Research Of Network Coding Optimization In The Mobile P2P Network

In recent years, with the rapid development of mobile communication technology, all kinds of mobile communication equipment is commonly used in everyday life. The optimization of the mobile P2P network system performance becomes a new developing direction. The characteristics of the mobile P2P network are network topology continual change, inconformity of network layer addressing and identification, strong network openness, nodes resource-constrained. These characteristics account for link unreliability, block scarcity and transport security and other challenges. Therefore the network coding technology is introduced into the mobile P2P network. However, using coding technology, we have to consider the energy of coding nodes, decod:ing complexity, and the data upload delay. How to effectively use the network coding technology improve mobile P2P network system performance, and reduce the energy consumption and uploading delay, this is one of the hot spots in the data distribution technology researches.The main research in this thesis includes the following two points:(1) Using generational network coding in mobile P2P network, coding node randomly select data blocks in a data segment and encode. The greater probability value of data segment, the more likely selected; the smaller probability value, the less chosen. Obviously, with the greater probability,the degree of a data segment is rising faster than the smaller probability. Consequently, it make the different data segment can not be evenly distributed in network. In allusion to the uneven distribution of different data a segment, priority coding strategy is proposed in this thesis. Using priority network coding technology, coding node firstly select data blocks with smaller weights, encode and forward, make different data segment to be uniform distribution.(2) The existing coding technology doesn’t control the behavior of coding node,which does or doesn’t encode. In allusion to this phenomenon,the feedback adjustment strategy is proposed in this thesis. According to network status, feedback adjustment strategy controls the behavior of coding node. When mobile P2P network is in a floating state,it will use data distribution technology of priority network coding strategy; when the mobile P2P network reaches saturation state, it will use the traditional technology of data distribution technology. Using the feedback adjustment strategy, uploading time delay and energy consumption can be effectively limited.The priority network coding strategy and feedback adjustment strategy proposed in this thesis,on the premise of guarantee the promotion network overall transmission performance ,can balance the distribution of different data information, reduce the additional storage and computing cost of encoding and decoding operation in forwarding nodes, reduce the network latency, and prolong the survival period of mobile node.