vii
TABLE OF CONTENTS
CHAPTER
TITLE
PAGE
TITLE PAGE
i
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF ABBREVIATION
xix
LIST OF NOTATIONS
xxiii
LIST OF SYMBOLS
xxix
LIST OF APPENDICES
xxx
INRODUCTION
1
Background
1
1.1.1 Wireless Communication Systems
1
1.1.2 Data Network Protocol Model
3
1.2
Issues and Challenges
5
1.3
Problem Statement
6
1.4
Research Objectives
7
1.5
Methodology
7
1.6
Research Scope
8
1.7
Contributions
10
1.8
Thesis Structure
11
1
1.1
viii
2
LITERATURE REVIEW
13
2.1
Introduction
13
2.2
IEEE 802.16 Standards Evolution
13
2.3
Mobile Multi-hop Relay WiMAX Network
15
2.3.1 Relay Modes of Operation
17
2.3.2 WiMAX Protocol Stack
19
2.3.2.1 End-to-end Quality of Service Support
23
2.3.2.2 OFDMA Frame Structure and Relaying
Modes
32
2.3.2.3 Network Entry and Call Admission
Control
38
2.3.2.4 Bandwidth Request and Resource
Allocation
2.3.2.5 Scheduling Architecture and Algorithms
2.4
40
44
Reliable Data Transmission Techniques in Wireless
Systems
45
2.4.1 Transmission Control Protocol (TCP)
46
2.4.1.1 TCP Variants and Specifications
51
2.4.1.2 Limitations of Conventional TCP over
Wireless Systems
52
2.4.1.3 Performance Enhancements Scheme of
TCP over Wireless Channel
2.4.2 Automatic Repeat reQuest (ARQ)
53
63
2.4.2.1 ARQ Parameters Optimization in
Wireless Network
2.4.2.2 ARQ for MMR WiMAX Network
2.5
3
Summary
65
66
68
ENHANCEMENT OF DATA TRANSMISSION
SCHEMES FOR MMR WIMAX NETWORK
70
3.1
Introduction
70
3.2
Related Works Analysis in MMR WiMAX Network
71
3.2.1 Related Works on Resource Management
71
3.2.2 Related Works on TCP optimization
74
ix
3.2.3 Related Works on Error Control
76
3.3
Research Framework
77
3.4
Functional Block diagram of the Proposed Schemes
for MMR WiMAX Networks
3.5
78
Design Concept of the Proposed Schemes for MMR
WiMAX Networks
79
3.5.1 Resource Management Scheme for MMR
WiMAX Networks
80
3.5.1.1 OFDMA Frame Structure for MMR
WiMAX Network
80
3.5.1.2 Bandwidth Request for MMR WiMAX
Network
80
3.5.1.3 Scheduling Architecture and Algorithm
for MMR WiMAX Network
81
3.5.1.4 Call Admission Control for MMR
WiMAX Network
84
3.5.2 Cross Layer Transmission Control for MMR
WiMAX Networks
85
3.5.3 Cross Layer Error Control for MMR WiMAX
Networks
89
3.6
System Model and Simulation
93
3.7
Summary
95
4
RESOURCE MANAGEMENT SCHEMES FOR MMR
WIMAX NETWORK
97
4.1
Introduction
97
4.2
NMF Frame Structure
98
4.2.1 Numerical Analysis of NMF Frame Capacity
100
NT-RS Uplink Bandwidth Demand Estimation
106
4.3.1 The GP Algorithm Numerical Analysis
109
4.3
4.4
QoS aware Call Admission Control for MMR
WiMAX Network
111
4.4.1 Call Admission Control Entity Placement in
the Ranging Sequence
112
x
4.5
4.6
4.4.2 QoS aware Call Admission Control Algorithm
115
Scheduling Algorithms for MMR WiMAX Network
116
4.5.1 Downlink Access Zone Scheduling Algorithm
117
4.5.2 Downlink Relay Zone Scheduling Algorithm
118
4.5.3 Uplink Access Zone Scheduling Algorithm
120
4.5.4 Uplink Relay Zone Scheduling Algorithm
121
Simulation and Performance Evaluation
122
4.6.1 New Multi-frame (NMF) Structure Performance
123
4.6.1.1 Capacity Evaluation of NMF
123
4.6.1.2 Link Layer and TCP Traffic Performances
129
4.6.2 Relay Link Bandwidth Demand Estimation
Algorithm
134
4.6.2.1 Accuracy of GP algorithm
134
4.6.2.2 Effect of Bandwidth Demand Estimation
Scheme in Link layer and TCP Traffic
4.7
5
Performances
137
4.6.3 Scheduling Algorithm Performance
140
Summary
143
CROSS LAYER TRANSMISSION CONTROL FOR
MMR WIMAX NETWORK
