Boris Ramos

Measuring rain with microwave links: A pilot experiment in Ecuador

This paper investigates the possibility of estimating the path averaged rainfall by means of single frequency microwave links. Microwave link attenuation measurements can supplement data gathered in the air (e.g. radars) or on the ground (e.g. raingauges), providing useful information about the rainfall on a virtually continuous time scale. We present here the results of a theoretical analysis conducted to derive the main operational parameters for the implementation of a system, currently under deployment, in the equatorial City of Guayaquil, Ecuador. The system performance is tested out by applying the Synthetic Storm Technique on rainfall time series, collected by raingauges located over the link area.

Rain rate estimation using a microwave link in Guayaquil City

This paper addresses a variation of the ITU-R P.838-3 rain attenuation estimation method to obtain an estimation of the rain rate based on the actual observed attenuation of a microwave radio link. The radio link is 18 kilometers long and uses the 5 GHz U-NII unlicensed band for this purpose. The experiment takes place in the tropical city of Guayaquil, Ecuador. The results are later evaluated by comparing them with the actual average rain rate given by four rain gauges installed along the propagation path. In addition, this research adapts the Synthetic Storm Technique for the use of multiple rain gauges in a region with a considerable level of rainfall spatial diversity to obtain preliminary calculations of radio link attenuation due to rain.

Towards a factory-of-things: Channel modeling and deployment assessment in PetroEcuador Esmeraldas oil refinery

Industry 4.0 and industrial Internet of Things (iIoT) trends are pushing towards the transformation of factories to provide more flexible production systems through the use of wireless networks. Technologies enabling the “Factory-of-Things” (FoT) paradigm allow the safe deployment of wireless field devices in industrial plants thanks to their low-battery usage that makes the maintenance cycle quite low, and highly reliable. The widespread adoption of these technologies should be paired with tools for predeployment network design and prediction of the wireless link quality to mimic the planning procedures applied to conventional industrial wired equipment. In factory sites, the strength of the radio signals is impaired by frequency, spatial and time-domain fading that influence the wireless link stability. In this paper, based on an extensive measurement campaign performed inside an active oil refinery, we propose and validate a novel channel model tailored for industrial wireless networks operating over 2.4 GHz and supporting a time-slotted channel hopping (TSCH) policy. Post-layout network performance verification has been finally carried out based on a WirelessHART industry standard system deployed in selected sites.

Performance comparison of linear equalization systems for wireless communications under Rayleigh channel

It is well known that multipath wireless channels generate Intersymbol Interference (ISI) and have a negative impact on the performance of wireless and digital communication systems. In this research we implement two types of linear equalizers, Zero-Forcing and Wiener, using Lab VIEW and the NI USRPs. The Zero-Forcing equalizer uses the inverse frequency response of the channel to retrieve the original signal, while the Wiener equalizer finds the minimum mean square error between the desired digital signal and the estimated one, in order to establish the optimum filter. These equalizers will be tested through an emulated Rayleigh channel, with different noise levels and digital modulation schemes, in order to analyze their performance response to ISI. The experiments undertaken in this work are supported by different elements of the Physical Layer Exploration Lab Using the NI USRP [1].

Modeling and policy design for promoting E-commerce in Ecuador

The purpose of this paper is to define a system dynamic model for the development of e-commerce applied the micro, small, and medium-sized enterprises of Ecuador. This model will allows us to explore and propose new policies and strategies for promoting the e-commerce in this developing country. Among the studied variables are on-line payment mechanisms and transactions security, quality of the website, and advertisement investment. The policy analysis and design implemented through system dynamics modeling is focused on increasing e-commerce transactions and customers, and improving the financial performance of e-commerce businesses in the country. The explored policies include strategies for increasing the number of Internet users, promoting the e-transactions, improving the international access to the Internet backbone, and a massive implementation of e-money.