Employing Coded Relay in multi-hop wireless networks

In this paper, we propose Coded Relay (Crelay) for multi-hop wireless networks. Crelay exploits both the partial packets and the overhearing capabilities of wireless nodes, and uses an error correction code in packet forwarding. When a node overhears a partial packet from an upstream node, it estimates the number of errors in the packet and informs the upstream node. The upstream node calculates the number of parity bytes required to correct the errors and can usually send only a small amount parity bytes instead of sending the complete packet, hence improving the network efficiency. We propose a novel protocol for packet forwarding with partial packets and overhearing, which forwards individual packets and will work seamlessly with upper layers. We also propose a practical algorithm for finding the packet forwarding path. We implement Crelay within the Click modular router and our experiments show that it can significantly improve the performance of wireless networks.