The Importance of Being Opportunistic: Practical Network Coding for Wireless Environments

TLDR

The paper applies network coding to wireless mesh networks and reports the first implementation results. The authors introduce COPE, an opportunistic network‑coding scheme that snoops the medium, learns neighbor states, detects coding opportunities, and encodes packets as long as receivers can decode, enabling efficient support of multiple unicast flows under dynamic, bursty traffic, and evaluate it with emulation and a testbed. Experimental results demonstrate that COPE significantly boosts throughput, achieving many‑fold gains over existing 802.11 mesh networks as flow count and contention rise.

Abstract

This paper applies network coding to wireless mesh networks and presents the first implementation results. It introduces COPE, an opportunistic approach to network coding, where each node snoops on the medium, learns the status of its neighbors, detects coding opportunities, and codes as long as the recipients can decode. This flexible design allows COPE to efficiently support multiple unicast flows, even when traffic demands are unknown and bursty, and the senders and receivers are dynamic. We evaluate COPE using both emulation and testbed implementation. Our results show that COPE substantially improves the network throughput, and as the number of flows and the contention level increases, COPE’s throughput becomes many times higher than current 802.11 mesh networks.