145
5.1
Introduction
145
5.2
Cross layer Transmission Control Development
146
5.2.1 RTT and RTO Estimation
146
5.2.2 ssthresh and CWNDmax Adjustment
148
5.2.3 TCP Acknowledgement Generation
149
5.3
RTO Smoothing Scheme
151
5.4
Simulation and Performance Analysis
153
5.4.1 Performance Analysis of the CLTC
154
5.4.2 Performance Analysis of the CLTC with
RTO Smoothing Scheme
5.5
Summary
168
181
xi
6
CROSS LAYER ERROR CONTROL FOR MMR
WIMAX NETWORKS
183
6.1
Introduction
183
6.2
The Proposed Cross Layer Error Control
184
6.2.1 ARQ Block Size Selection
184
6.2.2 ARQ Window Size Selection
186
6.2.3 ARQ Retry Timeout Selection
187
6.2.4 ARQ Block Lifetime Selection
192
6.2.5 Resource Aware AMC for Multiple Hops
193
The Performance Evaluation of the Proposed Schemes
194
6.3
6.3.1 Performance evaluation of hop aware ARQ
Block Size
195
6.3.2 Performance evaluation of hop aware ARQ
Window Size
200
6.3.3 Performance evaluation of hop aware ARQ
Retry Timeout
6.3.4 End to End ARQ versus RS-ARQ
208
215
6.3.5 Performance evaluation of RTO aware ARQ
Block Lifetime
219
6.3.6 Performance Evaluation of Resource aware
AMC algorithm
6.4
222
Summary
226
CONCLUSION AND FUTURE WORK
228
7.1
Introduction
228
7.2
Conclusion
228
7.2.1 Resource Management Scheme
229
7.2.2 Transmission Control Mechanism
230
7.2.3 Error Control Schemes
231
Future Work and Recommendations
232
REFERENCES
234
7
7.3
Appendices A - E
248-270
xii
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
T-RS and NT-RS features comparison
18
2.2
Modulation and coding rates
22
2.3
DiffServ and WiMAX services mapping
29
2.4
QoS parameters and application of WiMAX services
30
3.1
Related works on OFDMA frame structure
71
3.2
Related works on relay link bandwidth request
72
3.3
Related works on scheduling architecture and algorithms
73
3.4
Related works on CAC
74
3.5
Related works on TCP optimization for wireless systems
75
3.6
Related works ARQ parameters adjustment
76
3.7
Simulation parameters setting
95
5.1
ssthresh binary representations and their explanations
151
6.1
Improvement summary of hop aware ARQ block size
200
6.2
Performance improvement of hop aware ARQ window
size
6.3
207
Performance improvement of hop aware ARQ retry
timeout
215
xiii
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
TCP/IP protocol stack model
4
2.1
WiMAX standards evolution
14
2.2
MMR WiMAX network architecture
16
2.3
Relay stations functionalities
17
2.4
Functional block diagram of WiMAX protocol stack
19
2.5
DiffServ code point placement in IP header
25
2.6
QoS mapping between DiffServ and WiMAX in
an end-to-end path
28
2.7
QoS scheduling architecture of WiMAX
31
2.8
Transparent relaying frame structure
34
2.9
Non transparent relaying frame structure
35
2.10
Single frame structure for three hops
36
2.11
Multi frame structure for three hops
37
2.12
Distributed scheduling bandwidth request sequence
41
2.13
Slow start and congestion avoidance regions
49
2.14
Fast retransmit and fast recovery region
50
2.15
TCP over wireless performance improvements schemes
53
2.16
Link layer protocols
54
2.17
Transport layer protocols
57
2.18
Transition state diagram of RS-ARQ
68
3.1
Functional block diagram of the proposed schemes
79
3.2
Proposed QoS architecture of MMR WiMAX network
82
3.3
Scheduler state transition diagram
83
3.4
CAC state transition diagram
84
3.5
Functional block diagram of CLTC
86
xiv
3.6
CLTC state transition diagram
87
3.7
Functional block diagram of RTO smoothing scheme
