5G NR RedCap · Module 4 – Protocol & Signalling Deep Dive (RRC, MAC, PHY)

3GPP Specifications: TS 38.300 (architecture), 38.306 (UE capabilities), 38.331 (RRC), 38.321 (MAC), 38.211/214/213 (PHY) – all updated for RedCap in Rel‑17.
RRC Layer: SIB1 parameters (cellBarredRedCap1Rx/2Rx, halfDuplexRedCapAllowed) control access; RedCap‑specific initial BWP IEs enable narrow BWP.
MAC Layer: LCID values 37 and 38 identify RedCap UEs in MSG3; MAC CEs for half‑duplex scheduling.
PHY Layer: NCD‑SSB allows SSB inside RedCap BWP; PUSCH repetition Type B compensates for reduced coverage.
Amarisoft Configuration: Complete configuration examples for gNB and UE, plus log analysis patterns.

Recording Mode:

PUSCH repetition factor: 4 Coverage gain: 3.0 dB

💡 PUSCH repetition Type B improves uplink coverage for 1‑Rx RedCap UEs. 4 repetitions → ~3‑4 dB gain.

📡 Module 4: Protocol & Signalling Deep Dive (RRC, MAC, PHY)