Masood Ur Rehman is an Associate Professor in Electronic and Nanoscale Engineering at the University of Glasgow, UK. He is a Fellow of the Higher Education Academy UK and Senior Member of the IEEE and Associate Editor for IEEE Sensors Journal, IEEE Access, Microwave & Optical Technology Letters, and IET Electronics Letters. Muhammad Ali Jamshed is a Research Assistant at the University of Glasgow, UK. Muhammad earned his PhD from the University of Surrey, Guildford, UK, in 2021. He is a Senior Member of the IEEE and Associate Editor of IET Network.

• Editor Biography xiiList of Contributors xiiiPreface xv  1 Electromagnetic Field Exposure: Fundamentals and KeyPractices 1Muhammad Ali Jamshed, Fabien Héliot, Tim W.C. Brown, andMasood Ur Rehman1.1 Introduction 11.2 EMF Metric and Evaluation Framework 31.2.1 EMF Exposure Factors 41.2.1.1 Transmit Antenna Regions 41.2.1.2 Transmit Antenna Characteristics 51.2.1.3 Duration of Exposure 61.2.1.4 Electrical Properties of Biological Tissues 61.2.2 EMF Exposure Metrics 61.2.2.1 Specific Absorption Rate 71.2.2.2 Power Density 81.2.2.3 Exposure-Ratio 91.2.2.4 Dose 101.2.2.5 Composite/Generic Metric of EMF Exposure 101.3 Application of Metric for Setting Guidelines/Limits and ReducingExposure 101.3.1 SAR Reduction 111.3.2 PD Reduction 121.3.3 Exposure-Ratio Reduction 121.3.4 Dose Reduction 12Contents vii1.3.5 Composite EMF Exposure Reduction 131.4 Conclusion 13References 13  2 Exposure to Electromagnetic Fields Emitted from WirelessDevices: Mechanisms and Assessment Methods 19Yasir Alfadhl2.1 Fundamentals of EMF Interactions with the Human Body 192.1.1 Thermal Effect 212.1.2 Non-thermal Effects 222.2 Physical Models to Represent the Interaction of EMFs with BiologicalTissue 242.2.1 Interaction Mechanisms 242.2.1.1 Effects of Bound Charges 252.2.1.2 Effects of Dipole Orientations 252.2.1.3 Drift of Conduction Charges 252.2.2 Dielectric Properties of Biological Materials 262.2.2.1 Relaxation Theory 262.2.2.2 Age-Dependent Dielectric Properties 282.2.3 The Interaction of EM Fields with Biological Materials 282.2.3.1 Interactions on the Body Scale 292.2.3.2 Interactions on the Tissue Scale 302.2.3.3 Interaction on the Cellular and Sub-cellular Scales 302.3 Dosimetry Concepts 302.3.1 The Specific Absorption Rate (SAR) 312.3.1.1 SAR Measurement Techniques over the Frequency Spectrum 312.3.1.2 SAR Spatial Averaging 322.3.1.3 Tissue Mass Averaging Procedures 322.3.1.4 Localized and Whole-Body Averaged SAR 342.3.2 The Specific Absorption (SA) 342.4 Dosimetry Methodology 352.4.1 Experimental Dosimetry 352.4.2 Numerical Dosimetry 362.4.2.1 Theoretical Analysis 362.4.2.2 Numerical Modelling 372.5 Numerical Dosimetry at the Radiofrequency and MicrowaveRegions 382.5.1 Formulation of the Scattered-Field FDTD Algorithm 392.5.2 Discretization of Anatomical Models in FDTD 402.5.3 Comparisons of Numerical Results with Analytical Benchmarks 42References 46viii Contents  3 Numerical Exposure Assessments of CommunicationSystems at Higher Frequencies 49Muhammad