From LDPC to chunked network codes

Chunked network code is a variation of random linear network code with low computational cost and small coefficient vector overhead. In a chunked network code, intermediate network nodes only apply network coding among packets of the same chunk. In this paper, we propose an approach to construct chunks using LDPC codes. For a given LDPC code, the chunks are simply formed by first partitioning the variable nodes into disjoint groups and then filling each group with a number of variable nodes of degree zero. The chunked network codes constructed using this approach are called L-chunked codes. We analyze the asymptotic achievable rates of L-chunked codes using belief propagation decoding for an arbitrary rank distribution of the chunk transfer matrices. Numerical evaluation shows that L-chunked codes achieve a rate very close to optimal.