FlexSAN: A Flexible Regenerative Satellite Access Network Architecture

2025-09-09

AI Summary

Current satellite access networks (SANs) employ static payload configurations—either fully integrated gNBs or gNB-DUs only—resulting in suboptimal resource utilization and inconsistent user experience. This work proposes FlexSAN, a novel flexible SAN architecture enabling on-board regenerative payload reconfiguration, and introduces the first real-time, on-demand switching between gNB and gNB-DU operational modes. To address the NP-hard problem of dynamic configuration optimization, we design an adaptive greedy heuristic algorithm and validate it on a prototype system. Experimental results demonstrate that, compared to static configurations, FlexSAN achieves an average 36.1% improvement in user admission rate and reduces operational expenditure by 15%, while maintaining stringent QoS requirements. FlexSAN thus jointly optimizes radio resource efficiency and operational cost-effectiveness in LEO satellite networks.

Technology Category

• Search and Optimization: Algorithm Configuration
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Satisfiability

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

The regenerative satellite access network (SAN) architecture deploys next-generation NodeB (gNBs) on satellites to enable enhanced network management capabilities. It supports two types of regenerative payload, on-board gNB and on-board gNB-Distributed Unit (gNB-DU). Measurement results based on our prototype implementation show that the on-board gNB offers lower latency, while the on-board gNB-DU is more cost-effective, and there is often a trade-off between Quality-of-Service (QoS) and operational expenditure (OPEX) when choosing between the two payload types. However, current SAN configurations are static and inflexible -- either deploying the full on-board gNB or only the on-board gNB-DU. This rigidity can lead to resource waste or poor user experiences. In this paper, we propose Flexible SAN (FlexSAN), an adaptive satellite access network architecture that dynamically configures the optimal regenerative payload based on real-time user demands. FlexSAN selects the lowest OPEX payload configuration when all user demands are satisfied, and otherwise maximizes the number of admitted users while ensuring QoS for connected users. To address the computational complexity of dynamic payload selection, we design an adaptive greedy heuristic algorithm. Extensive experiments validate FlexSAN's effectiveness, showing a 36.1% average improvement in user admission rates and a 15% OPEX reduction over static SANs.

Problem

• Dynamic configuration of satellite regenerative payloads for optimal performance
• Overcoming static SAN limitations causing resource waste and poor QoS
• Balancing QoS and OPEX trade-offs in satellite access networks

Innovation

• Dynamic regenerative payload configuration
• Adaptive greedy heuristic algorithm
• Real-time user demand optimization