Sub-Rate Linear Network Coding

TL;DR

This paper introduces sub-rate coding in linear network coding, enabling partial decoding at sinks with limited max-flow without affecting overall network capacity.

Contribution

It formulates the theoretical conditions for sub-rate coding to be feasible in finite acyclic networks, expanding the capabilities of linear network coding.

Findings

Sub-rate coding allows partial message decoding at certain sinks.

Conditions for sub-rate sink legitimacy are established.

Enhances network utilization without reducing overall capacity.

Abstract

Increasing network utilization is often considered as the holy grail of communications. In this article, the concept of sub-rate coding and decoding in the framework of linear network coding (LNC) is discussed for single-source multiple-sinks finite acyclic networks. Sub-rate coding offers an add-on to existing LNC. It allows sinks whose max-flow is smaller than the source message-rate, termed \emph{sub-rate sinks}, to decode a portion of the transmitted message without degrading the maximum achievable rate of LNC sinks whose max-flow is equal (or greater) than the rate of the source node. The article studies theoretical aspects of sub-rate coding by formulating the conditions a node (and indeed the network) must fulfill so as to qualify as a legitimate sub-rate sink.