vii TABLE OF CONTENTS CHAPTER 1 TITLE PAGE DECLARATION ii DEDICATION iii ACKNOWLEDGMENT iv ABSTRACT v ABSTRAK vi TABLE OF CONTENTS vii LIST OF TABLES xiii LIST OF FIGURES xiv LIST OF ABBREVIATIONS xvii LIST OF APPENDICES xx INTRODUCTION 1 1.1 Overview 1 1.2 Background of Study 4 1.2.1 Finding the Nearest Sink in Multi-sink Mechanism 5 1.2.2 Mobile Sink Localization and Optimum Position for Sink Movement 6 1.2.3 Selecting the Best Next-hop Node in Single Path Geographic Routing 8 1.3 Problem Description 10 1.4 Statement of Objectives 11 1.5 Research Questions 12 1.6 Research Scope 12 1.7 Research Contributions 13 1.8 Significance of Research 15 viii 1.9 2 Organization of Thesis 16 LITERATURE REVIEW 17 2.1 Introduction 17 2.2 Background and Preliminaries 19 2.2.1 Wireless Sensor Network Architecture 19 2.2.2 Sources of Energy Consumption in WSNs 20 2.3 Classification of Routing Protocols Based on Network Structure in WSNs 21 2.3.1 Flat Routing Protocols 21 2.3.2 Hierarchical Routing Protocols 22 2.3.3 Geographic Routing Protocols 22 2.3.3.1 Merely Greedy Forwarding Scheme 23 2.3.3.2 Optimized Greedy Forwarding Scheme 2.4 Classification of Routing Mechanisms Based on Protocol Operation in WSNs 31 2.4.1 Multi-path Routing 32 2.4.2 QoS-based Routing 33 2.4.3 Bio-inspired Routing 33 2.4.4 Query-based Routing 34 2.4.5 Multi-sink Routing 35 2.4.5.1 Multiple Static Sinks Strategy 35 2.4.5.2 Multiple Mobile Sinks Strategy 39 2.4.5.3 Hybrid Strategy 41 2.4.6 Mobile Sink Routing 2.5 2.6 27 44 2.4.6.1 Random/Stochastic Sink Mobility 44 2.4.6.2 Fixed Path/Predictable Sink Mobility 47 2.4.6.3 Controlled Sink Mobility 48 Discussion on Limitations of Existing Routing Mechanisms 53 2.5.1 Network Structure Based Routing Mechanisms 54 2.5.2 Protocol Operation Based Routing Mechanisms 57 Chapter Summary 64 ix 3 RESEARCH METHODOLOGY 65 3.1 Introduction 65 3.2 Operational Framework 67 3.2.1 Phase 1: Investigation in WSNs 67 3.2.2 Phase 2: Algorithm Design and Development 67 3.2.2.1 Sink Selection Method 68 3.2.2.2 Sink Mobility Pattern 69 3.2.2.3 Forwarding Scheme 70 3.2.3 Phase 3: Evaluation 71 3.2.3.1 Comparison with Baseline Approaches 72 3.2.3.2 Metric of Comparison 73 3.2.3.3 Simulation Setup and Network Configuration 3.2.3.4 Reliability of the Simulation 3.3 4 73 74 3.2.4 Phase 4: Revision 76 Chapter Summary 79 ENERGY-EFFICIENT DUAL-SINK ALGORITHM WITH ROLE SWITCHING MECHANISM (EEDARS) 80 4.1 Introduction 80 4.2 Network Model and Preliminaries 80 4.2.1 Topology and Data Routing 81 4.2.2 Event Occurrence in Proposed Model 82 4.2.3 Modeling the Energy Consumption and Delay 83 The EEDARS Algorithm 88 4.3.1 Network Initialization 88 4.3.2 Network Functionality 89 4.3.3 The Role Switching Mechanism 90 4.3.4 Joint Routing Strategy and Sink Mobility 93 4.3 4.3.5 Analytical Analysis of Residual Energy and 4.4 Delay for EEDARS 95 4.3.5.1 Evaluation of Residual Energy 95 4.3.5.2 Evaluation of Delay 98 Multi-event Scenario 99 x 4.5 Simulation Results 100 4.5.1 Network Lifetime Evaluation for EEDARS 101 4.5.2 Residual Energy Evaluation for EEDARS 103 4.5.3 Number of Nodes Alive Evaluation for EEDARS 103 4.6 5 4.5.4 Delay Evaluation for EEDARS 104 4.5.5 Delivery Ratio Evaluation for EEDARS 107 4.5.6 Network Load Evaluation for EEDARS 109 4.5.7 Energy Consumption Evaluation for EEDARS 110 Chapter Summary 112 ENERGY-EFFICIENT DUAL-SINK ALGORITHM WITH FUZZY-BASED SINK MOBILITY PATTERN (EDAFSM) 113 5.1 Introduction 113 5.2 