88
3.8
Functional block diagram of CLEC
89
3.9
ARQ parameters selection transition state diagram
91
3.10
Resource aware AMC scheme state transition diagram
93
3.11
System model of MMR WiMAX network
94
4.1
NMF frame structures of MMR-BS and NT-RSs
99
4.2
Grey prediction algorithm
108
4.3
Proposed bandwidth grant messages sequence
109
4.4
First hop SS initial ranging sequence
113
4.5
Second hop SS initial ranging sequence
114
4.6
Third hop SS initial ranging sequence
114
4.7
Call admission control algorithm
116
4.8
Downlink access zone scheduling algorithm
118
4.9
Downlink relay zone scheduling algorithm
119
4.10
Uplink access zone scheduling algorithm
120
4.11
Uplink relay zone scheduling algorithm
121
4.12
Access and relay zones capacity utilization, scenario 1
124
4.13
Access and relay zones capacity utilization, scenario 2
125
4.14
Access and relay zones capacity utilization, scenario 3
125
4.15
Access and relay zones capacity utilization, scenario 4
126
4.16
Access and relay zones capacity utilization, scenario 5
126
4.17
Access and relay zones capacity utilization, scenario 6
128
4.18
Different hops link layer delay
129
4.19
Link layer throughput of different hops
130
4.20a
RTT comparisons of the first hop
131
4.20b
RTT comparisons of the second hop
131
4.20c
RTT comparisons of the third hop
132
4.21a
TCP congestion window development of the first hop
132
4.21b
TCP congestion window development of the second hop
133
4.21c
TCP congestion window development of the third hop
133
4.22
Average TCP throughput comparisons
134
4.23
Estimation of increasing traffic for NT-RS
135
4.24
Estimation of stable traffic for NT-RS
136
xv
4.25
Estimation of decreasing traffic for NT-RS
136
4.26
Estimation of fluctuating traffic for NT-RS
137
4.27
Average link layer throughput comparison
138
4.28a
RTT of the SSs at first hop
138
4.28b
RTT of SSs at second hop
139
4.28c
RTT of SSs at third hop
139
4.29
Average TCP throughput comparison
140
4.30
Frame utilization comparison
141
4.31
Throughput Comparison
142
4.32
QoS index Comparison
142
5.1
Timing diagram of sending one TCP packet successfully
147
5.2
Ssthresh and CWNDmax placement at TCP ACK header
150
5.3
RTO smoothing algorithm
153
5.4a
RTT and RTO of the SSs at first hop level
155
5.4b
RTT and RTO of the SSs at second hop level
155
5.4c
RTT and RTO of the SSs at third hop level
156
5.5a
TCP timeout occurrences of the SSs at first hop
157
5.5b
TCP timeout occurrences of the SSs at second hop
157
5.5c
TCP timeout occurrences of the SSs at third hop
158
5.5d
TCP timeout occurrences of the SSs at different hops
158
5.6a
Congestion window development of the SSs at first hop
159
5.6b
Congestion window development of the SSs at second hop
159
5.6c
Congestion window development of the SSs at third hop
160
5.7a
Utilization of the allocated resources of the SSs at first hop
161
5.7b
Utilization of the allocated resources of the SSs at second
hop
161
5.7c
Utilization of the allocated resources of the SSs at third hop
162
5.7d
Utilization of the allocated resources of the SSs at different
hops
162
5.8a
TCP throughput per second of the SSs at first hop
163
5.8b
TCP throughput per second of the SSs at second hop
164
5.8c
TCP throughput per second of the SSs at third hop
164
5.8d
Average TCP throughput of the SSs at different hops
165
5.9a
TCP goodput per second of the SSs at first hop
166
xvi
5.9b
TCP goodput per second of the SSs at second hop
166
5.9c
