Quantum Annealing Frequency Assignment for Mobile Network Cells

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Solution Overview

Problem

Mobile communications networks face challenges in optimizing frequency assignments to cells, leading to signal interference and suboptimal network capacity due to conventional methods' limitations in handling complex constraints and rapid re-assignment needs.

Innovation Solution

A computer-implemented method using a quantum concept processor to calculate an optimized frequency assignment by minimizing a stress function, considering frequency interference probabilities and constraints, to assign frequencies to unplanned cells while minimizing intra-cellular and inter-cellular interference and ensuring dense frequency usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If frequencies are assigned densely to enhance network capacity, then network capacity is improved, but signal interference increases between neighbouring cells

Engineering Contradiction:
Improvenetwork capacityVSAvoidsignal interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the parameter of frequency assignment from conventional iterative brute force methods to quantum annealing optimization. The quantum processor minimizes a stress function that quantifies interference between cells, thereby finding optimal frequency assignments that maximize network capacity while minimizing signal interference through quantum mechanical parameter optimization.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/iterative optimization process with a quantum mechanical system. The quantum annealing processor uses quantum effects (superposition, tunneling) to solve the frequency assignment problem, substituting classical computational mechanics with quantum computational mechanics to achieve superior optimization results.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If conventional iterative brute force optimization is applied, then local optimization at unsaturated cells is achieved, but interference at other cells deteriorates and frequency allocation becomes insufficient

Engineering Contradiction:
Improvelocal optimizationVSAvoidfrequency allocation sufficiency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The quantum annealing processor performs a single global optimization that simultaneously optimizes frequency assignments for all cells in the network, not just locally at unsaturated cells. This universal optimization approach ensures that frequency allocation is sufficient and interference-free across the entire network, eliminating the need for iterative local optimizations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the separate optimization steps (preliminary assignment and iterative local optimization) into a single unified quantum annealing process. The quantum processor considers all cells and their interrelationships simultaneously, combining what were previously separate operations into one comprehensive optimization that prevents interference deterioration and ensures sufficient frequency allocation.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If conventional optimization techniques are used, then preliminary frequency assignment is achieved, but optimization limits are quickly reached and re-planning is slow

Engineering Contradiction:
Improveoptimization speedVSAvoidoptimization capability
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces conventional computational optimization mechanics with quantum computational mechanics. The quantum annealing processor leverages quantum parallelism and tunneling effects to explore the solution space much more efficiently than classical algorithms, achieving superior optimization capability and speed without being limited by the polynomial time constraints of classical techniques.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4262305B9Method for optimizing an assignment of frequencies to cells in a mobile communications network
Publication Date: 2025.01.22 FUJITSU TECHNOLOGY SOLUTIONS GMBH
  • EP4262305B9 patent drawingFigure 1
  • EP4262305B9 patent drawingFigure 2
  • EP4262305B9 patent drawingFigure 3a~3b

AI summary

The invention pertains to a computer-implemented method for optimizing an assignment of frequencies (f) to cells (C) of a mobile communications network (1). The cells (C) are distributed for communication within the mobile communications network (1). A set of unplanned cells (2) in the mobile communications network (1) is specified. For each unplanned cell (2) a set of frequencies (f) to be potentially assigned to this unplanned cell (2) is specified. Frequency interference probabilities (p) of selected cell pairs are calculated, wherein each cell pair defines a relation of an unplanned cell (2) to another cell (c) within the mobile communications network (1). Then, terms of a stress function are formulated, each term connecting a calculated frequency interference probability (p) of a respective cell pair with a frequency relation between the cells (2, c) of the respective cell pair. An optimized assignment of frequencies (f) is determined by using a quantum concept processor (7), thereby selecting for each unplanned cell (2) a sub-set of frequencies (f) from the respective set of frequencies, such that the stress function is minimized.