Investing dBs to Defer CAPEX and

Save OPEX in Passive Optical Networks

Carsten StorbeckDirector Product Management

Mail: carsten.storbeck@adckrone.comPhone: +49-30 8453 1605

Realizing the Benefits of FTTHPlanning from the CO to the Premises

• Last-mile FTTH/B deployments must incorporate a physical growth path for – Cost-effective monitoring

– Maintenance

– Network modification

• Effective utilization of connectorization technology throughout the network achieves– Accessibility

– Flexibility

– Regulatory compliance

– Realizes full potential of optical budget

• Adopting connectorization strategies can guarantee– Network scalability – either in terms of bandwidth, distance or diffusion

– Minimum OPEX

– Maximum subscriber satisfaction.

• Installation of a fiber optic network can require millions of connections

• Connections are made one of two ways

– Splicing: Two fibers are coupled together using a splicing machine

– Connectorization: Connectors are added to the ends of bare fiber and “click” together mechanically at various junction points

What is Connectorization?

Where can Connectorized Solutions be used?

Reservations about Connectorization

– First Costs vs. Operational Expenses - “The capital expense savings of a spliced approach outweighs the operational expense savings associated with a connectorized approach”

– Unnecessary Test Access - “We don’t need to have more test access points because we don’t feel the number of failures will be large enough”

– Connector Performance – “Connectors are fine in the controlled environment of central exchanges. But in the outside plant?”

– Signal Loss - “Extra connection points will impact our loss budget and are just another opportunity for failure”

Practical Performance ValueTuned SC Connectors

• Value determined at 1310 nm and 1550 nm, measured by random mating

• Much better performance than specification requirements

• Attenuation grade B ≤ 0,25 dB is given for minimum of 97 % of samples

Histogram @ 1310nm

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25

0.05

0.075 0.1

0.125

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0.175 0.2

0.225

0.25

0.275 0.3 More

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y

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120.00%

FrequencyCumulative %

Histogram @ 1550 nm

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00.0

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0.075 0.1

0.125

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0.175 0.2

0.225

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0.275 0.3 Mor

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FrequencyCumulative %

Attenuation in dB Attenuation in dB

Häu

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Designing within the Optical Budget

• Typical optical budget for FFTH/B networks: –20 to -30dB (typically 26dB)

• Attenuation in typical OS1 singlemode: 0.4dB/km at 1310nm

• Operating margin: Between 3dB and 5dB

• Typical attenuation loss of SC or LC connector: 0.3dB (in worse case, it can be up to 0.5dB)

• Typically, return loss of SC or LC connector can be reduced by 65dB using angled physical contact (APC) connectors

• Given number of connectors, splices and splitters, the maximum fiber span length can be calculated

– Maximum span length for a GPON incorporating 1:32 splitters and having a 28dB optical budget: 20km

• Typical FTTH/B distances: Between 5km and 20km

Fiber Access Terminal

Optical Line Termination

1 x 32 Splitter

Fiber Distribution Hub

Fiber Access Terminal

• Concept : All splitters are located within the FDH OSP locations

• Theory : Centralized splitting will maximize OLT utilization and may provide a single point of access for testing, turn-up and troubleshooting.

• Reality : Provides the best OLT utilization and flexibility in limited take rates, allows for easy craft access for troubleshooting, increases the cost of the distribution fiber, but allows for the migration of new PON technologies.

Splitter Deployment Strategy – P2MP Centralized Splitting Strategy (Physical View)

Central Office/Head-End

F1

F2

F3

Splicing and ConnectorizationHealthy Mixture in the Network

Key Cost Drivers: Active/Passive Components, Take Rates, and Service Profiles

0 %

10

20

30

40

50

100

CO Electronics and Installation

(OLT)

Co

st P

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8%

40%

52%

Relative CostsPoint-to-Multipoint PON Deployment

Distribution Network (ODN)

CPE and Installation

(ONT)

Infrastructure Costs Breakdown

Construction 53%

Fiber8%

Couplers & Splitters

20%

Cabinets/ Closures

9%Engineering

10%

Conclusion

• Constant upgrade and evolution to networks offsets any impact on optical loss budget

• The larger and more complex the network becomes, the greater the need for simplified test access

• Spliced environments make customization of service offering difficult

• Connectorization permits easy service turn-up and maintenance

• Former concerns about use of connectors are no longer valid given improvements in today’s connectorized solutions

• Investment in dBs can help reduce downtime and save OPEX

• Appropriate use of both connectorized and spliced termination methods help build a future-ready FTTH network