Round-robin overlapping generations coding for fast content download

We analyze the download time of a large file, divided into chunks called generations, and transmitted over an erasure channel without feedback. For non-overlapping generations, we derive how the download time scales with the number of generations, for the round-robin and random scheduling policies. We then analyze coding with overlapping generations and show that the optimal overlap size is small compared to the number of generations, which implies that the download time can be reduced with only a small increase in computational complexity. Further, for a given overlap size, we propose overlap structures that have low complexity and are easy to implement, but still give file download as fast as the best previously proposed structures.