Carrier Aggregation Bearer Restriction for Unlicensed Spectrum

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Solution Overview

Problem

In 3GPP LTE systems, delay-sensitive data transmitted over unlicensed spectrum often face latency and reliability issues due to unstable radio conditions, which existing carrier aggregation technologies struggle to address effectively.

Innovation Solution

Implementing a configuration mechanism that restricts the transmission and reception of delay/reliability-sensitive radio bearers to only a subset of serving cells or carriers, using RRC signaling to provide configuration information such as ul-DataCellList, ensuring these bearers are only transmitted on licensed or 5G RAT carriers to meet latency and reliability requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If carrier aggregation is used to transmit delay-sensitive data over unlicensed spectrum, then data throughput is improved, but latency and reliability deteriorate due to unstable radio conditions

Engineering Contradiction:
Improvedata throughputVSAvoidlatency and reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the carrier aggregation into two distinct parts: licensed carriers for delay-sensitive data and unlicensed carriers for other data. This segmentation allows the system to benefit from the high throughput of unlicensed spectrum while ensuring that delay-sensitive services maintain reliable transmission on stable licensed carriers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different quality characteristics to different carriers based on their properties. Licensed carriers provide stable, reliable transmission for delay-sensitive data, while unlicensed carriers provide high-capacity transmission for non-delay-sensitive data. This localized optimization resolves the contradiction by matching data requirements with appropriate carrier characteristics.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If delay-sensitive bearers are transmitted on unlicensed carriers, then spectrum utilization is improved, but transmission stability deteriorates

Engineering Contradiction:
Improvespectrum utilizationVSAvoidtransmission stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent segments bearer transmission by creating separate transmission paths: delay-sensitive bearers are restricted to licensed carriers while other bearers can utilize unlicensed carriers. This segmentation enables full spectrum utilization without compromising transmission stability for critical services.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by applying different transmission stability requirements to different bearers based on their service characteristics. Delay-sensitive bearers receive the stable transmission environment of licensed carriers, while non-delay-sensitive bearers can exploit the high-capacity unlicensed spectrum, thereby achieving both spectrum utilization and transmission stability.

Inventive Principle:
Principle #3Local quality

3Productivity

If carrier aggregation allows flexible bearer mapping, then resource efficiency is improved, but control complexity increases

Engineering Contradiction:
Improveresource efficiencyVSAvoidcontrol complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the bearer mapping control into two categories: delay-sensitive bearers with restricted mapping to licensed carriers only, and other bearers with flexible mapping to any carrier. This segmentation simplifies control logic by establishing clear mapping rules while maintaining resource efficiency through flexible carrier selection for non-critical data.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3251443B1Carrier aggregation enhancements for unlicensed spectrum and 5g
Publication Date: 2023.10.11 APPLE INC
  • EP3251443B1 patent drawingFigure 1~2
  • EP3251443B1 patent drawingFigure 3
  • EP3251443B1 patent drawingFigure 4

AI summary

A user equipment (UE) may receiving, from an evolved NodeB (eNB), configuration information related to a restriction that one or more radio bearers are transmitted only on a subset of serving cells used in carrier aggregation of a long term evolution (LTE), LTE-advanced (LTE-A), and or 5G wireless network. The UE may transmit the one or more radio bearers to the eNB on one or more serving cells of the subset of serving cells in response to receiving the configuration information.