Almost Blank Subframe Proportioning for Wireless Interference Management

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Solution Overview

Problem

Wireless network operators face challenges in efficiently managing interference and loading between heterogeneous cells, such as macro and pico cells, which affects the number of customers that can be served and the overall network throughput.

Innovation Solution

The implementation of a system that monitors load metric information using proportional fair scheduling to update almost blank subframe proportioning, coordinating handover thresholds and resource allocation between macro and pico cells through standardized information elements in X2 messages, and adapting the proportion of almost blank subframes to balance load and minimize interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If almost blank subframes are used to reduce interference between macro and pico cells, then interference management is improved, but network throughput and load balance deteriorate due to resource underutilization

Engineering Contradiction:
Improveinterference between cellsVSAvoidnetwork throughput
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements dynamic adjustment of almost blank subframe proportion based on real-time load metric information. The system monitors load conditions in both macro and pico cells and adapts the ABS proportion accordingly, transitioning from static to dynamic resource allocation. This allows the network to optimize between interference reduction and throughput maximization based on current traffic conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of ABS proportion dynamically based on load metrics. By adjusting this key parameter according to monitored load conditions, the system can shift the balance between interference management and resource utilization, resolving the contradiction between reducing harmful interference and maintaining high network throughput.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If load metric information is monitored and ABS proportioning is updated dynamically, then load balance between cells is improved, but system complexity increases

Engineering Contradiction:
Improveload balance between cellsVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where load metric information is continuously monitored from both macro and pico cells, and this feedback is used to update ABS proportioning decisions. The system establishes a closed-loop control where performance metrics inform resource allocation adjustments, enabling automatic load balance optimization without manual intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-service by automatically monitoring its own load conditions and adjusting resource allocation accordingly. Each cell autonomously monitors its load metrics and makes intelligent decisions about ABS proportioning, reducing the need for external control and simplifying overall system operation despite the increased decision-making complexity.

Inventive Principle:
Principle #25Self-service

3Reliability

If the proportion of almost blank subframes is increased to protect pico cell users, then user protection is improved, but macro cell capacity is reduced

Engineering Contradiction:
Improveuser protection in pico cellsVSAvoidmacro cell capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically changes the ABS proportion parameter based on monitored load metrics from both macro and pico cells. When pico cell load is high, the ABS proportion is increased to protect pico users, but when macro cell load is high, the ABS proportion is reduced to preserve macro capacity. This dynamic parameter adjustment resolves the contradiction by adapting to real-time conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from static ABS configuration to dynamic adjustment based on load conditions. The system continuously adapts the ABS proportion to balance user protection needs against capacity utilization, allowing the network to optimize the trade-off between reliability and productivity based on current traffic patterns and cell loads.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2761797B1Methods and apparatus for interference management
Publication Date: 2020.09.09 NOKIA SOLUTIONS & NETWORKS OY
  • EP2761797B1 patent drawingFigure 1
  • EP2761797B1 patent drawingFigure 2
  • EP2761797B1 patent drawingFigure 3

AI summary

Systems and techniques for managing the use of almost blank subframes in wireless communication systems. Base stations in a wireless network monitor load information affecting network nodes. Load information may be in the form of load metric information. The load information may be exchanged between system elements, and an almost blank subframe proportioning may be updated by one or more of the base stations, and information relating to the updated proportioning. The updated almost blank subframe proportioning may be used in scheduling and load metric calculation, as well as almost blank subframe patterning. Updating of almost blank subframe information and load metric information may be performed iteratively.