Fuzzy Logic Based Optimization 114 5.3 Model of Network 114 5.4 The EDAFSM algorithm 115 5.4.1 Initialization Phase of Network 115 5.4.2 Fuzzy Sink Mobility Scheme 116 5.4.2.1 System Inputs 117 5.4.2.2 Fuzzification 117 5.4.2.3 Fuzzy Inference 119 5.4.2.4 Defuzzification 120 5.4.2.5 Determination of Sink Destination 120 5.5 Experimental Results 123 5.5.1 EDAFSM Network Lifetime Evaluation 123 5.5.2 EDAFSM Number of Nodes Alive Evaluation 125 5.5.3 EDAFSM Packet Loss Evaluation 127 5.5.4 EDAFSM End-to-end Delay Evaluation 128 5.5.5 EDAFSM Delivery Ratio Evaluation 130 5.5.6 EDAFSM Network Load Evaluation 131 5.5.7 EDAFSM Energy Consumption Evaluation 132 5.6 EEDARS versus EDAFSM 134 5.7 Chapter Summary 137 xi 6 JOINT DUAL-SINK AND FUZZY-BASED GEOGRAPHIC ROUTING (JDFGR) 138 6.1 Introduction 138 6.2 JDFGR-S and JDFGR-M Algorithms 139 6.2.1 Fuzzy-based Greedy Forwarding (FGF) Scheme 139 6.2.1.1 Fuzzy Inputs for FGF 140 6.2.1.2 Normalization Phase in FGF 141 6.2.1.3 Fuzzy Rules for FGF 142 6.2.1.4 Fuzzy Output for FGF 143 6.2.1.5 Determination of Next Hop by FGF 144 6.3 Integration of Dual-sink and FGF Scheme 146 6.4 Performance Evaluation 146 6.4.1 Evaluation the Network Lifetime for JDFGR-S and JDFGR-M 147 6.4.2 Evaluation the Average Residual Energy for JDFGR-S and JDFGR-M 149 6.4.3 Evaluation the Number of Nodes Alive for JDFGR-S and JDFGR-M 151 6.4.4 Evaluation the Packet Loss for JDFGR-S and JDFGR-M 153 6.4.5 Evaluation the End-to-end Delay for JDFGR-S and JDFGR-M 155 6.4.6 Evaluation the Delivery Ratio for JDFGR-S and JDFGR-M 157 6.4.7 Evaluation the Network Load for JDFGR-S and 6.5 7 JDFGR-M 159 Chapter Summary 161 CONCLUSION AND FUTURE WORKS 163 7.1 Objective Achievement 163 7.2 Discussion on Contributions 167 7.3 Limitations of the Research 169 7.4 Future Work 170 7.4.1 Multi-path Routing 170 xii REFERENCES Appendices A – B 7.4.2 Cross-layer Mechanism 170 7.4.3 Obstacle Avoidance Method 171 172 182 – 183 xiii LIST OF TABLES TABLE NO. TITLE 1.1 Research questions related to the study 2.1 Comparison of greedy forwarding mechanisms in geographic routings 2.2 13 56 Comparison of sink selection mechanisms in multi-sink routings 2.3 PAGE 58 Comparison of sink movement mechanisms in mobile sink routings 60 3.1 Simulation parameters and related values 75 3.2 Simulation results for two baselines in different researches 75 3.3 Research framework for proposed energy-efficient joint dual-sink and geographic routing 4.1 Energy saving through hop reduction for 10 packets on a path with 9 hops 4.2 77 97 The delay minimization through hop reduction for 10 packets on a path with 9 hops 99 5.1 Fuzzy rules in the knowledge base 119 5.2 The priority of neighboring nodes based on cost and energy 123 6.1 Fuzzy rules in the knowledge base 144 xiv LIST OF FIGURES FIGURE NO. 2.1 TITLE PAGE Taxonomy of energy-efficient routing protocols in wireless sensor networks 18 2.2 The structure of a typical wireless sensor node 20 2.3 The node x in greedy forwarding scheme is S’s nearest neighbor to D 2.4 23 Delaunay triangulation (DT) structure and data forwarding path on the edges of DTs 26 2.5 Path selection with minimum hop count 37 2.6 Different number of sojourn points and covered area by the sinks 43 2.7 Joint routing mechanism and sink mobility 48 2.8 Grid strategy to support sink mobility 51 3.1 The steps of research methodology (operational framework) 66 4.1 The sensor field and the source nodes (five dark gray