Research On Delay Tolerant Network Routing Strategies And Its Application On ANDROID Devices

Mobile communication systems utilize fixed infrastructures to make sure an end-to-end connection.In some hostile environments,base-stations or access points may fail to work properly,the coverage range cannot reach seamless requirement either.Delay-Tolerant Network(DTN)is proposed to mitigate these problems by introducing a bundle ayer between transport layer and application layer and using a store-and-forward scheme,so as to work in intermittent situations,becoming a hot research topic in wireless technology development.This paper analyses emergency scenarios where network infrastructures may fail due to catastrophes.In order to make users interconnect with others without the infrastructures,by programming,it implements DTN on Android smartphones,where DTN nodes can be self-organized and transfer bundles in a single or multiple DTN regions.The main research work can be summarized as followed:1.The starting point is from investigating DTN background,key techologies as well as the researching status in domestic and foreign.Development based on Android platform,it analysis and researches DTN architecture,summaries the components of DTN networks,routing strategies and DTN applications on multi platforrms,as well as analysis of DTN2 platform and Bytewalla project.2.Research,analysis and design the DTN communication system on Android platform.It focuses on implementing voice communication function,neighbour discovery function and dynamic routing function by programming.Enhance broadcast neighbour discovery process and list-exchanged epidemic routing algorithm.After DTN Service turns on,DTN node can detect and discover other peers in range by sending UDP broadcasting,and make use of the received addressing information to establish links and update routing tables,then forward the dedicated messages according to the exchanged lists.3.Test and verify the voice communication function,neighbour discovery function and dynamic routing function by experiments.DTN communication system is installed on Android devices as a mobile phone application,and verifies the above functions in two DTN regions.DTN node can transfer whatever it receives in one DTN region automatically to another DTN region in a relatively long lifetime and by this way it can accommodate the challenged environment.