Near-Optimal Co-Ordinated Coding in Wireless Multihop Networks

The recent work on COPE by Katti et al. demonstrates a practical application of network coding to wireless multihop networks. The authors note, however, that the opportunistic nature of COPE leaves it at the mercy of higher and lower layer protocols to create coding opportunities spontaneously. In this paper, they go one step beyond COPE's opportunism and study how to create coding opportunities in a more deterministic, yet still practical way. They start from the insight that in two-way traffic the existence of coding opportunities can be guaranteed through carefully coordinated packet scheduling, and establish general properties of protocols that are able to achieve this.