nodes on the circle) involved in an event 81 4.2 Path selection in EEDARS 82 4.3 Past events (event 1 & 2) and new event (event 3) accompany with sensors involved in routing 4.4 84 Rthreshold as maximum range for sink movement from the center of field based on the sink speed 91 4.5 Two scenarios for role switching mechanism in EEDARS 92 4.6 Sink movement pattern towards the source nodes. a-d) The sink moves three hops diagonally. e) The sink moves one hop horizontally 94 xv 4.7 The number of diagonal and horizontal hops between the mobile sink and the center of event region in an example with 9 hops and 10 packets 95 4.8 The Multi-event scenario 100 4.9 Average lifetime and related standard deviation value (source nodes produce 10 packets) 4.10 101 Average lifetime and related standard deviation value (source nodes produce 30 packets) 102 4.11 Average residual energy 104 4.12 Average number of nodes alive 105 4.13 Average end-to-end delay and related standard deviation value for all six strategies (source nodes produce 10 packets) 106 4.14 Average end-to-end delay and related standard deviation value for all six strategies (source nodes produce 30 packets) 107 4.15 Average delivery ratio 108 4.16 Network load at the end of simulation for all six strategies 109 4.17 Energy consumption for all strategies 111 5.1 Three simultaneous events accompany with sensors involved in routing 5.2 115 Membership functions for the fuzzy input variables cost and E 118 5.3 Membership functions for the output variable “priority” 120 5.4 Determining next destination by fuzzy-based sink mobility scheme. 5.5 Average network lifetime and standard deviation value (source nodes report 10 packets) 5.6 122 124 Average network lifetime and standard deviation value (source nodes report 30 packets) 125 5.7 Average number of nodes alive 126 5.8 Average packet loss 127 5.9 Average delay and standard deviation values for all strategies (sources produce 10 packets) 5.10 Average delay and standard deviation value for all 128 xvi strategies (sources produce 30 packets) 129 5.11 Average delivery ratio 130 5.12 Network load for all six strategies at the end of simulation 132 5.13 Energy consumption diagrams for all mobile sink strategies 133 5.14 Average network lifetime for single-event scenario 134 5.15 Average residual energy for single-event scenario 135 5.16 Average number of nodes alive for single-event scenario. a) Source nodes report 10 packets. b) Source nodes report 30 packets 5.17 135 Average packet loss for single-event scenario. a) Source nodes report 10 packets. b) Source nodes report 30 packets 136 5.18 Average end-to-end delay for single-event scenario 136 5.19 Average delivery ratio for single-event scenario. a) Source nodes report 10 packets. b) Source nodes report 30 packets 137 6.1 Number of source neighbors closer to the sink 140 6.2 Membership functions for the fuzzy input variables Hop, E and Radius 142 6.3 Membership functions for the output variable “priority” 143 6.4 Average network lifetime for single-event scenario 148 6.5 Average network lifetime for multi-event scenario 149 6.6 Average residual energy for single-event scenario 150 6.7 Average residual energy for multi-event scenario 151 6.8 Average number of nodes alive for single-event scenario 152 6.9 Average number of nodes alive for multi-event scenario 153 6.10 Average packet loss for single-event scenario 154 6.11 Average packet loss for