5G • RAN
Timer T304
Handover Execution Timer
Timer supervising handover completion; started upon receiving RRCReconfiguration with handover command.
Technical Explanation
When the UE receives an RRCReconfiguration containing reconfigurationWithSync (handover command), it starts timer T304 (values 50ms to 2000ms). The UE must synchronize with the target cell, complete RACH, and transmit RRCReconfigurationComplete. If T304 expires, handover failure is declared, triggering re-establishment to the source cell.
Key Functions
- Supervises physical synchronization and RACH on target handover cell
- Started upon reception of reconfigurationWithSync handover command
- Triggers handover failure and RRC connection re-establishment upon expiry
Specifications
3GPP TS 38.331
Interfaces
Uu
Related 5G Concepts
Want to memorize 5G concepts like this one?
Study it with SuperMemo SM-2 spaced repetition flashcards.