Rafaqat Ali Qureshi, Yasir Alfadhl, and Xiaodong Chen3.1 Introduction 493.2 Exposure Configuration 503.3 PlaneWave Exposure Assessment of E-field Absorption Within theSkin Using SAR as a Function of Frequency 513.3.1 Comparisons of SAR Levels on Dry-Skin andWet-Skin 523.4 PlaneWave Exposure Assessment of E-field Absorption WithinMulti-layer Model Using SAR as a Function of Frequency 583.4.1 Comparisons of SAR Levels on Dry-Skin and Multi-layer Model 593.5 PlaneWave Exposure Assessment of E-field Absorption Within theEye Using SAR as a Function of Frequency 633.5.1 Comparisons of SAR Levels on HEECM and Multi-layer Model 643.6 Chapter Summary 68Appendix 3.A 69References 74  4 Age Dependent Exposure Estimation Using NumericalMethods 77Muhammad Rafaqat Ali Qureshi, Yasir Alfadhl, Xiaodong Chen, andMasood Ur Rehman4.1 Introduction 774.2 Numerical Human Models 784.2.1 Adult Voxel Models 784.2.2 Child Voxel Model 794.3 Age-Dependent Tissue Properties 814.3.1 Measured Tissue Properties 824.3.2 Age-dependent Human Dielectric Properties Extraction fromMeasured Data 834.3.3 Novel Calculation Methods of Age-dependent DielectricProperties 834.3.3.1 Single Frequency Age-Dependent Method 844.3.3.2 Dispersive Age-Dependent Method 864.3.3.3 Implementation of the Cole–Cole Model on Age-DependentProperties 904.3.3.4 Accuracy Among the Age-dependent Methods 914.4 Numerical Validation 954.4.1 Comparison with an Analytical Benchmark 954.5 Chapter Summary 97Appendix 4.A 97References 111Contents ix  5 Antenna Design Considerations for Low SAR MobileTerminals 115Muhammad Ali Jamshed, Tim W.C. Brown, and Fabien Héliot5.1 Introduction 1155.2 SAR Reduction and Dual Coupling of Antenna 1175.3 Coupling Manipulation Simulation Campaign 1185.4 SAR Analysis and Surface Current 1235.5 Resilience to Different Head Use Cases 1275.6 Analysis of MIMO Performance in Data Mode 1305.7 Conclusion 132References 1326 MIMO Antennas with Coupling Manipulation for Low SARDevices 135Muhammad Ali Jamshed, Tim W.C. Brown, and Fabien Héliot6.1 Introduction 1356.2 Working Principle and Antenna Geometry 1366.2.1 Antenna Dimensions 1366.2.2 Surface Current Distribution 1386.2.3 Frequency Region Analysis 1396.3 Antenna Measurements 1416.3.1 MIMO Performance 1416.4 Efficiency and SAR Analysis 1436.5 Conclusion 148References 148  7 Reinforcement Learning and Device-to-DeviceCommunication for Low EMF Exposure 151Ali Nauman, Muhammad Ali Jamshed, and Sung Won Kim7.1 Introduction 1517.1.1 Contribution of Chapter 1537.1.2 Chapter Organization 1547.2 Background 1547.2.1 Narrowband Internet of Things (NB-IoT) 1557.2.1.1 Frame Structure 1557.2.2 Device-to-Device (D2D) Communication 1577.2.3 Machine Learning 1607.2.3.1 Reinforcement Learning 1607.2.3.2 Q-Learning 1627.3 RelatedWorks 1637.4 System Model, Problem Formulation, and Proposed RL-ID2D 164x Contents7.4.1 Network Model 1647.4.1.1 Channel Model 1647.4.1.2 Mobility Model 1647.4.1.3 Signal-to-Interference-Noise-Ratio (SINR) 1667.4.2 Definitions 1667.4.2.1 Packet Delivery Ratio 