Research On High Efficiency Scheduling Algorithm Of Streaming Media Service In Concurrent Multipath Transfer

With the rapid development of Internet communication technology,streaming media technology has brought a revolutionary leap for online media.Streaming media services are continuous,real-time and time-consuming.The existing network with best-effort feature cannot provide the QoS guarantee for transmission.The use of Concurrent Multipath Transfer(CMT)is an important solution to improve the quality of streaming media transmission.The Concurrent Multipath Transfer based on SCTP is a bandwidth aggregation technology which can effectively improves the throughput of the end-to-end communication and ensures the reliability and fault tolerance of the system.But the current SCTP-CMT protocol uses the round robin algorithm to select the transmission path and does not distinguish the packet priority.Because each transmission path has the different characteristics,the packet out-of-order arrival may occur to the receiver.In this situation,the use of CMT may reduce the quality of streaming media services.In view of the above problems,the main work of this paper is as follow:Firstly,it describes four kinds of commonly packet scheduling strategies and analyzes its advantages,disadvantages and applicable scenarios.It details three kinds of streaming media encoding and decoding techniques and extracts the characteristics of streaming media data frames which lay a theoretical foundation for subsequent research.Sencondly,it proposes a packet scheduling strategy--MRDF based on the minimum path relative delay which adds three new control block formats for time stamping of data transmission and reception.It defines and derives the formula of the relative one-way delay and details the specific operations of the sender and receiver in the multiple transmission states.Through the algorithm,the terminals can select the path with the minimum one-way delay to send the data packets and try the best to ensure the data packets arriving in sequence.Thirdly,it presents a streaming media video quality assessment framework and modifies the NS2 SCTP module to achieve the MRDF algorithm and assessment framework.It simulates the data stream and video stream transmission of MRDF and RR algorithm in variety scenarios.It respectively uses TSN,throughput,CWND,PSNR and MOS to evaluate the system which verifies the MRDF algorithm can effectively reduce the out-of-sequence of data packets and ensure the data arriving in sequence.MRDF can enhance the quality of streaming video services and ensure the video playback smoothly.