A Unified Future: Integrated Sensing and Communication (ISAC) in 6G

Integrated Sensing and Communication (ISAC) is among the early feature areas being explored for 6G in 3GPP standards. It involves the seamless integration of communication and sensing functions within a unified system architecture, where a single base station (also known as gNB), is inherently capable of supporting both roles. This paper reviews recent developments in ISAC within 3GPP, focusing on key use cases and relevant channel models, including target and background environment channels. It provides an overview of different sensing topologies and outlines ISAC requirements across various deployment contexts. The discussion then extends to link budget analysis, waveform design, beamforming strategies, and associated hardware considerations. Lastly, the paper highlights several Proof-of-Concept (PoC) systems that showcase practical implementations of ISAC concepts.