Research On Routing Mechanism Based On Ant Colony Over Mobile Peer-to-Peer Networks

With the great success of peer-to-peer mode over wired networks and the rapid development of wireless communication technology, mobile peer-to-peer network (MP2P), as a new kind of network, appears. It is a peer-to-peer self-organization system which consists of a set of mobile nodes with wireless transmission and receiving equipments connected through multi-hop. MP2P draws extensive attention, due to its promising application prospect in disaster relief, multi-users cooperative work, etc. Routing mechanism is a key issue in MP2P. One of important tasks is how to design effective routing mechanisms to deal with its characteristics such as limited energy, probable selfish nodes, rapidly changing network topology, etc.For the advantages of self-organization, ant colony optimization (ACO) has been successfully applied to many fields. Routing mechanism over MP2P is an appropriate example. Though some routing mechanisms based on ant colony optimization have been proposed recently, they only focus on dynamic topology, ignoring some other characteristics, such as rational and selfish nodes, heterogeneous and limited energy. Apparently, there exist some drawbacks when they are applied in MP2P. This dissertation firstly proposes a common framework of ant routing mechanisms and a basic ant routing process, and then proposes three routing mechanisms aiming at three characteristics of MP2P separately. Lastly, it integrates these three mechanisms into a cooperative energy-saving ant QoS routing mechanism. The main contributions are generalized as follows.(1) First of all, this dissertation proposes a common framework of ant routing mechanism and develops a basic ant routing process based on that framework. It analyzes the core principles of routing without extra overhead. Taking into account no free lunch theory, ant routing mechanisms are divided into four key components:route discovery, route maintenance (including route failure handling), data forwarding and pheromone evaporation. Every kind of settings in each component is analyzed and tested through simulation experiments.(2) To meet rapidly changing network application requirements in MP2P, a multiple-metric ant QoS routing mechanism is proposed. Every QoS metric parameter is reflected by a kind of pheromone. Based on different application requirements, its weighting is adjusted in order to provide appropriate routing. Simulation experiments show its performance.(3) For selfish nodes in MP2P, an ant routing mechanism based on selfish node detection and punishment is proposed. The detection is implemented by allowing nodes to express their subjective forwarding probability freely and choosing nodes with high integrated forwarding probability. The punishment is implemented by punishing selfish behaviors and forcing them to cooperate. Simulation experiments show its performance.(4) For heterogeneous and limited node energy in MP2P, an energy-saving ant routing mechanism based on self-aware is proposed. Through HELLO packets used to keep network connected, nodes can know the quality and the future living trend of routing, the remaining node energy, etc. Then nodes choose the most appropriate routing and balance energy to prolong the network lifetime. Simulation experiments show its performance.(5) For the characteristics of MP2P, a cooperative energy-saving ant QoS routing mechanism which integrates three routing mechanisms above is proposed. It combines selfish node detection and punishment, self-aware technology and multiple-metric to choose appropriate routing. It provides QoS assurance for different applications and achieves cooperation and energy-saving. Simulation experiments show its performance.