Routing Protocol Research Based On Formal Categorization Of Characteristics

Opportunistic network is a kind of ad hoc networks which exploits the nodes' meeting opportunities to transmit messages. The concept of opportunistic networks covers a wide field of wireless of wired-wireless combined ad hoc networks which have complex and unstable topology, and are intermittent connected or even non-connected because of the nodes'movements. The applications of opportunistic networks have extensive prospects. The research on opportunistic networks has prospective significance.The current research on opportunistic networks is relatively loose due to the complex and unstable network topology, therefore a certain routing protocol usually has poor adaptability for different applications of opportunistic networks. In order to improve the routing protocols, a series of characteristics are extracted formally based on the collation and analysis of current research, and then a taxonomy research is performed. The routing protocol for uncooperative opportunistic networks and a series of heuristic routing protocols are given out based on the characteristics and taxonomy research. The main innovative contributions of this dissertation are as follows:This dissertation defines the category and concept of opportunistic networks, then has a comparative study on the synthetic mobility models and realistic mobility models. The behaviors of infrastructure nodes and uncooperative nodes are analyzed. The dissertation collated the current routing protocols and points out the evolvements of different protocols. The problems and prospects of the applications of opportunistic networks are demonstrated.This dissertation proposes a unified definition system on the concept of opportunistic networks, and then the network nodes, messages and routing protocols are formal defined in this system. The characteristics of the nodes'geographic preferences, time preferences, community partition, movement terminals (time and space limitations) and the characteristics of infrastructure nodes are studied and extracted based on the definition system, and these characteristics are formally defined. This definition system provides the research on opportunistic networks a new and open platform.This dissertation researches on the categorization of opportunistic networks according to the nodes' community characteristics, movement limitations and infrastructure characteristics. Evaluation standards for network knowledge acquisition degree and network structure design are proposed. The categorization and evaluation standards provide the research on opportunistic networks a top-down method.This dissertation researches the behaviors of the uncooperative nodes in opportunistic networks, points out a way for detecting the uncooperative nodes, and then proposes a judge-node-based method for detecting these nodes to improve the routing protocols. Experiment result shows that the detection method has a better performance than the ordinary ones in uncooperative opportunistic networks. This method is a new thinking of research on routing protocols in uncooperative opportunistic networks.This dissertation researches the characteristics of each category, and then proposes a series of heuristic rules in order to improve the routing protocols. Experiment result shows that the heuristic rules based on the characteristics categorization have better performances than the ordinary ones in opportunistic networks. The heuristic rules are open, extendable, and have high adaptability for different applications of opportunistic networks.