# Airborne-Platform-Assisted Transmission and Control Separation for Multiple Access in Integrated Satellite–Terrestrial Networks

## TL;DR

This paper introduces a new protocol for satellite communications that improves channel utilization by separating control and transmission processes using airborne platforms.

## Contribution

The novel STCA protocol separates access control to airborne platforms, enhancing performance in satellite-terrestrial networks.

## Key findings

- STCA outperforms IRSA in channel utilization by preventing satellite channel collisions.
- Simulation results show improved performance under heavy load and optimal frame sizes.
- Airborne platforms enable better load estimation for maximum access rates.

## Abstract

Currently, the primary random access protocol for satellite communications is Irregular Repetition Slotted ALOHA (IRSA). This protocol leverages interference cancellation and burst repetition based on probabilistic distributions, achieving up to 80% channel utilization in practical use. However, it faces three significant issues: (1) low channel utilization with smaller frame sizes; (2) drastic performance degradation under heavy load, where channel utilization can be lower than that of traditional Slotted ALOHA; and (3) even under optimal load and frame sizes, up to 20% of the valuable satellite channel resources are still wasted despite reaching up to 80% channel utilization. In this paper, we propose the Separated Transmission and Control ALOHA (STCA) protocol, which introduces a space–air–ground layered network and separates the access control process from the satellite to an airborne platform, thus preventing collisions in satellite channels. Additionally, the airborne-platform estimates the load to ensure maximum access rates. Simulation results demonstrate that the STCA protocol significantly outperforms the IRSA protocol in terms of channel utilization.