WDM
WDM
• The following slides were used for the WorldCom presentation – they were based on a generic network design and could be adapted …
Value of switch-transport integration
• 25% capex savings on whole network• Up to 46% capex savings on individual nodes
– Fewer network elements to manage
OC-192 LR/ULR Transponders
OC-192 LR/ULRTransponders
OC-192 LR/ULRTransponders
OC-192 SRTransponders
x
x
IntegratedTitanium
Stand- Alone
Integrated Vs Stand-alone Switch & Transport
Stand-Alone Switch + Transport Integrated Solution
Pri
ce
($
)
Value of integrated OADM
• Fewer transponders & smaller switch matrix reduces capex by further ~13%– Integrated management of pass through channels
xOC-192 LR/ULR
Transpondersall channels
Titanium o-e-o
x
OADM
OC-192 LR/ULRTransponders
Add-drop channels only
Titanium OADM Price Difference with & without OADMs
Solution without OADMs Solution with OADMs
Pri
ce (
$)
Common Equipment
OADMs
Optical Shelves
Switch Shelves
Transponder Shelves
Linear scalability
• Cost scales linearly with growth– All demands were increased by 20% period on period
Incremental Cost Increase
Period 1 Period 2 Period 3 Period 4
Pri
ce (
$)
Challenges in designing transport networks
Where should we use OADM’s?Where should we use Raman?
What is the best protection type for a given application?
How do we trade off transparency with connectivity when applying OADM’s?
How can we optimize customer network designs & minimize costs?
Where should we groom?
How valuable is integration?How scalable is
the solution?
How can we compare solutions?
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