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

TL;DR

This paper presents a comprehensive cross-layer framework for integrated sensing and communication in 6G networks, combining physical, hardware, AI, and protocol innovations to enable advanced, context-aware wireless systems.

Contribution

It introduces a novel cross-layer perspective for ISAC in 6G, integrating multiple technological and system-level insights from academia and industry.

Findings

Analysis of enabling technologies like MIMO, reconfigurable surfaces, and machine learning.

Development of a quantitative framework linking design parameters to performance.

Insights into how deep integration can transform 6G into a programmable platform.

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.