3GPP develops 5G NR specifications through a series of phased releases, each frozen on a fixed schedule and adding new capabilities on top of the previous baseline. Release 15 arrived in late 2018 as Phase 1, delivering the eMBB foundation with both Non-Standalone and Standalone deployment options. Release 16 followed in mid-2020 as Phase 2, strengthening URLLC with configured grant and packet duplication, adding NR-V2X for vehicle communication, NR-U for unlicensed spectrum access, and Integrated Access and Backhaul for self-backhauling small cells.