TCP goodput per second of the SSs at third hop
167
5.9d
Average TCP goodput of the SSs at different hops
167
5.10a
RTT and RTO of the SSs at first hop
169
5.10b
RTT and RTO of the SSs at second hop
169
5.10c
RTT and RTO of the SSs at third hop
170
5.11a
TCP timeout occurrences of the SS at the first hop
171
5.11b
TCP timeout occurrences of the SS at the second hop
171
5.11c
TCP timeout occurrences of the SS at the third hop
172
5.11d
TCP timeout occurrences for the SSs at different hops
172
5.12a
TCP development of the congestion window of the SS
at first hop
5.12b
The development of the congestion window of the SS
at second hop
5.12c
173
173
The development of the congestion window of the SS
at third hop
174
5.13a
Utilization of the allocated resources of the SS at first hop
175
5.13b
Utilization of the allocated resources of the SS at second hop 175
5.13c
Utilization of the allocated resources of the SS at third hop
5.13d
Utilization of the allocated resources of the SSs at
176
different hops
176
5.14a
TCP throughput per second for the SSs at the first hop
177
5.14b
TCP throughput per second for the SSs at the second hop
178
5.14c
TCP throughput per second for the SSs at the third hop
178
5.14d
Average TCP throughput for the SSs at different hops
179
5.15a
TCP goodput per second for the SS at the first hop
180
5.15b
TCP goodput per second for the SS at the second hop
180
5.15c
TCP goodput per second for the SS at the third hop
181
5.15d
Average TCP goodput for the SSs at different hops
181
6.1
Suitable ARQ packet size searching algorithm
186
6.2
Delay component of single hop system
188
6.3
Delay components of two hops system
190
6.4
Transition states machine of ARQ retry RS-ARQ
191
6.5
RS-ARQ retry timeout adjustment algorithm
192
xvii
6.6
Resource aware AMC algorithm
194
6.7
Link layer transmission efficiency of different hops
195
6.8
Link layer packet error rate for different hop levels
196
6.9
Average link layer throughput for different hop levels
197
6.10
Average link layer goodput for different hop levels
197
6.11
TCP timeout occurrences for different hop levels
198
6.12
TCP throughput comparisons for different hop levels
199
6.13
TCP goodput comparisons for different hop levels
199
6.14a
Percentage utilization of the allocated slots for SSs
at 1st hop
6.14b
201
Percentage utilization of the allocated slots for SSs
at 2nd hop
6.14c
202
Percentage utilization of the allocated slots for SSs
at 3rd hop
6.14d
202
Average utilization of the allocated slots for different
hop levels
6.15a
203
st
204
nd
Link layer throughput for SSs at 1 hop
6.15b
Link layer throughput for SSs at 2 hop
204
6.15c
Link layer throughput for SSs at 3rd hop
205
6.15d
Average link layer throughput for SSs at different hops
205
6.16
Average link layer goodput for SSs at different hops
206
6.17
Average TCP throughputs for SSs at different hops
207
6.18
Average link layer throughput comparisons- 100 ms
scienario
208
6.19
Average link layer goodput comparisons -100 ms scienario
209
6.20
Average numbers of retransmitted packets in the link layer100 ms scienario
209
6.21
Average TCP throughput comparisons -100 ms scienario
210
6.22
Average TCP goodput comparisons -100 ms scienario
211
6.23
Average link layer throughput comparisons - 40 ms scienario 211
6.24
Average link layer goodput comparisons - 40 ms scienario
6.25
Average numbers of retransmitted packets in the link layer -
6.26
212
40 ms scienario
213
Average TCP throughput comparisons - 40 ms scienario
