Greedy approach for efficient packet erasure coding

Abstract

We propose a packet level erasure coding scheme where packets are generated using a greedy strategy. The coding is started with a systematic round of the original file blocks. This gives footing for greedy packet generation, where the degree of each randomly generated packet is determined so as to maximize the probability for the packet to release a new decoded block immediately upon arrival at the receiving end. The coding scheme relies on the estimate of erasure probability of the channel, which is used by the sender to update the belief on the number of blocks the recipient has thus far decoded. The resulting greedy sequence of packet degrees is investigated by simulations to estimate the expected number of packets needed for decoding. The simulations exhibit low overheads and further indicate that the use of greedy sequence of packet degrees provides a way to perform efficient and practical packet erasure coding. We also discuss the robustness of the scheme along with some other practical considerations.