Dynamic ABS Ratio Control for LTE HetNet Interference

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Solution Overview

Problem

In LTE HetNet environments, setting too many Almost Blank Subframes (ABS) reduces macro base station throughput, while setting too few ABS subframes fails to eliminate interference at micro base stations, thereby reducing micro base station throughput.

Innovation Solution

A radio control system that detects communication quality by monitoring Radio Link Failure (RLF) occurrences and adjusts the ratio of ABS to non-ABS subframes in a cycle to optimize throughput and interference management between macro and micro base stations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the ratio of ABS subframes is increased to reduce interference at micro base station, then interference at micro base station is reduced, but throughput of macro base station is reduced

Engineering Contradiction:
Improveinterference at micro base stationVSAvoidthroughput of macro base station
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements dynamic adjustment of ABS subframe ratios based on real-time communication quality detection. The system continuously monitors RLF occurrences and adapts the ABS configuration accordingly, transitioning from static to dynamic resource allocation to resolve the contradiction between interference reduction and throughput maintenance

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent establishes a feedback mechanism where communication quality (RLF occurrences) is detected and used to control the ABS subframe ratio. This closed-loop control allows the system to respond to changing conditions and optimize both interference reduction and throughput based on actual network state

Inventive Principle:
Principle #23Feedback

2Productivity

If the ratio of ABS subframes is decreased to maintain throughput of macro base station, then throughput of macro base station is maintained, but interference at micro base station increases

Engineering Contradiction:
Improvethroughput of macro base stationVSAvoidinterference at micro base station
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the ABS subframe ratio based on detected communication quality, allowing flexible optimization that can favor either interference reduction or throughput maintenance depending on current network conditions, rather than being locked into a fixed configuration

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of ABS subframe ratio based on communication quality thresholds. When RLF occurrences exceed thresholds, the system increases ABS ratio to reduce interference; when thresholds are not exceeded, it maintains lower ABS ratio to preserve throughput

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If CRE is used to expand coverage of micro base station, then coverage of micro base station is expanded, but communication terminal in expanded area is affected by higher level of interference from macro base station

Engineering Contradiction:
Improvecoverage of micro base stationVSAvoidinterference from macro base station
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies different resource allocation qualities to different areas by using ABS specifically for terminals in expanded coverage areas. Terminals experiencing interference in CRE-expanded areas receive protected resource allocations during ABS subframes, while other terminals maintain normal service, creating localized quality adaptation

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3024265B1Radio control system, communication apparatus, radio resource control method, and recording medium
Publication Date: 2019.09.04 NEC CORP
  • EP3024265B1 patent drawingFigure 1
  • EP3024265B1 patent drawingFigure 2
  • EP3024265B1 patent drawingFigure 3

AI summary

A radio control system capable of avoiding decrease in a throughput of a macro base station and a micro base station or suppress interference in the micro base station is provided. The radio control system includes a macro base station 101 forming a macro cell 103 and a micro base station 102 forming a picocell 105 included in the macro cell 103. Further, the radio control system includes a communication quality detection unit 111 detecting a communication quality between the micro base station 102 and a communication terminal present in the picocell 105, and a management apparatus 110 controlling a ratio of a radio resource where data transmission is limited in the first base station, based on the communication quality.