What Is C-RNTI by Armin Derkaur

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)
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.