Towards Routing and Edge Computing in Satellite-Terrestrial Networks: A Column Generation Approach

TL;DR

This paper introduces a three-layer edge computing protocol for satellite-terrestrial networks, optimizing data processing and routing to significantly enhance computational capacity using a column generation approach.

Contribution

It proposes a novel three-layer edge computing framework with an optimization method to maximize capacity, addressing scalability with a column generation technique.

Findings

Achieves 60% capacity improvement with 5-hop routing latency.

Employs column generation to solve large-scale optimization efficiently.

Demonstrates the effectiveness of multi-hop routing in satellite networks.

Abstract

Edge computing that enables satellites to process raw data locally is expected to bring further timeliness and flexibility to satellite-terrestrial networks (STNs). In this letter, we propose a three-layer edge computing protocol, where raw data collected by the satellites can be processed locally, or transmitted to other satellites or the ground station via multi-hop routing for further processing. The overall computing capacity of the proposed framework is maximized by determining the offloading strategy and routing formation, subject to channel capacity and hop constraints. Given that the problem scale grows exponentially with the number of satellites and maximum-allowed hops, the column generation approach is employed to obtain the global optimal solution by activating only a subset of variables. Numerical results reveal that the proposed three-layer computing protocol, when tolerating a 5-hop routing latency, achieves a 60% improvement in computation capacity compared to the single-layer local computing configuration.