2. The Myth of Spectrum Scarcity: Hybrid Networks and Opportunistic Access to the Airwaves eComm Emerging Communications Conference October 30, 2009 Michael Calabrese Director, Wireless Future Program New America Foundation calabrese@newamerica.net

3. Wireless Future Program Mission: Pervasive Connectivity Universal Ubiquitous Affordable Means: Openness Open Spectrum Open Networks Open Technologies

4. Conventional Wisdom: Spectrum is Scarce

5. Exploding Demand for Mobile Data- iPhone: Canary in the Spectrum Coal Mine - Total US mobile data demand: 16 to 366 terabytes by 2013 (Cisco)

6. Reality: Spectrum Licenses are Scarce

7. Reality: Spectrum Capacity is Abundant (90% not in use)

8. “The spectrum is completely, unbelievably underutilized. It’s terribly inefficient and grossly unfair to rural America”– Tri-County Telephone Co-Op, Wyoming

9. More Conventional Wisdom:Meet Mobile Data Demand with Spectrum Auctions US Wireless Industry (CTIA): Petitions FCC for 800 Additional MHz of exclusively-licensed spectrum This is based on ITU Projections that advanced market economies require total allocations of roughly 1,300 MHz by 2015 and 1,720 by 2020 (vs. 500 MHz today in U.S.)

10. ITU Spectrum Requirements for Competitive Markets is Higher StillSource: ITU, Estimated total spectrum requirements for future development of IMT-2000 and IMT-Advanced (2006).

11. More Spectrum is Just One Part of the Solution to Exploding Mobile Data Demand Increase spectrum access Shrink cell sizes (spectrum re-use) More effective use of wired backhaul (offload data traffic) More efficient/cooperative wireless architectures and technologies

12. Exclusively-Licensed, Hub-Spoke, Tower-Based Model is Not Sustainable . . . Clearing incumbents off 800+ MHz not feasible Physical limits on cell capacity - ITU estimate assumes 4G at 75% of theoretical limit (Shannon’s Law) Limits on how close carrier-owned transmitters and backhaul can be brought to individual users - Total U.S. cell sites increased only 14% over past two years

13. . . . Nor Desirable . . . Most mobile data should flow short distances over shared spectrum to consumer-owned or shared backhaul Consumers should not pay for data transport over expensive carrier spectrum/infrastructure Carriers evolve into ‘quality of service’ component of hybrid networks - Consumers pay only for needed mobility, remote access and latency-sensitive aps

14. Carriers are Increasingly Offloading Data Traffic to WiFi Signs of the Times: AT&T: 25.6 million WiFi connections through June > double all of 2008. T-Mobile offering office and home service that default to WiFi, potentially replacing wired lines (but charging for ‘free’!) Devicescape survey: 81% of smartphone users prefer using WiFi for mobile browsing/email

15. Far More Spectrum Can be Freed Via Opportunistic Access by Cognitive Radios Tragedy of the Anti-Commons: Spectrum is infinitely renewable – bandwidth not used at any place/time is wasted. A band can be ‘white’ (underutilized) and shared on a number of dimensions: Geographically (not in use everywhere) Time (not continually in use) Spatially (in the air, not on the ground) Angle of Reception (directional or ‘smart antennas’)

16. Underlay: Sharing Underutilized Frequency Band Example: WiFi Backhaul Shares Upper 5 GHz with Military Radar – Listen Before Talk Sensing

17. Overlay: Filling Unoccupied FrequenciesExample: TV Guard Bands (“White Space”)

18. TV WS: Opportunistic Access to ‘Swiss Cheese’ Spectrum Majority of interleaved (TV WS) channels become useable on opportunistic, license-exempt basis if: -- Cognitive Radio: Occupied channel detection and frequency hopping via . . . - Geolocate database: Lists permitted channels, or - Listen-Before-Talk Sensing -- Low Power: - FCC (40 mW for mobile on channels adjacent to DTV) - OfCom (variable power when rely on geo-database) Some Benefits: - Spectrum efficiency: frequency re-use at low power - National availability (even in large Metro markets) - No permanent assignment channels: bands and access conditions changeable with CR

19. FCC’s TV White Space Order Adopted Nov. 4, 2008: 5-0 Vote Unlicensed access to all unassigned channels - Mobile: 40mW (or 50mW non-adjacent) - Fixed Access: 4 W (non-adjacent only) Devices must have GPS & Check Location Against Online Database of Licensed transmitters - Reliance on sensing/DFS unresolved

20. UK and EU ‘Digital Dividend’ OfCom(July ‘09): Adopts license-exempt access to ‘interleaved’ channels by CRs relying on geo-permission database ECC/CEPT Working Group (Oct. ‘09): Draft Report on technical and operational requirements for CR systems in the ‘white spaces’ (WG-SE43) “[T]he digital dividend presents an opportunity to introduce a more flexible spectrum approach, giving Europe a competitive edge over other regions.” --EC Consultation Document, July ‘09

21. Future: Opportunistic Access Let ‘Smart Radios’ Operate Around the Dinosaurs Clarify License Rights: Protect only incumbent services, not unused spectrum capacity Open unused spectrum for non-interfering use, millisecond to millisecond

22. Rules of the Road: Like Public Highways and Ocean Shipping Lanes, Exclusive Licenses are Inefficient for Low-Power Use of the Airwaves

23. Next Steps to Open Spectrum Inventory the Airwaves In U.S., legislation pending to survey assigned and actual uses, frequency-by-frequency, to identify ‘white spaces’ and where sharing is possible Actual use measurement & monitoring is key – and increasingly affordable Add Available Frequencies to TV White Space Database Devices with GPS and/or sensing can identify open frequencies locality by locality. Software defined radio allows devices to dynamically hop across a very wide range of frequencies: opportunistic access.

24. Market-Based Sticks & Carrots: Levy annual lease fees on all government and private license holders that do not open unused capacity for opportunistic sharing. At a minimum, require license holders to take micro-payments for unused bandwidth.