Front Cover. Cover 2. Cover 3. Cover 4. Table of Contents. Progress in Opening Access to Spectrum above 100 GHz. Opportunities and Challenges of mmWave NR. Comsoc Membership. Space Information Networks. Effects of Solar Scintillation on Deep Space Communications: Challenges and Prediction Techniques. Multiple-User Transmission in Space Information Networks: Architecture and Key Techniques. Application of the Time Modulated Array in Satellite Communications. IoT Applications and Services in Space Information Networks. Bidirectional Mission Offloading for Agile Space-Air-Ground Integrated Networks. Compressed Robust Transmission for Remote Sensing Services in Space Information Networks. Broadband LEO Satellite Communications: Architectures and Key Technologies. Ultra-Dense LEO: Integration of Satellite Access Networks into 5G and Beyond. QoE Driven Resource Allocation in Next Generation Wireless Networks. Crowd-Powered Sensing and Actuation in Smart Cities: Current Issues and Future Directions. Deep Learning in Physical Layer Communications. Massive MIMO in Sub-6 GHz and mmWave: Physical, Practical, and Use-Case Differences. Integrated Millimeter Wave and Sub-6 GHz Wireless Networks: A Roadmap for Joint Mobile Broadband and Ultra-Reliable Low-Latency Communications. Layered-Division-Multiplexing for High Spectrum Efficiency and Service Flexibility in Next Generation ATSC 3.0 Broadcast System. Non-Uniform Full-Dimension MIMO: New Topologies and Opportunities. Engineering Radio Maps for Wireless Resource Management. Target Wake Time: Scheduled Access in IEEE 802.11ax WLANs. Cover 4 Front Cover Cover 3 Cover 2 Table of Contents Message from the Editor-in-Chief ComSoc Membership Scanning the Literature Enabling Efficient 5G NR and 4G LTE Coexistence Spectrum Policy and Regulatory Issues Guest Editorial LTE Ground-to-Air Field Measurements in the Context of Flying Relays Is 5G Ready for Drones: A Look into Contemporary and Prospective Wireless Networks from a Standardization Perspective Machine Learning for Wireless Connectivity and Security of Cellular-Connected UAVs Fundamental Trade-offs in Communication and Trajectory Design for UAV-Enabled Wireless Network UAV-Assisted Emergency Networks in Disasters UAV Communications Based on Non-Orthogonal Multiple Access Research Challenges and Opportunities of UAV Millimeter-Wave Communications ComSoc Training Multiple Access MmWave Design for UAV-Aided 5G Communications Millimeter-Wave Propagation Modeling and Measurements for 5G Mobile Networks Narrowband IoT: A Survey on Downlink and Uplink Perspectives Vehicular Fog Computing: Enabling Real-Time Traffic Management for Smart Cities Toward Future Unmanned Aerial Vehicle Networks: Architecture, Resource Allocation and Field Experiments