A Wireless Tipping Point,
Open Spectrum Implications



         Brough Turner
    http://www.broughturner.com
1920s consumer radio receivers
                                         Philips 2501
 Very early tech, i.e. primitive
    ...
Radio Spectrum Occupancy

 Urban areas, 30 MHz to 3 GHz. Above 3 GHz mostly vacant.




    As measured by Shared Spectrum...
New York City
Unusually heavy communications during Republican National Convention
August 30 to September 3, 2004 brought ...
Most spectrum idle most of the time
            806 – 928 MHz




            Dublin Ireland Spectrum Occupancy Measuremen...
Most spectrum idle most of the time
            806 – 928 MHz




            Dublin Ireland Spectrum Occupancy Measuremen...
Most spectrum idle most of the time
            806 – 928 MHz




            Dublin Ireland Spectrum Occupancy Measuremen...
Open Spectrum
Noise, Interference, Chaos … !
   How could it work?




                                 8
Open Spectrum
Noise, Interference, Chaos … !
   How could it work?


Focus on Receiver Performance




                   ...
Visible light analogy
               Our vision system
               (eyes + visual cortex)
               = extremely ef...
Spatial discrimination




For Humans:
~ 1/60th of a degree

                         11
Enormous knowledge base
Detailed catalog of the characteristics of most
potential visible light sources




              ...
Leveraging source motion
to increase received information …




                                     13
1920: Regulation made sense




                              14
1920: Regulation made sense
2009: We’ve come a long way




                              15
1920: Regulation made sense
2009: We’ve come a long way



Shared use of unlicensed spectrum
Enormous value creation



  ...
1920: Regulation made sense
2009: We’ve come a long way



Shared use of unlicensed spectrum
Enormous value creation



  ...
Open spectrum prospects
Regulation    Vested interests

TV White Spaces
             Crippled for now…




               ...
Open spectrum prospects
Regulation    Vested interests

TV White Spaces
             Crippled for now…

   What about high...
Spectrum Myth
TV Spectrum is “beach front” spectrum




                                        20
Spectrum Myth
TV Spectrum is “beach front” spectrum




 Based on legacy technology, not physics!
   Travels farther – No!...
Refraction and reflections

          More at shorter wavelengths




          Multiple versions   “Multipath”
          ...
MIMO: Multiple Input Multiple Output
Multiple paths improve link reliability and
increase spectral efficiency (bps per Hz)...
Rich Indoor MIMO Multipath




           Source: Fanny Mlinarsky, Octoscope
                                             ...
Municipal Multipath Environment




            Source: Fanny Mlinarsky, Octoscope   25
TVWS – Beach-front Property?
MIMO antenna separation
>= ½ wavelength
 2.1 meters at 70 MHz
 21 cm at 700 MHz


But
 2.5 cm...
Multiple radios per chip
Like CPU cores …            Intel

  2x2 MIMO – 2008
  4x4 MIMO – 2010-11
then
                  ...
Beamforming
2014: >200 Mbps Wi-Fi to >1 Km
at mass market prices ?



4x4 MIMO
with 12-16
 antenna
 elements




         ...
Beamforming
2014: >200 Mbps Wi-Fi to >1 Km
at mass market prices ?



4x4 MIMO
with 12-16
 antenna
 elements




         ...
Gaining spectrum for open use

Seeking only “Secondary access”
 No interference with existing users
   Geographic database...
Wi-Fi 802.11y - 2008
Rich protocol set for “secondary access”




                                           31
Open spectrum

Wireless tipping point ahead
Focus on spectrum blocks above 3 GHz
  More access at 5 GHz (4.9-6 GHz)
  Anyt...
Thank You


 Brough Turner
 broughturner@gmail.com
 rbt@ashtonbrooke.com
Credits
 Beyond those noted on individual pages…
    Images…
    Office building facade: http://commons.wikimedia.org/wiki...
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A Wireless Tipping Point, Open Spectrum Implications

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As presented at eComm Europe, October 2009.

Are we using radio spectrum efficiently? No. Is this likely to change? Not soon.

"Smart" radios have the potential to support much more efficient and productive use of spectrum, but spectrum regulation is a political issue with well established stakeholders. What's more, our limited experiments with commons-based spectrum management have had widely differing results: WiFi, enormous success; UltraWideBand, disappointment.

WiFi's success happened in "junk" spectral bands where established players weren't interested. That will be difficult to repeat, but Brough will describe some very simple physical principals of radio propagation which, when combined with the next five years of Moore's law progress in semiconductors, suggest a path forward that's very different from TV white spaces. Indeed, the most important result of regulatory decisions on UltraWideBand and TV white spaces is they validate the concept of secondary access.

