Aproximación de la calidad de voz y cobertura en una red GSM de emergencia

This paper contains the results obtained by measuring the voice quality parameters in a mobile telecommunications network for disaster attention in an emergency situation. The infrastructure used free software, an IP telephony system based on Asterisk, to interconnect calls, also used communications protocols of GSM (Global System Mobile) in the DCS-1800 (Digital Cellular Service band - 1800MHz) that facilitates the use of any commercial mobile terminal. The system also used USRP (Universal Software Radio Peripheral), that  is responsible for emulating the operation of a BTS (Base Transceiver Station) performing the functions of a PBX (Private Branch Exchange), further allows the coordination of different entities in charge of responding to these type of emergencies. The measurements of network performance were made from three probabilistic parameters: GoS (Grade of Service), DCR (Dropped Call Rate) and MOS (Mean Opinion Score). Using eight mobile stations and choosing a GoS of 2%, traffic up to 3.6 Erlang was generated. This measurement was performed using probabilistic models of Erlang B. Comparison the coverage of the BTS is carried out by applying the model Okumura-Hata without amplifiers.En este documento se muestran los resultados obtenidos al medir los parámetros de calidad de voz en una solución propuesta de telecomunicaciones para la atención de desastres en situaciones de emergencia, haciendo uso de software libre para interconectar llamadas, protocolos de comunicaciones empleados en las redes GSM (Global System Mobile) en la banda DCS-1800 (Digital Cellular Service - 1800MHz), que facilita el uso de cualquier terminal móvil comercial, utilizando un USRP (Universal Software Radio Peripheral) en conjunto con sistema de telefonía IP basado en Asterisk. El USRP se encarga de emular la operación de una BTS (Base Transceiver Station) al ejecutar las funciones de un PBX (Private Branch Exchange), permitiendo la coordinación de las entidades responsables de responder y atender este tipo de emergencias. Las mediciones del desempeño de la red se realizaron a partir de tres parámetros probabilísticos: GoS (Grade of service), DCR (Dropped Call Rate) y MOS (Mean Opinion Score). Con el uso de 8 terminales y escogiendo un GoS del 2% se generó un tráfico de hasta 3,6 Erlang. Esta medición se realizó empleando modelos probabilísticos de Erlang B. Se realiza el comparativo de la cobertura de la red aplicando el modelo Okumura-Hata sin el uso de amplificadores

A LoRaWAN Architecture for Communications in Areas without Coverage: Design and Pilot Trials

This research was partially funded by the Andalusian Knowledge Agency (projects A-TIC-241-UGR18 and B-TIC-568-UGR20), the Spanish Ministry of Science and Innovation (project PID2019-108713RB-C53), the Spanish Ministry of Economic Affairs and Digital Transformation (project TSI-063000-2021-28) and the Spanish Ministry of Universities (FPU Grant Number: 20/02621).This article proposes a system based on a long-distance communications system with low economic and energy costs that allows connectivity to be carried out independently from the existing cellular coverage in the area. In addition, it describes the design, development, implementation and analysis of an Internet of Things (IoT) architecture based on Long-RangeWide-Area Network (LoRaWAN). Moreover, the system has been deployed as a prototype, and the behavior and scope of the system have been analyzed in various real environments: urban, rural and natural. The results obtained from the analysis show that the system is suitable for working in areas without coverage such as mountains.Andalusian Knowledge Agency A-TIC-241-UGR18 B-TIC-568-UGR20Spanish Government PID2019-108713RB-C53Spanish Ministry of Economic Affairs and Digital Transformation TSI-063000-2021-28Spanish Ministry of Universities (FPU) 20/0262

A Lightweight Ad-hoc ICT Infrastructure for Post-Disaster Situations

One cannot expect communication resources to be readily available at disaster- affected site. Moreover, Information and Communication Technology (ICT) rescue supplies tends to be for heavy-duty and limited in quantity. This affects the information exchange and may cause delay in rescue operation, which is highly undesirable. In this thesis, we aim to utilize the time between rescue workers reaching the disaster-affected site and when the Internet connection is made available. The idea is to start the local communication and information exchange without waiting for the recovery of Internet connection. We propose a self-contained software package in the form of Linux Live USB flash drive.Our solution requires that Linux Live USB flash drives, laptop computers and external USB Wi-Fi NICs are provided to rescue workers as rescue supplie

Heavy Gas Cloud Boundary Estimation and Tracking using Mobile Sensors, Journal of Telecommunications and Information Technology, 2016, nr 3

This paper addresses issues concerned with design and managing of monitoring systems comprised of mobile wireless sensing devices (MANETs). The authors focus on self-organizing, cooperative and coherent networks that maintain a continuous communication with a central operator and adopt to changes in an unknown environment to achieve a given goal. The attention is focused on the development of MANET for heavy gas clouds detection and its boundary estimating and tracking. Two strategies for constructing the MANET are described, in which sensors explore the region of interest to detect the gas cloud, create temporary network topology and finally, cover the cloud boundary, and track the moving cloud. The utility and efficiency of the proposed strategies has been justified through simulation experiments

