Spreadtrum · 10.5.1.2

Spreadtrum proposes that all necessary PRACH features be integrated into a unified random access framework from 6GR Day-1, citing limited commercial deployment of post-Rel-16 NR features as justification. They propose studying PRACH capacity increases via RO configuration and SBFD rather than increasing the number of preambles per RO beyond 64. For preamble sequences, they prefer reusing NR ZC sequences and require a structured gap analysis process before considering any new sequence designs. They propose a joint configuration for coverage level determination across all random-access-related channels and a joint coverage request from the UE. They support native integration of SBFD into the random access procedure to avoid separate configurations, power control, and RO-to-SSB mapping for SBFD and non-SBFD ROs.

Spreadtrum proposes a unified and integrated PRACH/RACH framework from 6GR Day-1 to avoid the fragmentation and compatibility issues observed in NR Releases 16-20, where enhanced coverage features achieved limited commercial deployment. They require natively supporting random access in SBFD symbols rather than maintaining separate SBFD and non-SBFD procedures as in NR, specifically opposing the separate RO-to-SSB mapping configurations and independent power control parameters currently used for SBFD RO. They propose studying a joint coverage configuration and joint coverage request from UE spanning all related channels during random access, replacing NR's per-channel independent RSRP threshold configuration. They support reusing NR ZC sequences, NR short and long preamble formats, and NR SSB-RO association patterns as baselines, while proposing further study on RO-SSB mapping rules for PRACH repetition and SBFD/non-SBFD joint mapping. They propose removing the NR dependency where MSG3 and MSG4 HARQ-ACK PUCCH scheduling in SBFD symbols is conditional on MSG1 transmission via SBFD, advocating full independent scheduling.