Task-Oriented Direct-to-Cell Satellite Communications for Closed-Loop Operations

TL;DR

This work addresses the challenge of directing D2C satellite networks for autonomous operations by shifting from conventional, data-rate–driven design to task-oriented optimization within a sensing–communication–computing–control (SC$^3$) closed loop. It introduces an entropy-based performance metric, the closed-loop neg-entropy rate ($CNER$), and develops an integrated architecture that supports computing across satellites, gateway servers, and ISLs, with downlink control to robots. To manage complexity, the system is decomposed into collaborative sensing, computing, and control structures, each addressing core subproblems, enabling joint optimization of sensing, communication, computing, and control to maximize $CNER$. A case study demonstrates that the proposed task-oriented design outperforms conventional schemes in task completion metrics (e.g., lower LQR cost), and multi-loop optimization reveals resource trade-offs and adaptive power allocation under varying channel conditions. The paper also highlights open challenges, including security, dynamics, and digital twin integration, essential for practical deployment of SC$^3$-driven D2C autonomous operations.

Abstract

Direct-to-cell (D2C) satellite communications have emerged as a crucial alternative and complement to terrestrial communication networks for autonomous operations due to their wide-area coverage capability. Unlike human-oriented communications, robot-oriented D2C communications in autonomous operations place greater emphasis on task completion rather than solely on data transmission. Such differences require us to evaluate the performance of each stage in the system and consider the integrated optimization. Motivated by this, we model the system in a sensing-communication-computing-control (SC3) closed-loop manner and analyze it from an entropy-based perspective, based on which a task-oriented system design method is developed. Furthermore, to manage the complexity of the closed-loop system, we decompose it into fine-grained functional structures and investigate the key challenges associated with collaborative sensing, collaborative computing, and collaborative control. A case study is presented to compare the proposed task-oriented scheme with conventional communication-oriented schemes, showing that the proposed method performs better in terms of task controlling. Finally, we discuss several open research challenges that need to be addressed for practical implementation.

Figures (5)

• Figure 1: Professional service robots sales (2020–2024).
• Figure 2: The architecture of the task-oriented D2C satellite communication system for closed-loop operations
• Figure 3: Comparison of the reflex arc and the SC$^3$ closed loop.
• Figure 4: Illustration of the single SC$^3$ closed loop, three extended collaborative structures, and the complex system constructed from these structures.
• Figure 5: Simulations of the case study.