Research On Efficient Transmission Mechanism In Wireless Networks

Wireless network transmission has become an indispensable part of daily work and life.Wireless network itself has the defect of high bit error rate,so improving the efficiency and reliability of wireless network has always been the research focus of wireless network.In recent years,forward error-correcting codes have been applied to wireless transmission.By adding redundant packets,they can be repaired without retransmitting.This thesis studies the fountain code technology in forward error-correcting code technology.RaptorQ is used on UDP to achieve efficient and reliable data transmission under poor channel quality.At the same time,an efficient mechanism for multipath transmission is designed.This thesis proposes a RQUDP(RaptorQ UDP)based on UDP framework,which uses RaptorQ coding to transmit data.It can provide efficient and reliable data transmission for high bandwidth and packet loss-prone networks.Firstly,the encoding and decoding process of RaptorQ is optimized by changing the execution order of the encoding module and adding multi-threads.The redundancy is automatically adjusted by evaluating the channel packet loss rate to improve the decoding efficiency.By testing the efficiency of different encoding sizes,the most suitable encoding size is determined.The scheme of feedback plus forward error correction is adopted to make full use of the channel;the two schemes cooperate with each other to ensure efficient transmission and reliability;the rate is controlled by sliding window,and the traffic is dynamically allocated according to the state of different paths in multi-path transmission,thus realizing the efficient traffic control mechanism in wireless network,making the transmission more fair and efficient.In order to avoid congestion,the reason of packet loss is judged when packet loss occurs,and different reasons for packet loss are dynamically adjusted to make it more compatible with the transmission mechanism of RQUDP,and the congestion control mechanism for multipath transmission is designed;the connection management mechanism,path management mechanism and packet scheduling mechanism in MPUDP are realized;and the transmission system of wireless network with high efficiency is tested in different delays.The transmission speed under delay and packet loss rate proves the efficiency of RQUDP in wireless network transmission.