vii
TABLE OF CONTENTS
CHAPTER
1
2
SUBJECT
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xi
LIST OF FIGURES
xii
LIST OF ABBREVIATION
xvi
LIST OF APPENDICES
xix
LIST OF SYMBOLS
xx
INTRODUCTION
1.1. Introduction
1
1.2. Problem Statement
3
1.3. Objective of The Research
4
1.4. Scope of The Research
4
1.5. Significance of Project
5
1.6. Thesis Outline
6
LITERATURE REVIEW
2.1. Introduction
7
2.2. IEEE 802.11 Architecture
8
2.2.1.
Autonomous WLAN Architecture
9
viii
2.2.2.
Distributed WLAN Architecture
9
2.2.3.
Centralized WLAN Architecture
10
2.3. IEEE 802.11 Authentication Mechanism
13
2.3.1.
Open-System Authentication
14
2.3.2.
Secure Authentication
15
2.4. Existing Fast Re-authentication techniques
2.4.1.
Context Transfer Method
2.4.1.1.
Related work on CT Technique
20
21
23
2.4.1.1.1. Proactive Neighbor Caching (PNC)
23
2.4.1.1.2. Proactive Key Distribution (PKD)
24
2.4.1.1.3. Selective Neighbor Caching (SNC)
25
2.4.1.1.4. CAPWAP Handover Protocol
26
(CAPWAPHP)
2.4.1.1.5. Adaptive Neighbor Caching (ANC)
28
2.4.1.1.6. Cluster-Chain-based Context Transfer
28
3
(C T)
2.5. Handover Decision
2.5.1.
Related work on RSS-Based Handover
33
35
Decision
2.5.1.1.
Adaptive Preferred-Network Life-
35
Prediction of RSS Transition Pattern
38
Time
2.5.1.2.
2.6. Summary
3
43
METHODOLOGY
3.1. Introduction
44
3.2. Implementation
45
3.3. Testbed Architecture
45
3.4. Flow of Predictive Context Transfer (PCT)
51
3.5. Design Framework of PCT
55
3.5.1.
Handover Threshold in PCT
56
3.5.2.
Early RSS Transition Pattern Technique
57
3.5.3.
Hypothesis of Client’s Moving Weight
61
ix
4
3.6. PCT Framework Design
71
3.7. Summary
74
PERFORMANCE ANALYSIS ON THE PCT
ALGORITHM IN CENTRALIZED ARCHITECTURE
4.1. Introduction
75
4.2. Experiment of Handover Latency
77
4.2.1.
Handover Latency without PCT
4.2.1.1.
Re-Authentication Latency
79
79
Experiment without PCT
4.2.1.2.
Re-authentication Latency Experiment
82
with Error
4.2.1.3.
Comparison of re-authentication
87
The Affect of Distance in Re-
88
latency
4.2.1.4.
authentication Latency
4.2.2.
Handover Latency with PCT
4.2.2.1.
Re-Authentication Latency with PCT
4.3. Experiment for Performance of Handover Decision
4.3.1.
Outdoor Experiment for PCT
4.3.1.1.
Cache Hit: Successful Handover for
91
91
93
96
98
Outdoor Experiment
4.3.1.2.
False Alarm: Unnecessary Handover
99
for Outdoor Experiment
4.3.2.
Indoor Experiment for PCT
4.3.2.1.
Cache Hit: Successful Handover for
100
102
Indoor Experiment
4.3.2.2.
