Generalized LUI propagation model for UAVs communications using terrestrial cellular networks

This work proposes an empirical propagation model to obtain the path loss and therefore determine the average received power of a signal for a specific outdoor urban scenario with UAVs. The proposed 3D propagation model for terrestrial cellular networks generalizes the LUI model and is valid in the frequency ranges of GSM, UMTS and LTE technologies. We report experimental work in 3D space, considering the height, the antennas base station tilt, sectorziation, angle and distances profile The experimental work included in this study is in good agreement with the proposed theoretical model, corroborating the idea that this model is a good contribution for cellular planning tools.info:eu-repo/semantics/acceptedVersio

Planning and dynamic spectrum management in heterogeneous mobile networks with QoE optimization

The radio and network planning and optimisation are continuous processes that do not end after the network has been launched. To achieve the best trade-offs, especially between quality and costs, operators make use of several coverage and capacity enhancement methods. The research from this thesis proposes methods such as the implementation of cell zooming and Relay Stations (RSs) with dynamic sleep modes and Carrier Aggregation (CA) for coverage and capacity enhancements. Initially, a survey is presented on ubiquitous mesh networks implementation scenarios and an updated characterization of requirements for services and applications is proposed. The performance targets for the key parameters, delay, delay variation, information loss and throughput have been addressed for all types of services. Furthermore, with the increased competition, mobile operator’s success does not only depend on how good the offered Quality of Service (QoS) is, but also if it meets the end user’s expectations, i.e., Quality of Experience (QoE). In this context, a model for the mapping between QoS parameters and QoE has been proposed for multimedia traffic. The planning and optimization of fixed Worldwide Interoperability for Microwave Access (WiMAX) networks with RSs in conjunction with cell zooming has been addressed. The challenging case of a propagation measurement-based scenario in the hilly region of Covilhã has been considered. A cost/revenue function has been developed by taking into account the cost of building and maintaining the infrastructure with the use of RSs. This part of the work also investigates the energy efficiency and economic implications of the use of power saving modes for RSs in conjunction with cell zooming. Assuming that the RSs can be switched-off or zoomed out to zero in periods when the traffic exchange is low, such as nights and weekends, it has been shown that energy consumption may be reduced whereas cellular coverage and capacity, as well as economic performance may be improved. An integrated Common Radio Resource Management (iCRRM) entity is proposed that implements inter-band CA by performing scheduling between two Long Term Evolution – Advanced (LTE-A) Component Carriers (CCs). Considering the bandwidths available in Portugal, the 800 MHz and 2.6 GHz CCs have been considered whilst mobile video traffic is addressed. Through extensive simulations it has been found that the proposed multi-band schedulers overcome the capacity of LTE systems without CA. Result shown a clear improvement of the QoS, QoE and economic trade-off with CA

Algoritmo para desenvolver uma ferramenta de planeamento para o sistema de comunicações móveis LTE

O trabalho desenvolvido nesta dissertação visa propor um algoritmo para o planeamento do sistema de comunicações móveis LTE (Long-Term Evolution). O algoritmo apresentado evidencia as alterações necessárias a aplicar a uma ferramenta já implementada da Alcatel-Lucent, A9155, para o planeamento do sistema WiMAX (Worldwide Interoperability for Microwave Access), por forma a utilizar a mesma plataforma da ferramenta de planeamento. Para compreender as alterações a aplicar à ferramenta foi analisado o sistema de comunicações móveis LTE e as principais técnicas utilizadas neste sistema, comparando-as com o sistema de comunicações móveis WiMAX. Escolheu-se modelos de propagação e tráfego a considerar na ferramenta de planeamento. Desenvolveu-se um algoritmo que consiste em analisar as necessidades dos utilizadores da rede e os serviços que estes utilizam de modo a obter a capacidade necessária por célula. Este algoritmo permite a opção de obter uma dada capacidade necessária para um conjunto de utilizadores, ou, como alternativa obter a capacidade, quando existe constrangimento económico para a implementação da rede.The work developed in this dissertation aims to propose an algorithm for the planning of a LTE mobile communication system. The presented algorithm demonstrates the necessary changes to apply to an existent Alcatel-Lucent tool, A9155, for the WiMAX (Worldwide Interoperability for Microwave Access) mobile communication system, in order to use the same platform. The LTE mobile communication system and its techniques were analyzed and compared to the WiMAX mobile communication system, in order to understand the changes needed. Propagation and traffic models were chosen for the planning tool. It was developed an algorithm that analyzes the network users needs and the services they user, in order to obtain the required capacity per cell. This algorithm allows the option of obtaining required capacity for a given set of users, or, the capacity when there is an economic constraint to the implementation of the network

