XG Communications Program Information Briefing

1. Preston Marshall DARPA ATO Program Manager September 2004 ITU Study Group 8 XG Communications Program Information Briefing

2. 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 Approved for Public Release - Distribution Unlimited

3. XG Program Components Measurements Policy - Based Controls Measurements 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 Approved for Public Release - Distribution Unlimited

4. 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 Approved for Public Release - Distribution Unlimited

5. Top-Level Functional Architecture System Policy Policy Reasoner System Strategy Reasoner Radio Platform Sense Transmit Accredited Policy Device Configuration Approved for Public Release - Distribution Unlimited

6. Top-Level CONOPS RF Resource Request Develop Request Process Request Determine Opportunities Select Opportunities RF Transmit Plan Bound: Yes/No Unbound: Binding Constraints Approved for Public Release - Distribution Unlimited

7. 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 Approved for Public Release - Distribution Unlimited

8. 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? Approved for Public Release - Distribution Unlimited

9. Levels of Policy Regulation Interference Prevention National National Gov’t Non-Gov’t DoD Services Agencies Commercial & Civil Owners QOS, Cost Optimization Unit Unit User User User User User Regional Policy Authority Policy Focus Ontology-Based Policy Controls Enable Combining and Processing Rules From Multiple Authorities Approved for Public Release - Distribution Unlimited

10. Dimensions of Policy Definition Radio-Specific Policies Spectrum Regulatory Policies Network-Specific Policies Approved for Public Release - Distribution Unlimited

11. 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 XG Policy Language Technology Independent Mathematical Rigor and Logic Approved for Public Release - Distribution Unlimited

12. Technology and Policy Evolution Operating Area • 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 Approved for Public Release - Distribution Unlimited

13. 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 Approved for Public Release - Distribution Unlimited

14. 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, API’s, 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@darpa.mil • List Server: http://list.ir.bbn.com/mailman/listinfo/xg-public • Technical – Not Regulatory Process Approved for Public Release - Distribution Unlimited

15. 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 Approved for Public Release - Distribution Unlimited

16. 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 Lab Demos Final Demo Approved for Public Release - Distribution Unlimited