he initial analysis, design, and spatial planning of wireless networks are conditioned propagation environment property transmissions. Due to the complexity of phenomena, the practical assessment of propagation influence on the effectiveness of wireless transmission paths is based on simulation studies. This applies to both modern and upcoming (5G and beyond) cellular, satellite, Internet of Things (IoT), body area (BANs), vehicle-to-everything (V2X), ad-hoc mobile (MANETs), and wireless sensor networks (WSNs). In this case, adequate modeling of the system components (i.e., transmitter/receiver/sensor, base station/user equipment) and radio networks (i.e., higher layers of the ISO Open Systems Interconnection (OSI) Reference Model), properly reflecting the influence of the propagation environment, is crucial. It is worth highlighting that the propagation channel is one of the physical-layer elements that is significantly decisive for the efficiency of the designed radio links, networks, and entire systems. Hence, it follows that the application of the propagation models and channels verified in real conditions has a significant impact on the efficiency and determines the correctness of the planning process of wireless radio networks. Therefore, these models should ensure the reflection of propagation effects on a received-signal form, which corresponds to results obtained in actual conditions. This goal is achieved when the basis for channel modeling is propagation measurement results that are obtained under real environmental conditions. Such measurements should consider the specificity of the developed systems, including the used frequency ranges, environment character, parameters and patterns of antenna systems, etc.
5G and beyond networks will be based on millimeter-wave and terahertz bands. However, the emerging systems also use lower microwave ranges, including centimeter waves. However, path loss increases when wavelengths decrease. For this reason, multi-antenna systems (including massive-MIMO) are used, which enable beamforming, increasing their energy gain and the spatial multiplexing of radio resources. Therefore, the development of propagation and channel models for designing and planning the new emerging wireless networks, considering the patterns and parameters (i.e., gain, beamwidth, radiation/reception directions) of the antenna systems, is important.
This Special Issue covers topics related to new and emerging technologies in communication systems and networks, focusing on channel modeling and propagation measurements on 5G networks and beyond. We invite authors to submit new research and review papers considering (but not limited to) the topics below:
- Channel modeling for cellular, IoT, V2X, satellite networks, BANs, WSNs, MANETs, etc.;
-Propagation measurements in the range of centimeter, millimeter, and terahertz waves;
- Channel measurements and modeling for various environments (indoor/outdoor, urban street-canyon, etc.) and specific communication systems (e.g., V2X, IoT, high-speed train, highway, military MANETs, and WSNs);
- Novel estimation methods of current channel state (i.e., parameters and transmission characteristics of channels) on the basis of measurement data;
- Accuracy and error conditioning in estimating current state of channels;
- Channel models in systems with a spatially limited propagation area by the use of beamforming, massive-MIMO, and multi-antenna systems;
- Machine learning and artificial intelligence algorithms for propagation modeling;
- Measurements and modeling of channel dispersion in time, frequency (i.e., Doppler effect), and reception angle domains,
- Analytical, geometric, statistical, stochastic, or deterministic approaches to modeling stationary or time-varying channels;
- Methods of signal processing and synthesis to determine channel transmission characteristics (channel impulse response, power delay profile, angular power spectrum, Doppler spectrum, etc.);
- Parameters and transmission characteristics of propagation models and real measurements in effectiveness analysis (e.g., capacity, interference) of wireless links;
- Channel models in the assessment of the coexistence and electromagnetic compatibility of different systems operating in the same frequency bands or adjacent channels;
- Building of electromagnetic situation awareness in cognitive radio networks with the use of measurements or propagation modeling;
- Designing, spatial planning, and modeling the emerging and future wireless networks considering channel model and propagation measurements.