Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-30T19:56:59Z No. of bitstreams: 1 FernandoCasteloBranco.pdf: 834917 bytes, checksum: 637b3f82aba4cce981014b690d89cb95 (MD5) / Made available in DSpace on 2017-05-30T19:56:59Z (GMT). No. of bitstreams: 1 FernandoCasteloBranco.pdf: 834917 bytes, checksum: 637b3f82aba4cce981014b690d89cb95 (MD5) Previous issue date: 2016-07-25 / In recent decades, the increasing use of mobile technologies has motivated the development of new techniques and algorithms to provide high transmission rates in mobile networks. Among them, LTE (Long Term Evolution) technology is one of the most significant standards for fourth generation (4G) mobile telephony. Due to its high data rates, LTE becomes very attractive to several kinds of applications. However, the quality of the transmissions can be severely impacted by the radio resources scheduling process, since it can lead to fluctuations in the delay and in the application data rates. To perform resource allocation in LTE networks, the scheduler uses various parameters estimated from the radio environment. This process can lead to the occurrence of erroneous estimates, which should be mitigated in order to deal with the inaccuracies of the wireless environments. In this context, this master thesis presents a fuzzy-based downlink scheduler for LTE networks, named PAFS (Performance-Aware Fuzzy Scheduler). The results show that the proposed scheduler promotes a suitable allocation of the radio resources, improving the performance of different QoS (Quality of Service) parameters without compromising the fairness among the system users. / Nas últimas d´ecadas, o aumento da utilização de tecnologias de comunicações móveis tem motivado o desenvolvimento de novas técnicas e algoritmos capazes de prover altas taxas de transmissão em redes celulares. Entre elas, a tecnologia LTE (Long Term Evolution) é um dos padrões mais significativos para a telefonia móvel de quarta geração (4G). Devido às suas elevadas taxas de dados, o LTE torna-se muito atraente para vários tipos de aplicações. No entanto, a qualidade das transmissões pode ser severamente impactada pelo processo de escalonamento de recursos de rádio, uma vez que pode levar a flutuações no atraso e nas taxas de dados das aplicações. Para executar a alocação de recursos em redes LTE, o escalonador utiliza vários parâmetros estimados a partir do ambiente de rádio. Esse processo pode levar à ocorrência de estimativas erradas, o que deve ser mitigado de forma a lidar com as imprecisões dos ambientes sem fio. Neste contexto, este trabalho apresenta um escalonador de enlace de descida baseado em lógica nebulosa chamado PAFS (Performance-Aware Fuzzy Scheduler ). Os resultados mostram que o escalonador proposto promove uma alocação adequada dos recursos de rádio, melhorando o desempenho de diferentes parâmetros de QoS (Quality of Service – Qualidade de Servi¸co) sem comprometer a justiça entre os usuários do sistema.

<p>Cell Broadcast (CB) is a possible technical realisation of a global emergency alert system. It is a technique used for sending short text messages to all mobile stations (MSs) in a defined geographical area. An potential effect of using CB is the increase in battery consumption of the MS due to the fact that an extra channel has to be used to make the service available even when the network is otherwise congested. Another part of the service which leads to a potential problem is making CB messages available in different languages. Investigating these problems is the objective of this thesis and the studies it includes. During the first part of the thesis, we measured the battery consumption of MSs in different modes of operation in order to analyse how CB affects the amount of current drained. The tests showed that battery consumption increased only slightly when CB messages were being received at the MS. Although some of the results can be, and are, discussed, we believe that CB would have a small effect on the power consumption of an MS, particularly in a context where it would be used for emergency warning messages only. This mentioned, it would however be wishful to confirm the conclusions further through the realisation of long-term testing. The second part of the thesis deals with the investigation of the MSs’ support for CB messages with different coding schemes. Based on the investigation’s result, we have come to the conclusion that in the long term the usage of different coding schemes on the same channel is preferred. However, the usage of one, global, emergency channel is hard to realise since that requires a standardisation between all countries. In our opinion this may be achieved first in the long run and until then, the usage of separate channels seems to be necessary.</p>

