Selective Time Stamp PDCP PDU for Uplink Delay Measurement

Solution Overview

Problem

Current wireless communication systems face challenges in accurately measuring uplink packet delay due to overhead issues when including time information in each PDCP PDU, which affects the efficiency of UL packet delay measurements.

Innovation Solution

The method involves the User Equipment (UE) transmitting a Time Stamp PDCP PDU only when the queuing delay of a PDCP SDU exceeds a threshold, reducing overhead by selectively including time information in PDCP PDUs, and configuring the periodicity of this transmission through RRC messages or PDCP Control PDUs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If time information is included in each PDCP PDU for UL packet delay measurement, then measurement accuracy is improved, but protocol overhead increases

Engineering Contradiction:

ImproveUL packet delay measurement accuracyVSAvoidprotocol overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by selectively including time stamp information only in specific PDCP PDUs that meet certain criteria (e.g., when queuing delay exceeds a threshold), rather than uniformly including it in all PDUs. This localized approach maintains measurement accuracy for critical packets while reducing overall overhead.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements partial action by including time stamps in only a subset of PDCP PDUs rather than all of them. The selection is based on specific conditions such as delay thresholds or packet types, providing sufficient measurement data without the excessive overhead of universal time stamping.

Inventive Principle:

Principle #16Partial or excessive action

2Loss of information

If time stamp is included in every PDCP PDU, then complete delay measurement data is obtained, but transmission efficiency decreases

Engineering Contradiction:

Improvedelay measurement data completenessVSAvoidtransmission efficiency

Core Design Contradiction:

Loss of informationVSProductivity

Solution Approach 1:

The patent applies local quality by selectively including time stamp information only in specific PDCP PDUs that meet certain criteria (e.g., when queuing delay exceeds a threshold), rather than uniformly including it in all PDUs. This localized approach maintains measurement accuracy for critical packets while reducing overall overhead.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements partial action by including time stamps in only a subset of PDCP PDUs rather than all of them. The selection is based on specific conditions such as delay thresholds or packet types, providing sufficient measurement data without the excessive overhead of universal time stamping.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP3335383B1Method for performing uplink packet delay measurements in a wireless communication system and a device therefor

Publication Date: 2020.09.02 LG ELECTRONICS INC

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AI summary

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing UL packet delay measurement in a wireless communication system, the method comprising: checking whether a value of queuing delay of a PDCP SDU is above a threshold, and generating and transmitting a PDCP PDU including the PDCP SDU and a time stamp for the PDCP SDU, if the value of the queuing delay is above the threshold, wherein a value of the time stamp for the PDCP SDU is set to a time when the PDCP SDU is received from the upper layer.