Device-to-Device (D2D) communication plays a crucial role in public safety by ensuring connectivity among first responders, even in areas without network coverage. This session will explore the evolution of 3GPP standardization in supporting D2D communications, covering advancements from sidelink to single-hop and multi-hop relay technologies. Additionally, this session will present performance evaluations of multi-hop relay networks. As in previous years, our goal is not only to share key research findings but also to gain valuable insights into stakeholder interests in D2D research opportunities and mission-critical communication applications.