Research On LT Coding In Peercast File-broadcasting System

Peer-to-peer technology is also called equivalence Internet technology. It is a newnetwork technology, depending on the computing power and bandwidth of theparticipants in the internet, and not relying on several servers. One of the importantgoals of P2P network is to let all the clients provide resources, including bandwidth,storage space and computing power.File sharing has been an important impetus of the development of networktechnology, and is the most typical application of P2P technology. But common filesharing system has such shortcomings as the dependence on seed node, and networkbandwidth utilization rate being not high. These problems are difficult to solve throughthe P2P technology itself.As a new technology in the communication field, Network coding has beenwidespread concerned and researched. As digital fountain codes, LT coding, thecharacteristics of low error rate in the satellite communication, multimedia broadcasting,wireless communications and other fields has a good application prospect. How toimprove LT coding decodes performance and applied to the P2P file radio system tosolve the existing problems is discussed in this paper.The main job in This paper are as follows:1. This paper introduced the present situation and the development of the P2Ptechnology, and expounds the thoughts and the Constructing algorithm Of LT coding.2. Analyzing the PeerCast file broadcasting system, this paper studied its workingprinciple, agreements, and main algorithms are.3. Analyzes the disadvantage and deficiency of existing PeerCast file radio system,in the thorough research LT coding on the basis of tectonic and advantages, this paperputs forward a kind of PeerCast documents based on LT coding of the implementationscheme of broadcasting system, analying and comparing the the selection of decodingalgorithm and determing appropriate decoding algorithm eventually.4. In PeerCast file broadcasting system, this paper illustrated the realizationmethod of decode download based on to file upload using LT coding and download enduse LT coding, and the actual PeerCast file broadcast system, thus the system test basedon the PeerCast documents LT coding was broadcast system.