Integrated Sensing and Communications: A Research Roadmap
Integrated sensing and communications (ISAC) is emerging as a major architectural direction for next-generation wireless systems. By jointly designing environmental sensing and wireless data transmission within a unified framework, ISAC offers the potential for simultaneous gains in spectral efficiency, hardware reuse, energy efficiency, and situational awareness. This paper provides a comprehensive research roadmap for ISAC, tracing its evolution from radar–communication coexistence to dual-function radar–communication architectures, networked sensing infrastructures, and perceptive sixth-generation (6G) wireless networks. The survey is organized around five pillars: information-theoretic foundations, physical-layer design, networked operation, enabling platform technologies, and application domains. It further examines emerging regimes and deployment extensions that challenge conventional assumptions, including near-field operation, terahertz systems, AI-native transceivers, reconfigurable and digital-twin-assisted environments, low-power and backscatter-based sensing, and non-terrestrial ISAC. Across these topics, the paper identifies open gaps, formulates a unified set of grand research challenges, reviews representative prototype and measurement-oriented studies, and outlines both near-term deployment paths and longer-horizon transformative directions. The goal is to provide a coherent reference and roadmap for the continued development of ISAC as a foundation for future wireless, sensing, and cyber-physical systems.