Research on connectivity for vehicular sensor networks based on directed diffusion
基于定向扩散的车辆传感器网络连通性研究

Aims to the problem of connectivity in vehicular sensor networks,proposed a kind of directed diffusion gradient field with slidable roadside-node gradient(DDGF-SRG),and gave the dynamically adjusting rules for DDGF-SRG.By giving an invariable gradient value to every roadside node,divided the large scale vehicular sensor network into several local sub reigns around the relevant roadside node,to achieve the purpose of distributed setting up the directed diffusion gradient field for every sub reign and enhancing the real time operation function.By giving a variable data-aggregating gradient value to every vehicular node,formed the directed diffusion gradient from vehicular nodes to the corresponding roadside node.By giving a variable data-aggregating gradient value to every roadside node,set up the directed diffusion gradient from roadside nodes to the corresponding lower-gradient-level sub reign,and linked all the local directed diffusion gradients into one global directed diffusion gradient field,namely the DDGF-SRG.Theoretical analysis and simulation results invalidate that the real time connectivity will be improved greatly with the help of dynamical adjusting and vehicular-nodes’ carrying capability for data packets in the period of delay tolerant time.