Sub-rate linear network coding

Increasing network capacity is undoubtedly a critical aspect of modern communication systems. In this paper, the concept of sub-rate coding and decoding in the framework of linear network coding (LNC) is introduced for single-source multiple-sinks finite acyclic networks. This methodology offers a modification to existing LNC so that the source transmits its messages in a manner in which a given set of sinks (termed sub-rate sinks), whose max-flow is smaller than the source's message-rate, can still decode a portion of the transmitted messages, without degrading the maximum achievable rate of LNC sinks whose max-flow is equal (or greater) than the source rate. The paper sets the conditions which a set of sub-rate sinks has to satisfy in order for that methodology to be applicable.