Research Of Network Coding-based Wireless Data Transmission Technology

Network coding allows the relay nodes code the received data which sentout by different source nodes, and then forwards the coded data to thedestination nodes. According to the established protocol, the destination nodesdecode the coded data into some original information, they can obtain their data.Network coding can improve the system throughput and network bandwidth.Researching on wireless network coding, has important implications for thedevelopment and promotion of this technology, as well as carrying out thefollow-up study applications. In practice of the wireless network applications,since the signal has the characteristics of multicast, other nodes within thebroadcast range of each node, can receive the message that node sends out.Therefore, a series of data information will be coded to a packet. Transmittingthe same amount of data can contain more useful information. The transmissionmay burden more available information to raise channel utilization and networkthroughput.In view of this, the paper studies the wireless data transmission technologybased on network coding, in order to further this technology matures, andprovides a better choice for practical applications. The paper studies thefollowing:First, the paper detailed introduces the operational principle of severalnetwork coding protocols. Some protocols are implemented in the networksimulator, the paper analyzes the data results.Second, specific to wireless network data packet scheduling, the paperresearches the opportunistic and fairness scheduling mechanism based onnetwork coding. The relay node keeps different queues in its buffer for differentflows. Whether a packet is transmitted with network coding, it is determined bythe queue state and traffic arrival rate. And then the paper makes a quantitativeanalysis, how big the buffer size the relay nodes needs.Third, on the basis of the opportunistic and fairness scheduling mechanismbased on network coding, based on existing network coding algorithms, thepaper improves insufficient performance, establishes a new model of networkcoding algorithm, analyzes of its performance. The paper studies existingretransmission methods, analyzes the strengths and weaknesses of theirperformance, on this basis, proposes the modified way, a wireless unicastretransmission mechanism with network coding and queue schedulingmechanism. The proposed packet selection algorithm will select packets toencode and retransmit according to packet bitmap. The paper also proposes apriority based packet scheduling algorithm and introduces the performance efficiency of the retransmission mechanism from its packet loss rate, delay andpacket number ratio.Fourth, the paper studies wireless multicast data transmission betweenmulti nodes, determines multi-node packet queuing model in wireless multicastnetwork. And then, according to the message queue model, proposes a wirelessnetwork coding algorithm based on node set. The algorithm classifies each typeof network nodes as a set based on the broadcast domain of every node. On thedata exchange behavior between sets, the paper researches wireless datatransmission technology based on network coding in wireless multicastenvironment.