Overlay multi-hop FEC scheme for video streaming

Overlay networks offer promising capabilities for video streaming, due to their support for application-layer processing at the overlay forwarding nodes. In this paper, we focus on the problem of providing lightweight support at selected intermediate overlay forwarding nodes to achieve increased error resilience on a single overlay path for video streaming. We propose a novel overlay multi-hop forward error correction (OM-FEC) scheme that provides FEC encoding/decoding capabilities at intermediate nodes in the overlay path. Based on the network conditions, the end-to-end overlay path is partitioned into segments, and appropriate FEC codes are applied over those segments. Architecturally, this flexible design lies between the end-to-end and hop-by-hop paradigms, and we argue that it is well suited to peer-based overlay networks. We evaluate our work by both simulations and controlled Planet-Lab network experiments. These evaluations show that OM-FEC can outperform a pure end-to-end strategy up to 10-15 dB in terms of video peak signal-to-noise ratio (PSNR), and can be much more efficient than a heavyweight hop-by-hop strategy.