1667.4.2.2 Potential Relay Set 1677.4.2.3 End-to-End Delivery Ratio 1677.4.3 Problem Formulation 1677.4.4 Reinforcement Learning Enabled Relay Selection 1687.4.4.1 Q-Learning Framework 1687.4.5 Proposed Intelligent D2D Mechanism 1717.5 Performance Evaluation 1747.5.1 Simulation Deployment Scenario and Analysis 1747.5.1.1 Analysis of Q-Learning Behavior in NB-IoT UE 1747.5.1.2 Analysis of EDR Under Various Parameters 1787.5.1.3 Analysis of E2E Delay Under Various Parameters 1797.5.1.4 Comparative Analysis of RL-ID2D with Opportunistic andDeterministic Model 1807.6 Conclusion 183References 183  8 Unsupervised Learning Based Resource Allocation for LowEMF NOMA Systems 187Muhammad Ali Jamshed, Fabien Héliot, and Tim W.C. Brown8.1 Introduction 1878.1.1 ExistingWork 1888.1.2 Motivation and Contributions 1898.1.3 Structure of the Chapter 1908.2 EMF-Aware PD-NOMA Framework 1928.2.1 System Model 1928.2.2 Problem Formulation 1958.3 Machine Learning Based User Grouping/Subcarrier Allocation 1968.4 Power Assignment 1988.5 Numerical Analysis 2018.5.1 Simulation Results 2028.5.2 Scheme Validity for Real Applications 2068.6 Conclusion 208References 208Contents xi  9 Emission-Aware Resource Optimization forBackscatter-Enabled NOMA Networks 213Muhammad Ali Jamshed, Wali Ullah Khan, Haris Pervaiz,Muhammad Ali Imran, and Masood Ur Rehman9.1 Introduction 2139.1.1 Motivation and Contributions 2149.2 System Model 2159.2.1 Problem Formulation 2179.3 Proposed Solution 2189.3.1 Sub-carrier Allocation 2189.3.2 Power Allocation 2189.4 Performance Evaluation 2219.5 Conclusion 223References 223  10 Road Ahead for Low EMF User Proximity Devices 225Muhammad Ali Jamshed, Fabien Héliot, Tim W.C. Brown, andMasood Ur Rehman10.1 Introduction 22510.2 Perception and Physiological Impact of EMF 22610.2.1 Public’s Perception of Exposure and Risk Assessment 22610.2.2 Physiological Impact 22710.2.2.1 Age Range and Exposure 22710.2.2.2 mmWave and Exposure 22710.2.2.3 Brain Tumour and Exposure 22810.3 EMF Exposure Evaluation Metric and Regulations: A FuturePerspective 22910.3.1 Expected Exposure Contribution of Future Wireless CommunicationTechnologies 22910.3.1.1 Exposure and mmWave 22910.3.1.2 Exposure and Massive MIMO 22910.3.1.3 Exposure and Densification 23010.3.2 Open Issues and Future Research Tracks 23110.3.2.1 New EMF Limits and Guidelines 23110.3.2.2 EMF Mitigation Techniques and New Metrics 23110.3.2.3 Other Open Issues 23210.4 Conclusion 232References 233Index 237

Masood Ur Rehman is an Associate Professor in Electronic and Nanoscale Engineering at the University of Glasgow, UK. He is a Fellow of the Higher Education Academy UK and Senior Member of the IEEE and Associate Editor for IEEE Sensors Journal, IEEE Access, Microwave & Optical Technology Letters, and IET Electronics Letters. Muhammad Ali Jamshed is a Research Assistant at the University of Glasgow, UK. Muhammad earned his PhD from the University of Surrey, Guildford, UK, in 2021. He is a Senior Member of the IEEE and Associate Editor of IET Network.

