Dynamic Uplink Interference Control for WCDMA Capacity

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Solution Overview

Problem

Conventional radio resource management in WCDMA networks using pre-defined fixed total interference leads to imbalanced capacity and reduced coverage, as base stations schedule mobile stations without considering inter-cell interference, resulting in reduced schedulable resources and potential 'coverage holes'.

Innovation Solution

A method where base stations measure and report both total and intra-cell interference to the radio network controller, allowing for dynamic adjustment of allowed total interference and resource allocation to optimize network capacity and balance, using inter-cell interference metrics to prioritize resource allocation based on cell utilization and interference levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a base station schedules mobile stations up to a pre-defined upper limit of total interference, then the base station can maximize the number of supportable mobile stations or total uplink data throughput, but the schedulable radio resources are reduced and capacity imbalance occurs between cells

Engineering Contradiction:

Improvetotal uplink data throughputVSAvoidschedulable radio resources

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements dynamic adjustment of the total interference parameter from a fixed pre-defined value to a variable that changes based on real-time inter-cell interference conditions. The base station measures inter-cell interference from neighboring cells and adjusts the total interference parameter accordingly, allowing the system to adapt to changing network conditions and maximize schedulable resources while maintaining throughput.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent establishes a feedback mechanism where the base station measures inter-cell interference from neighboring cells and uses this information to adjust the total interference parameter. This closed-loop control enables the system to respond to actual interference conditions, preventing capacity imbalance and optimizing both throughput and schedulable resources.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If the radio network controller assigns equal total interference for both cells, then the number of mobile stations of both cells appears identical, but inter-cell interference causes capacity imbalance and reduced overall network capacity

Engineering Contradiction:

Improveequal resource assignmentVSAvoidoverall network capacity

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent applies local quality by allowing different base stations to have different total interference parameters based on their specific inter-cell interference conditions. Instead of uniform assignment, each base station receives a customized interference parameter tailored to its local environment, optimizing overall network capacity while maintaining operational simplicity through automated measurement and adjustment.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the total interference parameter from a static equal value to a dynamic value that varies by base station based on measured inter-cell interference. This parameter adjustment resolves the contradiction by enabling unequal but optimized interference assignments that maximize overall network capacity while maintaining ease of operation through automated processes.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If a base station increases scheduling resource to schedule more mobile stations, then the total interference increases affecting neighboring cells, but reducing scheduling resource reduces network coverage and creates capacity imbalance

Engineering Contradiction:

Improvenumber of mobile stationsVSAvoidinter-cell interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent uses feedback by measuring inter-cell interference from neighboring cells and adjusting the total interference parameter accordingly. This allows the base station to increase scheduling resources when inter-cell interference is low while reducing resources when interference is high, optimizing the number of supportable mobile stations without excessively affecting neighboring cells.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent converts the harmful effect of inter-cell interference into a useful measurement signal. By measuring the interference from neighboring cells, the system gains information about the actual interference environment, which is then used to optimize resource allocation. The harmful interference becomes the basis for intelligent decision-making that improves overall network performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS7747221B2Method of uplink radio resource control, base station apparatus, and radio network controller

Publication Date: 2010.06.29 NEC CORP

AI summary

A method for controlling uplink radio resource which can improve the capacity and coverage of a mobile communication network includes the steps of: measuring, at base stations, both total interference and intra-cell interference values; reporting measured values to a radio network controller; calculating, at the radio network controller, allowed total interference for individual cells in response to the reporting from the base stations; sending information about the allowed total interference to the base stations; and scheduling, in response to the allowed total interference by the base stations, uplink data packet transmission of mobile stations not to exceed the allowed total interference calculated for the respective cells.