NCSA: A New Protocol for Random Multiple Access Based on Physical Layer Network Coding

TL;DR

This paper proposes NCSA, a novel satellite communication protocol that leverages physical-layer network coding and error correction to significantly enhance data throughput in random access channels.

Contribution

It introduces NCSA, a new protocol combining PNC and error correction for improved satellite data transmission, extending CRDSA concepts.

Findings

Achieves over 0.7× maximal throughput in simulations

Density evolution analysis confirms performance gains

Potential for further improvement by integrating collided bursts

Abstract

This paper introduces a random multiple access method for satellite communications, named Network Coding-based Slotted Aloha (NCSA). The goal is to improve diversity of data bursts on a slotted-ALOHA-like channel thanks to error correcting codes and Physical-layer Network Coding (PNC). This scheme can be considered as a generalization of the Contention Resolution Diversity Slotted Aloha (CRDSA) where the different replicas of this system are replaced by the different parts of a single word of an error correcting code. The performance of this scheme is first studied through a density evolution approach. Then, simulations confirm the CRDSA results by showing that, for a time frame of $400$ slots, the achievable total throughput is greater than $0.7\times C$, where $C$ is the maximal throughput achieved by a centralized scheme. This paper is a first analysis of the proposed scheme which open several perspectives. The most promising approach is to integrate collided bursts into the decoding process in order to improve the obtained performance.