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A Wireless Tipping Point, Open Spectrum Implications

  1. 1. A Wireless Tipping Point, Open Spectrum Implications Brough Turner http://www.broughturner.com
  2. 2. 1920s consumer radio receivers Philips 2501 Very early tech, i.e. primitive Crystal, Regenerative, Tuned RF … Poor selectivity, low sensitivity, low stability Tuned RF Crystal 2
  3. 3. Radio Spectrum Occupancy Urban areas, 30 MHz to 3 GHz. Above 3 GHz mostly vacant. As measured by Shared Spectrum Company and the University of Kansas Center for Research for the NSF National Radio Network Research Testbed (NRNRT) 3
  4. 4. New York City Unusually heavy communications during Republican National Convention August 30 to September 3, 2004 brought spectrum occupancy up to 13%. 4
  5. 5. Most spectrum idle most of the time 806 – 928 MHz Dublin Ireland Spectrum Occupancy Measurements Collected On April 16-18, 2007 Shared Spectrum Company, www.sharedspectrum.com 5
  6. 6. Most spectrum idle most of the time 806 – 928 MHz Dublin Ireland Spectrum Occupancy Measurements Collected On April 16-18, 2007 Shared Spectrum Company, www.sharedspectrum.com 6
  7. 7. Most spectrum idle most of the time 806 – 928 MHz Dublin Ireland Spectrum Occupancy Measurements Collected On April 16-18, 2007 Shared Spectrum Company, www.sharedspectrum.com 7
  8. 8. Open Spectrum Noise, Interference, Chaos … ! How could it work? 8
  9. 9. Open Spectrum Noise, Interference, Chaos … ! How could it work? Focus on Receiver Performance 9
  10. 10. Visible light analogy Our vision system (eyes + visual cortex) = extremely efficient 400-790 THz receiver The product of years of evolution! 10
  11. 11. Spatial discrimination For Humans: ~ 1/60th of a degree 11
  12. 12. Enormous knowledge base Detailed catalog of the characteristics of most potential visible light sources 12
  13. 13. Leveraging source motion to increase received information … 13
  14. 14. 1920: Regulation made sense 14
  15. 15. 1920: Regulation made sense 2009: We’ve come a long way 15
  16. 16. 1920: Regulation made sense 2009: We’ve come a long way Shared use of unlicensed spectrum Enormous value creation 16
  17. 17. 1920: Regulation made sense 2009: We’ve come a long way Shared use of unlicensed spectrum Enormous value creation Thermex Thermatron RF Dryers 17
  18. 18. Open spectrum prospects Regulation Vested interests TV White Spaces Crippled for now… 18
  19. 19. Open spectrum prospects Regulation Vested interests TV White Spaces Crippled for now… What about higher frequencies? 19
  20. 20. Spectrum Myth TV Spectrum is “beach front” spectrum 20
  21. 21. Spectrum Myth TV Spectrum is “beach front” spectrum Based on legacy technology, not physics! Travels farther – No! Goes thru walls – Not that different… 21
  22. 22. Refraction and reflections More at shorter wavelengths Multiple versions “Multipath” 22
  23. 23. MIMO: Multiple Input Multiple Output Multiple paths improve link reliability and increase spectral efficiency (bps per Hz), range and directionality 23
  24. 24. Rich Indoor MIMO Multipath Source: Fanny Mlinarsky, Octoscope 24
  25. 25. Municipal Multipath Environment Source: Fanny Mlinarsky, Octoscope 25
  26. 26. TVWS – Beach-front Property? MIMO antenna separation >= ½ wavelength 2.1 meters at 70 MHz 21 cm at 700 MHz But 2.5 cm for 5.8 GHz Wi-Fi D-Link DAP-2553 Wavion Networks 26
  27. 27. Multiple radios per chip Like CPU cores … Intel 2x2 MIMO – 2008 4x4 MIMO – 2010-11 then Fujitsu 8 radios, 16 radios?, … what to use the silicon for? Beam-forming ! AMD 27
  28. 28. Beamforming 2014: >200 Mbps Wi-Fi to >1 Km at mass market prices ? 4x4 MIMO with 12-16 antenna elements 28
  29. 29. Beamforming 2014: >200 Mbps Wi-Fi to >1 Km at mass market prices ? 4x4 MIMO with 12-16 antenna elements 29
  30. 30. Gaining spectrum for open use Seeking only “Secondary access” No interference with existing users Geographic database; Listen-before-talk License-exempt stations under positive control of a “lightly” licensed station 30
  31. 31. Wi-Fi 802.11y - 2008 Rich protocol set for “secondary access” 31
  32. 32. Open spectrum Wireless tipping point ahead Focus on spectrum blocks above 3 GHz More access at 5 GHz (4.9-6 GHz) Anything between 6-10 GHz “Secondary use” Light licensing – 802.11y protocols 32
  33. 33. Thank You Brough Turner broughturner@gmail.com rbt@ashtonbrooke.com
  34. 34. Credits Beyond those noted on individual pages… Images… Office building facade: http://commons.wikimedia.org/wiki/User:Beek100 Laptop icon: http://www.flickr.com/photos/ichibod/ Microwave oven: http://www.flickr.com/photos/code_martial/ 802.11n performance in the field http://www.tomshardware.com/reviews/beamforming-wifi-ruckus,2390.html http://www.muniwireless.com/2009/02/23/80211n-dramatically-improves- outdoor-wifi/ 34

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