Method and apparatus for forward error correction in packet networks

摘要

A method for applying forward error correction in a transmission network includes the steps of choosing one of a plurality of possible error correction codes, using an appropriate field to encode a complete forward-error-correcting (FEC) code algorithm in each FEC packet to be transmitted. The packet stream, consisting of media packets and FEC packets can be sent to both FEC-capable and FEC-incapable receivers. Decoding methods are independent of the forward-error-correcting code transmitted. The sender can adapt the forward-error-correction code algorithm and the degree of error correction provided on a one-time basis or even more dynamically. Decoding and recovery at the receiver require no prior notification from the sender. Applying the FEC code algorithm to decode includes interrogating the bits in an offset bit mask in each FEC packet to yield links with media packets, and applying other fields of the FEC header to obtain instructions to recover lost data in one of the media packets. Based thereon, reiterative decoding of media packets ensures that lost data recoverable with combinations of media packets and FEC packets are recovered.