5G • RAN
Default BWP
Default Downlink Bandwidth Part
Fallback BWP to which the UE autonomously reverts when the BWP inactivity timer expires.
Technical Explanation
Configured via RRC parameter defaultDownlinkBWP-Id, this is typically a narrow BWP (e.g. 20 MHz). When a UE operating on a wide 100 MHz Active BWP has no data activity, the bwp-InactivityTimer expires, causing the UE to autonomously switch back to the Default BWP to save power.
Key Functions
- Provides low-power fallback state when data traffic ceases
- Triggered autonomously upon expiration of bwp-InactivityTimer
- Prevents battery drain from maintaining wideband baseband processing
Specifications
3GPP TS 38.213, TS 38.331
Interfaces
Uu
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