| As Internet technology continues to upgrade or improve, video broadcast technologyhas evolved from the early days of the client/server model to the transformation of themode of P2P technology. Thus it improves the performance of the broadcast network, andreduces the dependence on server bandwidth. But there is always a considerable part of thenode’s upload bandwidth which is not being fully utilized. For this deficiency, networkcoding was introduced into the P2P network, network coding effectively enhances networkperformance and improves network throughput.This paper presents a new P2P video broadcast system based on network coding.Compared with the traditional P2P live streaming, the video data is divided into largervideo segments, each segment has a unique identifier, then each segment continue to bedivided into a plurality of data blocks, all data in the sub-block will be randomly assignedwith a coefficient. A new block of data generates after multiplying these data blocks by thecoefficient of the coefficient vector, then this data block is forwarded to the downstreamnode, together with the unique identifier and the coefficient vector, downstream nodereceives the encoded data block from a plurality of different neighbor node, when receivedenough amount of linearly independent coded blocks within a segment, the original videosegment can be decoded.In this article, nodes push Buffer map (BM) to each other. The frequency of nodebuffer state changes is low due to the use of a larger video segment, thus the BM exchangefrequency is reduced, which effectively reduces the impact of the network bandwidth due toredundant pair of control information. Nodes which receive BM will take the initiative topush the encoded video segment. In this article, if no data is buffered when a node receivesa BM from neighbor, it will forward the BM to its neighbors once, thus the data pullefficiency improves effectively thereby improving the node data transmission efficiency. Inaddition, the nodes in the network will use the Gauss-Jordan elimination method for dataelimination while receiving data at the same time, data reception and elimination processare in parallel, which effectively reduce the decoding delay. It is also proposed that thereceived encoded data and the decoded data should be cached for some time, this cangreatly increase the amount of live video streaming data sources. Because coded data blockcontains a summary of all of the information of an video segments, each coded data blocks within the same video Break are equivalent, so that multiple nodes can be simultaneouslysent to a downstream node coded data blocks, without the concern of sending duplicate data,and even if there is a loss of the encoded data blocks, we do not need a retransmission, aslong as a certain number of coded data blocks received from other nodes original segmentscan be successfully decoded, and therefore unreliable transport protocol UDP can be usedin the transport layer which reduces the overhead of network transmission.In order to verify the efficiency of the proposed algorithm, the article finally achievethe realization of two contrasting protocol, one is a conventional live P2P protocol, theother is the inclusion of network coding P2P Streaming Agreement. Through the simulation,the data obtained were compared. In a variety of network conditions, and compared withthe existing conventional P2P video broadcast technology, the transmission schemepresented in this paper to enhance the overall performance of the network. |
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