Uplink Scheduling Request Suppression for VoIP Traffic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE wireless communication systems, the existing uplink scheduling mechanisms face challenges in distinguishing between different priority data flows, leading to unnecessary delays and inefficient resource allocation, particularly for delay-sensitive data like signaling radio bearers and voice over IP (VoIP), due to the lack of differentiation between semi-persistent and dynamic scheduling requests.
Innovation Solution
A method where the wireless terminal determines the priority of data in its buffer and either sends or delays the uplink transmission scheduling request based on priority, using a timer to manage semi-persistent resource allocations and prevent unnecessary scheduling requests, allowing higher priority data to be transmitted promptly while avoiding delays for lower priority VoIP data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a scheduling request is triggered for every packet arriving at an empty buffer under semi-persistent scheduling, then the buffer status is reported to the network, but unnecessary scheduling requests are generated for VoIP data that does not require dynamic resource allocation
Solution Approach 1:
The patent applies local quality by differentiating the treatment of scheduling requests based on data priority. High-priority data (e.g., signaling radio bearers) triggers scheduling requests as before, while low-priority data (e.g., VoIP under semi-persistent scheduling) suppresses scheduling requests. This selective approach allows the system to maintain reliable buffer status reporting for critical data while eliminating unnecessary scheduling overhead for non-critical data.
2Speed
If the scheduler responds to all scheduling requests dynamically, then high-priority data is transmitted promptly, but semi-persistent scheduling benefits are lost due to extensive PDCCH grants
Solution Approach 1:
The patent implements local quality by applying different scheduling response strategies based on data priority. For high-priority data, the scheduler responds dynamically with prompt resource allocation. For low-priority data matching semi-persistent scheduling patterns, the scheduler maintains the resource allocation without generating additional PDCCH grants. This differentiated approach preserves the energy-saving benefits of semi-persistent scheduling while ensuring timely transmission of critical data.
3Loss of energy
If scheduling requests are suppressed for semi-persistent data, then control signaling is reduced, but high-priority data may be delayed until the next semi-persistent resource
Solution Approach 1:
The patent applies segmentation by dividing the scheduling request handling into separate priority-based paths. The system segments data into high-priority and low-priority categories, with distinct scheduling request triggers for each. This segmentation ensures that high-priority data maintains its ability to trigger scheduling requests and receive prompt resource allocation, while low-priority data follows the semi-persistent scheduling path with suppressed requests, thereby avoiding delays for critical data while reducing overall signaling overhead.
Data Source
AI summary
Uplink transmission scheduling requests (SRs) may be prohibited for a lower priority data flow, logical channel group (e.g., VoIP configured with semi-persistent resource allocation), or other grouping but may still be triggered for higher priority traffic (e.g., data connected to a signaling radio bearer (SRB)). More efficient scheduling is also achieved by allowing an uplink transmission scheduler to distinguish between different priority flows or groups (e.g., LCGs) without a buffer status report (BSR). As a result, when a semi-persistent resource is scheduled for the lower priority data, there is less delay for high priority data while eliminating uplink and downlink control signaling, i.e., fewer scheduling requests (SRs) and uplink grants, for the lower priority data.