UE Codec Rate Adaptation via Dual-Cell Bit Rate Queries

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Solution Overview

Problem

In wireless communication systems, particularly in VoLTE/ViLTE, existing solutions for codec rate adaptation during ongoing calls are inefficient, as user equipment (UE) often fails to adjust codec rates optimally after handovers or radio link failures, leading to suboptimal voice/video quality due to inadequate bit rate recommendations from the radio access network.

Innovation Solution

A communication device and method that enable the UE to query and adapt codec rates based on bit rate recommendations from both the initial and target cells during handovers or radio resource control reestablishments, ensuring optimal codec rates are selected for improved quality, and incorporating efficient query management to conserve radio resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the UE queries bit rate recommendations from both initial and target cells during handover, then codec rate adaptation quality is improved, but radio resource consumption increases

Engineering Contradiction:
Improvecodec rate adaptation qualityVSAvoidradio resource consumption
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The UE performs bit rate recommendation queries to the target cell before completing the handover process. This preliminary action allows the UE to obtain codec rate information in advance, enabling optimal codec rate selection after handover without requiring post-handover queries that would consume additional radio resources.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the UE receives bit rate recommendations from the network based on current radio conditions, and uses this feedback to dynamically adjust the codec rate. The UE compares recommendations from both initial and target cells, selecting the optimal rate that balances quality and resource efficiency.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the UE maintains the first codec rate after handover, then device complexity is reduced, but voice/video quality deteriorates

Engineering Contradiction:
Improvecodec rate management complexityVSAvoidvoice/video quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The codec rate is made dynamic rather than static. After handover, the UE does not maintain a fixed first codec rate but instead adapts the codec rate based on bit rate recommendations received from the target cell. This dynamic adjustment mechanism allows the system to optimize voice/video quality according to current radio conditions while keeping the adaptation logic straightforward.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the UE queries bit rate recommendations frequently, then codec rate adaptation accuracy is improved, but signaling overhead increases

Engineering Contradiction:
Improvecodec rate adaptation accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

Instead of frequent continuous queries, the UE performs bit rate recommendation queries periodically at key events such as handover preparation and radio resource control reestablishment. This periodic action ensures accurate codec rate adaptation is obtained when most needed while minimizing unnecessary signaling overhead during stable connection periods.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3331277B1Device and method of performing a codec rate adaptation in a wireless communication system
Publication Date: 2020.07.15 HTC CORP
  • EP3331277B1 patent drawingFigure 1
  • EP3331277B1 patent drawingFigure 2
  • EP3331277B1 patent drawingFigure 3

AI summary

A communication device for performing a codec rate adaptation comprises a storage device for storing instructions and a processing circuit coupled to the storage device. The processing circuit is configured to execute the instructions stored in the storage device. The instructions comprise triggering a first transmission of a first Medium Access Control (MAC) Control Element (CE) for a bit rate query or a delay budget reporting, and a second transmission of a data; making a first determination that a transmission priority of the first MAC CE is lower than a transmission priority of the data; comprising the data in a MAC Protocol Data Unit (PDU) in response to the first determination; comprising the first MAC CE in the MAC PDU in response to the first determination, if a remaining space in the MAC PDU is sufficient for comprising the first MAC CE after comprising the data; and transmitting the MAC PDU to a base station (BS).