Design And Performance Research Of TCP Wireless Communication Based On Embedded System

With the constant progress of communication technology recent years,wireless communication technology based on embedded system have been more and more widely used in industry,agriculture and so on.Fast,reliable and safe wireless communication technology is also one of the important research contents in “industry 4.0” and “intelligent manufacture” concept.Under this background,this paper design an embedded wireless communication platform and focus on the congestion control algorithm of TCP protocol to improve the performance of communication.Compared with other short distance wireless communication technologies,Wi-Fi has the advantages of high communication rate and good safety performance which can meet the requirement of industry application very well.In this case,this paper choose MediaTek chip of MT7620 a to develop Wi-Fi hardware platform,describe the main hardware circuit explicitly and transplant OpenWrt operating system into it to realize Wi-Fi wireless communication.The TCP protocol which based on wired communication network will reduce the sending window and slow down the data transmission rate when network congestion happened.While in wireless network,the TCP protocol will also slow down data transmission rate when loss packets because of bits error and come to the result that the bandwidth utilization decreased.In this case,this paper propose a bandwidth estimation adaptive algorithm according to current popular wireless TCP protocols such as TCP Westwood,TCP Vegas and so on.The new algorithm will estimates the current available bandwidth and analyze the network congestion status according to the packet round-trip time,reasonably adjust the sending rate to improve the TCP wireless communication performance.Then simulate the bandwidth estimation adaptive algorithm on NS2 platform and the result shows that this algorithm can effectively improve network throughput.Finally transport the bandwidth estimation adaptive algorithm into MT7620 a embedded platform,dynamically load the algorithm module to OpenWrt system and use Netperf network performance testing tool to test it,the result shows that the algorithm can also effectively improve network throughput and latency.