Low Electromagnetic Field Exposure Wireless Devices: Fundamentals and Recent Advances

Cover
Title Page
Copyright
Contents
Editor Biography
List of Contributors
Preface
Chapter 1 Electromagnetic Field Exposure: Fundamentals and Key Practices
	1.1 Introduction
	1.2 EMF Metric and Evaluation Framework
		1.2.1 EMF Exposure Factors
			1.2.1.1 Transmit Antenna Regions
			1.2.1.2 Transmit Antenna Characteristics
			1.2.1.3 Duration of Exposure
			1.2.1.4 Electrical Properties of Biological Tissues
		1.2.2 EMF Exposure Metrics
			1.2.2.1 Specific Absorption Rate
			1.2.2.2 Power Density
			1.2.2.3 Exposure‐Ratio
			1.2.2.4 Dose
			1.2.2.5 Composite/Generic Metric of EMF Exposure
	1.3 Application of Metric for Setting Guidelines/Limits and Reducing Exposure
		1.3.1 SAR Reduction
		1.3.2 PD Reduction
		1.3.3 Exposure‐Ratio Reduction
		1.3.4 Dose Reduction
		1.3.5 Composite EMF Exposure Reduction
	1.4 Conclusion
	References
Chapter 2 Exposure to Electromagnetic Fields Emitted from Wireless Devices: Mechanisms and Assessment Methods
	2.1 Fundamentals of EMF Interactions with the Human Body
		2.1.1 Thermal Effect
		2.1.2 Non‐thermal Effects
	2.2 Physical Models to Represent the Interaction of EMFs with Biological Tissue
		2.2.1 Interaction Mechanisms
			2.2.1.1 Effects of Bound Charges
			2.2.1.2 Effects of Dipole Orientations
			2.2.1.3 Drift of Conduction Charges
		2.2.2 Dielectric Properties of Biological Materials
			2.2.2.1 Relaxation Theory
			2.2.2.2 Age‐Dependent Dielectric Properties
		2.2.3 The Interaction of EM Fields with Biological Materials
			2.2.3.1 Interactions on the Body Scale
			2.2.3.2 Interactions on the Tissue Scale
			2.2.3.3 Interaction on the Cellular and Sub‐cellular Scales
	2.3 Dosimetry Concepts
		2.3.1 The Specific Absorption Rate (SAR)
			2.3.1.1 SAR Measurement Techniques over the Frequency Spectrum
			2.3.1.2 SAR Spatial Averaging
			2.3.1.3 Tissue Mass Averaging Procedures
			2.3.1.4 Localized and Whole‐Body Averaged SAR
		2.3.2 The Specific Absorption (SA)
	2.4 Dosimetry Methodology
		2.4.1 Experimental Dosimetry
		2.4.2 Numerical Dosimetry
			2.4.2.1 Theoretical Analysis
			2.4.2.2 Numerical Modelling
	2.5 Numerical Dosimetry at the Radiofrequency and Microwave Regions
		2.5.1 Formulation of the Scattered‐Field FDTD Algorithm
		2.5.2 Discretization of Anatomical Models in FDTD
		2.5.3 Comparisons of Numerical Results with Analytical Benchmarks
	References
Chapter 3 Numerical Exposure Assessments of Communication Systems at Higher Frequencies
	3.1 Introduction
	3.2 Exposure Configuration
	3.3 Plane Wave Exposure Assessment of E‐field Absorption Within the Skin Using SAR as a Function of Frequency
		3.3.1 Comparisons of SAR Levels on Dry‐Skin and Wet‐Skin
	3.4 Plane Wave Exposure Assessment of E‐field Absorption Within Multi‐layer Model Using SAR as a Function of Frequency
		3.4.1 Comparisons of SAR Levels on Dry‐Skin and Multi‐layer Model
	3.5 Plane Wave Exposure Assessment of E‐field Absorption Within the Eye Using SAR as a Function of Frequency
		3.5.1 Comparisons of SAR Levels on HEECM and Multi‐layer Model
	3.6 Chapter Summary
	References
Chapter 4 Age Dependent Exposure Estimation Using Numerical Methods
	4.1 Introduction
	4.2 Numerical Human Models
		4.2.1 Adult Voxel Models
		4.2.2 Child Voxel Model
	4.3 Age‐Dependent Tissue Properties
		4.3.1 Measured Tissue Properties
		4.3.2 Age‐dependent Human Dielectric Properties Extraction from Measured Data
		4.3.3 Novel Calculation Methods of Age‐dependent Dielectric Properties
			4.3.3.1 Single Frequency Age‐Dependent Method
			4.3.3.2 Dispersive Age‐Dependent Method
			4.3.3.3 Implementation of the Cole–Cole Model on Age‐Dependent Properties
