Research On Congestion Control Of Audio And Video Transmission In Mobile Networks Based On Rate Adaptation

With the development of communication technology and streaming media technology,There are more and more audio and video content in the network.The network congestion may cause the transmission delay to increase sharply and the network performance to decrease rapidly.The real-time audio and video data transmission generally used the RTP protocol or UDP protocol,neither of which provide quality of service assurance or network congestion control,so the audio and video applications should be considered the congestion control while using the two protocols.According to the characteristics of audio video applications,this paper focuses on the congestion control technology to improve the quality of audio video data transmission on the premise of protecting the TCP data flow.Congestion control mechanisms need to consider the following three points.Firstly,the new congestion control should be in good agreement with the congestion control mechanism of TCP,that is,the new TCP congestion control mechanism should be TCP-friendly.Then,as real-time audio and video applications require a certain quality of service guarantee,so the congestion control mechanism for audio and video applications should not excessive adjustments to avoid audio and video applications are not available.Finally,in the mobile network environment,because of its high bit error rate,congestion control is needed to consider more.For the problems concerned above,the main work of this paper is as follows:1.The congestion control mechanisms is compared and the congestion control mechanism of TFRC(TCP Friendly Rate Control)is analyzed concretely.On this basis,TFRC is used in the mobile network environment to transmit audio and video data.2.Using the spike algorithm based on the TFRC protocol,So that TFRC can distinguish the reasons for packet loss to avoid unnecessary reduction of data transmission.3.Aiming at the service quality requirements of audio and video applications,the TFRC mechanism is improved to ensure the availability of audio and video applications and avoid serious network congestion.4.The improved TFRC mechanism is simulated,and the experiment results show that the improvement has achieved good effect.