ISAC Integration With Emerging Wireless Network Technologies: A Comprehensive Survey

Integrated Sensing and Communication (ISAC) has emerged as a fundamental paradigm for Sixth-Generation (6G) wireless networks, enabling the unified use of spectral and hardware resources for simultaneous data transmission and environmental sensing. This convergence offers significant improvements in spectral efficiency, resource utilization, and network intelligence compared to conventional disjoint system designs. This survey presents a comprehensive and systematic review of ISAC, with particular emphasis on its integration with three key enabling technologies: Orthogonal Frequency-Division Multiplexing (OFDM), Massive Multiple-Input Multiple-Output (mMIMO), and Reconfigurable Intelligent Surfaces (RIS). A unified classification framework is introduced to categorize ISAC systems by integration level, waveform design strategy, and hardware architecture. Building on this framework, the paper critically analyzes state-of-the-art methodologies and examines a wide range of applications, including localization, tracking, secure communications, and energy-efficient network operation. In addition to synthesizing existing literature, this survey identifies critical challenges that remain insufficiently addressed, such as sensing–communication performance trade-offs, algorithmic scalability, hardware constraints, and practical deployment considerations. Finally, it outlines key open research directions toward the realization of efficient and scalable ISAC-enabled wireless systems.