1. ANCIT WORKSHOP Torino, 30-31 March 1998 Cost optimisation of optical access networks Peter Hale, Martin Davies Pirelli Cables, UK David Brittain University of Bristol, UK

2. ANCIT WORKSHOP Torino, 30-31 March 1998 Summary Conventional cables or Blown Fibre? ‘Simple’ analysis –Results –Further work ‘Comprehensive’ analysis –Genetic algorithms –Results Conclusions and discussion

3. ANCIT WORKSHOP Torino, 30-31 March 1998 Conventional or Blown Fibre? Optical fibre in the access network –Must be cost-effective Alternative approaches –Conventional loose-tube? –Blown Fibre? Generic approach to modelling –‘Simple’ –‘Comprehensive’

4. ANCIT WORKSHOP Torino, 30-31 March 1998 ‘Simple’ analysis Considers component costs Methodology –Feeder network –Distribution network Building blocks –Spines –Stars Planning –Less simple with Blown Fibre

5. ANCIT WORKSHOP Torino, 30-31 March 1998 Spines and stars

6. ANCIT WORKSHOP Torino, 30-31 March 1998 Results Spine Star

7. ANCIT WORKSHOP Torino, 30-31 March 1998 ‘Comprehensive’ analysis Genetic Algorithm (GA) approach –Based on biological evolution Operators –Crossover –Mutation Detailed costing approach..0 1 1 0 0 1Mother..1 1 0 1 0 0Father..0 1 0 1 0 0Sister..1 1 1 0 0 1Brother Genes ‘swapped’ from here

8. ANCIT WORKSHOP Torino, 30-31 March 1998 Basis of model Outline of costing approach –Cable and plant –Installation costs –Net present value –Price erosion Does not include –Disposal costs at end of life –Duct and sub-duct costs

9. ANCIT WORKSHOP Torino, 30-31 March 1998 GA costing spreadsheet

10. ANCIT WORKSHOP Torino, 30-31 March 1998 GA network map Exchange Primary node S Possible secondary node site St Customer site Duct

11. ANCIT WORKSHOP Torino, 30-31 March 1998 GA - cost versus generation

12. ANCIT WORKSHOP Torino, 30-31 March 1998 GA solutions - 1 Conventional cable Blown fibre

13. ANCIT WORKSHOP Torino, 30-31 March 1998 GA solutions - 2 Conventional cable Blown Fibre Some nodes have same position One additional node for conventional cable

14. ANCIT WORKSHOP Torino, 30-31 March 1998 Topology - differences and features Cost differences –Generally conventional cable installed earlier –Blown Fibre installed just-in-time –Blown Fibre plant generally less expensive Node placement –Additional conventional node Deferred installation saves cost –‘Cluster’ of customers around nodes

15. ANCIT WORKSHOP Torino, 30-31 March 1998 GA cost results

16. ANCIT WORKSHOP Torino, 30-31 March 1998 Conclusions and discussion Blown Fibre more cost effective –Both models –Less labour –Blow through joints - no splice trays/splices –Less plant - only install required fibres –Just-in-time installation Topology differences –Ability to defer costs