Design And Implementation Of A Routing Recommendation System For DTN Oriented To Handheld Devices

In recent years,with the rapid development of the handheld devices(such as the mobile phone and the smart wearable device,etc.)and the promotion of its short-distance communication capabilities,the Handheld DTN network emerges at the right moment.The Hand-held DTN Network,also known as the Pocket Switched Network(PSN),is a kind of Ad Hoc Network formed from the handheld devices to achieve DTN protocols,which owns its simple structure,fast networking,convenient usage,strong survivability,rand network communications without infrastructure as well as other characteristics and has become a hotspot in the DTN network.The handheld device makes use of a certain fixed routing algorithm to complete the message transmission,where exists some limitations.In addition,it will also bring another problems including considerable resource consumption,high packet loss rate and cannot provide various communication services for users.Therefore,a DTN routing recommendation system for handheld devices is proposed.Firstly,considering the fact that the handheld devices only use a single fixed DTN routing algorithm for communication,which causes larger resource consumption,higher packet loss rate and less diversification of communication,the thesis constructs a handheld DTN routing recommendation model for handheld devices.It meets various communicative demands of users through expanding diverse routing algorithms in the bottom communication module.Besides,it recommends the optimal routing algorithm to the bottom communication module making use of the recommendation module.The bottom communication module calls the routing algorithm recommended by the recommendation module to complete the message transmission,so as to reduce the resource consumption,the packet loss rate and meet the diverse needs of users.Secondly,in order to select the optimal or suboptimal routing algorithm,this thesis presents a recommendation method based on adaptive equipment local resources with the consideration of the demands of users,system resources and equipment density.Among them,the demands of users are converted to the desired network performance.Meanwhile,the resource equipment and the equipment density decide the single and multi-copy routing protocol probability.Eventually,the routing algorithm with less equipment resource consumption,which can meet the demands of users,will be selected depending on the network performance and the selective probability.Then it will transmit the routing algorithm to the underlying communication module for execution.Finally,the thesis implements a routing recommendation system for DTN oriented to handheld devices,with invoking a variety of routing algorithms to complete message transmission to verify the validity of the routing model.The system verifies the validity of the proposed method by setting the experimental parameters such as the density,the message size,the message format,the resource and so on.