214
xviii
6.27
Average TCP goodput comparisons - 40 ms scienario
6.28
Comparison of the percentage utilization of the allocated
214
resources
216
6.29
Link layer throughput comparison of SSs at different hops
217
6.30
Number of retransmitted packets from the MMR-BS
218
6.31
Comparison of link layer goodput for SSs at different hops
218
6.32
Comparison of TCP throughput for SSs at different hops
219
6.33
Average numbers of timeouts for SSs at different hops
220
6.34
Average link layer throughputs for SSs at different hops
220
6.35
Average link layer goodputs for SSs at different hops
221
6.36
Average TCP throughputs for SSs at different hops
221
6.37
Average TCP goodputs for SSs at different hops
222
6.38
Average link layer throughput for SSs at different hops
223
6.39
Number of link layer packets retransmitted at different hops
224
6.40
Link layer goodput for SSs at different hops
225
6.41
TCP throughputs for SSs at different hops
225
xix
LIST OF ABBREVIATIONS
ACK
-
positive Acknowledgement
AGO
-
Accumulated Generation Operation
AIRMAIL
-
Asymmetric Reliable Mobile Access In Link Layer
AMC
-
Adaptive Modulation and Coding
ARQ
-
Automatic Repeat reQuest
ATM
-
Asynchronous Transfer Mode
BE
-
Best Effort
BER
-
Bit Error Rate
BS
-
Base Station
BW
-
Bandwidth
CAC
-
Call Admission Control
CC
-
Convolution Coding
CDMA
-
Code Division Multiple Access
CID
-
Connection Identifier
CRC
-
Cyclic Redundancy Check
CS
-
Convergence Sub-layer
CPS
-
Common Part Sub-layer
CRC
-
Cyclic Redundancy Check
CWND
-
Congestion Window
CWNDmax
-
Maximum Congestion Window
DAA
-
Delayed Duplicate Acknowledgement
DAWL
-
Delayed ACK on wireless Link
DC
-
Direct Current
DL
-
Downlink
DL-AZ
-
Downlink Access Zone
DL-MAP
-
Slot allocation for downlink transmission
DL-RZ
-
Downlink Relay Zone
xx
DSL
-
Digital Subscriber Line
EBSN
-
Explicit Bad State Notification
ELN
-
Explicit Loss Notification
E-mail
-
Electronic Mail
ERR
-
Extra Resource Reservation
ertPS
-
Extended Real Time Polling Service
FCH
-
Frame Control Header
FEC
-
Forward Error Correction
FFT
-
Fast Fourier Transform
FH
-
Fixed Host
FTP
-
File Transfer Protocol
FUSC
-
Fully Used Sub-Carrier
GHz
-
Giga Hertz
GMH
-
Global Management Header
HARQ
-
Hybrid Automatic Repeat reQuest
I-AGO
-
Inverse Accumulated Generation Operation
ID TLV
-
Type, Length and value of the Identifier
IE
-
Information Element
IEEE
-
Institute of Electrical and Electronics Engineering
I-TCP
-
Indirect Transmission Control Protocol
LLE-TCP
-
Link Layer ARQ Exploitation TCP
LOS
-
Line Of Sight
MAC
-
Medium Access Control
METP
-
Mobile End Tranport Protocol
MHz
-
Mega Hertz
MMR
-
Mobile Multi-hop Relay
MPDU
-
Multiple Packet Data Unit
MSDU
-
Multiple Service Data Unit
NACK
-
Negative Acknowledgement
NLOS
-
Non Line Of Sight
nrtPS
-
Non Real Time Polling Service
NT-RS
-
Non Transparent Relay Station
OFDM
-
Orthogonal Frequency Division Multiplexing
OFDMA
-
Orthogonal Frequency Division Multiple Access
xxi
ORS
-
OFDMA Relay Scheduler
OSI
-
Open System Interconnection
PDU
-
Packet Data Unit
PER
-
Packet Error Rate
PKM
-
Privacy Key Management
PMP
-
Point to Multi Point
PSK
-
Phase Shift Keying
PHY
-
Physical Layer
PUSC
-
Partially Used Sub-Carrier
QAM
-
Quadrature Amplitude Modulation
QoS
-
Quality of Service
QPSK
-
Quadrature Phase Shift Keying
RF
-
Radio Frequency
R-FCH
-
Relay Frame Control Header
R-MAC
-
Relay Medium Access Control
R-MAP
-
Slot allocation for Relay Station transmission
RNG-REQ
-
