The document discusses the heterogeneous wireless future and the implications of increased spectrum sharing. It argues that no single wireless platform will dominate due to the scarcity of radio frequency spectrum. Spectrum must be shared more extensively across services, networks, and infrastructure using software defined radio and cognitive radio technologies. These technologies are essential enablers of dynamic spectrum access and more flexible spectrum management approaches. The future involves greater end-user control over wireless networks and specialized networks operating alongside more integrated platforms.

1. Heterogeneous Wireless Future:
Business & Policy Implications
William Lehr John Chapin
wlehr@mit.edu jchapin@mit.edu
Computer Science and Artificial Intelligence Laboratory
Research Laboratory of Electronics
Massachusetts Institute of Technology
First IBBT-MIT Joint Workshop on
Cognitive Radio Standardization & Markets
Brussels, Belgium May 11, 2009
© Lehr & Chapin, 2009

2. Outline
Wireless future is heterogeneous (no single platform will dominate)
Spectrum must be shared much more intensively (aka DSA)
Software defined & cognitive radio are key enabling technologies
© Lehr & Chapin, 2009 2

3. From: Lehr & Chapin (2009), "Rethinking wireless broadband platforms"
Wireless Platform Vision: Same as Wired (?)
Mobile Voice Mobile TV Mobile Data
L3 Net Switched Voice 1way Broadcast IP
L1/2 Link GSM or equiv MediaFLO or DVB HSPA or 1xEVDO
Media 2G Spectrum Dedicated spectrum 3G Spectrum
Triple play bundle, separate networks → LTE or other 4G integrated network
Application Voice Internet Video Data
L3 Net IP
L1/2 Link LTE, WiMax, or equivalent
Media Operator’s licensed spectrum (across all bands)
© Lehr & Chapin, 2009 3

4. Wireless evolves to heterogeneous networks…
Wired Wireless Implication for wireless
Capacity Abundant Scarce RF strictly limited.
Topology Point-to-point Broadcast Few v. many. Lower entry costs.
Low/Hi power architectures.
Reliability Reliable Unreliable Propagation variability favors
specialized wireless networks.
Mobility Fixed Mobile End-user can select network,
have multiple providers.
Layering Effective Inefficient Cross-layer design important.
Bus Model Carrier-centric Mixed Wireless supports end-user
provided, ad hoc, or mesh also
Scarcity of RF spectrum is key difference….
© Lehr & Chapin, 2009 4
From: Lehr & Chapin (2009), "Rethinking wireless broadband platforms"

5. Wireless Data Trends
Terabytes
4,000
3,000 3G
2,000
2G
1,000
0
Source: Dick Lynch, CTO Verizon, February 2009
2004 2008
© Lehr & Chapin, 2009 5

6. Predicted spectrum needs by 2020
Spectrum requirements (MHz) for cellular voice and data
Allocations must be below 5 GHz
Europe, Middle
2020 East, and Africa Americas Asia-Pacific, Iran
Demand Predicted
2006 Increase 2006 Increase 2006 Increase
model Total
Low 1280 693 587 723 557 749 531
High 1720 693 1027 723 997 749 971
Analysis included
• Traffic projections and requirements
Source: ITU-R Working Party 8F • Service and application requirements
Report M.2078 [IMT.ESTIMATE] • Spectrum efficiency
• Radio transmission characteristics
May, 2006 • Harmonized use of spectrum
• Technical solutions to facilitate global roaming
• Sharing and compatibility analysis
© Lehr & Chapin, 2009 6

7. Future is shared spectrum
decoupling of spectrum frequencies
from applications (& infrastructure)
Domain Trend is towards Drivers and Enablers
Technology Frequency agility Smart radio systems
(capabilities) Improved capability for OFDM and spread spectrum
spectrum sharing Growth of fast data networks
Revenue 24/7 availability Heterogeneous networks
(customer experience) Simplicity of use 3G+WiFi, wireless+wired
global roaming
Seamless mobility
Costs Lower costs per byte Bursty traffic, Multimedia
(provisioning) Intermodal competition services, Fat-tailed usage
profiles, Mergers & Acquisitions
Policy Reduction of artificial Technology neutrality
(spectrum reform) scarcity Market-based licensing
Unlicensed spectrum mgmt
© Lehr & Chapin, 2009 7