• Editor Biography xiiList of Contributors xiiiPreface xv  1 Electromagnetic Field Exposure: Fundamentals and KeyPractices 1Muhammad Ali Jamshed, Fabien Héliot, Tim W.C. Brown, andMasood Ur Rehman1.1 Introduction 11.2 EMF Metric and Evaluation Framework 31.2.1 EMF Exposure Factors 41.2.1.1 Transmit Antenna Regions 41.2.1.2 Transmit Antenna Characteristics 51.2.1.3 Duration of Exposure 61.2.1.4 Electrical Properties of Biological Tissues 61.2.2 EMF Exposure Metrics 61.2.2.1 Specific Absorption Rate 71.2.2.2 Power Density 81.2.2.3 Exposure-Ratio 91.2.2.4 Dose 101.2.2.5 Composite/Generic Metric of EMF Exposure 101.3 Application of Metric for Setting Guidelines/Limits and ReducingExposure 101.3.1 SAR Reduction 111.3.2 PD Reduction 121.3.3 Exposure-Ratio Reduction 121.3.4 Dose Reduction 12Contents vii1.3.5 Composite EMF Exposure Reduction 131.4 Conclusion 13References 13  2 Exposure to Electromagnetic Fields Emitted from WirelessDevices: Mechanisms and Assessment Methods 19Yasir Alfadhl2.1 Fundamentals of EMF Interactions with the Human Body 192.1.1 Thermal Effect 212.1.2 Non-thermal Effects 222.2 Physical Models to Represent the Interaction of EMFs with BiologicalTissue 242.2.1 Interaction Mechanisms 242.2.1.1 Effects of Bound Charges 252.2.1.2 Effects of Dipole Orientations 252.2.1.3 Drift of Conduction Charges 252.2.2 Dielectric Properties of Biological Materials 262.2.2.1 Relaxation Theory 262.2.2.2 Age-Dependent Dielectric Properties 282.2.3 The Interaction of EM Fields with Biological Materials 282.2.3.1 Interactions on the Body Scale 292.2.3.2 Interactions on the Tissue Scale 302.2.3.3 Interaction on the Cellular and Sub-cellular Scales 302.3 Dosimetry Concepts 302.3.1 The Specific Absorption Rate (SAR) 312.3.1.1 SAR Measurement Techniques over the Frequency Spectrum 312.3.1.2 SAR Spatial Averaging 322.3.1.3 Tissue Mass Averaging Procedures 322.3.1.4 Localized and Whole-Body Averaged SAR 342.3.2 The Specific Absorption (SA) 342.4 Dosimetry Methodology 352.4.1 Experimental Dosimetry 352.4.2 Numerical Dosimetry 362.4.2.1 Theoretical Analysis 362.4.2.2 Numerical Modelling 372.5 Numerical Dosimetry at the Radiofrequency and MicrowaveRegions 382.5.1 Formulation of the Scattered-Field FDTD Algorithm 392.5.2 Discretization of Anatomical Models in FDTD 402.5.3 Comparisons of Numerical Results with Analytical Benchmarks 42References 46viii Contents  3 Numerical Exposure Assessments of CommunicationSystems at Higher Frequencies 49Muhammad Rafaqat Ali Qureshi, Yasir Alfadhl, and Xiaodong Chen3.1 Introduction 493.2 Exposure Configuration 503.3 PlaneWave Exposure Assessment of E-field Absorption Within theSkin Using SAR as a Function of Frequency 513.3.1 Comparisons of SAR Levels on Dry-Skin andWet-Skin 523.4 PlaneWave Exposure Assessment of E-field Absorption WithinMulti-layer Model Using SAR as a Function of Frequency 583.4.1 Comparisons of SAR Levels on Dry-Skin and Multi-layer Model 593.5 PlaneWave Exposure Assessment of E-field Absorption Within theEye Using SAR as a Function of Frequency 633.5.1 Comparisons of SAR Levels on HEECM and Multi-layer Model 643.6 Chapter Summary 68Appendix 3.A 69References 74  4 Age Dependent Exposure Estimation Using NumericalMethods 77Muhammad Rafaqat Ali Qureshi, Yasir Alfadhl, Xiaodong Chen, andMasood Ur Rehman4.1 