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.
@article{arxiv.2505.10933,
title = {Cross-layer Integrated Sensing and Communication: A Joint Industrial and Academic Perspective},
author = {Henk Wymeersch and Nuutti Tervo and Stefan Wänstedt and Sharief Saleh and Joerg Ahlendorf and Ozgur Akgul and Vasileios Tsekenis and Sokratis Barmpounakis and Liping Bai and Martin Beale and Rafael Berkvens and Nabeel Nisar Bhat and Hui Chen and Shrayan Das and Claude Desset and Antonio de la Oliva and Prajnamaya Dass and Jeroen Famaey and Hamed Farhadi and Gerhard P. Fettweis and Yu Ge and Hao Guo and Rreze Halili and Katsuyuki Haneda and Abdur Rahman Mohamed Ismail and Akshay Jain and Sylvaine Kerboeuf and Musa Furkan Keskin and Emad Ibrahim and Bilal Khan and Siddhartha Kumar and Stefan Köpsell and Apostolos Kousaridas and Pekka Kyösti and Simon Lindberg and Mohammad Hossein Moghaddam and Ahmad Nimr and Victor Pettersson and Aarno Pärssinen and Basuki Priyanto and Athanasios Stavridis and Tommy Svensson and Sonika Ujjwal},
journal= {arXiv preprint arXiv:2505.10933},
year = {2025}
}