Split-Path Jitter Buffer for Zero-Latency VoIP QoS Measurement

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Jitter buffering in VoIP sessions introduces unnecessary latency when both endpoints use the same codec, affecting voice quality by inaccurately calculating packet loss and other QoS metrics.

Innovation Solution

A media gateway apparatus with a data path splitter that directs packet data to both the switch fabric and a jitter buffer, allowing for QoS measurement without introducing latency into the primary data path, by only buffering packets that require transcoding or have different codecs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If jitter buffering is inserted in VoIP session, then QoS measurement accuracy is improved, but bearer path latency increases

Engineering Contradiction:

ImproveQoS measurement accuracyVSAvoidbearer path latency

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the data path into two separate paths: a measurement path that includes the jitter buffer for accurate QoS metrics collection, and a media path that bypasses the jitter buffer for zero-latency voice transmission. This segmentation allows QoS measurement functionality to be isolated from the primary media flow, achieving both measurement accuracy and low latency simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a copy mechanism as an intermediary, where packet data is copied to a measurement path for QoS analysis while the original data flows through the media path without delay. The measurement path acts as a mediator that enables accurate QoS measurement without interfering with the timing-critical media transmission.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If jitter buffering is inserted in transcoding-free VoIP session, then packet loss calculation accuracy is improved, but voice quality deteriorates due to unnecessary latency

Engineering Contradiction:

Improvepacket loss calculation accuracyVSAvoidvoice quality degradation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent creates separate measurement and media paths, allowing packet loss calculation to be performed accurately on copied packets in the measurement path while the original packets traverse the media path with minimal latency, thus maintaining voice quality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses packet copying to create a duplicate data stream for QoS measurement purposes. The copied packets are buffered and analyzed for packet loss calculation, while the original packets are transmitted without delay, ensuring both measurement accuracy and voice quality are maintained.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS7965627B2QoS measurement with split-path zero-latency virtual jitter buffer

Publication Date: 2011.06.21 GENBAND US LLC

AI summary

An apparatus that includes a packet data ingress, a packet data egress, and a packet data switching matrix configured to switch packet data from the packet data ingress to the packet data egress. The apparatus may further include a packet data jitter buffer and a packet data splitter, wherein the packet data splitter interposes the packet data ingress and the packet data switching matrix and is configured to multicast the packet data to the packet data switching matrix and the jitter buffer.