Introduction 774.2 Numerical Human Models 784.2.1 Adult Voxel Models 784.2.2 Child Voxel Model 794.3 Age-Dependent Tissue Properties 814.3.1 Measured Tissue Properties 824.3.2 Age-dependent Human Dielectric Properties Extraction fromMeasured Data 834.3.3 Novel Calculation Methods of Age-dependent DielectricProperties 834.3.3.1 Single Frequency Age-Dependent Method 844.3.3.2 Dispersive Age-Dependent Method 864.3.3.3 Implementation of the Cole–Cole Model on Age-DependentProperties 904.3.3.4 Accuracy Among the Age-dependent Methods 914.4 Numerical Validation 954.4.1 Comparison with an Analytical Benchmark 954.5 Chapter Summary 97Appendix 4.A 97References 111Contents ix  5 Antenna Design Considerations for Low SAR MobileTerminals 115Muhammad Ali Jamshed, Tim W.C. Brown, and Fabien Héliot5.1 Introduction 1155.2 SAR Reduction and Dual Coupling of Antenna 1175.3 Coupling Manipulation Simulation Campaign 1185.4 SAR Analysis and Surface Current 1235.5 Resilience to Different Head Use Cases 1275.6 Analysis of MIMO Performance in Data Mode 1305.7 Conclusion 132References 1326 MIMO Antennas with Coupling Manipulation for Low SARDevices 135Muhammad Ali Jamshed, Tim W.C. Brown, and Fabien Héliot6.1 Introduction 1356.2 Working Principle and Antenna Geometry 1366.2.1 Antenna Dimensions 1366.2.2 Surface Current Distribution 1386.2.3 Frequency Region Analysis 1396.3 Antenna Measurements 1416.3.1 MIMO Performance 1416.4 Efficiency and SAR Analysis 1436.5 Conclusion 148References 148  7 Reinforcement Learning and Device-to-DeviceCommunication for Low EMF Exposure 151Ali Nauman, Muhammad Ali Jamshed, and Sung Won Kim7.1 Introduction 1517.1.1 Contribution of Chapter 1537.1.2 Chapter Organization 1547.2 Background 1547.2.1 Narrowband Internet of Things (NB-IoT) 1557.2.1.1 Frame Structure 1557.2.2 Device-to-Device (D2D) Communication 1577.2.3 Machine Learning 1607.2.3.1 Reinforcement Learning 1607.2.3.2 Q-Learning 1627.3 RelatedWorks 1637.4 System Model, Problem Formulation, and Proposed RL-ID2D 164x Contents7.4.1 Network Model 1647.4.1.1 Channel Model 1647.4.1.2 Mobility Model 1647.4.1.3 Signal-to-Interference-Noise-Ratio (SINR) 1667.4.2 Definitions 1667.4.2.1 Packet Delivery Ratio 1667.4.2.2 Potential Relay Set 1677.4.2.3 End-to-End Delivery Ratio 1677.4.3 Problem Formulation 1677.4.4 Reinforcement Learning Enabled Relay Selection 1687.4.4.1 Q-Learning Framework 1687.4.5 Proposed Intelligent D2D Mechanism 1717.5 Performance Evaluation 1747.5.1 Simulation Deployment Scenario and Analysis 1747.5.1.1 Analysis of Q-Learning Behavior in NB-IoT UE 1747.5.1.2 Analysis of EDR Under Various Parameters 1787.5.1.3 Analysis of E2E Delay Under Various Parameters 1797.5.1.4 Comparative Analysis of RL-ID2D with Opportunistic andDeterministic Model 1807.6 Conclusion 183References 183  8 Unsupervised Learning Based Resource Allocation for LowEMF NOMA Systems 187Muhammad Ali Jamshed, Fabien Héliot, and Tim W.C. Brown8.1 Introduction 1878.1.1 ExistingWork 1888.1.2 Motivation and Contributions 1898.1.3 Structure of the Chapter 1908.2 EMF-Aware PD-NOMA Framework 1928.2.1 System Model 1928.2.2 Problem Formulation 1958.3 Machine Learning Based User Grouping/Subcarrier Allocation 1968.4 Power Assignment 1988.5 Numerical Analysis 2018.5.1 Simulation Results 2028.5.2 Scheme Validity for