Integrated Sensing and Communication in 6G: Motivations, Use Cases, Requirements, Challenges and Future Directions

In 6G, it is envisaged that the function of sensing and communication will coexist and be fully integrated in one system, sharing the same resources in time, frequency and space domains, as well as key elements including waveform, signal processing, hardware, etc. This paper discusses novel applications, key performance requirements, challenges and future research directions for Integrated Sensing and Communication (ISAC) design in 6G. First, four categories of ISAC use cases are described as new services in 6G together with their corresponding performance requirements on 6G design. In addition, it is demonstrated how the information obtained through sensing can significantly improve the performance of communication. Thereafter, the challenges in the design and evaluation of a practical ISAC system are discussed, including sensing and communication performance tradeoffs, hardware imperfections, as well as the investigation of an appropriate channel model. Finally, future research directions are presented to set the path for designing an efficient ISAC network.