Dynamic Spectrum Manager Asynchronous Silent Period Coordination

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Solution Overview

Problem

Cognitive radio (CR) networks face challenges in efficiently coordinating silent periods for spectrum sensing, leading to inefficiencies and interference issues when detecting primary users and switching to alternative bands, especially in environments with diverse primary users and wireless technologies.

Innovation Solution

A Dynamic Spectrum Manager (DSM) is introduced to coordinate asynchronous silent periods across CR nodes, allowing for dynamic allocation of bandwidth and scheduling of quiet intervals to minimize interference and optimize spectrum utilization, using a centralized controller to manage spectrum sensing and allocate resources efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If periodic spectrum sensing is implemented to meet evacuation time requirements, then primary user detection reliability is improved, but network overhead and context switching complexity increase

Engineering Contradiction:
Improveprimary user detection reliabilityVSAvoidcontext switching complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements periodic silent periods at predetermined intervals where CR nodes suspend transmissions to perform spectrum sensing. This periodic structure ensures reliable detection of primary users while maintaining manageable complexity through predictable, scheduled operations rather than continuous monitoring

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent schedules silent periods in advance at predetermined times, allowing CR nodes to prepare for spectrum sensing operations beforehand. This preliminary scheduling reduces last-minute context switching complexity while ensuring detection reliability is maintained through consistent periodic monitoring

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If CR nodes perform spectrum sensing simultaneously, then spectrum availability detection is improved, but interference from other CR node transmissions increases

Engineering Contradiction:
Improvespectrum availability detectionVSAvoidinterference from CR node transmissions
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent merges the spectrum sensing operations of multiple CR nodes by coordinating them to occur simultaneously during network-wide silent periods. This consolidation improves measurement precision through coordinated detection while eliminating interference by ensuring all nodes are quiet during sensing intervals

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a dynamic spectrum manager as an intermediary that coordinates and schedules silent periods for all CR nodes. This mediator ensures simultaneous sensing occurs without interference by controlling the timing and duration of silent periods across the network

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If silent periods are scheduled periodically, then spectrum sensing coverage is improved, but time efficiency and overhead increase

Engineering Contradiction:
Improvespectrum sensing coverageVSAvoidspectrum sensing overhead
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements partial silent periods of limited duration at selective intervals rather than continuous monitoring. This approach provides sufficient spectrum sensing coverage to detect primary users while minimizing time loss and overhead by conducting sensing only when necessary according to the periodic schedule

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent uses periodic silent periods spaced at predetermined intervals to achieve adequate spectrum sensing coverage. This periodic approach balances detection reliability with time efficiency by concentrating sensing efforts at specific moments rather than requiring continuous monitoring

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2502437B1Coordination of asynchronous silent periods for dynamic spectrum manager (DSM)
Publication Date: 2019.06.12 INTERDIGITAL PATENT HOLDINGS INC
  • EP2502437B1 patent drawingFigure 1A
  • EP2502437B1 patent drawingFigure 1B
  • EP2502437B1 patent drawingFigure 1C

AI summary

A method for use in a Dynamic Spectrum Manager (DSM) for coordinating asynchronous silent periods in a network, the method comprising detecting a primary user in the network, transmitting a Silent Period Start Control Message to one or more cognitive radio (CR) nodes in the network, wherein the message indicates the start and duration of a silent period and initiates spectrum sensing,receiving a Measurement Report Control Message from the one or more CR nodes in the network indicating results of spectrum sensing, and transmitting a message to the one or more CR nodes, wherein the message instructs the one or more CR nodes to move to a different frequency based on the spectrum sensing results.