Small cells in a big city

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This presentation provides and overview of deploying multipoint microwave to backhaul a small cell network and was presented bu Dr John Naylon, CTO at CBNL, at the Packet Microwave and Backhaul Forum 2012.

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Small cells in a big city

  1. 1. www.cbnl.comDeploying multipoint microwaveto backhaul a small cell networkSmall Cells in a Big CityDr John Naylon, Chief Technology Officer,Cambridge Broadband Networks Limited
  2. 2. Topics Covered• Choosing from the famous ‘backhaul toolbox’• Observations from a live small cell deployment using multipoint microwave• Conclusions www.cbnl.com Commercial in confidence 2
  3. 3. Backhaul Toolbox Satellite Bonded Copper Multipoint Microwave Fibre P-P Microwave WiFi / Unlicensed P-P 60GHzFree-Space Optical (E-Band) Multipoint NLoS P-P 70/80GHzwww.cbnl.com Commercial in confidence 3
  4. 4. Backhaul Toolbox Satellite Bonded Copper Multipoint Microwave Fibre P-P Microwave WiFi / Unlicensed P-P 60GHzFree-Space Optical (E-Band) Multipoint NLoS P-P 70/80GHzwww.cbnl.com Commercial in confidence 4
  5. 5. Choosing from the Toolbox 1. The solution has to work − Not just today, but sustainably as the access network evolves 2. It has to be cost-effective to deploy en massewww.cbnl.com Commercial in confidence 5
  6. 6. The Solution Has To Work: Spectrum Considerations millimetre wave Unlicensed 18.3GHz Light licensed Microwave: 16.4GHz for terrestrial Link licenced (PTP) fixed links Area Licensed (PMP) Sub 6GHz: Area Licensed 1.54 GHz for licensed and Unlicensed unlicensed fixed & mobile Source: "Frequency Band Review for Fixed Wireless Service", for Ofcom, Nov 2011, http://goo.gl/7S26pwww.cbnl.com Commercial in confidence 6
  7. 7. The Solution Has To Work: Spectrum Considerations Sub 6GHz: Area Licensed 1.54 GHz for licensed and Unlicensed unlicensed fixed & mobile• Access share of < 6GHz has risen from 1% to 10% in 20 years• Regulators are seeking to release 500MHz (~10%) more• Backhaul gets economically squeezed out of < 6GHz• Unlicensed could be a possibility today … but tomorrow?www.cbnl.com Commercial in confidence 7
  8. 8. The Solution Has To Work: Spectrum Considerations millimetre wave Unlicensed 18.3GHz Light licensed Microwave: 16.4GHz for terrestrial Link licenced (PTP) fixed links Area Licensed (PMP)• Microwave and millimetre wave offer future-proof capacity• Tried and tested backhaul technologies for macro networkwww.cbnl.com Commercial in confidence 8
  9. 9. Backhaul Toolbox Satellite Bonded Copper Multipoint Microwave Fibre P-P Microwave WiFi / Unlicensed P-P 60GHzFree-Space Optical (E-Band) Multipoint NLoS P-P 70/80GHzwww.cbnl.com Commercial in confidence 9
  10. 10. Backhaul Toolbox Satellite Bonded Copper Multipoint Microwave Fibre P-P Microwave WiFi / Unlicensed P-P 60GHzFree-Space Optical (E-Band) Multipoint NLoS P-P 70/80GHzwww.cbnl.com Commercial in confidence 10
  11. 11. Cost Effective Deployment: What’s New About Small Cells?Macro cells Small cells Core CoreLots of aggregation in Little aggregation in Many morethe RAN the RAN siteswww.cbnl.com Commercial in confidence 11
  12. 12. Cost Effective Deployment: Coping with Many More SitesSmall cells • Three major determinants of solution cost: • Frequency • Topology Core • Licensingwww.cbnl.com Commercial in confidence 12
  13. 13. Cost Effective Deployment: Cost versus Frequency Volume Cost: RF Power Amplifier$160 • RF parts get significantly$140$120 more expensive at high$100 $80 frequencies $60 $40 • e.g. 71—76GHz PA is 5× $20 $0 the cost of a 16—33GHz PA 0 20 40 60 80 100 at the same volume Volume Cost: Low Noise Amplifier$160 • Low yield, demanding$140$120 device geometry, less$100 $80 volume, awkward packages $60 $40 • Reflected in equipment $20 $0 costs! 0 20 40 60 80 100 Frequency (GHz) Sources: Hittite Microwave Corp, Digikeywww.cbnl.com Commercial in confidence 13
  14. 14. Cost Effective Deployment: Less is MorePoint-to-point Topology • P-P topologies (star, ring, tree) need 2 ODUs per link • Multipoint needs a single sectoral ODU and one directional ODU per link • Mean number of links perMultipoint Topology multipoint sector is 4: 5 ODUs with multipoint 8 ODUs with P-P • 40% fewer ODUs deployed: significant cost savingwww.cbnl.com Commercial in confidence 14
