Reduced-complexity network coding for multicasting over ad hoc networks

Network coding generalizes the conventional routing paradigm by allowing nodes to mix information received on its incoming links to generate information to be transmitted to other nodes. As a result, network coding improves throughput, resource efficiency, robustness, manageability, etc., in wired and wireless ad hoc networks. In particular, it was established that network coding can achieve the maximum rate for multicasting information from a source node to multiple destination nodes. The objective of this work is to show how to achieve the aforementioned multicast capacity with lower processing/implementation complexity than that proposed in the literature. We classify the links in a network into two categories: 1) links entering relay nodes; and 2) links entering destinations. We show the same multicast capacity can be achieved by applying (non-trivial) network coding only on the links entering relay nodes. In other words, links entering destinations only require routing, which leads to a saving in the complexity. The novelty of this work lies in a new algorithm, its proof of correctness, and a complexity analysis.