Research On Bundle Protocol And Design Of Simulation Platform

Delay tolerant network is a new kind of network architecture. It is designed for the challenged network environments which are characterized by limited long delay and intermittent connection.Under the extreme network environment, the path of end to end from the source to destination node may not exist.The absence of continuous end-to-end path among nodes result in a great challenge to the reliability of the network.The traditional end-to-end transport protocol cannot apply to delay tolerant network.So Bundle protocol was proposed by IRTF organization, by point-to-point custody transfer mechanism to ensure the end-to-end reliability of data transmission.This paper studies the reliability of the Bundle protocol in intermittent connected network and the simulation platform building, mainly includes the following contents:Analyzed and studied the delay tolerant network development present situation and the system architecture.Analyzed the key technologies involved in the Bundle protocol specification.According to the protocol specification,this paper studied the modular design of Bundle protocol,and described the concrete realization of each module.The scheme supports the core of the message processing,including transport, forwarding, dispatch, receipt, delivery, custody, deleting, etc.For intermittent connected network,this paper analyzed the inadaptability of traditional end to end transport protocol.Studied the point-to-point custody transfer mechanism of the the Bundle protocol.The mechanism made the end-to-end transmission into multiple point-to-point transmission by using predictable connection,reduced the blindness of sending messages,improved the delivery rate of the message, and protected the reliability of data transmission.Construction of a continuous time markov chain model to analyze the effect of link disruption on delay.The performance of TCP protocol and Bundle in the intermittent connectivity network is verified by simulation,the results showed that the latter had a better performance.According to the implementation scheme,Bundle protocol simulation platform was designed, and implemented on a Linux system.The implementation scheme introduced the overall architecture of the simulation platform and main functions of the protocol simulation software modules.In view of the overall scheme,built a test environment of simulation platform based on Leo satellite network,designed the multiple test scripts, collected the test data and analyzed the test results.Verified the effectiveness of the protocol implementation schemes and the performance advantages of the Bundle protocol in intermittent connectivity network.The research achievements of this paper provided high reference value for carrying out the interconnected network of space-ground to our country.The transmission performance of the protocol still faced severe challenges,since the DTN network had a various type of network and a complicated environment.Therefore,it is needed to continue to optimize the data transmission performance of the Bundle protocol in future research work.The simulation platform implemented in this paper had a extensibility insufficient which can't support any network scenarios,and therefore build highly scalable simulation platform is also need to to be considered in the future research work.