False Alarm: Unnecessary Handover
104
for Indoor Experiment
4.4. Conclusion
105
x
5
CONCLUSION
5.1. Introduction
106
5.2. Recommendation For Future Works
108
REFERENCES
109
Appendices A
114
xi
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Guidance for IP QoS classes
8
2.2
List of functionalities for layer protocol in centralized IEEE
13
802.11
2.3
Summary of context transfer technique for fast re-
30
authentication
2.4
Summary of RSS-based handover decision technique
41
3.1
Testbed hardware and software specification
47
3.2
The optimization results for the client’s MW using MWD for
70
indoor
3.3
The optimization results for the client’s MW using MWD for
71
outdoor
4.1
Experiment parameters and values
94
xii
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Typical topology of a WLAN
2
2.1
Autonomous WLAN architecture
9
2.2
Distributed WLAN architecture
10
2.3
Centralized WLAN architecture
11
2.4
Three architectural of MAC within AP in centralized
12
architecture
2.5
Handover latency components for secure network connection
14
using WPA2-Enterprise
2.6
Timing Diagram for handover process for WPA2-Enterprise
16
authentication mechanism in centralized WLAN architecture
2.7
Security exchange in WPA2-Enterprise
17
2.8
4-way handshake process
19
2.9
Existing fast re-authentication technique in WLANs
20
2.10
Context transfer technique
21
2.11
Proactive Neighbour Caching (PNC) technique
23
2.12
Proactive Key Distribution (PKD) technique
24
2.13
Selective Neighbour Caching (SNC) technique
26
2.14
Association request scenario for local MAC WTPs in
27
CAPWAPHP technique
2.15
Association request scenario for split MAC WTPs in
27
CAPWAPHP technique
2.16
(a) An illustrated neighbour graph; (b) AN illustrated motion
29
example; in the C3T technique
2.17
Network coverage overlap using (a) low handover; (b) high
handover threshold
35
xiii
2.18
Flow chart of ALIVE-HO
37
2.19
Flow chart of Ping-Pong avoidance algorithm
40
3.1
The testbed architecture
46
3.2
Floor layout for testbed
49
3.3
Network coverage for AP1
50
3.4
Secure authentication process for WPA2-Enterprise (a) without
51
context transfer; (b) with context transfers
3.5
Context cache for context transfer method
52
3.6
First time authentication with context transfer implemented (a)
54
without handover prediction; (b) with handover prediction
3.7
Framework Diagram of PCT
55
3.8
Collected client’s RSS for a minute when a mobile user not
57
moving
3.9
RSS transition pattern technique using (a) Normal RSS
58
transition pattern; (b) Early RSS transition pattern
3.10
The disadvantage of normal RSS transition pattern
60
3.11
The advantage of early RSS transition pattern
60
3.12
Collected client’s RSS in static mode for three different
62
locations
3.13
Client’s θ at (a) Location 1; (b) Location 2; (c) Location 3 for
63
MW(5), MW(10) and MW(15)
3.14
Moving Weight Discovery (MWD) algorithm
65
3.15
Moving Wight Discovery (MWD) method
66
3.16
The average sample collected using MW(5) at (a) Location 1;
67
(b) Location 2; (c) Location 3; for MWD method
3.17
The average sample collected using MW(10) at (a) Location 1;
68
(b) Location 2; (c) Location 3; for MWD method
3.18
The average sample collected using MW(15) at (a) Location 1;
69
(b) Location 2; (c) Location 3; for MWD method
3.19
Predictive Context Transfer (PCT) algorithm
72
3.20
Predictive Context Transfer (PCT) method
73
4.1
Flow chart diagram of experiment
76
xiv
4.2
Hierarchy chart diagram of handover latency experiment
77
4.3
Sniffer using AirMagnet WiFi Analyzer tool
78
4.4
Re-authentication latency for open-system authentication
80
method
4.5
Re-authentication latency for WPA2-Personal authentication
81
method
4.6
Re-authentication latency for WPA2-Enterprise authentication
82
method
4.7
Latency of Open-System authentication method in error
83
scenario
4.8
Comparison latency of authentication and association phase in
84
Open-System authentication method
4.9
Latency of WPA2-Personal authentication method in error
84
scenario
4.10
Comparison latency of 4-way handshake phase in WPA2-
85
Personal authentication method
4.11
Latency of WPA2-Enterprise authentication method in error
86
scenario
4.12
Comparison latency of 802.1x authentication in WPA2-
86
Enterprise authentication method
4.13
Comparison of authentication latency for open system, WPA2-
87
Personal and WPA2-Enterprise authentication method
4.14
Comparison of authentication latency for open-system, WPA2-
88
Personal and WPA2-Enterprise authentication method in
without and with error scenario
4.15
Layout for location of mobile user at each distance from AP in
89
Department 1
4.16
Percentage comparison of 802.1x authentication latency for
90
different distance between AP and mobile user
4.17
Re-authentication latency in WPA2-Enterprise network (a)
