On Topological Properties of Diffusion Network for Instant Messaging System

We propose and study a message diffusion network model of IM system with local-world preferential connections and acquaintance introduction mechanisms, which exist in IM system. We put forward the algorithms to generate the message diffusion network model and through simulation results we talk about the topological properties of this network. The topological properties such as degree distribution, clustering coefficient, average path length along with the community structure are simulated and analyzed. We can draw the conclusion that the degree distribution of this network obeys the power-law distribution, and this network has a short average path length and a high clustering coefficient. In a word, the simulation result shows that the message diffusion network of IM system is a complex network possessing properties of scale-free, small-world and clear community structure.