XG Communications Program Information Briefing

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XG Communications Program Information Briefing
ITU Study Group 8

• Preston Marshall
• DARPA ATO Program Manager
• September 2004

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DARPA XG Program
All Spectrum May Be Assigned, But
XG is Developing the Technology and System
Concepts to Dynamically Access Available Spectrum
Most Spectrum Is Unused!
Goal Demonstrate Factor of 10 Increase in
Spectrum Access
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XG Program Components
Measurements
Measurements
Policy
-
Based Controls
Policy
-
Based Controls
Measurements
Policy
-
Based Controls
Temporal, Spectral,
Temporal, Spectral,
Control of Features,
Control of Features,
Dimensional, Energy
Dimensional, Energy
Priorities, Allocations,
Priorities, Allocations,
Characteristics
Characteristics
Exclusions,
Exclusions,
XG Behaviors
XG Behaviors
XG Behaviors
Communications and
Communications and
Sensor Applications
Sensor Applications
XG Products
XG Products
Transition to User Community
Initial XG Implementation
Initial XG Implementation
Initial XG Implementation
The Primary Product XG Program is Not a New
Radio, but a Set of Advanced Technologies for
Dynamic Spectrum Access
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XG Policy-Based Controls

• XG Being Developed In Advance of Policy Framework
• Implementations Must Fit With National And
  International Regulations
• Algorithms Must be Adaptable
• Regional and operational situations
• Evolving policies
• Policy-Based Metalanguage
• Translates Policy Rules Into Radio Behavior
  Controls
• Decouples XG Technology From Regulatory Process
• Control Operating Rules Based on Policies and
  Situations
• Using Semantic Web Technologies (DAML/OIL/OWL)

Policy-Based Controls Will Draw on Practices
Methodologies Currently Employed Manually by
Spectrum Managers
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Top-Level Functional Architecture
System Policy
Policy Reasoner
System Strategy Reasoner
Radio Platform
Sense
Transmit
Accredited Policy
Device Configuration
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Top-Level CONOPS
RF Resource Request
Develop Request
Process Request
Determine Opportunities
Select Opportunities
RF Transmit Plan
Bound Yes/No Unbound Binding Constraints
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XG Key Principles

• Suitable for Range of Architectural
  Implementations
• Centralized and decentralized
• Identify Interference-Preventing Core Set
• Extensible to other features (subleasing,
  microcharging,...)
• Separate Policies From Engineering
• Avoid advocacy for specific spectrum sharing
  policies
• XG being developed In advance of Policy
  Frameworks
• Provide For Richness/Complexity of Policies
• Regulations neither flat nor hierarchical
• Allow For Diversity of Policy Sources
• Peer-Peer and hierarchical policy authorities
• Enable extension to cognitive optimizing logic

Policy Layer Flexible for Implementations to
Use Without Revisiting for Engineering Policy
Changes
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The XG Problem SpaceHow Do We?
Policy Language Common Approaches that Must Be
Agreed on, and Can be Adopted Widely
Describe Worst-Case Interference?
Infer Ambiguous Policies?
Resolve Inconsistent Policies?
Reflect Nation -Policies?
Reflect Band- Specific Policies?
Abstract Capabilities (Behaviors)
Implementation Design Specific Approaches that
Can be Implemented in Many Ways to Develop Unique
Products
Infer Potential Interference?
Account for Propagation Differences?
Protect Hidden Nodes?
Optimize System Performance?
Measure Instantaneous Spectrum Usage?
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Levels of Policy Regulation
Regional
Policy Authority
Policy Focus
Ontology-Based Policy Controls Enable Combining
and Processing Rules From Multiple Authorities
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Dimensions of Policy Definition
Radio-Specific Policies
Spectrum Regulatory Policies
Network-Specific Policies
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XG Policy Language

• Need to Express Policies In A Way That The Radio
  Can Understand
• Current regulatory policies are implicit in radio
  hardware policy and technology are coupled and
  costly to change
• Need to be able to select and update policies in
  situ
• New locations, updated policies, new
  authorizations, ...
• Web Ontology Language (OWL) Being Used For
  Developing XG Policy Language
• Basis for semantic web technology W3C
  recommendation
• Provides structure and richness needed to express
  policies
• Includes general theorem proving/reasoning
  engines for deductive inference
• OWL Is NOT Another Programming Language
  structured way to build representations of
  knowledge, facts, and rules/policies for machine
  understanding

Technology Independent Mathematical Rigor and
Logic
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Technology and Policy Evolution

• 1. Enhance Policy Flexibility by Opening Up the
  Envelope
• Confidence Gained From Experience

• 2. Increase Capability to Dynamically Sense and
  Adapt
• Faster Spectrum Analyzers, More Instantaneous
  Bandwidth

Dimension 2
Operating Area

• Develop Radios Waveform Standards that Can
  Exploit Sharing Policies
• Wider Coverage, Better Antennas, Adaptive
  Waveforms

Dimension 1
XG Approach Allows the Operating Envelope To
Autonomously Change Over Time as Policies and
Technologies Evolve Independently
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XG Policy Language Features

• Resolve Multiple Sources Of Policy Without
  Causing Failure
• Allows for Multiple Uncoordinated Sources of
  Policy
• Approachable Implementation
• Growing Community Of DAML/OWL Users, Features and
  Authoring Tools
• Class Extensible
• Maximizes Generality and Reduces Complexity
• Everyone Can Extend Policies To Their Needs
• Rapid Adoption Of New Policy Concepts And
  Technologies
• Provable Structure
• Set Theory, Logical Reasoning And Theorem Proving
• Host Implementation Independent
• All Policies Can Run On Any Compliant Device

Transition from Describing Self-Operation to
Defining Effects on Others
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Community Input to XG Protocol Development

• Based on Original ARPA/ Internet Protocol
  Request for Comment Process
• Aspects of XG Standard that Implement
  Interference Trust
• Protocols, APIs, Behaviors, Certificates
• Not Design/Implementation Specific
• Web Sites Set Up to Host Draft Documents and
  Public Discussions
• Users Can Access and Comment on Drafts
• RFC http//www.darpa.mil/ato/programs/XG/rfcs.htm
  
• Comments Accepted at XGProgram_at_darpa.mil
• List Server http//list.ir.bbn.com/mailman/listin
  fo/xg-public
• Technical Not Regulatory Process

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Accomplishments

• Collected RF Environment For Many Scenarios
• Data Being Used As Basis For Phase 2 Design
  Evaluations
• First Version Of Sensor Completed
• Provides Needed Capability For Rapid Wideband
  Sensing
• Next Revision To Explore High-Risk/High-Payoff
  Enhancements
• Three Feasible Designs For Interference
  Avoidance, Network Operation, And Rendezvous
• Nearing Phase 2 Evaluations And Competition For
  Phase 3 Participation
• Policy Language And Radio Interface Defined
• Policy Language RFC v1 Composed And Released
• Extensible to Future Cognitive Technology

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Program Development Plan
FY02 FY03 FY04
FY05 FY06
Policy Language Development
System Integration

System Integration
XG System End-to-End Mobile Demo

Sensing
High Risk Technologies
10X Reuse (Lab)
CDR
10X Reuse Possible
Final Demo
Lab Demos