without context transfer implemented; (b) with PCT
implemented
92
xv
4.18
Comparison of re-authentication latency for without and with
93
PCT method implemented
4.19
Hierarchy chart diagram for handover decision experiment
94
4.20
Outdoors Environment layout
97
4.21
Percentage of cache hit (successful handover) when a mobile
98
user moves to outside of coverage for outdoor environment
4.22
Percentage of false alarm (unnecessary handover) when mobile
99
users in static and not moving for outdoor environment
4.23
Layout for movement path for handover decision experiment
101
when a mobile user move from (a) Location 1; (b) Location 2;
(c) Location 3; to other department
4.24
Percentage of cache hit (successful handover) when a mobile
102
user moves from network coverage of AP1 to AP2 for indoor
environment
4.25
Comparison for Ping-Pong algorithm and PCT technique for
103
cache hit (successful handover) for indoor environment
4.26
Percentage of false alarm (unnecessary handover) when a
mobile user in static and not moving for indoor environment
104
xvi
LIST OF ABBREVIATIONS
AA
-
Authenticator Address
AAA
-
Authentication, Authorization and Accounting
AC
-
Access Controller
AKM
-
Authentication and Key Management
AKMP
-
Authentication and Key Management Protocol
ANounce
-
Authenticator Nounce
ARP
-
Address Resolution Protocol
AP
-
Access Point
API
-
Application Programming Interface
AS
-
Authentication Server
ASST
-
Application Signal Strength
BSS
-
Basic Service Set
CAPWAP
-
Control And Provisioning Wireless Access Point
CI
-
Confidence Interval
CT
-
Context Transfer
DHCP
-
Dynamic Host Configuration Protocol
DNS
-
Domain Name System
EAP
-
Extensible Authentication Protocol
EAP-AKA
-
EAP-Authentication and Key Agreement
EAP-POTP
-
EAP-Protected One-Time Password
EAP-SIM
-
EAP-Subscriber Identify Module
EAP-TLS
-
EAP-Transport Layer Security
EAP-TTLS
-
EAP-Tunneled Transport Layer Security
EAPOL
-
Extensible Authentication Protocol Over LANs
GMK
-
Group Master Key
GTK
-
Group Temporal Key
GTKSA
-
Group Temporal key Security Association
GUI
-
Graphical User Interface
xvii
IAPP
-
Inter-Access Point Protocol
IBSS
-
Independent Basic Service Set
ICMP
-
Internet Control Message Protocol
IEEE
-
Institute of Electrical and Electronics Engineers
IETF
-
Internet Engineering Task Force
ITU
-
International Telecommunication Union
ITU-T
-
ITU-Telecommunication Standardization Sector
KCK
-
EAPOL-Key Confirmation Key
KEK
-
EAPOL-Key Encryption Key
LAN
-
Local Area Network
LEAP
-
Lightweight Extensible Protocol
LS
-
Least Square
LTE
-
Long Term Evolution
LWAPP
-
LightWeight Access Point Protocol
MAC
-
Medium Access Control
MI
-
Moving In
MIC
-
Message Integrity Code
MN
-
Mobile Node
MO
-
Moving Out
MU
-
Mobile User
MW
-
Moving Weight
MWD
-
Moving Weight Discovery
PCT
-
Predictive Context Transfer
PDA
-
Personal Digital Assistant
PMK
-
Pairwise Master Key
PMKID
-
Pairwise Master Key Identifier
PMKSA
-
Pairwise Master Key Security Association
PRF
-
Pseudo-Random Function
PSK
-
Pre-Shared Key
PTK
-
Pairwise Transient Key
PTKSA
-
Pairwise Transient Key Security Association
QoS
-
Quality of Service
RADIUS
-
Remote Authentication Dial In User Service
RFC
-
Request For Comments
xviii
RSN
-
Robust Security Network
RSNA
-
Robust Security Network Association
RSS
-
Received Signal Strength
RSSI
-
Received Signal Strength Indicator
RTA
-
Real Time Application
SNounce
-
Supplicant Nounce
SPA
-
Supplicant Address
STA
-
associated Station
TCP
-
Transmission Control protocol
TKIP
-
Temporal Key Integrity Protocol
UAM
-
Universal Access Method
UDP
-
User Datagram Protocol
UMTS
-
Universal Mobile Telecommunications System
VoIP
-
Voice over IP
WEP
-
Wired Equivalent Privacy
Wi-Fi
-
mechanism for wirelessly connecting electronic devices
WiMax
-
Worldwide interoperability for Microwave access
WLAN
-
Wireless Local Area Network
WLC
-
Wireless LAN Controller
WPA
-
Wi-Fi Protected Access
WTP
-
Wireless Termination Point
WWW
-
World Wide Web
xix
LIST OF APPENDICES
APPENDIX
A
TITLE
The experiment results for MWD for outdoor environments
PAGE
114
xx
LIST OF SYMBOLS
thandover
-
Handover latency
tscan
-
Scanning latency
tre-authentication
-
Re-authentication latency
tauthentication
-
Authentication phase latency
tassociation
-
Association phase latency
t802.1x authentication
-
802.1x authentication latency
t4-way handshake
-
4-way handshake latency
si
-
Measured strength of client’s signal strength
ti
-
Time for data sampling of client’s signal strength
tMW
-
Time for collected client’s RSS data for Moving Weight
θ
-
Slope of the least square algorithm of the collected line
σ
-
Intersection point of the least square and the y-axis
TH
-
Handover threshold
MWI
-
Client’s MW for moving in
MWO
-
Client’s MW for moving out