Analysis of coexistence and mutual interference between mobile and digital television systems

La creciente demanda de servicios de comunicaciones inalámbricas multimedia es un factor clave en los mercados más desarrollados. Así, las palabras de moda en las comunicaciones personales “acceso para cualquier persona, en cualquier sitio, en cualquier momento y para el servicio deseado”, implican una demanda notoria y creciente del Espectro Radioeléctrico. En este sentido, la última Conferencia Mundial de Radiocomunicaciones 2007 (CMR-07) atribuyó la parte alta de la banda UHF a las redes móviles como servicio co-primario a partir del 2015 en la Región 1, aprovechando el Dividendo Digital debido a la mayor eficiencia espectral de la TV digital con respecto a la analógica. Esto tiene el potencial de causar una interferencia perjudicial entre los sistemas de televisión y los sistemas móviles y necesita ser analizado con atención. En este artículo presentamos un estudio del problema de la interferencia co-canal en dicho escenario, proponiendo una metodología para tener en cuenta la interferencia entre una red móvil LTE y un sistema televisivo DVB-T, poniendo de relieve el comportamiento diferente de los dos radioenlaces.The ever increasing demand for multimedia wireless communication systems is a key feature of more advanced markets. The buzzwords of personal communications, meant to provide “access to anyone, anywhere, at anytime to the wanted service”, implies that radio spectrum demands are dramatically increasing in most developed markets. The last World Radiocommunication Conference (WRC-07) allocated on a co-primary basis the upper part of the UHF band to mobile services as from 2015 in Region 1, taking advantage of the Digital Dividend due to the higher spectrum efficiency of digital TV with respect to the analogue system. This will cause potentially harmful mutual interference between TV and mobile radio services, that needs to be carefully analysed. In this paper we present a study of the co-channel interference problem, proposing a methodology to take into account the mutual interference between a LTE mobile network and a DVB-T system and highlighting the different behaviour of the two radio links

A Method for the Electromagnetic Characterization of Construction Materials Based on Fabry–Pérot Resonance

The determination of the complex permittivity of low-loss construction materials at frequency bands above 6 GHz that are being proposed to allocate forthcoming mobile radio services is of critical importance for the design and deployment of future wireless systems. In this paper, a simple free-space method for the electromagnetic characterization of construction materials that does not require multiple reflection or transmission coefficient measurements for different incidence angles or complex optimization procedures is proposed and tested. The method is shown to yield permittivity and conductivity values in agreement with the literature for some common-use materials using a relatively simple measurement setup and procedure

Characterizing the UAV-to-Machine UWB Radio Channel in Smart Factories

In this work, the results of Ultra-Wideband air-to-ground measurements carried out in a real-world factory environment are presented and discussed. With intelligent industrial deployments in mind, we envision a scenario where the Unmanned Aerial Vehicle can be used as a supplementary tool for factory operation, optimization and control. Measurements address narrow band and wide band characterization of the wireless radio channel, and can be used for link budget calculation, interference studies and time dispersion assessment in real factories, without the usual limitation for both radio terminals to be close to ground. The measurements are performed at different locations and different heights over the 3.1-5.3 GHz band. Some fundamental propagation parameters values are determined vs. distance, height and propagation conditions. The measurements are complemented with, and compared to, conventional ground-to-ground measurements with the same setup. The conducted measurement campaign gives an insight for realizing wireless applications in smart connected factories, including UAV-assisted applications

A Study on mm-Wave Propagation In and Around Buildings

mm-waves are envisaged as a key enabler for 5G and 6G wireless communications, thanks to the wide bandwidth and to the possibility of implementing large-scale antenna arrays and advanced transmission techniques, such as massive MIMO and beamforming, that can take advantage of the multidimensional properties of the wireless channel. In order to analyze in depth the peculiar characteristics of mm-wave propagation, joint measurement and simulation campaigns in indoor and outdoor microcellular environments have been carried out. The investigation highlights that the assumption that mm-wave NLoS connectivity is hardly feasible is not necessarily true as significant reflections, scattering and even transmission mechanisms can provide good NLoS coverage in the considered indoor and outdoor scenarios. This is also reflected in the limited angle-spread differences between LoS and NLoS locations in some cases. Finally, the contribution of different propagation mechanisms (reflection, diffraction, scattering and combination of them) to the received signal is analyzed in the paper with the help of ray tracing simulations. These outcomes can be helpful to predict the performance of mm-wave wireless systems and for the development of deterministic and geometric-stochastic mm-wave channel models

smart metering wireless networks at 169 mhz

Intelligent metering systems are being rolled-out on a large-scale worldwide, enabling consumer to make informed choices about consumption patterns and energy saving, while supporting the development of new retail services and products. Unfortunately, the lack of established and shared international standards represents a serious hindrance to be overcome for a complete development of a profitable market. The identification of suitable communication protocols and cost-effective network architectures represent a challenging aspect. In this framework, different network design solutions for wireless smart metering systems at 169 MHz are considered and investigated in this paper, aiming at cost efficient deployment based on extensive re-use of existing infrastructures in urban scenarios, namely, macro-cellular and lighting networks. Coverage assessment and frequency planning issues are addressed, together with an ad hoc measurement campaign carried out to fill the gap in the knowledge of urban propagation in the 169 MHz band. Results show that cost-effective deployment of the intelligent metering network is achievable. Notably, a spatial reuse factor larger than the overall number of available frequency channels might be necessary, thus meaning that the spectral resources shall be also allocated according to a time division scheme, where the hubs are switched off at turn. Anyway, this requirement should not affect the overall reading rate in practical applications. 2017 IEEE

Item level characterization of mm-wave indoor propagation

According to the current prospect of allocating next generation wireless systems in the underutilized millimeter frequency bands, a thorough characterization of mm-wave propagation represents a pressing necessity. In this work, an “item level” characterization of radiowave propagation at 70 GHz is carried out. The scattering properties of several, different objects commonly present in indoor environment are investigated by means of measurements carried out in an anechoic chamber. The measured data have been also exploited to tune some parameters of a 3D ray tracing model

Ray-tracing-based mm-wave beamforming assessment

The use of large-size antenna arrays to implement pencil-beam forming techniques is becoming a key asset to cope with the very high throughput density requirements and high path-loss of future millimeter-wave (mm-wave) gigabit-wireless applications. Suboptimal beamforming (BF) strategies based on search over discrete set of beams (steering vectors) are proposed and implemented in present standards and applications. The potential of fully adaptive advanced BF strategies that will become possible in the future, thanks to the availability of accurate localization and powerful distributed computing, is evaluated in this paper through system simulation. After validation and calibration against mm-wave directional indoor channel measurements, a 3-D ray tracing model is used as a propagation-prediction engine to evaluate performance in a number of simple, reference cases. Ray tracing itself, however, is proposed and evaluated as a real-time prediction tool to assist future BF techniques

HABITAT: An IoT Solution for Independent Elderly

In this work, a flexible and extensive digital platform for Smart Homes is presented, exploiting the most advanced technologies of the Internet of Things, such as Radio Frequency Identification, wearable electronics, Wireless Sensor Networks, and Artificial Intelligence. Thus, the main novelty of the paper is the system-level description of the platform flexibility allowing the interoperability of different smart devices. This research was developed within the framework of the operative project HABITAT (Home Assistance Based on the Internet of Things for the Autonomy of Everybody), aiming at developing smart devices to support elderly people both in their own houses and in retirement homes, and embedding them in everyday life objects, thus reducing the expenses for healthcare due to the lower need for personal assistance, and providing a better life quality to the elderly users