vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF ABBREVIATIONS
xii
INTRODUCTION
1
1.1
Motivation and Background
1
1.2
Problem Statement
4
1.3
Project Objectives
5
1.4
Scope of the Project
6
1.5
Thesis Organization
6
LITERATURE REVIEW
8
2.1
Introduction
8
2.2
Cognitive Radio Networks
8
2.3
Cognitive Radio Network Architecture
10
viii
2.4
2.5
2.3.1 Spectrum Sensing
12
2.3.2 Spectrum Decision
13
2.3.3 Spectrum Sharing
14
2.3.4 Spectrum Mobility
15
Opportunistic Spectrum Sharing Model
16
2.4.1 Without Forced Termination
17
2.4.2 With Forced Termination
18
An Overview of IEEE 802.22
18
2.5.1 Physical (PHY) Layer For WRAN
21
2.5.1.1
Symbol Description
22
2.5.1.2
Data Rates
23
2.5.1.3
Physical Layer Functional Block Diagram
24
2.5.2 WRAN Medium Access Control (MAC) Layer
2.6
3
26
2.5.2.1
General Superframe Structure
27
2.5.2.2
Superframe Structure For Normal Mode
27
WRAN Quality of Service Classes
29
2.6.1 Unsolicited Grant Services (UGS).
30
2.6.2 Extended Real-Time Polling Services (ertPS)
31
2.6.3 Real-Time Polling Services (rtPS).
31
2.6.4 Non-Real-Time Polling Services (nrtPS)
31
2.6.5 Best Effort Services (BE)
32
2.7
Scheduling policies for Wireless Networks
32
2.8
Related Work On Scheduling In Cognitive Radio Network
34
2.9
Summary
37
COGNITIVE RADIO SYSTEM MODEL
38
3.1
Introduction
38
3.2
Network Architecture
39
3.3
PU Activity model
40
3.3.1 PU Activity Log File Format
41
3.3.2 Link-Layer Frame Structure
44
3.4
CRU traffic Model
45
3.5
Summary
46
ix
4
CHANNEL AVAILABILITY AND QUEUING AWARE
47
EARLIEST DEADLINE FIRST (CAQA-EDF)
SCHEDULING ALGORITHM
4.1
Introduction
47
4.2
Channel Availability and Queuing Aware Earliest Deadline
48
First (CAQA- EDF) Scheduling Algorithm
4.3
4.4
4.5
5
6
CAQA-EDF Buffer Selection
49
4.3.1 BE Traffic Differentiator
50
4.3.2 nrtPS Traffic Differentiator
50
4.3.3 Delay Sensitive Application Differentiator
51
CAQA-EDF Packet Scheduling Mechanism
52
4.4.1 CAQA-EDF Slot Allocation Mechanism
53
Summary
55
SIMULATION RESULT AND PERFORMANCE ANALYSIS
56
5.1
Introduction
56
5.2
Simulation Setup
56
5.3
Performance Analysis
59
5.3.1 Delay Analysis
59
5.3.2 Throughput Analysis
62
5.3.3 Fairness among SU traffic
67
CONCLUSION AND FUTURE WORK
71
6.1
Conclusion
71
6.2
Future Work
72
REFERENCES
73
x
LIST OF TABLES
TABLE NO.
TITLE
PAGE
Dynamic Frequency Selection timing requirements in
IEEE 802.22
21
2.2
System parameters for WRAN
22
2.3
OFDM parameters for the three channel bandwidths
23
2.4
Physical Modes and their related modulations, coding
rates and data rates for TCP = TFFT/16
Simulation parameters and settings
24
2.1
3.1
58
xi
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Spectrum utilization
2
2.1
A structure of the Cognitive Radio Network
10
2.2
The Cognitive Radio Network architecture
11
2.3
Timing for sensing mechanism in IEEE 802.22
20
2.4
Transmitter and receiver block diagram for the OFDMA
2.5
General Superframe structure WRAN 802.22
25
28
2.6
Time/Frequency structure of a MAC frame
29
3.1
39
3.2
Illustration of a single cell cognitive radio network with
centralized control
ON-OFF model
3.3
PU Activity flow chart
44
3.4
Link-layer frame structure for CRU
45
4.1
49
4.2
Flow chart for CAQA-EDF scheduling algorithm in
CRN
CAQA EDF buffer selection algorithm
4.3
CAQA -EDF slot allocation algorithm
54
5.1
Packets arrival and departure time at Pon  0.2
60
5.2
Packets arrival and departure time at Pon  0.4
61
5.3
Packets arrival and departure time at Pon  0.6
61
5.4
Effect of Pd on Throughputs performance
62
5.5
Effect of Pon on rtPS Throughput performance
63
5.6
Effect of Pon on BE Throughput performance
64
5.7
Throughput performance with respect Pon  0.2
65
5.8
Throughput performance with respect Pon  0.4
66
5.9
Throughput performance with respect Pon  0.6
67
40
52
xii
5.10
Fairness among service flows when Pon  0.2
68
5.11
Fairness among service flows when Pon  0.4
69
5.12
Fairness among service flows when Pon  0.6
70
xiii
LIST OF ABBREVIATIONS
BE
-
Best Effort
BS
-
Base Station
CAQA
-
Channel Availability and Queuing Aware
CBR
-
Constant Bit Rate
CCTT
-
Channel Closing Transmission Time
CDT
-
Channel Detection Time
CID
-
Connection Identifier
CMT
-
Channel Move Time
CP
-
Cyclic Prefix
CPE
-
Customer-Premises Equipment
CR
-
Cognitive Radio
CRBS
-
Cognitive radio base station
CRN
-
Cognitive radio network
CRU
-
Cognitive radio user
CTMC
-
Continuous Time Markov Chain
DFS
-
Dynamic Frequency Selection
DL
-
Downlink
DSA
-
Dynamic Spectrum Access
DSM
-
Dynamic Spectrum Management
DSS
-
Dynamic Spectrum Sensing
EDD
-
Earlier Due Date
EDF
-
Earlier Deadline First
ertPs
-
Extended Real Time Polling Service
FCC
-
Federal Communication Commission
xiv
FIFO
-
First In First Out
FFT
-
Fast Fourier Transforms
FTP
-
File Transfer Protocol
FUSC
-
Fully Used Sub Channel
HTTP
-
Hyper Text Transfer Protocol
IDT
-
Incumbent Detection Threshold
ISI
-
Inter-Symbol Interference
MAC
-
Medium Access Control
NPEDF
-
Non-Preemptive Earliest Deadline First
nrtPs
-
None Real Time Polling Service
OFDM
-
Orthogonal Frequency Division Multiplexing
OSA
-
Opportunistic Spectrum Access
PEDF
-
Preemptive Earliest Deadline First
PP
-
Poisson Process
PU
-
Primary user
QAM
-
Quadrature Amplitude Modulation
QoS
-
Quality of Service
QPSK
-
Quaternary Phase Shift Keying
RR
-
Round Robin
rtPs
-
Real Time Polling Service
SCH
-
Superframe Control header
SDR
-
Software defined radio
SF
-
Service Flow
SFID
-
Service Flow Identification
STE
-
Shortest Time to Extinction
SU
-
Secondary user
UGS
-
Unsolicited Grant Service
VBR
-
Variable Bit Rate
VC
-
Video Conference
VoIP
-
Voice-Over- IP
WFQ
-
Weighted Fair Queuing
WRAN
-
Wide Range Area Network