  15. 15. Cost Effective Deployment: The Licensing Continuum • Regulator ‘round-trip time’ Link Licensed and high per-link license fees mean that: • Traditional, link-licensed microwave is too expensiveCost per Area Licensed link and too slow for small cells Light Licensed • Area licensed, light licensed and unlicensed are Unlicensed all workable • None is completely “free” Bureaucracy per link due to internal coordination www.cbnl.com Commercial in confidence 15
  16. 16. Cost Effective Deployment: AggregationMacro cells Small cells Core CoreLots of aggregation in Little aggregation in Many morethe RAN the RAN siteswww.cbnl.com Commercial in confidence 16
  17. 17. Why Does Aggregation Matter? • Mobile backhaul traffic is already quite bursty, because it is data dominated: HSPA+ Macro Node B backhaul traffic Peak: 23.31 Mbps Mean: 5.54 Mbps Ratio: 4.20 MbpsMbps www.cbnl.com Commercial in confidence 17
  18. 18. Bursty Traffic is Hard to Carry Efficiently mean channel utilisation 1 • Efficiency = = = 25% average peak channel capacity peak to mean ratio HSPA+ Macro Node B backhaul traffic Peak: 23.31 Mbps Mean: 5.54 Mbps Ratio: 4.20 MbpsMbps www.cbnl.com Commercial in confidence 18
  19. 19. Looking at Data… 60s Resolution mean channel utilisation 1 • Efficiency = = = 25% average peak channel capacity peak to mean ratio HSPA+ Macro Node B backhaul traffic Peak: 23.31 Mbps Mean: 5.54 Mbps Ratio: 4.20 MbpsMbps www.cbnl.com Commercial in confidence 19
  20. 20. Looking at Data… 15m Resolution mean channel utilisation 1 • Efficiency = = = 28% average peak channel capacity peak to mean ratio HSPA+ Macro Node B backhaul traffic Peak: 20.03 Mbps Mean: 5.54 Mbps Ratio: 3.62 MbpsMbps www.cbnl.com Commercial in confidence 20
  21. 21. Looking at Data… 1h Resolution mean channel utilisation 1 • Efficiency = = = 37% average peak channel capacity peak to mean ratio HSPA+ Macro Node B backhaul traffic Peak: 15.04 Mbps Mean: 5.54 Mbps Ratio: 2.71MbpsMbps www.cbnl.com Commercial in confidence 21
  22. 22. Small Cell Backhaul Traffic Live small cell network • Much higher peak-to-mean (as expected) Peak: 32.67 Mbps Mean: 1.37 Mbps Ratio: 23.85 Mbps • A dedicated (point-to-point) tail link in this example would have 4% utilisation • Does this matter if theMbps spectrum is unlicensed? • Yes: this figure is the utilisation of the expensive box at each end as well! www.cbnl.com Commercial in confidence 22
  23. 23. Multipoint Backhaul: Packet Switched not Circuit SwitchedMbps Mbps• Point-to-point links are statically provisioned circuits• Packet switching (multipoint) much more efficient for data• Statistical multiplexing gain increases in small cell networkswww.cbnl.com Commercial in confidence 23
  24. 24. Multipoint Backhaul for Small Cells: Less Waste, More GainStatistical multiplexing gain Peak-to-mean ratio of backhaul traffic • Multipoint efficiency advantage increases as traffic becomes more bursty (like in a small cell network) www.cbnl.com Commercial in confidence 24
  25. 25. Multipoint Backhaul for Small Cells: Less Waste, More GainStatistical multiplexing gain Nodes per multipoint backhaul sector • Multipoint efficiency advantage increases as network gets denser (like in a small cell network) www.cbnl.com Commercial in confidence 25
  26. 26. Current CBNL Small Cell Activities • Building on years of macro backhaul experience CBNL are deploying and trialling small cell backhaul with numerous operators and vendors LTE Picocell Metro lightRadio Antennas WiFi VectaStar Backhaul VectaStarVectaStar BackhaulBackhaul www.cbnl.com Commercial in confidence 26
  27. 27. Conclusions •Small cell backhaul is different: • Good end-user quality of many more cells to backhaul, non- experience requires much more traditional locations and even backhaul capacity than there is low burstier data frequency backhaul spectrum • Both microwave and millimetre • Multipoint microwave for small cell wave, P-P and multipoint, can “do tail links offers significant cost the job” for small cell backhaul savings through higher utilisation of equipment and spectrumVectaStar from Cambridge Broadband Networks is the market leader in multipoint microwave cbnl.com/smallcells 27

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