multi-event scenario 155 6.12 Average delay for single-event scenario 156 6.13 Average delay for multi-event scenario 157 6.14 Average delivery ratio for single-event scenario 158 6.15 Average delivery ratio for multi-event scenario 159 6.16 Network load for single-event scenario 160 6.17 Network load for multi-event scenario 161 xvii LIST OF ABBREVIATIONS ACO - Ant Colony Optimization ADV - Advertisement AGEM - Adaptive Greedy-Compass Energy-Aware Multi-path AODV - Ad hoc On-demand Distance Vector APTEEN - Adaptive Periodic Threshold-sensitive Energy-Efficient sensor Network protocol CAGIF - Channel-Aware Geographic-Informed Forwarding CD - Critical Degree CDMA - Code Division Multiple Access CHs - Cluster Heads CPL - Cumulative Path Load CPU - Central Processing Unit CTS - Clear To Send DD - Directed Diffusion D-MPR - Disjoint Multi-path Routing DSA - Dynamic Sampling Algorithm DSR - Dynamic Source Routing DT - Delaunay Triangulation DT-MSM - Delay-Tolerant Mobile Sink Model EAM - Efficient Advancement Metric EAR - Energy-Aware Routing EEABR - Energy-Efficient Ant Based Routing EEDARS - Energy-Efficient Dual-sink Algorithm with Role Switching Mechanism ED - Exploratory Data EDAFSM - Energy-efficient Dual-sink Algorithm with Fuzzy-based Sink Mobility Pattern xviii ELBR - Energy Level Based Routing EM-GMR - Energy and Mobility-aware Geographical Multipath Routing FEEM - Fault-tolerant and Energy-Efficient Multi-path routing FGF - Fuzzy-based Greedy Forwarding GAF - Geographic Adaptive Fidelity GEAR - Geographic and Energy Aware Routing GLOBAL - Gradient-based routing protocol for LOad BALancing GMR - Geographical Multipath Routing GPS - Global Positioning System GPSR - Greedy Perimeter Stateless Routing ID - Identifier IEEE - Institute of Electrical and Electronics Engineers ILP - Integer Linear Programming JDFGR-M - Joint Dual-sink and Fuzzy-based Geographic Routing for enhancing lifetime in Mingle-event JDFGR-S - Joint Dual-sink and Fuzzy-based Geographic Routing for enhancing lifetime in Single-event LEAN - Local Event ANnouncer LEACH - Low-Energy Adaptive Clustering Hierarchy MAC - Media Access Control MCFA - Minimum Cost Forwarding Algorithm MFR - Most Forwarding Routing MGF - Merely Greedy Forwarding MLBRF - Multi-Sink Load Balanced Reliable Forwarding protocol M-MPR - Mesh Multi-path Routing MS - Mobile Sink MSDD - Multi-Sink Directed Diffusion MSLBR - Multi-Sink and Load-Balance Routing MSRP - Mobile Sink Based Routing Protocol NS2 - Network Simulator 2 OBGR - Online-Battery aware Geographic Routing algorithm PBR - Primary Based Routing PEGASIS - Power-Efficient Gathering in Sensor Information Systems PR - Packet Replication xix QoS - Quality of Service REDR - Residual Energy Depletion Rate REM - Rule Evaluation Method RFID - Radio Frequency Identification RTS - Request To Send RWP - Random Way Point SF - Selective Forwarding SPIN - Sensor Protocols for Information via Negotiation SPR - Shortest Path Routing SS - Static Sink TDMA - Time Division Multi Access TEEN - Threshold-sensitive Energy-Efficient sensor Network protocol TTDD - Two Tier Data Dissemination TTL - Time To Live WLDT - Weighted Localized Delaunay Triangulation-based data forwarding WLDT w/c - Weighted Localized Delaunay Triangulation-based data forwarding without checkpoints WSNs - Wireless Sensor Networks xx LIST OF APPENDICES APPENDICES TITLE PAGE A Calculating the Centroid of N Point 182 B A List of Publications 183