La interfaz radio de los sistemas de comunicaciones móviles es normalmente considerada como la única limitación de capacidad en la red de acceso radio. Sin embargo, a medida que se van desplegando nuevas y más eficientes interfaces radio, y de que el tráfico de datos y multimedia va en aumento, existe la creciente preocupación de que la infraestructura de transporte (backhaul) de la red celular pueda convertirse en el cuello de botella en algunos escenarios. En este contexto, la tesis se centra en el desarrollo de técnicas de gestión de recursos que consideran de manera conjunta la gestión de recursos en la interfaz radio y el backhaul. Esto conduce a un nuevo paradigma donde los recursos del backhaul se consideran no sólo en la etapa de dimensionamiento, sino que además son incluidos en la problemática de gestión de recursos. Sobre esta base, el primer objetivo de la tesis consiste en evaluar los requerimientos de capacidad en las redes de acceso radio que usan IP como tecnología de transporte, de acuerdo a las recientes tendencias de la arquitectura de red. En particular, se analiza el impacto que tiene una solución de transporte basada en IP sobre la capacidad de transporte necesaria para satisfacer los requisitos de calidad de servicio en la red de acceso. La evaluación se realiza en el contexto de la red de acceso radio de UMTS, donde se proporciona una caracterización detallada de la interfaz Iub. El análisis de requerimientos de capacidad se lleva a cabo para dos diferentes escenarios: canales dedicados y canales de alta velocidad. Posteriormente, con el objetivo de aprovechar totalmente los recursos disponibles en el acceso radio y el backhaul, esta tesis propone un marco de gestión conjunta de recursos donde la idea principal consiste en incorporar las métricas de la red de transporte dentro del problema de gestión de recursos. A fin de evaluar los beneficios del marco de gestión de recursos propuesto, esta tesis se centra en la evaluación del problema de asignación de base, como estrategia para distribuir el tráfico entre las estaciones base en función de los niveles de carga tanto en la interfaz radio como en el backhaul. Este problema se analiza inicialmente considerando una red de acceso radio genérica, mediante la definición de un modelo analítico basado en cadenas de Markov. Dicho modelo permite calcular la ganancia de capacidad que puede alcanzar la estrategia de asignación de base propuesta. Posteriormente, el análisis de la estrategia propuesta se extiende considerando tecnologías específicas de acceso radio. En particular, en el contexto de redes WCDMA se desarrolla un algoritmo de asignación de base basado en simulatedannealing cuyo objetivo es maximizar una función de utilidad que refleja el grado de satisfacción de las asignaciones respecto los recursos radio y transporte. Finalmente, esta tesis aborda el diseño y evaluación de un algoritmo de asignación de base para los futuros sistemas de banda ancha basados en OFDMA. En este caso, el problema de asignación de base se modela como un problema de optimización mediante el uso de un marco de funciones de utilidad y funciones de coste de recursos. El problema planteado, que considera que existen restricciones de recursos tanto en la interfaz radio como en el backhaul, es mapeado a un problema de optimización conocido como Multiple-Choice Multidimensional Knapsack Problem (MMKP). Posteriormente, se desarrolla un algoritmo de asignación de base heurístico, el cual es evaluado y comparado con esquemas de asignación basados exclusivamente en criterios radio. El algoritmo concebido se basa en el uso de los multiplicadores de Lagrange y está diseñado para aprovechar de manera simultánea el balanceo de carga en la intefaz radio y el backhaul.

