Research On Sociability-based Data Forwarding Scheme In Opportunistic Networks

Wireless Ad Hoc network has attracted more and more attention recently. However, inpractical, due to environmental constraint and node’s frequent movement, it is difficult toestablish and maintain a stable end-to-end connection between source node and destination node,which makes the traditional transmission mode inapplicable in such network. To achieve datatransmission in such network, a new highly flexible network with novel transfer mode is proposed,which is called opportunistic network. Opportunistic network can achieve data transmission viathe opportunistic contact formed by node mobility; therefore, it is more adapted to the practicalnetwork environment and has very promising future in the military, commercial and civil fields.As it relates to the practical application of opportunistic network, data forwarding mechanismis the most important issue which needs to be researched, but it also faces great challenge due tothe intermittent connection of network. Moreover, the application areas of opportunistic networkare varied; the mobile characteristic of nodes in different application area is vastly different,which requires us to work closely with practice scenarios when designing data forwardingmechanism; that is to say, it is difficult to design a common data forwarding mechanism that canbe applied to all application area. Against the human-carried mobile devices application scenariosin opportunistic network, this paper proposes sociability-based data forwarding mechanismaccording to the comprehensive analysis of nodes encounter characteristics and mainly includesthe following two aspects:(1)Spray and wait is a classic data forwarding mechanism in opportunistic network, it caneffectively reduce network overload by limiting the number of message copies in the network;however, in human-carried devices formed opportunistic network, due to the existence of socialrelationship, the message forwarding capability of node is quiet different, which makes spray andwait inefficient in such networks. Against this problem, this paper improves spray and wait byapplying the sociability of nodes to it and gets its performance improved effectively.(2) In human-carried devices formed opportunistic network, the encounter characteristic ofsocial nodes varies with time, which affects the data forwarding capacity of nodes. According tothis, TEMF, a data transmission scheme based on time-evolving meeting factor prediction isproposed. TEMF acquires efficient message delivery by choosing different nodes to forwardmessage in different time according to node’s forwarding capability.