ACE/RUS School and SymposiumCorralling the Broadband Stampede

ActiveVs.

Passive Optical Networks

Rob WilkinsonVice President, Planning & Design

Presented By

Technology Review Passive Optical Network (PON)

Generic GPON technology and topology

OLT (Optical Line Terminal) Splitter ONT (Optical Network Terminal)

Feeder fiber Distribution fiber Drop

Advantages

• Lower cost for equipment

• Smaller cross-section of fibers (lower cost)

• Easy to add splitter for unexpected growth

Disadvantages

• Reduced bandwidth to subscriber (2.4 Gbps shared)

• Limitation of distances to sub (20 Km with 32:1 splits)

Technology Review Active (Dedicated Plant)

Active Ethernet technology and topology

OLT (CO or field electronics) ONT (Optical Network Terminal)

Feeder fiber Distribution fiber Drop

Advantages

• Maximum bandwidth to each subscriber (1 GB per sub)

• Distance to subscriber could reach 80 Km (50 mi)

• Most future safe – not as concerned about an evolution plan

Disadvantages

• Larger fiber cross sections to meet present and future growth

• Typically higher cost electronics

Approach Identify and Define Study Areas

Three types of study areas

• Low density, low growth rural area

• High density, high growth rural area

• Urban area

• Design & Costs Used a “square” layout scenario for consistency

Cable sizing was completed using a cable fill chart

• Economic breakeven years

• Percent growth

• Costs do NOT include common costs of both scenarios (not project costs)

Study Details Study Areas

Low density, low growth rural area

• 100 square miles

• 2 subs per route mile

• 140 route miles/280 subs served

• 2% growth per year

High density, high growth rural area

• 100 square miles

• 10 subs per route mile

• 140 route miles/1400 subs served

• 6% growth per year

Study Details Study Areas

Urban Area (approx. 5,000 population)

• 144 blocks (12 blocks x 12 blocks)

• 16 subs per block

• 23 route miles/2304 subs served

• 2% growth per year

Cost AnalysisPon Design

Size $/mile Miles Total

BFO 12 $ 11,580 88 $1,019,040 COE Electronics

BFO 24 $ 13,340 48 $ 640,320 Quantity Per Sub

BFO 36 $ 15,100 4 $ 60,400 280 $ 180 $ 50,400

BFO 48 $ 16,860 $ -

BFO 72 $ 20,380 $ -

BFO 96 $ 23,910 $ - Splitters

BFO 144 $ 30,950 $ - Quantity Each

BFO 216 $ 41,510 $ - 16 $ 1,600 $ 25,600

BFO 288 $ 52,080 $ -

BFO 360 $ 62,640 $ - Elec Total $ 76,000

BFO 432 $ 73,200 $ -

BFO 504 $ 83,770 $ -

BFO 576 $ 94,330 $ -

BFO 648 $ 104,900 $ -

BFO 720 $ 115,460 $ -

140 $1,719,760 Total Cost $1,795,760

Cost Analysis Summary

Design Plan Subs Miles Fiber PlantCOE

Electronics Splitters Total

Low Density Rural

PON Design 280 140 $1,719,760 $50,400 $25,600 $1,795,760

Active Design 280 140 $1,938,200 $77,000 $0 $2,015,200 11%

High Density Rural

PON Design 1400 140 $3,044,120 $252,000 $148,800 $3,444,920

Active Design 1400 140 $3,163,840 $565,000 $0 $3,728,840 8%

High Density Urban

PON Design 2304 23 $831,610 $414,720 $223,200 $1,469,530

Active Design 2304 26 $1,438,007 $633,600 $0 $2,071,607 29%

Study Results Low density, low growth rural area

Small difference in cost (11%)

• PON = $1,795,000

• Active = $2,015,000

• High density, high growth rural area• Even smaller difference in cost (8%)

• PON = $3,445,000

• Active = $3,729,000

• High density urban area• Higher difference in cost (29%)

• PON = $1,469,000

• Active = $2,071,000

Study Results Technical Differences

PON has varying distance limitations which could impact fiber sizes

• Changing splits can extend reach

Standard Active reach is 20 Km, but could go 80 Km with extended lasers

• Enhances reach in low density very rural areas

• Distance is less important in high density areas vs. fiber cross sections

• Place additional electronics within area to keep fiber sizes lower and manageable

• Bandwidth capacity

• PON provides shared bandwidth to customer

• Active provides dedicated bandwidth to customer

• Each has a common bottleneck to the world (10 GigE backplane)

Conclusions

So what’s the answer?

It’s a bladder control issue!

It DEPENDS!

Conclusions Cost Basis

PON still provides the lowest cost scenario

Technical Basis Active provides maximum amount of distribution bandwidth at minimal cost increase

How do you chose?

Do BOTH!!!