Range Request message
RNG-RSP
-
Range Response message
RS
-
Relay Station
RS-ARQ
-
Relay Station support Automatic Repeat reQuest
RS-ID
-
Relay Station Identifier
RSSI
-
Received Signal Strength Indicator
RTG
-
Receive to Transmit Gap
RTO
-
Retransmission Time Out
rtPS
-
Real Time Polling Service
RTT
-
Round Trip Time
SACK
-
Selective Acknowledgement
SC
-
Single Carrier
SDU
-
Service Data Unit
SFID
-
Service Flow Identifier
SINR
-
Signal to Interference and Noise Ratio
SNR
-
Signal to Noise Ratio
SQSA
-
Scalable QoS Scheduling Architecture
SRTT
-
Smoothed Round Trip Time
xxii
SS
-
Subscriber Station
ssthresh
-
Slow Start Threshold
T-CID
-
Tunnel Connection Identifier
TCP
-
Transmission Control Protocol
TCP/IP
-
Transmission Control Protocol/Internet Protocol
TDMA
-
Time Division Multiple Access
TDD
-
Time Division Duplex
TLV
-
Type, Length and value of any parameter
TRG
-
Transmit to Receive Gap
T-RS
-
Transparent Relay Station
UGS
-
Unsolicited Grant Service
UL
-
Uplink
UL-AZ
-
Uplink Access Zone
UL-MAP
-
Slot allocation for uplink transmission
UL-RZ
-
Uplink Relay Zone
UWB
-
Ultra Wide Band
VoIP
-
Voice of Internet Protocol
VRTT
-
Variance of Round Trip Time
Wi-Fi
-
Wireless Fidelity
WiMAX
-
World wide Interoperability of Microwave Access
WLAN
-
Wireless Local Area Network
WMAN
-
Wireless Metropolitan Area Network
WPAN
-
Wireless Personal Area Network
WTCP
-
Wireless Transmission Control Protocol
WWAN
-
Wireless Wide Area Network
xxiii
LIST OF NOTATIONS
Notation
-
Explanation
opt
ARQblock
_ life
-
Optimum ARQ block lifetime
-
Optimum ARQ packet size
-
Optimum ARQ retry timeout
-
Optimum ARQ retry timeout for Q hops
ARQwopt_ size
-
Optimum ARQ window size
BER i
-
Bit error rate at instance i
-
Optimum Call Admission Control
-
Optimum maximum congestion window
DFQ
-
Delay factor of hop number Q
(DLRatio)MMRBS
-
Downlink Ratio of MMR-BS OFDMA frame
ARQpopt_ size
opt
ARQretry
_ time
Q _ hops
ARQretry
_ time
CAC
opt
CWND
opt
max
 DL _ AZ MMR  BS -
Downlink access zone of the MMR-BS
 DL
Downlink access zone of the NT-RS number n in the 1st
_ AZ
NT  RS
-
n
1
tier
 DL
_ AZ
 NT  RS
Downlink access zone of the NT-RS number n in the 2nd
-
n
2
tier
 DL
_ RZ
 MMR
 DL
_ RZ
 NT  RS
 DL
_ RZ
 NT  RS
Dwired
-
Downlink relay zone of the MMR-BS
n
1
-
Downlink relay zone of the NT-RS number n in the 1st tier
n
2
-
Downlink relay zone of the NT-RS number n in the 2nd tier
-
The delay of the wired part of the network
 BS
xxiv
FPS
Link
per
-
Frame per second
-
Link layer performance
MAX
ARQ
_packet
_size
Mod
opt
all _ links
N avail
, slots
-
Optimum modulation scheme
-
available slots in the all the links between the MMR-BS
and access link where the SS located
all _ NT  RS
N total
, SSs
All_packets
_
Nslots
Maximum ARQ packet size
q
NTRS
i
-
Total number of SSs served by the all NT-RS
-
Number of slots required to forward the packets stored
in a queue of NT-RSi
-
all _ SSs
N excess
, slots
Excess slots allocated to other SSs in the access link where
the new coming SS located
Number of available slots in the access zone of the RS
available
Nslots
 DL MMR  BS
N channels
-
 DL MMR  BS
N slots
-
Number of slots in the downlink of the MMR-BS
 DL MMR BS
N symb
-
Number of OFDMA symbols in the downlink sub-frame
 DL_ AZ MMRBS
Nremain
, slots
-
 DL _ AZ
N slots
-
 MMR
Number of logical channels in the downlink of the
MMR-BS
of the MMR-BS
 BS
Remain of SSs in the downlink access zone of the
MMR-BS
Number of slots in the downlink access zone of the
