ABSTRACT
CONTENTS 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 5.2 Understanding and Modeling Opportunistic Networks . . . . . . . . . . . . . . . 126
5.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 5.2.2 Related Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 5.2.3 Characterizing and Modeling Human Mobility . . . . . . . . . . . . . 128
5.2.3.2 The Underlying Markov Chain . . . . . . . . . . . . . . . . . 130
5.2.4 Fundamental Properties of Opportunistic Networks in STEPS 132
5.2.4.1 Inter-Contact Time Distribution . . . . . . . . . . . . . . . . . 133 5.2.4.2 Contact Time Distribution . . . . . . . . . . . . . . . . . . . . . . 133
5.3 Small-World Structure of Opportunistic Networks . . . . . . . . . . . . . . . . . . . 135 5.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 5.3.2 Related Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 5.3.3 Small-World Phenomenon in Opportunistic Networks . . . . . . 137
5.3.3.1 Dynamic Small-World Metrics . . . . . . . . . . . . . . . . . 138 5.3.3.2 Opportunistic Network Traces Analysis . . . . . . . . . 141
5.3.4 Modeling Dynamic Small-World Structure with STEPS . . . . . 144 5.3.5 Information Diffusion in Dynamic Small-World Networks . . 145
5.4 Mobile Cloud Opportunistic Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 5.4.1 Related Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 5.4.2 Impact of Mobility on Mobile Cloud Computing . . . . . . . . . . . 149
5.4.2.1 Mobility Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 5.4.2.2 Particle Swarm Optimization . . . . . . . . . . . . . . . . . . . 150 5.4.2.3 Simulation Results and Discussion . . . . . . . . . . . . . . 151
5.4.3 Impact of Network Structure on Mobile Cloud Computin . . . 153 5.4.4 Resilience of Mobile Cloud Computing Service . . . . . . . . . . . . 153
5.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
5.1 Introduction Opportunistic networks are dynamic networks based on nodes’ intermittent contacts. This type of network was shown to be the sole communication means in many extreme situations, especially when an infrastructure-based communication is not possible, for instance, deep space communications, disaster recovery networks, and battlefield networks. Opportunistic networks pave the way to a pervasive and universal communication environment in which opportunistic communication can play an important role by its capacity to free users from infrastructure.
