Wireless local area network planning: an overview

When planning a wireless local area network, there are design issues that need to be considered. In this paper, the fundamentals of planning a wireless local area network are introduced and discussed to highlight the requirements involved. Network constraints, as their relevance to wireless network design is investigated. The paper concludes with an overview of wireless network planning solutions including commercial and free software, and an introduction to the author’s research

An experimental study of the temporal statistics of radio signals scattered by rain

A fixed-beam bistatic CW experiment designed to measure the temporal statistics of the volume reflectivity produced by hydrometeors at several selected altitudes, scattering angles, and at two frequencies (3.6 and 7.8 GHz) is described. Surface rain gauge data, local meteorological data, surveillance S-band radar, and great-circle path propagation measurements were also made to describe the general weather and propagation conditions and to distinguish precipitation scatter signals from those caused by ducting and other nonhydrometeor scatter mechanisms. The data analysis procedures were designed to provide an assessment of a one-year sample of data with a time resolution of one minute. The cumulative distributions of the bistatic signals for all of the rainy minutes during this period are presented for the several path geometries

Computational Methods for Network-Aware and Network-Agnostic IoT Low Power Wide Area Networks (LPWANs)

In this paper, we tackle the design issue of optimal deployment of low power wide area network (LPWAN) Internet of Things (IoT) gateways (GWs). We classify GW deployment problem into two different categories, i.e., network-aware and network-agnostic. In network-aware GW deployment, precise location of IoT end devices (EDs) is known and thus the design questions are: 1) where to place GWs, i.e., to maximize received signal strength and 2) given received signal strength which GW should the ED be associated with to balance the network load. For, Network-agnostic GW deployment, same questions are answered in the absence of precise knowledge for the locations of EDs. For the network-aware deployment we borrow tools from machine-learning such as ${K}$ -means clustering for determination of optimal GW location. Subsequently, the link assignment problem is presented as an integer linear programming optimization. We prove that the network-agnostic GW deployment principle of placement of GWs at highest altitudes, if applied automatically, may lead to very deteriorated network performance increasing the network operational costs. Consequently, we introduce the concept of network-agnostic GW placement algorithm whereby the location of GWs can be estimated without prior knowledge of specific locations of EDs and we use it as a guiding principle to design spatial algorithm for finding GW locations. We show that spatial algorithm can, in principle, provide effective GW placement suggestions compared to a network-aware method such as ${K}$ -means clustering. We show that using a computational method for GW placement like ${K}$ -means or spatial algorithm, has a potential of creating competitive network performance using just the same number of GWs, thus cutting down the financial costs of the network and increasing its sustainability

The Political Legacy of Entertainment TV

We investigate the political impact of entertainment television in Italy over the past thirty years by exploiting the staggered introduction of Silvio Berlusconi's commercial TV network, Mediaset, in the early 1980s. We find that individuals in municipalities that had access to Mediaset prior to 1985 - when the network only featured light entertainment programs - were significantly more likely to vote for Berlusconi's party in 1994, when he first ran for office. This effect persists for almost two decades and five elections, and is especially pronounced for heavy TV viewers, namely the very young and the old. We relate the extreme persistence of the effect to the relative incidence of these age groups in the voting population, and explore different mechanisms through which early exposure to entertainment content may have influenced their political attitudes.url : http://www.rubendurante.net/mediaset_politics.pdf doi

Analyzing the impacts of tree canopy on cellular radio networks

The purpose of this research was to investigate the impacts of vegetation on cellular signal strength. The research was conducted in Buckingham County, VA, located approximately 60 miles west of Richmond, VA. The county is mostly rural. Dillwyn, a small town, serves as the county's major metropolitan area. Signal strength observations were collected over a nine month period. The first set of samples was collected in September/October 2008 and compared directly to samples taken in January 2009. A third set of samples was collected in May 2009 and compared to predictions from a free-space loss model. Each sample was assigned a National Land Cover Dataset (NLCD) value for Deciduous, Evergreen or Open Area. The Open Area class was used to verify the accuracy of the free-space loss model. Significant differences between the signal strengths captured in September/October 2008 and January 2009 were observed. The signal strength was stronger in the winter than in the fall. There was no significant difference between land cover classes when all signal strength differences obtained were examined. However, there was a significant difference between the Deciduous/Open areas and Evergreen classes when only the negative signal strength differences were examined. A weak negative correlation was found between distance from the tower and the signal strength difference for the Evergreen class