MMR-BS
DL_ AZMMRBS NSSs
Number of SSs in the downlink access zone of the
DL_ AZMMRBS
Nunserved
,SSs
-
Number of un-served SSs in the downlink access zone of
 DL _ AZ  NT  RS 1n
-
N slots
 DL _ AZ  NT  RS 2n
N slots
 DL _ RZ  MMR  BS
N slots
MMR-BS
the MMR-BS
Number of slots in the downlink access zone of the 1st tier
NT-RS
-
Number of slots in the downlink access zone of the 2 nd
tier NT-RS
-
Number of slots in the downlink relay zone of the
MMR-BS
xxv
 DL
N slots
_ RZ
 NT  RS 1n
 DL _ RZ NT RS2n
N slots
-
Number of slots in the downlink relay zone of the 1 st tier
NT-RS
-
Number of slots in the downlink relay zone of the 2 nd tier
NT-RS
frame
NCont
, subcarr
-
frame
N Data
, subcarr
-
frame
N subcarr
-
Number of frequency sub-carriers per frame
frame
N symb
-
Number of OFDMA symbols per frame
-
Required slots to satisfy the maximum data rate of the new
new _ SS
N max_
rate , slots
new _ SS
N min_
rate , slots
N
NT  RS in
Number of frequency sub-carriers per frame used to send
control messages
Number of frequency sub-carriers per frame used to send
data
coming SS
-
Required slots to satisfy the minimum data rate of the new
coming SS
-
SSs
Number of SSs served by the NT-RS number n in the ith
tier
NTRSi _ fair_ usage
Nslots
Number of slots that satisfy fair usage of the available
NTRSi _grey
_ pred Nslots
Number of slots calculated from the bandwidth demand
required
Nslots
-
resources of the NT-RSi
estimated by the grey prediction algorithm for the NT-RSi
Number of slots required to send the data stored in RS’
queue
SS
N requested
, slots
-
Number of slots requested by the SS to send its uplink data
SS
N required
, slots
-
Required slots to send the SS data
SS _ fair _ usage
N slots
Number of slots that can satisfy fair usage of the available
UL MMR BS
N channels
-
Number of logical channels in the uplink of the MMR-BS
UL MMR BS
N slots
-
Number of slots in the uplink of the MMR-BS
UL MMR BS
N symb
-
Number of OFDMA symbols in the uplink sub-frame of
UL_ AZMMRBS
Nremain
,slots
-
resources among SSs
the MMR-BS
Remain of SSs in the uplink access zone of the MMR-BS
xxvi
UL _ AZ MMR  BS
N slots
-
Number of slots in the uplink access zone of the MMR-BS
UL_ AZMMRBS NSSs
Number of SSs in the uplink access zone of the MMR-BS
UL_ AZMMRBS Nunserved
,SSs
Number of un-served SSs in the uplink access zone of the
UL _ AZ  NT  RS1n
N slots
-
MMR-BS
Number of slots in the uplink access zone of the 1st tier
NT-RS
UL_ AZ NTRS2n
Nslots
-
Number of slots in the uplink access zone of the 2 nd tier
NT-RS
UL _ RZ  MMR  BS
N slots
-
Number of slots in the uplink relay zone of the MMR-BS
UL _ RZ  NT  RS1n
-
Number of slots in the uplink relay zone of the 1st tier
N slots
NT-RS
UL _ RZ NT RS2n
N slots
-
Number of slots in the uplink relay zone of the 2nd tier
NT-RS
N RTO _ expired
-
Number of RTO timer expiration
N SS
-
Number of subscriber stations
1
PTCP
_ loss
-
The probability of the TCP packet loss sent for one hop
Q
PTCP
_ loss
-
The probability of the TCP packet loss sent across Q hop
PTCP _ loss _ N
-
TCP packet loss estimation at iteration N
Packetsize
-
Packet
size_ optimum
Link layer packet size in bytes
Optimum link layer packet size in bytes
-
Packet error rate for the second and third hops
PERi
-
Packet error rate at instance i
PLQ
-
Packet loss factor of hop number Q
SS
R allocated
-
Allocated resources for a given SS
SS
R available
-
Available resources for a given SS
SS
R link
-
Link layer rate of a given SS
