Cooperative Integrated Sensing and Communication in 6G: From Operators Perspective

Novel application scenarios expected in the future wireless communication, such as unmanned aerial vehicle (UAV) regulation and autopilot, require sensing function with high accuracy. To realize sensing in the upcoming fifth-generation-advanced (5G-A) and sixth-generation (6G) mobile networks, integrated sensing and communication (ISAC) systems become attractive to operators. Making use of widespread nodes including base stations or communication devices, sensing function is expected to be upgraded, based on the existing communication hardware at low cost, to provide services in wide areas. In addition, multiple sensing nodes can be cooperative where sensing results from different nodes can be jointly processed to further improve the sensing accuracy. However, several key technical challenges and protocol design problems need to be addressed in such cooperative ISAC systems, for example, asynchronization among sensing nodes, identifying and detecting object in non-line-of-sight (NLOS) path, and sensing information interaction for sensing services. In this article, we provide a comprehensive overview of the implementation of cooperative ISAC systems, covering the technical advantages, nodes deployment, key performance indicators, technical research problems, sensing related protocol design, and their solutions. Future research directions and expansions to the existing results are also discussed.