Real Applications 2068.6 Conclusion 208References 208Contents xi  9 Emission-Aware Resource Optimization forBackscatter-Enabled NOMA Networks 213Muhammad Ali Jamshed, Wali Ullah Khan, Haris Pervaiz,Muhammad Ali Imran, and Masood Ur Rehman9.1 Introduction 2139.1.1 Motivation and Contributions 2149.2 System Model 2159.2.1 Problem Formulation 2179.3 Proposed Solution 2189.3.1 Sub-carrier Allocation 2189.3.2 Power Allocation 2189.4 Performance Evaluation 2219.5 Conclusion 223References 223  10 Road Ahead for Low EMF User Proximity Devices 225Muhammad Ali Jamshed, Fabien Héliot, Tim W.C. Brown, andMasood Ur Rehman10.1 Introduction 22510.2 Perception and Physiological Impact of EMF 22610.2.1 Public’s Perception of Exposure and Risk Assessment 22610.2.2 Physiological Impact 22710.2.2.1 Age Range and Exposure 22710.2.2.2 mmWave and Exposure 22710.2.2.3 Brain Tumour and Exposure 22810.3 EMF Exposure Evaluation Metric and Regulations: A FuturePerspective 22910.3.1 Expected Exposure Contribution of Future Wireless CommunicationTechnologies 22910.3.1.1 Exposure and mmWave 22910.3.1.2 Exposure and Massive MIMO 22910.3.1.3 Exposure and Densification 23010.3.2 Open Issues and Future Research Tracks 23110.3.2.1 New EMF Limits and Guidelines 23110.3.2.2 EMF Mitigation Techniques and New Metrics 23110.3.2.3 Other Open Issues 23210.4 Conclusion 232References 233Index 237

Masood Ur Rehman is an Associate Professor in Electronic and Nanoscale Engineering at the University of Glasgow, UK. He is a Fellow of the Higher Education Academy UK and Senior Member of the IEEE and Associate Editor for IEEE Sensors Journal, IEEE Access, Microwave & Optical Technology Letters, and IET Electronics Letters. Muhammad Ali Jamshed is a Research Assistant at the University of Glasgow, UK. Muhammad earned his PhD from the University of Surrey, Guildford, UK, in 2021. He is a Senior Member of the IEEE and Associate Editor of IET Network.

• Editor Biography xiiList of Contributors xiiiPreface xv  1 Electromagnetic Field Exposure: Fundamentals and KeyPractices 1Muhammad Ali Jamshed, Fabien Héliot, Tim W.C. Brown, andMasood Ur Rehman1.1 Introduction 11.2 EMF Metric and Evaluation Framework 31.2.1 EMF Exposure Factors 41.2.1.1 Transmit Antenna Regions 41.2.1.2 Transmit Antenna Characteristics 51.2.1.3 Duration of Exposure 61.2.1.4 Electrical Properties of Biological Tissues 61.2.2 EMF Exposure Metrics 61.2.2.1 Specific Absorption Rate 71.2.2.2 Power Density 81.2.2.3 Exposure-Ratio 91.2.2.4 Dose 101.2.2.5 Composite/Generic Metric of EMF Exposure 101.3 Application of Metric for Setting Guidelines/Limits and ReducingExposure 101.3.1 SAR Reduction 111.3.2 PD Reduction 121.3.3 Exposure-Ratio Reduction 121.3.4 Dose Reduction 12Contents vii1.3.5 Composite EMF Exposure Reduction 131.4 Conclusion 13References 13  2 Exposure to Electromagnetic Fields Emitted from WirelessDevices: Mechanisms and Assessment Methods 19Yasir Alfadhl2.1 Fundamentals of EMF Interactions with the Human Body 192.1.1 Thermal Effect 212.1.2 Non-thermal Effects 222.2 Physical Models to Represent the Interaction of EMFs with BiologicalTissue 242.2.1 Interaction Mechanisms 242.2.1.1 Effects of Bound Charges 252.2.1.2 Effects of Dipole Orientations 252.2.1.3 Drift of Conduction Charges 252.2.2 Dielectric Properties of Biological