Opportunities and Challenges of Native Sensing in 6G: A Survey on Research and Standardization

The integration of sensing and communication would enable wireless networks to monitor the surrounding environment in addition to communications tasks. In other words, the sensing capability, traditionally used in radar systems, would be integrated into the communication system to build a symbiotic framework known as integrated sensing and communication (ISAC). Since radar sensing and wireless communication share similar characteristics, this integration would lead to spectrum efficiency and reduction in hardware cost compared to two separate systems. However, the co-design of sensing and communication poses several challenges and complexities in the physical and network layers, as well as security and privacy aspects of wireless systems. While there is a wealth of research addressing the above-mentioned challenges, a gap still remained between current research activities and the requirements of ISAC. Recently, 3GPP Rel-19 introduced 32 ISAC use cases along with their requirements. This paper reviews the 3GPP use cases to identify the required technologies and expected sensing outcomes, highlighting the gap between current research activities and ISAC requirements. The paper further explores concepts required to support the use cases, such as positioning, and different sensing sources (e.g., ambient radio frequency and radar signals). Following this, we explore the mutual benefits of integrated sensing with communication, security, radio access networks, digital twin, advanced antenna technologies, and multiple physical dimension transmission. Finally, the paper details the current progress of 3GPP technical specification groups and studies open challenges, available tools, and datasets in ISAC.