5G • RAN
Initial BWP
Initial Bandwidth Part
Default BWP configured in SIB1 used for initial cell access, RACH, and RRC connection establishment.
Technical Explanation
Before dedicated RRC configuration, a UE cannot utilize full carrier bandwidth. The Initial BWP is broadcast in SIB1 (initialDownlinkBWP and initialUplinkBWP). It encompasses CORESET 0 and PRACH occasions, allowing all UEs (including low-complexity devices) to execute cell access within a restricted bandwidth (e.g. 20 MHz).
Key Functions
- Carries broadcast control and paging before dedicated RRC configuration
- Contains PRACH occasions and RAR scheduling resources
- Enables initial connection setup for UEs of all bandwidth capabilities
Specifications
3GPP TS 38.211, TS 38.331
Interfaces
Uu
Related 5G Concepts
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