Cross-layer Theoretical Analysis of NC-aided Cooperative ARQ Protocols in Correlated Shadowed Environments (Extended Version)

TL;DR

This paper develops a cross-layer analytical model for NC-aided cooperative ARQ protocols in correlated shadowed environments, providing insights into network parameters and protocol performance through theoretical analysis and extensive simulations.

Contribution

It introduces a comprehensive cross-layer model that links physical layer expressions with MAC layer performance for NC-based cooperative ARQ in shadowed channels, validated by Monte Carlo simulations.

Findings

Number of active relays is independent of shadowing correlation.

Trade-offs between throughput and energy efficiency are identified.

The analytical model accurately predicts protocol performance.

Abstract

In this paper, we propose a cross-layer analytical model for the study of Network Coding (NC)-based Automatic Repeat reQuest (ARQ) Medium Access Control (MAC) protocols in correlated slow faded (shadowed) environments, where two end nodes are assisted by a cluster of relays to exchange data packets. The goal of our work is threefold: i) to provide general Physical (PHY) layer theoretical expressions for estimating crucial network parameters (i.e., network outage probability and expected size of the active relay set), applicable in two-way communications, ii) to demonstrate how these expressions are incorporated in theoretical models of the upper layers (i.e., MAC), and iii) to study the performance of a recently proposed NC-aided Cooperative ARQ (NCCARQ) MAC protocol under correlated shadowing conditions. Extensive Monte Carlo experiments have been carried out to validate the efficiency of the developed analytical model and to investigate the realistic performance of NCCARQ. Our results indicate that the number of active relays is independent of the shadowing correlation in the wireless links and reveal intriguing trade-offs between throughput and energy efficiency, highlighting the importance of cross-layer approaches for the assessment of cooperative MAC protocols.