Materials 262.2.2.1 Relaxation Theory 262.2.2.2 Age-Dependent Dielectric Properties 282.2.3 The Interaction of EM Fields with Biological Materials 282.2.3.1 Interactions on the Body Scale 292.2.3.2 Interactions on the Tissue Scale 302.2.3.3 Interaction on the Cellular and Sub-cellular Scales 302.3 Dosimetry Concepts 302.3.1 The Specific Absorption Rate (SAR) 312.3.1.1 SAR Measurement Techniques over the Frequency Spectrum 312.3.1.2 SAR Spatial Averaging 322.3.1.3 Tissue Mass Averaging Procedures 322.3.1.4 Localized and Whole-Body Averaged SAR 342.3.2 The Specific Absorption (SA) 342.4 Dosimetry Methodology 352.4.1 Experimental Dosimetry 352.4.2 Numerical Dosimetry 362.4.2.1 Theoretical Analysis 362.4.2.2 Numerical Modelling 372.5 Numerical Dosimetry at the Radiofrequency and MicrowaveRegions 382.5.1 Formulation of the Scattered-Field FDTD Algorithm 392.5.2 Discretization of Anatomical Models in FDTD 402.5.3 Comparisons of Numerical Results with Analytical Benchmarks 42References 46viii Contents  3 Numerical Exposure Assessments of CommunicationSystems at Higher Frequencies 49Muhammad Rafaqat Ali Qureshi, Yasir Alfadhl, and Xiaodong Chen3.1 Introduction 493.2 Exposure Configuration 503.3 PlaneWave Exposure Assessment of E-field Absorption Within theSkin Using SAR as a Function of Frequency 513.3.1 Comparisons of SAR Levels on Dry-Skin andWet-Skin 523.4 PlaneWave Exposure Assessment of E-field Absorption WithinMulti-layer Model Using SAR as a Function of Frequency 583.4.1 Comparisons of SAR Levels on Dry-Skin and Multi-layer Model 593.5 PlaneWave Exposure Assessment of E-field Absorption Within theEye Using SAR as a Function of Frequency 633.5.1 Comparisons of SAR Levels on HEECM and Multi-layer Model 643.6 Chapter Summary 68Appendix 3.A 69References 74  4 Age Dependent Exposure Estimation Using NumericalMethods 77Muhammad Rafaqat Ali Qureshi, Yasir Alfadhl, Xiaodong Chen, andMasood Ur Rehman4.1 Introduction 774.2 Numerical Human Models 784.2.1 Adult Voxel Models 784.2.2 Child Voxel Model 794.3 Age-Dependent Tissue Properties 814.3.1 Measured Tissue Properties 824.3.2 Age-dependent Human Dielectric Properties Extraction fromMeasured Data 834.3.3 Novel Calculation Methods of Age-dependent DielectricProperties 834.3.3.1 Single Frequency Age-Dependent Method 844.3.3.2 Dispersive Age-Dependent Method 864.3.3.3 Implementation of the Cole–Cole Model on Age-DependentProperties 904.3.3.4 Accuracy Among the Age-dependent Methods 914.4 Numerical Validation 954.4.1 Comparison with an Analytical Benchmark 954.5 Chapter Summary 97Appendix 4.A 97References 111Contents ix  5 Antenna Design Considerations for Low SAR MobileTerminals 115Muhammad Ali Jamshed, Tim W.C. Brown, and Fabien Héliot5.1 Introduction 1155.2 SAR Reduction and Dual Coupling of Antenna 1175.3 Coupling Manipulation Simulation Campaign 1185.4 SAR Analysis and Surface Current 1235.5 Resilience to Different Head Use Cases 1275.6 Analysis of MIMO Performance in Data Mode 1305.7 Conclusion 132References 1326 MIMO Antennas with Coupling Manipulation for Low SARDevices 135Muhammad Ali Jamshed, Tim W.C. Brown, and Fabien Héliot6.1 Introduction 1356.2 Working Principle and Antenna Geometry 1366.2.1 Antenna Dimensions 1366.2.2 Surface Current Distribution 1386.2.3 Frequency Region Analysis 1396.3 