[Performance Related Security Issues in Cognitive Radio Networks]

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ACKNOWLEDGEMENT

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

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ABSTRACT

In this article, a non-preemptive (NP) mechanism is proposed to improve the quality-of-service (QoS) of secondary users (SUs) in joint leasing and sensing-based cognitive radio networks (CRNs). In this spectrum-sharing mechanism, a primary user (PU) could not forcibly terminate a SU with ongoing transmission. Both the typical preemptive and the proposed NP mechanisms are modeled by multi-dimensional Markov chains with three state variables. A decomposition-approximated method is used to derive the closed-form solutions of the steady-state probabilities in the Markov chains. The analytical results are verified by numerical results. System parameters that affect performance metrics are also investigated in these two mechanisms. The simulation results show that in the proposed mechanism the performance metrics of SUs such as force-termination probability and mean system delay are improved significantly, with an acceptable loss of PUs' QoS in terms of mean waiting time and blocking probability. A QoS tradeoff can be achieved between the primary and the secondary systems. For QoS improvement of SUs, the proposed NP mechanism outperforms the preemptive mechanism in joint leasing and sensing-based CRNs.

TABLE OF CONTENTS

ABSTRACT4

CHAPTER 1: INTRODUCTION7

CHAPTER 2: LITERATURE REVIEW10

From Components to Networks10

Spectrum Policy versus Technology12

Cognitive Networking beyond DSA16

Attacks To Cognitive Radio Networks17

Primary user emulation attacks19

Common control data attack23

False feedback24

Lion attack25

Scope of the attacks26

CHAPTER 4: DESIGN AND IMPLICATION29

Preemptive mechanism31

NP mechanism33

Cognitive Radio Architecture & Design:36

Hardware architecture38

Heterogeneous block-based architecture39

Spectrum Scanning Algorithms:41

Adaptive Network Protocols:42

Baseband Hardware Platform Development44

Methods of obtaining knowledge45

Collecting information from components of CRS45

Geo-location45

Spectrum sensing46

Database access46

Listening to a wireless channel46

Collaboration between different radio systems47

Decision making and Adjustment of operational parameters and protocols48

Methods of decision and adjustment49

Centralized decision making49

Distributed decision making49

Method of adjustment based on SDR reconfiguration50

Method of adjustment based on [CRS component/hardware] reconfiguration50

Summary of the CRS concept51

CHAPTER 4: DISCUSSION AND RESULTS54

Evaluation and Integrated Experiments54

Securing Cognitive Radio55

Jamming countermeasures55

PUEA countermeasures56

OFA countermeasures59

Mitigation of the Lion attack59

General countermeasures62

CHAPTER 5: CONCLUSION64

REFERENCES65

CHAPTER 1: INTRODUCTION

Cognitive radio (CR) has been considered as a viable technique to improve the utilization of spectral resources in a licensed (primary) system. The secondary users (SUs) in the unlicensed (secondary) system are allowed to opportunistically utilize the spectrum holes that are temporarily unoccupied by primary users (PUs). The key enabler is the SU with CR technology, which can sense the spectrum hole and accordingly adjust its transmission parameters. The main idea of CR is that SUs exploit the spectrum holes and take advantage of them opportunistically. Therefore, the spectrum sharing mechanism in CR networks (CRNs) becomes a hot research topic.

According to the literature related to CRNs, previous study on dynamic spectrum access (DSA) can be categorized as sensing-based access ...