XORs in the air

TLDR

Network coding theory underpins the design, yet prior work has been largely theoretical and focused on multicast traffic. The study proposes the COPE architecture to bring network coding into practice for unicast, dynamic, bursty traffic in wireless mesh networks. COPE mixes packets at routers and was evaluated on a 20‑node wireless testbed. Intelligent packet mixing with COPE increases throughput, achieving gains from a few percent to several folds depending on traffic, congestion, and transport protocol.

Abstract

This paper proposes COPE, a new architecture for wireless mesh networks. In addition to forwarding packets, routers mix (i.e., code) packets from different sources to increase the information content of each transmission. We show that intelligently mixing packets increases network throughput. Our design is rooted in the theory of network coding. Prior work on network coding is mainly theoretical and focuses on multicast traffic. This paper aims to bridge theory with practice; it addresses the common case of unicast traffic, dynamic and potentially bursty flows, and practical issues facing the integration of network coding in the current network stack. We evaluate our design on a 20-node wireless network, and discuss the results of the first testbed deployment of wireless network coding. The results show that COPE largely increases network throughput. The gains vary from a few percent to several folds depending on the traffic pattern, congestion level, and transport protocol.