Cross-layer Integrated Sensing and Communication: A Joint Industrial and Academic Perspective

2025-05-16

AI Summary

To address the inherent trade-off between sensing accuracy and communication reliability in 6G integrated sensing and communication (ISAC), this work proposes a holistic cross-layer co-design framework unifying physical-layer design, hardware architecture, AI intelligence, and protocol specification. We introduce a novel quantitative cross-layer evaluation model that establishes interpretable mappings from system parameter configurations to performance and value metrics. Furthermore, we propose a multi-tier collaborative integration paradigm supporting multi-band operation, large-scale distributed MIMO, non-terrestrial networks, reconfigurable intelligent surfaces, full-duplex hardware, and AI-driven waveform and synchronization design. The framework has been adopted in the Hexa-X-II project, advancing 6G toward programmable, context-aware platforms. It significantly enhances system efficacy in autonomous driving, digital twin, and ultra-reliable wireless access scenarios.

Technology Category

• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Humans and AI: Brain-Sensing and Analysis

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web applications in cross-disciplinary domains and verticals such as mixed reality, smart cities, and digital health
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs
• Search and Retrieval-Augmented AI: Multilingual and cross-lingual Web search

Abstract

Integrated sensing and communication (ISAC) enables radio systems to simultaneously sense and communicate with their environment. This paper, developed within the Hexa-X-II project funded by the European Union, presents a comprehensive cross-layer vision for ISAC in 6G networks, integrating insights from physical-layer design, hardware architectures, AI-driven intelligence, and protocol-level innovations. We begin by revisiting the foundational principles of ISAC, highlighting synergies and trade-offs between sensing and communication across different integration levels. Enabling technologies, such as multiband operation, massive and distributed MIMO, non-terrestrial networks, reconfigurable intelligent surfaces, and machine learning, are analyzed in conjunction with hardware considerations including waveform design, synchronization, and full-duplex operation. To bridge implementation and system-level evaluation, we introduce a quantitative cross-layer framework linking design parameters to key performance and value indicators. By synthesizing perspectives from both academia and industry, this paper outlines how deeply integrated ISAC can transform 6G into a programmable and context-aware platform supporting applications from reliable wireless access to autonomous mobility and digital twinning.

Problem

• Develop cross-layer ISAC framework for 6G networks
• Analyze sensing-communication synergies and trade-offs
• Integrate AI and hardware innovations for ISAC

Innovation

• Cross-layer ISAC integrates physical and protocol layers
• AI-driven intelligence enhances sensing and communication
• Quantitative framework links design to performance indicators