Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

A Case for Generic Interfaces in Cognitive Radio Networks

Vinay Kolar, Petri Mähönen, Marina Petrova, Janne RiihijärviRWTH Aachen University

Germany

Mahesh Sooriyabandara, Tim FarnhamToshiba Research Europe Limited,

United Kingdom

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Overview

• Motivation• Research objectives• Approach

– Architecture– Design

• Link layer interfaces• Network level interfaces• Application interfaces

• Conclusions and outlook

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Motivation

• Capabilities of CRNs: Agile radios, powerful optimisation

• But, solutions are infeasible at a system level– Heterogeneity: Portability, stakeholder cooperation– Harder to express application needs– Higher development cost and skill-requisite

• Direct impact:– Realization of cognitive radio network systems is harder. – Weak motivation for business cases. – Development is hindered

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Research Objectives

• Develop Generic APIs for Cognitive radio network systems

• Identify parameters and functionalities at different layers– Should help cross-layered solutions

• Classify the interfaces and map them to stakeholders

• Propose system architecture and design a proof-of-concept solution

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

System Architecture

• Generic APIs in a system

– How and where?

• Identify heterogeneity– Functionality– Stakeholders

Transport

Application

RadioLink

NetworkCognitiveResourceManager

CAPRI

GENI

ULLA

Layers Functionality Stakeholders Nomenclature

Radio, Link Handshake between immediate neighbours

Device manufacturer Unified Link Layer API (ULLA)

Network, Transport

Network level coordination

Service provider,

Operating system

GEneric Network Interface (GENI)

Application Various QoS demands Product providers, Zillions of users

Common Application Program Requirement Interface (CAPRI)

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Design – ULLA

• ULLA Core– ULLA Query processing:SELECT interfaceId FROM Link WHERE jitter < 2ms

– ULLA command processing:UPDATE Link SET modulation=BPSK WHERE dest=nodeB

– ULLA event handling:Notify when link attribute matches a subscription request

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Design – GENI

• Captures the notion of network and transport layer

– New provider and information classes– Query and command similar to ULLA

UPDATE Conn SET tcpFlavour='reno' WHERE dest=nodeB

• Provide transparency for distributed operations – Common control Channel – Propagate queries to other nodes, collect and

merge results

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

CAPRI

• Utility maximization is a popular theoretical problem– e.g. General Network Utility Maximization (GNUM)

• Goal: Realize them in systems for providing QoS

• Each application specifies its utilityattach_utility(utilitySpecification, id)

utilitySpecification = "minimize (alpha*delay + (1-alpha) throughput)", "delay < 10ms"

id = unique identifier for the application (e.g. process id)

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

CAPRI

• Utility specification– Express simple mathematical expressions in a textual format

• CAPRI completes the formulation of the the overall optmisation problemMaximize/Minimize <utlitySpecification>such that<application Constraints><system Constraints><policy Constraints>

• Provide macros for common utility specification for easing development costs

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Conclusion and outlook

• Proposed architecture and functionality of generic interfaces

– Enables realism– Enhances portability– Cuts down development costs

• Identified and mapped stakeholders as one of the key consideration for interface design

– New business opportunities through cooperation– Stakeholders can still protect proprietary functionality

• Overall effort towards bringing in realism and ease in development of cognitive radio network systems

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Future Work

• Immediate goals: – Refine CAPRI by enabling rich mathematical constructs– Sniffing and measuring key parameters (at all layers)

• Short-term goals:– Building an intelligent Cognitive Resource Manager that

includes Generic Interfaces as a sub-component

• Long-term:– Providing necessary functionalities for specific forms of

cognitive radio networks– Realizing commercial deployments

Session 3a, 10 June 2009 ICT-MobileSummit 2009 Copyright 2009 ARAGORN project

Questions?

• And my thanks to all ARAGORN members