**What is a Cell Radio-Network Temporary Identifier (C-RNTI)?** A C-RNTI is *a unique identifier allocated to a UE within a specific cell controlled by an eNodeB.* > **What is User Equipment (UE)?** [(1)](https://en.wikipedia.org/wiki/User_equipment) > UE is *any device used directly by an end-user to communicate.* > > **What is an eNodeB?** > An eNodeB is a *base station in LTE or 5G NR networks.* > > **What is the primary purpose of the C-RNTI?** > The primary purpose of the C-RNTI is *to address an individual UE during communication within the cell.* **How does an eNodeB use the C-RNTI when transmitting control information?** When transmitting control information, an eNodeB uses the C-RNTI to *scramble the Cyclic Redundancy Check (CRC) bits on the Physical Downlink Control Channel (PDCCH).* > **What does scrambling the CRC bits with the C-RNTI ensure?** > Scrambling the CRC bits with the C-RNTI ensures *different UEs in the same cell receive distinct control channel information.* **When does an eNodeB assign a C-RNTI to a User Equipment (UE)?** The eNobeB assigns a C-RNTI to a UE *when the UE connects.* > **What happens to the C-RNTI when a UE moves to a different cell due to handover or mobility?** > When the UE moves to a different cell due to handover or mobility, the C-RNTI *may be reallocated by the new eNodeB.* > > **What does the reallocation of a the C-RNTI when switching to a different cell ensure?** > The reallocation of the C-RNTI when switching to a different cell ensures that *the UE maintains a unique identifier.* **What does an INT-RNTI address?** An INT-RNTI addresses *a group of UEs.* **What does a SI-RNTI address?** An SI-RNTI addresses *all UEs in the cell.*