Scheduling Request Triggering for Measurement Gap Data Stalling
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Solution Overview
Problem
In wireless communication systems, particularly in 5G NR, data transmissions are inefficiently stalled due to incorrect assumptions about user equipment (UE) being in discontinuous reception (DRX) mode, caused by lack of measurement gap coordination between base stations, leading to inaccurate HARQ feedback and reduced data throughput.
Innovation Solution
The UE transmits a scheduling request to the serving base station after performing measurements, informing it that it is not in the DRX off duration and has data to transmit, by determining a decrease in received data or uplink grants before and after the measurement gap, thereby preventing incorrect assumptions about DRX mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the UE performs measurements during measurement gaps, then measurement accuracy is improved, but data transmission efficiency deteriorates due to incorrect DRX mode assumptions by the base station
Solution Approach 1:
The UE provides feedback to the base station by transmitting a scheduling request after performing measurements, indicating that it is not in DRX off duration. This feedback mechanism resolves the contradiction by informing the base station of the UE's actual state, preventing incorrect assumptions about DRX mode, and allowing data transmission to continue efficiently during measurement gaps.
2Use of energy by moving object
If the base station assumes the UE is in DRX off duration during measurement gaps, then energy saving is improved, but data throughput deteriorates due to stalled data transmissions
Solution Approach 1:
The scheduling request transmitted by the UE serves as feedback that corrects the base station's incorrect assumption about DRX mode. This allows the base station to maintain energy-saving DRX operation while avoiding data stalling, as the feedback mechanism ensures accurate state information is available when needed.
3Reliability
If the UE transmits scheduling requests frequently to indicate availability, then data transmission reliability is improved, but signaling overhead increases
Solution Approach 1:
The UE transmits scheduling requests selectively rather than continuously - specifically after performing measurements when data becomes available. This partial action approach maintains reliability by ensuring the base station is informed of availability when it matters, while avoiding excessive signaling overhead that would result from frequent or continuous requests.
Data Source
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AI summary
Aspects are provided which allow a UE to trigger initiation of an SR procedure in response to a decrease in an amount of received data or uplink grants following a measurement gap. The UE receives data from a first base station. The UE performs a measurement of a downlink signal from a second base station based on a measurement configuration. The UE transmits a scheduling request in response to a decrease in at least one of an amount of received downlink data or a number of received grants to transmit uplink data after the measurement is performed. As a result, inefficient data stalls caused by erroneous DRX determinations by a base station may be avoided.