Analysis of using convolutional codes to recover packet losses over burst erasure channels

The ability of convolutional-code-based FEC to recover from packet losses over a channel subjected to burst erasure is evaluated. We analyze the maximum lengths of a burst packet loss that can be recovered. We assume that only one burst packet loss has occurred, and consider the recovery conditions for given lengths, that is, numbers of lost packets. We also present conditions for the generator matrices, which are used to encode and decode convolutional-code-based redundant packets. We then apply a packet loss model based on a two-state Markov chain and use computer simulation to examine the ability of our approach to recover packets lost in transmission over bursty erasure channels. We show that this ability changes with the constraint length of the applied code and with the generator matrix, and find conditions for a matrix to have high levels of ability. Finally, we apply our method to the transfer of graphic data over the Internet, and use convolutional codes in the recovery process.