PDCP SDU Forwarding with Sub-Windows for Lower Latency

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in managing service data units (SDUs) due to the need to wait for missing SDUs within a PDCP window, leading to increased latency and potential loss of data.

Innovation Solution

Implementing a timer-based mechanism at the user equipment (UE) to selectively deliver a portion of SDUs within a forwarding sub-window before the timer expires, utilizing artificial intelligence (AI) and machine learning (ML) models to predict optimal delivery based on SDU attributes and priorities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the system waits for all SDUs to be received before forwarding, then data completeness is improved, but latency increases

Engineering Contradiction:

Improvedata completenessVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The PDCP window is divided into multiple sub-windows, allowing the system to forward SDUs in segments rather than waiting for the entire window. This enables partial forwarding of received SDUs while maintaining the ability to detect missing data through timer mechanisms for each sub-window.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs partial forwarding by delivering SDUs that fall within the forwarding sub-window before the timer expires, rather than waiting for complete reception. This partial action reduces latency while the timer mechanism ensures detection of potentially missing SDUs.

Inventive Principle:

Principle #16Partial or excessive action

2Productivity

If the system uses AI/ML predictions to determine delivery, then forwarding efficiency is improved, but system complexity increases

Engineering Contradiction:

Improveforwarding efficiencyVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

AI/ML models perform preliminary analysis and predictions about which SDUs should be forwarded before the timer expires. This preliminary action enables the system to make informed forwarding decisions based on predicted outcomes, improving efficiency while the models handle the complexity of decision-making.

Inventive Principle:

Principle #10Preliminary action

3Loss of time

If the system delivers SDUs before timer expiration, then latency is reduced, but data loss risk increases

Engineering Contradiction:

ImprovelatencyVSAvoiddata loss risk

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The system uses timer expiration as a feedback mechanism to detect missing SDUs. By monitoring whether expected SDUs are delivered before the timer expires, the system can identify potential data loss and take corrective actions, enabling reliable early forwarding decisions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250386243A1Selective service data unit forwarding techniques

Publication Date: 2025.12.18 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may deliver one or more service data units SDUs within a packet data convergence protocol (PDCP) window to an upper protocol layer before an expiration of a timer associated with the PDCP window. The UE may forward the one or more SDUs based on a forwarding rule, as part of a forwarding sub-window of the PDCP window, or both. The UE may deliver the portion of the set of SDUs based on one or more predictions of a machine learning (ML) model and/or functionality associated with SDUs of the PDCP window. In some examples, the UE may report information associated with the PDCP window to a network entity. The UE may receive one or more control messages indicating information associated with the PDCP window.