LPWAN Frequency Planning Using Mobility Zones and Terrain Data

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

LPWAN-type communication systems lack an effective method to define and apply a frequency plan, which limits interference management and terminal mobility, as they do not employ cellular network principles like cell switching and handover.

Innovation Solution

A method involving a server that defines a frequency plan by obtaining mobility hierarchies, terrain measurements, and calculating average probabilities for each frequency band, allocating them to gateways and terminals based on mobility zones, ensuring efficient communication and mobility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a frequency plan is defined in LPWAN systems, then interference management is improved, but device complexity increases due to the need for terrain measurements and mobility zone management

Engineering Contradiction:
Improveinterference managementVSAvoidfrequency plan definition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs self-configuration by automatically defining frequency plans based on terrain measurements and mobility zones. The server autonomously calculates frequency allocations without requiring manual intervention, reducing operational complexity while maintaining reliable interference management through data-driven frequency assignment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary terrain measurements and mobility zone definitions before deploying the frequency plan. By pre-characterizing the propagation environment and mobility patterns, the system establishes a foundation for automatic frequency allocation that simplifies ongoing operations while ensuring reliable interference management from the outset.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If automatic frequency plan definition is implemented, then productivity is improved through automation, but measurement precision requirements increase for terrain and mobility characterization

Engineering Contradiction:
Improvefrequency plan definition efficiencyVSAvoidterrain measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system uses feedback from actual communication performance and mobility patterns to refine frequency plan definitions. By continuously monitoring system behavior and adjusting frequency allocations based on observed performance, the system maintains high productivity while reducing the need for extremely precise preliminary measurements, as the system adapts to actual conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system implements frequency plan definition with sufficient rather than excessive measurement precision. By focusing measurements on the most critical parameters and using probabilistic frequency allocation based on average terrain characteristics, the system achieves practical productivity improvements without requiring exhaustive measurement campaigns that would demand extreme precision.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If frequency bands are allocated based on mobility zones, then terminal mobility is improved, but device complexity increases due to mobility tree traversal and probability calculations

Engineering Contradiction:
Improveterminal mobilityVSAvoidmobility management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments the service area into mobility zones organized in a hierarchical tree structure, with each zone having specific frequency allocations. This segmentation allows terminals to efficiently determine their mobility zone and access appropriate frequencies without requiring complex global calculations, improving mobility while distributing computational complexity across simplified zone-level decisions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies local frequency allocations tailored to each mobility zone's characteristics rather than using uniform frequency plans. By determining average probabilities of signal quality within each local zone and allocating frequencies accordingly, the system enhances terminal mobility adaptability while reducing overall complexity through localized, independent zone management.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3258736B1Method for defining and applying a frequency plan
Publication Date: 2020.07.29 SAGEMCOM ENERGY & TELECOM SAS
  • EP3258736B1 patent drawingFigure 1~2
  • EP3258736B1 patent drawingFigure 3
  • EP3258736B1 patent drawingFigure 4

AI summary

In an LPWAN-type communication system comprising a server and a plurality of gateways intended to perform wireless communications with terminals of said communication system, the server: obtains (501) a description of a mobility hierarchy in which types of mobility are hierarchically defined; obtains (502) a description of a mobility tree in which mobility zones are hierarchically defined, in accordance with the mobility hierarchy; obtains (503) terrain measurements associated with each mobility zone defined in the mobility tree; establishes (504) a frequency plan based on the mobility tree and the terrain measurements; and configures (505) the gateways and the terminals according to the established frequency plan.