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Abstract-In the framework of the ITALSAT campaign various European institutions carried out propagation measurements at V band. In this frequency band, signal reception in a satellite-to- Earth or Earth-to-satellite path may suffer severely from signal attenuation due to meteorological effects such as rain, snow, hail, fog, clouds, etc., where rain provides the most significant contribution. In this paper, a joint analysis of the ITALSAT propagation measurement campaigns at 39.6 GHz (precisely 39.592 GHz) carried out at both Oberpfaffenhofen, close to Munich, Germany, and Spino d'Adda, close to Milan, Italy, is presented. For both stations long-term attenuation statistics are available and reveal that signal attenuation due to meteorological effects depends very much on the season and on the time of the day. Signal attenuation can be compensated by an appropriate fade margin. In this paper, we show that the required fade margin to guarantee a target link availability has to be chosen very carefully, since it depends very much on the time interval upon which availability is defined. We consider complete years, ITU-R recommendations, all single months of the year, worst months, and spring, summer, fall, and winter. Furthermore, we evaluate diurnal variations for four time intervals: 00:00-06:00, 06:00-12:00, 12:00-18:00, and 18:00-24:00. [ABSTRACT FROM AUTHOR]

These days, security and efficiency of transportation networks are usually supported by wireless communication systems. In all cases, the radio-link reliability strongly depends on propagation properties and, therefore, effective prediction tools and models are requested in the design and planning phases of the radio system. In this paper, a mixed rays—modes approach to the propagation modeling in real tunnels is presented. The propagating field is computed as the superimposition of many characteristic modes, whose amplitudes are properly estimated thanks to a limited and, therefore, fast ray-tracing procedure; the geometrical optics rules are also used to model the main effects of the possible tunnel curvature. Moreover, an equivalent wall roughness is introduced in order to approximately account for the actual tunnel transversal shape and for the presence of inner elements and objects. The model is compared with some other different existing models and with measurements carried out inside an underground line in a neighborhood of Naples. The achieved performance is in line with the published scientific data. [ABSTRACT FROM PUBLISHER]

The IEEE Transactions on Antennas and Propagation (TAP) introduced an Associate Editor for Communications and Membership in December 2020. Prof. Marco Salucci, University of Trento, Italy, became the first to fulfill this role. The purpose of this new position is twofold. One purpose is to communicate to readers, external and internal to IEEE, the value of our contributions to the technologies that are used daily by billions of people around the world. Another purpose is to increase membership by introducing creative strategies to: 1) attract people that exploit the devices and methodologies developed by our authors; 2) to educate and inform people about our society; and 3) reach out to people traditionally affiliated with other societies. [ABSTRACT FROM AUTHOR]

MultiEXCELL, a new rainfall model oriented to the analysis of radio propagation impairments which was developed on the basis of a comprehensive rain field database collected by the weather radar sited in Spino d'Adda (Italy), is presented. Single rain cells are modeled by an analytical exponential profile which best represents real single-peaked rain structures. The rain cells' probability of occurrence is analytically derived from the local rainfall statistics. The spatial features of the rain field at mid- and large-scale are investigated through their natural aggregative process. The clusters (aggregates) of cells are studied in terms of distance between individual cells, number of cells per aggregate, and distance between aggregates. Finally, the fractional area covered by rain, which the rainfall spatial correlation strongly depends on, is derived from radar data through the comparison with the same quantity provided by global long-term numerical weather products. The MultiEXCELL procedure for the generation of spatially correlated synthetic rain fields is duly presented and the model's accurateness is preliminary assessed against the available radar dataset. Although MultiEXCELL is mainly oriented to propagation-related applications, its cellular approach may reveal useful also in hydrology, for the prediction/management of water resources, and in meteorology, for the nowcasting of the temporal evolution of rain structures. [ABSTRACT FROM AUTHOR]

A model is presented that extends the applicability of the propagation data collected during a long measurements campaign in a particular site and for a particular radiolink, to a generic link in a generic site. In fact, the objective of the model is to create a set of attenuation time series to be used in the design of advanced TLC systems. The model assumes that the marked differences of the rain statistics observed in various locations are, in first approximation, mainly due to the different frequency of occurrence of the various rainy events rather than to their shape. Starting from this assumption the model selects, from a large database of rain attenuation events collected in a particular site, a subset that, after an appropriate frequency and elevation scaling, can be used to represent time series of attenuation recorded in other experimental conditions (as for both site and link). The model has been applied to the attenuation data collected at Spino d'Adda (Milan, Italy) during the ITALSAT propagation campaign in order to simulate attenuation time series in several different links and sites. The model demonstrated good performance both in link conditions and climates, similar and different from the Spino d'Adda ones. [ABSTRACT FROM AUTHOR]

We have performed a propagation measurement campaign at the University of Rome br Vergata, Rome, Italy. We have sounded the channel by a probing signal at a carrier frequency of 4.78 GHz modulated by a train of pulses having a duration of 0.4 ns shaped by a pseudonoise (PN) sequence. The measurement band falls (3.6-6 GHz) in the frequency range allowed by the FCC ruling for ultrawide-band (UWB) operations. To characterize the channel behavior over the large and the small scale, the transmitter is moved in six different positions on the floor, while the receiver is moved in 625 different locations within each room. The receiver locations are arranged in a square grid of 25 × 25 points with 2 cm spacing, i.e., less than half of the minimum wavelength of the transmitted signal. A total of 625 × 16 impulse responses are recorded in nonline-of-sight (NLOS) conditions, 625 in line-of-sight (LOS) conditions within the rooms and 11 LOS measurements are made in the corridor at incremental spacing of 1 m. We describe the measurement technique as well as the procedure by which we process the experimental data to extract the amplitude, phase and delay associated to each component of the multipath profiles. We also derive path-loss and shadowing models for the UWB indoor channel in both LOS and NLOS conditions. Finally, we present an accurate analysis of the time dispersion of the UWB channel. [ABSTRACT FROM AUTHOR]