Propagation model for cellular mobile networks used in UAVcommunications environmentss

Recognizing the growth of the drone market in recent years, it is crucial to evaluate the capacity of the mobile communications technologies as well as their infrastructure to verify if these are capable to support various applications and services that may associate with these type of vehicles, achieving lower costs to the users. The type of application chosen for this thesis is a video streaming that is able to assume different qualities depending on the RF conditions, in order to overcome the limitation of radio communications, in which the user is only able to communicate with the drone when in his line of sight. It was necessary to take into account a propagation model that considered the unique characteristics of an UAV, since the most commonly used models only consider a typical mobile user moving below the level of the BSs and their respective antennas using a short/medium frequency interval that is not able to consider the third and fourth generation technologies at once. In order to choose the ideal model, a theoretical study was carried out, which allowed to conclude that Lisbon University Institute Model is the most accurate since it is able to fulfill the requirements associated to a flying drone, considering a larger frequency spectrum, allowing the use of third and fourth generation technologies that are fundamental to support multimedia services, such as video streaming. To verify the viability of mobile communications, measurements were made in three real scenarios in rural areas using a spectrum analyzer carried by a flying drone, in order to monitor, read and write the data related to the signal’s behavior into a file, during the flight route. Based on this approach, it was possible to analyze the viability of mobile communications for a video streaming service using a drone, in a rural environment and considering UMTS and LTE technologies. In addition, evaluate the signal’s performance when the drone is above the antennas where the “hole phenomenon” occurs, theoretically.Tendo em conta o crescimento que o mercado de drones tem tido nos últimos anos, é importante considerar as tecnologias de comunicações móveis assim como as respectivas infraestruturas e verificar se estas são capazes de suportar diversas aplicações que podem estar associadas a estes veículos, permitindo isto um custo inferior para os utilizadores dos mesmos. O tipo de aplicação escolhida para esta tese foi uma streaming de vídeo, com o objetivo de ultrapassar a limitação das comunicações rádio, em que o utilizador apenas consegue comunicar com o drone caso este se encontre no seu campo de visão. Foi necessário ter em conta um modelo de propagação que considerasse as características únicas de movimentação dum drone, uma vez que os modelos mais utilizados apenas consideram um utilizador móvel comum que se desloque abaixo do nível das estações base e respetivas antenas para um espectro de frequências curto/médio. Para a escolha deste modelo, foi realizado um estudo teórico que permitiu concluir que o Lisbon University Institute Model é o mais acertado, uma vez que é capaz de cumprir os requisitos associados a um drone, considerando um intervalo de frequências maior, permitindo a utilização das tecnologias de terceira e quarta geração, que são fundamentais para suportar aplicações multimedia, como é o caso da streaming de vídeo. Para verificar a viabilidade das comunicações móveis, foram feitas medições em três cenários reais em zona rural recorrendo a um analisador de espectros transportado por um drone, com o objetivo de monitorizar, fazer a leitura e gravação de dados associados ao comportamento do sinal para um ficheiro durante a rota de voo. Com esta abordagem, foi possível analisar a viabilidade das comunicações móveis para a aplicação de streaming de vídeo num drone, em cenário rural, considerando as tecnologias UMTS (3G) e LTE (4G). Para além disso, foi ainda possível avaliar o comportamento do sinal quando o drone se encontra acima do eixo vertical das antenas, onde o “fenómeno do buraco” ocorre