Research And Application Of Reliable Multicast Based On The Stream Media

With the development of the IP multicast technology, the stream media application alsogets more and more widespread. However, the real-time applications of stream media have thecharacteristics that data quantity is big, the detention and the vibration are high, so that the streammedia data often has burst loss. Moreover, the IP multicast inherent has the transmission mode of"does everything possible". Therefore, the IP multicast application of the stream media is unableto guarantee the reliability of the data transmission, so that the feeling view quality of the streammedia is affected seriously by the media which returns. Thus, the reliability of the stream mediareal-time application is an urgent question to solute. This article mainly is to the stream mediacharacteristic and the limitation of the IP multicast, the reliability of the IP multicast gets to befurther researched. The following is mainly several points:First, the characteristic of the reliable multicastThe essential reliability multicast technologies were researched such as data missing andexamination, feedback, re-transmit and data reliability, then the reliable multicast protocols isanalyzied detailedly, whose good and bad points were carried on detailed comparions. Thus it laysthe solid foundation for the reliable mechanism in the third chapter.Second, the reliable multicast control mechanism is proposed.Primarily, the existing error control mechanisms were studied such as the error correctioncode way, the automatic re-transmit feedback way as well as the mix error controlmechanisms, whose good and bad points were carried on comparative analysis. According to thestream media data which has burst loss characteristic, the Interweave code technology is proposed,and its principle was exoatiated on detailedly. Then, the entia of the mix mistakecontrol way andInterweaves code technology mechanism was proposed.Next, according to the present situation of network congestion and IP multicast itself, theextension of the congestion control protocol mechanism and TCP-Friendly fairness characteristicwere studied, the predecessor's congestion control methods were analized, the improvedcongestion control mechanism of reliable multicast based on the sent rates is proposed.Third, the reliable multicast system of the stream media was designed and realized. According to the error control mechanism and the congestion control mechanism whichproposed according to the third chapter, the reliable multicast system frame of the stream media isdesigned separately from the overall,the server and the client in the fourth chapter. And from themodule function angle, the reliable multicast system software is developed and tested in thewindows platform using vc++.