-
Sending rate in bits per frame for the DL_AZ of the
PER2
nd
&3rd
R  DL _ AZ  MMR  BS
MMR-BS
xxvii
R  DL _ RZ  MMR  BS
-
R max_
-
Required resources to satisfy the maximum sustained rate
R min_ reserved
-
Required resources to satisfy the minimum reserved rate
R UL _ AZ  MMR  BS
-
Sending rate in bits per frame for the UL_AZ of the
R UL _ RZ
-
sustained
 MMR
 BS
Sending rate in bits per frame for the DL_RZ of the
MMR-BS
MMR-BS
Sending rate in bits per frame for the UL_RZ of the
MMR-BS
R utilized
-
Utilization of the allocated resources
Reoverlap
-
Retransmission overlapping from different layers
Reun _ necess
-
Un-necessary retransmission
RTTavg, k
-
Average round trip time at instance k
opt
RTO smoothed
-
Optimum smoothed retransmission timeout
-
Optimum scheduling
SNRi
-
Signal to noise ratio at instance i
SRTT(k )
-
Smoothed round trip time at instance K
-
Optimized slow start threshold value
-
Normalized slow start threshold value
TEff
-
Transmission Efficiency
TEff _ N
-
Transmission Efficiency at iteration N
TLink _ ACK, receive
-
The time when all link layer ACKs received
t proc
-
Processing time
t prop
-
Propagation time
Tre cov
-
Error recovery time
TTCP _ ACK, send
-
The time when TCP ACK is sent from the MMR-BS
TTCP, receive
-
The time when the TCP packet is received at the MMR-BS
Schedule
ssthresh
ssthresh
opt
opt
norm
xxviii
TTCP, send
-
The time when the TCP packet is sent from the fixed host
TCP
-
Transmission Control Protocol performance
TCPseg _ size
-
TCP segment size in bytes
(ULRatio )MMR BS
-
Uplink Ratio of MMR-BS OFDMA frame
per
UL
_ AZ
MMR  BS -
Uplink access zone of the MMR-BS
UL
_ AZ
 NT  RS
n
1
-
Uplink access zone of the NT-RS number n in the 1st tier
UL
_ AZ
 NT
n
2
-
Uplink access zone of the NT-RS number n in the 2nd tier
UL
_ RZ
 MMR
-
Uplink relay zone of the MMR-BS
UL
_ RZ
 NT  RS
n
1
-
Uplink relay zone of the NT-RS number n in the 1st tier
UL
_ RZ
 NT
n
2
-
Uplink relay zone of the NT-RS number n in the 2nd tier
VRTT (k )
-
Variation of round trip time at instance k
 DL _ frame
-
Downlink sub-frame duration
UL _ frame
-
Uplink Sub-frame duration
 RS
 BS
 RS
xxix
LIST OF SYMBOLS
a
-
Development Coefficient of Grey Prediction algorithm
b
-
Input to the Grey Predictor
D
-
Net data packet size in bytes
e
-
Exponential constant
h
-
Packet header size in bytes
i
-
Hop count
m
-
Weight constant
M
-
Modulation index
N
-
Number of fragments of one TCP packet
k
-
Forecasting Step Size of Grey Prediction algorithm
Q
-
Number of hops
R
-
Number of retransmissions
t
-
Time
α
-
Exponential smoothing parameter
β
-
Smoothing parameter
τ
-
OFDMA frame duration
ѱ
-
The order of RS where the packet is corrupted
φ
-
Number of sequence values used in Grey Prediction algorithm
xxx
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A.1
List of Related Publication
248
B.1
TCP Header Format
250
B.2
IP Header Format
252
C.1
Call Admission Control Flowchart
255
C.2
Downlink Access Zone Scheduling Algorithm Flowchart
257
C.3
Downlink Relay Zone Scheduling Algorithm Flowchart
258
C.4
Uplink Access Zone Scheduling Algorithm Flowchart
259
C.5
Uplink Relay Zone Scheduling Algorithm Flowchart
260
D.1
More Results on Cross Layer Error Control (CLEC)
261
D.2
More Results on End-to-end ARQ versus RS-ARQ
266
D.3
More Results on resource aware AMC
268
E.1
Validation of Frame Structure Simulation
270
E.2
Validation of TCP Traffic Simulation
271
E.3
Validation of Link Layer Simulation
274