A Platform for Large-Scale Regional IoT Networks

The Internet of Things (IoT) promises to allow everyday objects to connect to the Internet and interact with users and other machines ubiquitously. Central to this vision is a pervasive wireless communication network connecting each end device. For individual IoT applications it is costly to deploy a dedicated network or connect to an existing cellular network, especially as these applications do not fully utilize the bandwidth provided by modern high speeds networks (e.g., WiFi, 4G LTE). On the other hand, decades of wireless research have produced numerous low-cost chip radios and effective networking stacks designed for short-range communication in the Industrial, Scientific and Medical Radio band (ISM band). In this thesis, we consider adapting this existing technology to construct shared regional low-powered networks using commercially available ISM band transceivers. To maximize network coverage, we focus on low-power wide-area wireless communication which enables links to reliably cover 10 km or more depending on terrain transmitting up to 1 Watt Equivalent Isotropically Radiated Power (EIRP). With potentially thousands of energy constrained IoT devices vying for extremely limited bandwidth, minimizing network coordination overhead and maximizing channel utility is essential. To address these challenges, we propose a distributed queueing (DQ) based MAC protocol, DQ-N. DQ-N exhibits excellent performance, supporting thousands of IoT devices from a single base station. In the future, these networks could accommodate a heterogeneous set of IoT applications, simplifying the IoT application development cycle, reducing total system cost, improving application reliability, and greatly enhancing the user experience

Análisis de desempeño del IEEE802.11 para la conectividad de zonas rurales de Colombia

In this paper, we present the performance characteristics of IEEE802.11 standard in point to point reaching over rural sites in Colombia. To explain this performance is first should be carried out a detailed description of the behavior of the physical and MAC layer in the deployment of long-range networks, this is done by analyzing the existing regulation for maximum equivalent isotropic radiated power in the ISM band, the propagation losses, the reception level of commercial Wi-Fi radios, the frame error rate and considering the parameters DIFS, and ACKTimeout SLOTTIME that are part of medium access control affect the implementation of radio links of several kilometers. Following from this theoretical models in the literature and one proposed by the authors calculate the saturated throughput UDP unidirectional and bidirectional function of the distance considering the different transmission speeds; After a couple of prototype autonomous Wi-Fi communication photovoltaic powered laboratory designed and built, a group performed experimental measurements of saturated UDP throughput in point to point links between Bucaramanga and rural sites surrounding metropolitan area in the range of 0-10.4 km distances, measurements are performed using the iperf traffic generator sending UDP packets of unidirectional and bidirectional, then the measurements are compared with those obtained theoretically.Dentro de este artículo se presenta las características de desempeño del estándar IEEE802.11 en enlaces punto a punto de largo alcance sobre emplazamientos rurales en Colombia. Para explicar este desempeño primero se realiza una descripción detallada del comportamiento de la capa física y MAC en el despliegue de redes de largo alcance, esto se realiza mediante análisis de la regulación existente para la máxima potencia isotrópica radiada equivalente en la banda ISM, las pérdidas por propagación, el nivel de recepción de los radios Wi-Fi comerciales, la tasa de error de frame y considerando como los parámetros DIFS, Slottime y ACKTimeout que hacen parte del control de acceso al medio e inciden en la implementación de radio enlaces de varios kilómetros. Posteriormente a partir de unos modelos teóricos presentes en la literatura y uno propuesto por los autores se calcula el throughput UDP saturado unidireccional y bidireccional en función de la distancia consideradas las diferentes velocidades de transmisión; después con un par de prototipos de comunicación Wi-Fi autónomos alimentados con energía fotovoltaica diseñados y construidos en laboratorio, se realizan un grupo de medidas experimentales de throughput UDP saturado en enlaces punto-punto entre Bucaramanga y emplazamientos rurales circundantes a su área metropolitana en el rango de distancias de 0-10.4km, las mediciones se realizaron con el generador de tráfico IPERF enviando paquetes UDP de forma unidireccional y bidireccional, posteriormente las mediciones realizadas se comparan con los obtenidos de forma teórica