ACE/RUS School and Symposium Corralling the Broadband Stampede Active Vs. Passive Optical Networks Rob Wilkinson Vice President, Planning & Design Presented By

Technology Review  Passive Optical Network (PON)  Generic GPON technology and topology OLT (Optical Line Terminal)SplitterONT (Optical Network Terminal) Feeder fiberDistribution fiberDrop  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 fiberDistribution fiberDrop  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)

5 yy subs xx subsyy fibers z subsxx fibers y subsz fibers x subsy fibers C.O.x fibers x subs x fibersy subs y fibersz subs z fibersxx subs xx fibersyy subs yy fibers

Fiber Fill Chart Breakeven YearsFibersAvailable2%4%6%8%10%

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 Analysis Pon Design Size$/mileMilesTotal BFO 12 $ 11,58088 $1,019,040COE Electronics BFO 24 $ 13,34048 $ 640,320QuantityPer Sub BFO 36 $ 15,1004 $ 60, $ 180 $ 50,400 BFO 48 $ 16,860 $ - BFO 72 $ 20,380 $ - BFO 96 $ 23,910 $ -Splitters BFO 144 $ 30,950 $ -QuantityEach 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 $ $1,719,760Total Cost $1,795,760

Cost Analysis Summary Design PlanSubsMilesFiber Plant COE ElectronicsSplittersTotal Low Density Rural PON Design280140$1,719,760$50,400$25,600$1,795,760 Active Design280140$1,938,200$77,000$0$2,015,20011% High Density Rural PON Design $3,044,120$252,000$148,800$3,444,920 Active Design $3,163,840$565,000$0$3,728,8408% High Density Urban PON Design230423$831,610$414,720$223,200$1,469,530 Active Design230426$1,438,007$633,600$0$2,071,60729%

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!!!