Intra- and Inter-Session Network Coding in Wireless Networks

TL;DR

This paper introduces I2NC, a cross-layer network coding scheme for wireless networks that combines intra- and inter-session coding to improve resilience and efficiency in lossy environments, with practical implementations and simulation validation.

Contribution

The paper presents I2NC, a novel cross-layer network coding approach that integrates intra- and inter-session coding based on a network utility maximization framework, with practical stateful and stateless schemes.

Findings

I2NC improves resilience to packet loss in wireless networks.

The proposed schemes outperform traditional coding methods in simulations.

I2NC effectively balances redundancy and coding decisions based on loss rates.

Abstract

In this paper, we are interested in improving the performance of constructive network coding schemes in lossy wireless environments.We propose I2NC - a cross-layer approach that combines inter-session and intra-session network coding and has two strengths. First, the error-correcting capabilities of intra-session network coding make our scheme resilient to loss. Second, redundancy allows intermediate nodes to operate without knowledge of the decoding buffers of their neighbors. Based only on the knowledge of the loss rates on the direct and overhearing links, intermediate nodes can make decisions for both intra-session (i.e., how much redundancy to add in each flow) and inter-session (i.e., what percentage of flows to code together) coding. Our approach is grounded on a network utility maximization (NUM) formulation of the problem. We propose two practical schemes, I2NC-state and I2NC-stateless, which mimic the structure of the NUM optimal solution. We also address the interaction of our approach with the transport layer. We demonstrate the benefits of our schemes through simulations.