Comunicações TETRA, no Sistema de Proteção e Socorro e os seus constrangimentos

Atualmente, verifica-se um aumento de ocorrências no que diz respeito a catástrofes, sendo que os seus efeitos são cada vez mais devastadores. Neste contexto, o papel da proteção civil é cada vez mais relevante, ou seja, em proteger e socorrer pessoas e bens, sendo, portanto, transversal a toda a sociedade. Neste âmbito, a existência de um sistema de comunicação de emergência fiável e rápido é um fator importante no que concerne à possibilidade de resposta atempada e eficaz relativamente a situações de risco ou a catástrofes. A eficácia e eficiência das operações de proteção civil vai depender da articulação entre os diversos agentes, articulação essa que tem como um dos pilares-base o seu sistema de comunicação. No entanto, tanto o Sistema Integrado das Redes de Emergência e Segurança de Portugal (SIRESP), como a Rede Operacional de Bombeiros (ROB), apresentam ainda algumas lacunas no seu funcionamento. O que se traduz em constrangimentos na atuação destes atores, que podem pôr em causa a segurança das pessoas e dos seus bens. Este trabalho teve então como objetivo identificar as dificuldades de interligação entre os vários agentes de proteção e socorro, que utilizam as redes de emergência, recorrendo, para tal, a um estudo de carácter quantitativo. Problemas na articulação entre os diferentes atores, a independência entre as diferentes entidades e níveis de segurança bastante profundos, revelam-se prejudiciais para o bom funcionamento das redes de comunicação. A formação dos profissionais revela-se uma boa estratégia para colmatar estes problemas, devido ao correto conhecimento e manuseamento dos rádios do SIRESP e ROB

As ausências de cobertura ou rede nas comunicações dos agentes de Proteção Civil no concelho de Figueiró dos Vinhos

Atualmente ainda existem problemas de comunicações das zonas-sombra onde será pretendido que se faça um levantamento no concelho de Figueiró dos Vinhos e identifique-se o problema e reporte-se as entidades responsáveis com o intuito de corrigir para futuras situações de Emergência e Catástrofe. As zonas-sombra dificultam e muito as ausências das comunicações nos teatro de operações, devendo existir uma entidade responsável em ter equipamentos de redundância para resolver o problema que surge naquele preciso momento. Efetuou-se um questionário que auxiliou a entender se todos os agentes de Proteção Civil no concelho de Figueiró dos Vinhos sentem as dificuldades nas comunicações e perceber-se se as dificuldades advêm por falta de manuseamento do equipamento “SIRESP” ou se a entidade detentora das redes não consegue implementar o aumento de sinal nessas zonas. Contudo, a Camara Municipal de Figueiró dos Vinhos colaborou através do Gabinete de “SIG” para elaborar um mapa do concelho por freguesias com a altimetria tendo como intuito final definir pontos estratégicos para que sejam colocados equipamentos em redundância onde os operacionais nunca fiquem sem comunicações.info:eu-repo/semantics/publishedVersio

Investigating Hastily-Formed Collaborative Networks

This research explores both the human and technical aspects of the network centric environment in the context of a major disaster or incident of national significance. The National Incident Management System (NIMS) is viewed by the authors as a social network, and an organizational topology is developed to improve its effectiveness. A rapid Network Deployment Kit (RNDK) using commercial off the shelf (COTS) wireless networking technology is also proposed that facilitates immediate NIMS implementation. The integration of logical and technical analyses forms a comprehensive systems engineering proposal to facilitate collaboration in a net-centric environment. It is envisioned that the methodology used herein to derive and evaluate comprehensive networks proves extendable to other contexts thereby contributing to the netcentric body of knowledge

Analysis, design, and implementation of an infrastructure-less situation awareness application

This work aims to implement an application based on opportunistic communication. It must be operational in a disaster situation when the cellular network is not available. During this work, a first part was consecrated to the study of the several types of ad hoc networks and the various technologies related to them. This has served as a foundation for the study of ad hoc networks in smartphones since an android application was developed. In a second phase, we defined the main requirements and features of the application. After that, the analysis of the existing solution was effectuated. We took care to emphasize the differences between the market solution and our implementation of the use case. It was necessary for us to know if such an application had its place in the market and if it was the case, in which way it differs from the competition

Network virtualization in next-generation cellular networks: a spectrum pooling approach

The hardship of expanding the cellular network market results from the tremendous high cost of mobile infrastructure, i.e. the capital expenditures (CAPEX) and the operational expenditures (OPEX). Spectrum Sharing is one of the proposed solution for the high-cost of scalability of cellular networks. However, most of the proposed spectrum pooling frameworks in the literature are mostly approached from a technical view besides there are no good cost models based on real datasets for quantifying the circumstances under which sharing the spectrum and network resources would be beneficial to mobile operators. In this thesis, by studying different sharing scenarios in a fiber-based backhaul mobile network, we assess the incentives for service providers (SPs) to share spectrum/infrastructure in different cellular market areas/economic areas (CMA/BEAs) with different population density, allocated bandwidth (BW), spectrum bid values and considering different network topologies. Moreover, we look at the technical problem of sharing the spectrum between two SPs sharing the same basestation (BS), yet they have different traffic demand as well as different QoS constraints. We design a resource allocation scheme to provision real-time (RT), non-real-time (NRT) as well as Ultra-reliable Low Latency Communications (URLLC) traffic in a single shared BS scenario such that SPs achieve isolation, fairness and enforce their QoS constraints. Finally, we exploit spectrum pooling to develop an approach for dynamically re-configuring the base stations that survive a disaster and are powered by a microgrid to form a multi-hop mesh network in order to provide local cellular service