5G • RAN
Msg3
Scheduled Transmission (Msg3 / RRC Setup Request)
Uplink transmission on PUSCH carrying the initial RRC connection request and UE identity.
Technical Explanation
Using the grant provided in Msg2 RAR, the UE transmits Msg3 on PUSCH. For initial access, Msg3 carries the RRCSetupRequest message containing the UE identity (random value or 5G-S-TMSI) and establishment cause. It is scrambled with TC-RNTI and protected by HARQ retransmissions.
Key Functions
- Carries initial RRCSetupRequest or RRCResumeRequest message
- Transmits UE identity for subsequent contention resolution
- Protected by HARQ with soft combining on PUSCH
Specifications
3GPP TS 38.213, TS 38.321, TS 38.331
Interfaces
Uu
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