			4.3.3.4 Accuracy Among the Age‐dependent Methods
	4.4 Numerical Validation
		4.4.1 Comparison with an Analytical Benchmark
	4.5 Chapter Summary
	References
Chapter 5 Antenna Design Considerations for Low SAR Mobile Terminals
	5.1 Introduction
	5.2 SAR Reduction and Dual Coupling of Antenna
	5.3 Coupling Manipulation Simulation Campaign
	5.4 SAR Analysis and Surface Current
	5.5 Resilience to Different Head Use Cases
	5.6 Analysis of MIMO Performance in Data Mode
	5.7 Conclusion
	References
Chapter 6 MIMO Antennas with Coupling Manipulation for Low SAR Devices
	6.1 Introduction
	6.2 Working Principle and Antenna Geometry
		6.2.1 Antenna Dimensions
		6.2.2 Surface Current Distribution
		6.2.3 Frequency Region Analysis
	6.3 Antenna Measurements
		6.3.1 MIMO Performance
	6.4 Efficiency and SAR Analysis
	6.5 Conclusion
	References
Chapter 7 Reinforcement Learning and Device‐to‐Device Communication for Low EMF Exposure
	7.1 Introduction
		7.1.1 Contribution of Chapter
		7.1.2 Chapter Organization
	7.2 Background
		7.2.1 Narrowband Internet of Things (NB‐IoT)
			7.2.1.1 Frame Structure
		7.2.2 Device‐to‐Device (D2D) Communication
		7.2.3 Machine Learning
			7.2.3.1 Reinforcement Learning
			7.2.3.2 Q‐Learning
	7.3 Related Works
	7.4 System Model, Problem Formulation, and Proposed RL‐ID2D
		7.4.1 Network Model
			7.4.1.1 Channel Model
			7.4.1.2 Mobility Model
			7.4.1.3 Signal‐to‐Interference‐Noise‐Ratio (SINR)
		7.4.2 Definitions
			7.4.2.1 Packet Delivery Ratio
			7.4.2.2 Potential Relay Set
			7.4.2.3 End‐to‐End Delivery Ratio
		7.4.3 Problem Formulation
		7.4.4 Reinforcement Learning Enabled Relay Selection
			7.4.4.1 Q‐Learning Framework
		7.4.5 Proposed Intelligent D2D Mechanism
	7.5 Performance Evaluation
		7.5.1 Simulation Deployment Scenario and Analysis
			7.5.1.1 Analysis of Q‐Learning Behavior in NB‐IoT UE
			7.5.1.2 Analysis of EDR Under Various Parameters
			7.5.1.3 Analysis of E2E Delay Under Various Parameters
			7.5.1.4 Comparative Analysis of RL‐ID2D with Opportunistic and Deterministic Model
	7.6 Conclusion
	References
Chapter 8 Unsupervised Learning Based Resource Allocation for Low EMF NOMA Systems
	8.1 Introduction
		8.1.1 Existing Work
		8.1.2 Motivation and Contributions
		8.1.3 Structure of the Chapter
	8.2 EMF‐Aware PD‐NOMA Framework
		8.2.1 System Model
		8.2.2 Problem Formulation
	8.3 Machine Learning Based User Grouping/Subcarrier Allocation
	8.4 Power Assignment
	8.5 Numerical Analysis
		8.5.1 Simulation Results
		8.5.2 Scheme Validity for Real Applications
	8.6 Conclusion
	References
Chapter 9 Emission‐Aware Resource Optimization for Backscatter‐Enabled NOMA Networks
	9.1 Introduction
		9.1.1 Motivation and Contributions
	9.2 System Model
		9.2.1 Problem Formulation
	9.3 Proposed Solution
		9.3.1 Sub‐carrier Allocation
		9.3.2 Power Allocation
	9.4 Performance Evaluation
	9.5 Conclusion
	References
Chapter 10 Road Ahead for Low EMF User Proximity Devices
	10.1 Introduction
	10.2 Perception and Physiological Impact of EMF
		10.2.1 Public's Perception of Exposure and Risk Assessment
		10.2.2 Physiological Impact
			10.2.2.1 Age Range and Exposure
			10.2.2.2 mmWave and Exposure
			10.2.2.3 Brain Tumour and Exposure
	10.3 EMF Exposure Evaluation Metric and Regulations: A Future Perspective
		10.3.1 Expected Exposure Contribution of Future Wireless Communication Technologies
			10.3.1.1 Exposure and mmWave
			10.3.1.2 Exposure and Massive MIMO
			10.3.1.3 Exposure and Densification
		10.3.2 Open Issues and Future Research Tracks
			10.3.2.1 New EMF Limits and Guidelines
			10.3.2.2 EMF Mitigation Techniques and New Metrics
			10.3.2.3 Other Open Issues
	10.4 Conclusion
	References
Index
EULA