Six Integration Avenues for ISAC in 6G and Beyond

Integrated sensing and communication (ISAC) is a key technology for future 6G networks, enabling sensing and communication services by exploiting a single piece of equipment and waveform. This article introduces six novel integration strategies to enhance ISAC performance and unlock new applications, assuming a communication-centric approach. These include integrating multiple network elements, such as base stations (BSs) and user devices, to improve sensing accuracy and spatial resolution through coherent and incoherent processing. Multiband ISAC is also explored, highlighting the advantages of diverse frequency bands for optimized sensing and communication. We also discuss the potential of combining data from multiple network sensing configurations, terrestrial and nonterrestrial, and also including standalone sensors. The integration of data-driven and model-based methodologies is also discussed as an avenue to overcome limitations in the models and the methods exploited in conventional ISAC solutions. Cutting-edge hardware, including intelligent surfaces and metasurface antennas, is examined for its potential to revolutionize ISAC capabilities. Finally, we outline the challenges and future directions in achieving a fully integrated ISAC network, where sensing data drive network operations for enhanced efficiency and autonomy.