On the Benefits of Network Coding in Multi-Channel Wireless Networks

Wireless mesh networks have emerged as a favorable infrastructure that promises to unify the existing 802.11 wireless LANs. With multiple orthogonal channels and possibly multiple interfaces on the mesh nodes, such networks can provide broadband access for a large number of wireless clients. However, efficient assignment of channels to the available network interfaces has long been a daunting task for network designers. Existing heuristic and theoretical work unanimously focuses on joint design of channel assignment with the conventional transport/IP/MAC architecture. In this paper, we show that a new paradigm, network coding, is able to further increase the capacity of multi-channel mesh networks. We propose a joint optimization problem that accounts for routing, channel assignment, and network coding, and analyze its potential performance gains over the non-coding schemes. This problem inspires a practical algorithm that naturally combines network coding and routing. We also explore the benefits of network coding for emerging multi-channel wireless networks, including 802.16 and 802.11n, and derive the upper bound for its performance gains over existing channel assignment protocols.