On the Tradeoffs of Implementing Randomized Network Coding in Multicast Networks

TL;DR

This paper explores the performance tradeoffs of randomized network coding in multicast networks, focusing on limited randomization capabilities and the balance between reliability and capacity gains.

Contribution

It introduces a limited randomized network coding scheme and analyzes its performance bounds, along with examining the reliability-capacity tradeoff in generalized RNC.

Findings

L-RNC performs well with limited randomization capabilities.

Significant outage probability reduction is achievable near network capacity.

Performance bounds for L-RNC are analytically derived.

Abstract

Randomized network coding (RNC) greatly reduces the complexity of implementing network coding in large-scale, heterogeneous networks. This paper examines two tradeoffs in applying RNC: The first studies how the performance of RNC varies with a node's randomizing capabilities. Specifically, a limited randomized network coding (L-RNC) scheme - in which intermediate nodes perform randomized encoding based on only a limited number of random coefficients - is proposed and its performance bounds are analyzed. Such a L-RNC approach is applicable to networks in which nodes have either limited computation/storage capacity or have ambiguity about downstream edge connectivity (e.g., as in ad hoc sensor networks). A second tradeoff studied here examines the relationship between the reliability and the capacity gains of generalized RNC, i.e., how the outage probability of RNC relates to the transmission rate at the source node. This tradeoff reveals that significant reductions in outage probability are possible when the source transmits deliberately and only slightly below network capacity. This approach provides an effective means to improve the feasibility probability of RNC when the size of the finite field is fixed.