Packet Classification for Accurate Voice Quality Estimation

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Solution Overview

Problem

Current communication systems face challenges in accurately measuring perceptual voice quality due to packet loss, as existing methods do not effectively account for the varying impact of lost packets on voice quality over time.

Innovation Solution

The system classifies packets based on their position in the audio stream and attaches this classification to subsequent packets, allowing receivers to calculate perceptual voice quality by considering the impact of lost packets using embedded classification information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If packet loss statistics are used to measure call quality, then call quality measurement is enabled, but measurement precision is insufficient due to not accounting for varying impact of lost packets

Engineering Contradiction:
Improveperceptual voice quality measurement accuracyVSAvoidinformation about varying impact of lost packets
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments packet loss into different categories based on temporal position (e.g., initial packets, middle packets, tail packets) and applies different weighting factors to each segment. This segmentation allows the system to account for the varying impact of packet loss on perceptual quality, thereby improving measurement precision without losing critical information about when packets are lost.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different importance weights to packet losses occurring at different positions in the audio stream. For example, packet losses at the beginning or end of a frame may be weighted differently than losses in the middle, reflecting the local perceptual impact. This approach enhances measurement accuracy by capturing spatial/temporal variations in packet loss impact.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If simple packet loss statistics are collected, then measurement complexity is low, but measurement precision is insufficient

Engineering Contradiction:
Improvevoice quality estimation accuracyVSAvoidquality measurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by pre-defining weighting factors and classification rules for different packet loss scenarios before actual quality measurement. These pre-established parameters (e.g., weighting factors for different packet positions) are stored and applied during measurement, reducing real-time computational complexity while maintaining high measurement precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes parameters by introducing weighting factors that modify the contribution of different packet loss events to the overall quality metric. By adjusting these parameters based on packet position and type, the system achieves higher measurement precision without proportionally increasing system complexity, as the parameter changes are applied through straightforward mathematical operations.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If packet loss impact is not differentiated by position, then system complexity is low, but measurement precision deteriorates

Engineering Contradiction:
Improveperceptual quality measurement accuracyVSAvoidpacket classification system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the audio stream into distinct temporal regions (e.g., attack region, sustain region, release region) and assigns different weighting factors to each segment. This segmentation enables the system to differentiate packet loss impact by position, improving measurement precision while keeping the classification system relatively simple through clear temporal boundaries.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary classification of packets into categories based on their temporal position and importance before quality measurement. By pre-categorizing packets (e.g., marking which packets are critical vs. non-critical), the system reduces the complexity of real-time analysis while maintaining high measurement precision through the use of pre-established classification rules.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS9985855B2Call quality estimation by lost packet classification
Publication Date: 2018.05.29 DOLBY LABORATORIES LICENSING CORP
  • US9985855B2 patent drawing
  • US9985855B2 patent drawing
  • US9985855B2 patent drawing

AI summary

Described are: a method, an apparatus, and a tangible computer-readable storage medium comprising instructions to instruct one or more processors to carry out a method. One set of methods is for the transmit side of a communication link and another set of methods is for the receive side. A transmit side method includes assigning one of a set of classifications to media, e.g., voice/audio packets transmitted in a sequence, different classifications impacting differently a measure of perceptual quality calculated at the receive side if packets of the respective classifications are lost. A present packet is sent to the receive side containing the classification of a previous packet.