Broadband wireless communication technology is adopted by a wide range of users. However, the dependency of such networks on fixed infrastructure make them a liability in case of events that disrupt the set-up like terrorist attacks or natural disasters including floods, earthquakes, and tsunamis. This implies the need for an effective and efficient recovery solution to make up for the lost connection/s. A prospective feasible solution for realizing such recovery is to make use of airborne base stations on-board Unmanned Aerial Vehicles (UAVs), or drones. There are certain challenges facing with the successful implementation of an aerial base station (ABS) for communication purposes. Most importantly, the ABS must be deployable in a reasonable amount of time and should be able to provide an adequate quality of service (QoS) over a known area. In this work, the problem of quantifying the performance of an ABS in terms of coverage on ground is addressed. We present an analytical framework to calculate the percentage of covered users. The focus is on a fixed cell architecture to maximize the service quality for users inside the coverage radius. The proposed mathematical model relies on the urban statistical parameters that describe the city environment. This approach saves the need to obtain detailed 3D city models and time-consuming site-specific ray-tracing simulations. Moreover, these urban parameters can be tailored to represent different city structures and hence the scheme can be adopted as a general statistical model which can relate any urban environment to corresponding RF propagation conditions. The proposed approach considers a single ABS for a fixed cell area at a certain height and evaluates the performance in terms of coverage and pathloss. Different channel models proposed in literature for air to ground (A2G) communication are studied and analysed to select the one best suited to our application. After that, mathematical analysis is done to perform coverage calculations using system defined parameters and environment specifications. Analytical results are then compared with those obtained from simulations to check their validity and coherence. For this purpose, city environments are designed in a CAD modelling software and then simulations are performed on those models using a commercial ray tracing software. Results obtained are promising which give direction for future work in this research area.
La tecnologia di comunicazione wireless a banda larga è adottata da una vasta gamma di utenti. Tuttavia, la dipendenza di tali reti dalle infrastrutture fisse le rende una responsabilità in caso di eventi che interrompono l'insediamento come attacchi terroristici o calamità naturali tra cui alluvioni, terremoti e tsunami. Ciò implica la necessità di una soluzione di recupero efficace ed efficiente per compensare le connessioni perse. Una possibile soluzione possibile per realizzare tale recupero è quella di utilizzare stazioni base aeree a bordo di Unmanned Aerial Vehicles (UAV) o droni. Ci sono alcune sfide che devono affrontare l'implementazione di successo di una stazione base aerea (ABS) a fini di comunicazione. Ancora più importante, l'ABS deve essere implementabile in un periodo di tempo ragionevole e dovrebbe essere in grado di fornire un'adeguata qualità del servizio (QoS) su un'area nota. In questo lavoro viene affrontato il problema di quantificare le prestazioni di un ABS in termini di copertura a terra. Presentiamo un framework analitico per calcolare la percentuale di utenti coperti. L'attenzione si concentra su un'architettura a celle fisse per massimizzare la qualità del servizio per gli utenti all'interno del raggio di copertura. Il modello matematico proposto si basa sui parametri statistici urbani che descrivono l'ambiente urbano. Questo approccio evita la necessità di ottenere modelli dettagliati di città 3D e lunghe simulazioni di ray-tracing specifiche del sito. Inoltre, questi parametri urbani possono essere personalizzati per rappresentare diverse strutture urbane e quindi lo schema può essere adottato come un modello statistico generale che può mettere in relazione qualsiasi ambiente urbano con le corrispondenti condizioni di propagazione RF. L'approccio proposto considera un singolo ABS per un'area di cella fissa a una certa altezza e valuta le prestazioni in termini di copertura e perdita di percorso. Diversi modelli di canali proposti in letteratura per la comunicazione aria-terra (A2G) sono studiati e analizzati per selezionare quello più adatto alla nostra applicazione. Successivamente, viene eseguita un'analisi matematica per eseguire calcoli di copertura utilizzando parametri definiti dal sistema e specifiche ambientali. I risultati analitici vengono quindi confrontati con quelli ottenuti dalle simulazioni per verificarne la validità e la coerenza. A tale scopo, gli ambienti urbani sono progettati in un software di modellazione CAD e quindi vengono eseguite simulazioni su tali modelli utilizzando un software di ray tracing commerciale. I risultati ottenuti sono promettenti che danno la direzione per i lavori futuri in questo settore di ricerca.
Channel modelling and coverage estimation of an aerial base station
EHSAN, AMMARAH
2019/2020
Abstract
Broadband wireless communication technology is adopted by a wide range of users. However, the dependency of such networks on fixed infrastructure make them a liability in case of events that disrupt the set-up like terrorist attacks or natural disasters including floods, earthquakes, and tsunamis. This implies the need for an effective and efficient recovery solution to make up for the lost connection/s. A prospective feasible solution for realizing such recovery is to make use of airborne base stations on-board Unmanned Aerial Vehicles (UAVs), or drones. There are certain challenges facing with the successful implementation of an aerial base station (ABS) for communication purposes. Most importantly, the ABS must be deployable in a reasonable amount of time and should be able to provide an adequate quality of service (QoS) over a known area. In this work, the problem of quantifying the performance of an ABS in terms of coverage on ground is addressed. We present an analytical framework to calculate the percentage of covered users. The focus is on a fixed cell architecture to maximize the service quality for users inside the coverage radius. The proposed mathematical model relies on the urban statistical parameters that describe the city environment. This approach saves the need to obtain detailed 3D city models and time-consuming site-specific ray-tracing simulations. Moreover, these urban parameters can be tailored to represent different city structures and hence the scheme can be adopted as a general statistical model which can relate any urban environment to corresponding RF propagation conditions. The proposed approach considers a single ABS for a fixed cell area at a certain height and evaluates the performance in terms of coverage and pathloss. Different channel models proposed in literature for air to ground (A2G) communication are studied and analysed to select the one best suited to our application. After that, mathematical analysis is done to perform coverage calculations using system defined parameters and environment specifications. Analytical results are then compared with those obtained from simulations to check their validity and coherence. For this purpose, city environments are designed in a CAD modelling software and then simulations are performed on those models using a commercial ray tracing software. Results obtained are promising which give direction for future work in this research area.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/164422