Method for error control

Abstract

The invention discloses a method for error control, which is applicable to the field of communication. The method can effectively improve the reliability of network data transmission. The core of the method is to improve the defect that as the traditional UDP only retransmits information source packets when being applied to error retransmission, the retransmission times increase obviously under the network environment of high packet loss ratio; and by utilizing the method, the UDP also can retransmit redundant packets which can effectively restore information source packets except the information source packets when being applied to the error retransmission, thus being capable of reducing the retransmission times obviously under the network environment of high packet loss ratio. Under hightime-delay network environment or multicast environment, the method also can obtain good effect.

Description

technical field [0001] The invention relates to an error control method, which is suitable for the communication field. Background technique [0002] With the development of fixed broadband and mobile data networks, video and audio streaming media applications are widely used, such as visual communication, IPTV, VOD, etc. In these networks, data transmission is based on IP data packets. Due to various reasons, such as router buffer overflow and channel interference, the checksum of IP packets may be wrong, and data packets may be discarded during transmission. Therefore, most The application will have an error retransmission mechanism. Although TCP has an error retransmission mechanism, because it needs to ensure reliable transmission, it sometimes brings side effects such as long delays. Therefore, most video and audio streaming media applications are carried by UDP protocol and implemented on top of UDP as needed error control. Traditional UDP applications only retransm...

AI Technical Summary

Problems solved by technology

The Chinese patent with the patent application number 200510094410.8 has abandoned the traditional error retransmission mechanism: the sender encodes the source packets to generate more data packets than the source packets, and then sends these data packets at a certain rate To the receiving end, the transmission is not stopped until receiving the stop request from the receiving end, which effectively reduces the number of retransmissions, but the method adopted by this patent has two defects: one is that the encoded data packets are not systematic That is, the encoded data packet does not contain the source packet, which will increase the encoding and decoding delay and the amount of calculation; the second is that the encoding efficiency of the encoding method used in this patent is not ideal, that is, the number of packets received is equal to the number of source packets data packets, may not be able to restore all source packets

Since the University of California, Berkeley has a great influence on coding theory, it has a one-sided evaluation of the Cauchy encoding and decoding calculation results (when the data volume is 16MB, Professor Luby calculated that the Cauchy encoding operation time is based on sparse The Tornado code of the matrix is ​​7114 times, and the Cauchy decoding operation time is 7582 times that of the Tornado code), which misleads researchers to think that the Cauchy codec operation is too large to be practical

The Raptor codec proposed by the original University of California, Berkeley scientists (see US Patent No. 6307487) was finally adopted by 3GPP MBMS (Multimedia Broadcast / Multicast Service) and IETF RMT (ReliableMulticast Transport). However, the Raptor codec is encoded in small packets The efficiency is not ideal, and increasing the grouping will lead to an increase in decoding delay

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