XORs in the Air: Practical Wireless Network Coding

Sachin Katti, Hariharan Rahul, Wenjun Hu, Dina Katabi, Muriel Médard, Jon Crowcroft
IEEE/ACM Transactions on Networking, Volume 16, Issue 3, Pages 497-510, June 2008.

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 using COPE at the forwarding layer, without modifying routing and higher layers, increases network throughput. The gains vary from a few percent to several folds depending on the traffic pattern, congestion level, and transport protocol.

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Bibtex Entry:

@article{katti2008cope,
   author =       "Sachin Katti and Hariharan Rahul and Wenjun Hu and Dina Katabi and Muriel Medard and Jon Crowcroft",
   title =        "{XORs in the Air: Practical Wireless Network Coding}",
   journal =      {IEEE/ACM Transactions on Networking},
   year =         {2008},
   volume =       {16},
   number =       {3},
   pages  =       {497--510},
   month =        {June},
   publisher =    {IEEE Press},
   address =      {Piscataway, NJ, USA}
}