Network Model And Routing Strategy For DTN

Delay Tolerant Network(DTN)is a new type of network architecture proposed in the challenging environment where node resources are limited and the network has large delays or frequent interruptions.In this extreme network environment,how to perform effective routing becomes the key to improving network performance.Thanks to its strong survivability and multi-heterogeneity,delay tolerant network has broad application prospects in the field of disaster rescue communications.However,affected by the complex geographical environment and limited node resources,the delay tolerant network for disaster rescue scenarios is prone to reduce network performance due to excessive node energy consumption,and the limited ability of nodes to process messages will also cause network congestion.Therefore,how to use node energy reasonably and avoid network congestion become the key issues in the design process of delay tolerant network routing for disaster rescue.In response to the above problems,this thesis first proposes a delay tolerant network scenario model that combines the characteristics of disaster rescue.Considering the communication situation of multiple heterogeneous nodes in complex scenarios,the complex rescue devices that send messages,transmit messages,and receive messages in the network are abstracted as source node,intermediate nodes,destination node.In addition,this thesis describes the function and working mechanism of each DTN node in detail,and explains the selection method of neighbor nodes.Secondly,in view of the node energy consumption problem of the above model,based on the Max Prop routing algorithm of delay tolerant network,this thesis proposes an energy-aware Max Prop routing strategy(EA-Max Prop),which realizes the effective selection of the next hop node and achieves the effect of energy optimization.Compared with the existing Max Prop and Prophet,the average residual energy of nodes and the number of surviving nodes are improved,which can bring a relatively large improvement to the network performance.In addition,in response to the problem that Epidemic routing algorithm in delay tolerant network makes the load pressure of the nodes in the network too large,it is easy to exhaust network resources and cause network congestion.This thesis proposes an Epidemic with Bandwidth Feedback Routing Strategy(EBFRS).The method of bandwidth feedback and the possibility of data packet transmission are used for corresponding reservation or discarding,which realizes the congestion control of the network.Compared with the existing Epidemic and DRA routing algorithms under the same conditions,the proposed routing strategy has better performance in terms of average delay,packet transmission rate and average throughput,which is of practical significance.