Antenna Measurements 1416.3.1 MIMO Performance 1416.4 Efficiency and SAR Analysis 1436.5 Conclusion 148References 148  7 Reinforcement Learning and Device-to-DeviceCommunication for Low EMF Exposure 151Ali Nauman, Muhammad Ali Jamshed, and Sung Won Kim7.1 Introduction 1517.1.1 Contribution of Chapter 1537.1.2 Chapter Organization 1547.2 Background 1547.2.1 Narrowband Internet of Things (NB-IoT) 1557.2.1.1 Frame Structure 1557.2.2 Device-to-Device (D2D) Communication 1577.2.3 Machine Learning 1607.2.3.1 Reinforcement Learning 1607.2.3.2 Q-Learning 1627.3 RelatedWorks 1637.4 System Model, Problem Formulation, and Proposed RL-ID2D 164x Contents7.4.1 Network Model 1647.4.1.1 Channel Model 1647.4.1.2 Mobility Model 1647.4.1.3 Signal-to-Interference-Noise-Ratio (SINR) 1667.4.2 Definitions 1667.4.2.1 Packet Delivery Ratio 1667.4.2.2 Potential Relay Set 1677.4.2.3 End-to-End Delivery Ratio 1677.4.3 Problem Formulation 1677.4.4 Reinforcement Learning Enabled Relay Selection 1687.4.4.1 Q-Learning Framework 1687.4.5 Proposed Intelligent D2D Mechanism 1717.5 Performance Evaluation 1747.5.1 Simulation Deployment Scenario and Analysis 1747.5.1.1 Analysis of Q-Learning Behavior in NB-IoT UE 1747.5.1.2 Analysis of EDR Under Various Parameters 1787.5.1.3 Analysis of E2E Delay Under Various Parameters 1797.5.1.4 Comparative Analysis of RL-ID2D with Opportunistic andDeterministic Model 1807.6 Conclusion 183References 183  8 Unsupervised Learning Based Resource Allocation for LowEMF NOMA Systems 187Muhammad Ali Jamshed, Fabien Héliot, and Tim W.C. Brown8.1 Introduction 1878.1.1 ExistingWork 1888.1.2 Motivation and Contributions 1898.1.3 Structure of the Chapter 1908.2 EMF-Aware PD-NOMA Framework 1928.2.1 System Model 1928.2.2 Problem Formulation 1958.3 Machine Learning Based User Grouping/Subcarrier Allocation 1968.4 Power Assignment 1988.5 Numerical Analysis 2018.5.1 Simulation Results 2028.5.2 Scheme Validity for Real Applications 2068.6 Conclusion 208References 208Contents xi  9 Emission-Aware Resource Optimization forBackscatter-Enabled NOMA Networks 213Muhammad Ali Jamshed, Wali Ullah Khan, Haris Pervaiz,Muhammad Ali Imran, and Masood Ur Rehman9.1 Introduction 2139.1.1 Motivation and Contributions 2149.2 System Model 2159.2.1 Problem Formulation 2179.3 Proposed Solution 2189.3.1 Sub-carrier Allocation 2189.3.2 Power Allocation 2189.4 Performance Evaluation 2219.5 Conclusion 223References 223  10 Road Ahead for Low EMF User Proximity Devices 225Muhammad Ali Jamshed, Fabien Héliot, Tim W.C. Brown, andMasood Ur Rehman10.1 Introduction 22510.2 Perception and Physiological Impact of EMF 22610.2.1 Public’s Perception of Exposure and Risk Assessment 22610.2.2 Physiological Impact 22710.2.2.1 Age Range and Exposure 22710.2.2.2 mmWave and Exposure 22710.2.2.3 Brain Tumour and Exposure 22810.3 EMF Exposure Evaluation Metric and Regulations: A FuturePerspective 22910.3.1 Expected Exposure Contribution of Future Wireless CommunicationTechnologies 22910.3.1.1 Exposure and mmWave 22910.3.1.2 Exposure and Massive MIMO 22910.3.1.3 Exposure and Densification 23010.3.2 Open Issues and Future Research Tracks 23110.3.2.1 New EMF Limits and Guidelines 23110.3.2.2 EMF Mitigation Techniques and New Metrics 23110.3.2.3 Other Open Issues 23210.4 Conclusion 232References 233Index 237