5G • RAN
RLC Polling Bit
RLC Poll Bit (P-Bit)
Header flag set by RLC AM transmitter to demand an immediate RLC Status PDU from the receiver.
Technical Explanation
The transmitter sets the Poll (P) bit in the RLC AM header when its transmission buffer is empty, when window thresholds are reached (pollPDU or pollByte counters expire), or when timer t-PollRetransmit fires. Upon receiving P=1, the receiver is obligated to generate an RLC Status PDU.
Key Functions
- Demands immediate RLC Status PDU transmission from the receiver
- Triggered by buffer emptiness or periodic byte/PDU threshold counters
- Prevents transmitter stall when transmission windows are exhausted
Specifications
3GPP TS 38.322
Interfaces
Uu
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