Rate-Adaptation Protocol for Video Telephony Handovers

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Solution Overview

Problem

Video telephony experiences video quality reduction due to unnecessary rate-adaptation during temporary handovers between different radio access technologies, leading to poor user experience.

Innovation Solution

A method and apparatus for adjusting the rate-adaptation protocol during video telephony sessions based on information sets indicating the start and end of handovers between radio access technologies, preventing overreaction to temporary channel condition changes and optimizing multimedia user experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rate-adaptation protocol adjusts bit rate in response to channel condition changes during handover, then reliability of video transmission is improved, but video quality deteriorates due to unnecessary rate-adaptation during temporary handovers

Engineering Contradiction:
Improvevideo transmission reliabilityVSAvoidvideo quality
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The rate-adaptation protocol dynamically adjusts its behavior based on handover detection. When a handover is detected, the protocol temporarily suspends rate-adaptation to prevent unnecessary quality degradation, then resumes normal operation after handover completion. This dynamic switching between adaptation modes resolves the contradiction by making the system responsive to contextual conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback mechanisms by monitoring handover status and channel conditions. When handover information is received, the protocol receives feedback about the temporary nature of channel degradation and adjusts accordingly by pausing rate-adaptation. This feedback loop prevents overreaction to transient conditions while maintaining reliability during actual channel problems.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If rate-adaptation protocol responds to channel condition changes during handover, then adaptability of transmission is improved, but user experience deteriorates due to video quality reduction

Engineering Contradiction:
Improvetransmission adaptabilityVSAvoiduser experience
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The protocol dynamically switches between adaptive and non-adaptive modes based on handover detection. During normal operation, it maintains full adaptability to channel conditions. During detected handovers, it temporarily disables rate-adaptation to prevent user experience degradation, then resumes adaptability afterward. This dynamic behavior provides both adaptability when needed and stable user experience during transitions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the rate-adaptation protocol based on handover status. When handover is detected, it modifies the adaptation threshold or disables adaptation temporarily, effectively changing how the protocol responds to channel conditions. This parameter adjustment allows the system to maintain adaptability for genuine channel problems while avoiding adaptability-induced quality issues during handovers.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If rate-adaptation is continuously applied during handover, then channel condition changes are addressed, but video quality deteriorates due to temporary handover effects

Engineering Contradiction:
Improvechannel condition handlingVSAvoidvideo quality
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The protocol implements periodic checking of handover status and applies rate-adaptation only when appropriate. Instead of continuous adaptation, it periodically assesses whether channel condition changes are due to handover or genuine channel problems. This periodic action with conditional application prevents unnecessary quality degradation while maintaining reliability for actual channel issues.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system extracts or removes the rate-adaptation function temporarily during detected handovers. By taking out the adaptive response mechanism during these specific periods, it prevents the harmful effect of unnecessary rate adjustments while maintaining the function for genuine channel problems. This selective extraction resolves the contradiction by applying the principle of targeted removal of problematic functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS9674737B2Selective rate-adaptation in video telephony
Publication Date: 2017.06.06 QUALCOMM INC
  • US9674737B2 patent drawing
  • US9674737B2 patent drawing
  • US9674737B2 patent drawing

AI summary

A system and method for rate-adaptation of a video telephony (VT) session is disclosed. In one example, there is provided a method that includes receiving a first information set indicative of a start of a handover of a device from a first Radio Access Technology (RAT) to a second RAT. The method further includes receiving a second information set indicative of an end of the handover. The method further includes adjusting a rate-adaptation protocol for the VT session based at least in part on the first and second information sets.