8. SDR & Cognitive Radio: essential for DSA
Software Defined Radio and CR are independent
CR behavior most likely implemented using SDR techniques, but need not be.
Software radio => implementation techniques to add flexibility to a radio
Less expensive than hardware for design, deploy, reconfigure, upgrade
Allows reuse of generic modular components for different radio designs/standards
Cognitive radio => control techniques for exploiting radio flexibility
CR system makes radio operation “context” dependent (location, use, congestion)
Expands sharing options
Both SDR and CR are key enablers of DSA future
Many more options for spectrum sharing
Facilitates infrastructure and handset unbundling  componentization
Enables “future-proofing” (adaptability, interoperability)
© Lehr & Chapin, 2009 8

9. Handset economics
Forces favoring harmonization (eg. LTE everywhere)
Mobile handset cost economics dictate global scale
Service bundling/convergence: single device/”one-stop” shopping
Forces opposing harmonization
Application heterogeneity
Internet of things (iPOD, Kindle, sensors, smart cards)
Smart phones (v. globalization)
Technology evolution
Multiple radios-on-a-chip = less need for a single air interface
Likely future
Realize scale/scope economies at component level
Re-use/re-configure generic components into new radios
SDR/CR enable specialized networks with common hardware
and hide diversity of networks from users
© Lehr & Chapin, 2009 9

10. End-user control
Wireless heterogeneity => greater role for end-user
Selecting device, network, service
Consistent with trends elsewhere: self-service retail/gas/customer-
service, “Market of one” customization, end-user content
SDR and CR increase end-user role
Enable (more) decentralization of spectrum management
Unbundle services from infrastructure from spectrum
Interoperability through “gateways” instead of standards
Can imagine “infrastructure-less” wireless networking
Ad hoc/mesh, community (Muni-), end-user deployed
Flexible, self-install, self-configure
Networks not dumb, but edges are definitely smarter
© Lehr & Chapin, 2009 10

11. Implications for policy and business
Policy
• SDR/CR are critical technologies: policy should promote (or
at least not hinder) earlier commercialization.
• Don’t need to wait to harmonize.
• Let a hundred flowers blossom: too early to know what the
right model for SDR/CR is.
• Careful with definitions…
• e.g., CPC good option, but bad idea to mandate
• Minimize certification hurdles (consider wider range of enforcement
options – e.g., Chapin & Lehr (2007) “Time Limited Leases”)
Business
• New business models, new markets, new competition
• Be spectrum agile…
© Lehr & Chapin, 2009 11

12. Key takeaway points
Wireless future is heterogeneous (scarcity is key driver)
Spectrum must be shared much more intensively
across services, networks, infrastructure
across regulatory models (dedicated+shared)
SDR & CR are both critical path technologies
Thanks for your attention!
William Lehr John Chapin
ifaq.wap.org
wlehr@mit.edu jchapin@mit.edu
© Lehr & Chapin, 2009 12

13. Outline
Wireless future is heterogeneous (no single platform will dominate)
LTE is part of future, but not the future
Many types of specialized wireless access networks
Why? Physics, fundamental scarcity, history
(see, Lehr & Chapin (2009), “Rethinking Wireless Broadband Platforms”)
Spectrum must be shared much more intensively (aka DSA)
Among applications, users, networks, and operators
Single networks: use dedicated + shared
Shared can be non-cooperative (TVWS) or cooperative
(see Chapin & Lehr (2007), “Path to market success for Dynamic Spectrum Access Technology”)
Software defined & cognitive radio are key enabling technologies
Necessary but independent concepts
Implications for:
Handset economics
End-user choice/control
Interconnection/interoperability
© Lehr & Chapin, 2009 13