Στόχος της παρούσας διπλωματικής εργασίας είναι ο σχεδιασμός ενός συστήματος ασφαλούς μεταφοράς δεδομένων από κινητές τερματικές συσκευές όπως κινητά τηλέφωνα και PDAs (Personal Digital Assistants). Ένα τέτοιο σύστημα θα μπορούσε να χρησιμοποιηθεί για τη μετάδοση ευαίσθητων προσωπικών δεδομένων, όπως βιοϊατρικά δεδομένα που συλλέγονται από βιοαισθητήρες, ή για τη διενέργεια ηλεκτρονικών πληρωμών. Στην παρούσα εργασία κάνουμε μία σύνοψη των τελευταίων τεχνολογιών στην κινητή τηλεφωνία, τα πρωτόκολλα επικοινωνίας για διαδικτύωση σε περιβάλλον κινητών επικοινωνιών, καθώς και βασικών κρυπτογραφικών πρωτοκόλλων, ώστε να οδηγηθούμε ομαλά στο σχεδιασμό του επιθυμητού συστήματος. Τέλος, αναπτύξαμε και παρουσιάζουμε ένα σύστημα ηλεκτρονικών πληρωμών, που βασίζεται στο σύστημα για την ασφαλή ανταλλαγή πληροφορίας σε περιβάλλον κινητών επικοινωνιών, που σχεδιάσθηκε προηγουμένως, υλοποιώντας έτσι μια εφαρμογή του προταθέντος συστήματος. / The scope of this master thesis is the design of a system for secure data transfer from mobile terminal devices like cellular phones and PDAs (Personal Digital Assistants). Such a system could be used for the transmission of critical personal data, like biomedical data collected from biosensors, or the completion of electronic payments. In this work we present the state of the art in mobile telephony and communication protocols for networking in a mobile environment, also we present some basic cryptographic protocols, in order to design the wanted system. Finally, we develop and present an electronic payments system, based on the system for the secure exchange of information in the mobile communications environment we designed before, implementing in this way an application for the suggested system.

Σκοπός της διπλωματικής είναι η ανάπτυξη ενός ολοκληρωμένου σετ σημειώσεων για προγραμματισμό φορητών συσκευών με Windows Mobile και για τεχνολογίες ανάπτυξης εφαρμογών για κινητά.Με το πακέτο του .NET Compact Framework και το Visual Studio από κοντά, η διπλωματική αυτή συμβουλεύεται δειγματικούς κώδικες και εφαρμογές για να παρουσιάσει τις δυνατότητες του κόσμου αυτού των Windows εν κινήσει καθώς και τους περιορισμούς που θέτει η κίνηση αυτή σε σχέση με ένα σταθερό υπολογιστή. Αφού διαλέξει κάποιος την κινητή πλατφόρμα στην οποία στοχεύει να αναπτύξει τις εφαρμογές του και τα εργαλεία που θα χρησιμοποιήσει(και τα 2 παρουσιάζονται στον αναγνώστη με έμφαση στη λεπτομέρεια) ξεκινάει από ένα πρώτο χαμηλό προγραμματιστικό επίπεδο όπου λαμβάνει την βασική γνώση ώστε να ξεκινήσει με την ανάπτυξη μιας κινητής εφαρμογής.Γνωρίζει το υλικό των διαθέσιμων αυτή τη στιγμή κινητών συσκευών και εγκλιματίζεται στο περιβάλλον που καλείται να προγραμματίσει.Στη συνέχεια εισέρχεται πιο βαθιά στο υλικό και λογισμικό υπόβαθρο ώστε να προγραμματίσει αποτελεσματικές εφαρμογές με εργονομία και μοντέρνα λειτουργικότητα.Ζητήματα όπως η σύνδεση των κινητών εφαρμογών με βάσεις δεδομένων, η ασφάλεια, ο συγχρονισμός δεδομένων,η επικοινωνία με το τηλεπικοινωνιακό δίκτυο και η παροχή υπηρεσιών με Web Services εξετάζονται και παρουσιάζονται με παραδείγματα και εικόνες. Ευελπιστούμε πως ο αναγνώστης θα μπορέσει ύστερα από τη μελέτη της διπλωματικής αυτής να προγραμματίσει και σε προχωρημένο πλέον επίπεδο για τις αγαπημένες του εφαρμογές και να δοκιμάσει να εκμεταλευτεί τις νέες δυνατότητες και τεχνολογίες και να δημιουργήσει το δικό του κόσμο εν κινήσει! / -

Cell Broadcast (CB) is a possible technical realisation of a global emergency alert system. It is a technique used for sending short text messages to all mobile stations (MSs) in a defined geographical area. An potential effect of using CB is the increase in battery consumption of the MS due to the fact that an extra channel has to be used to make the service available even when the network is otherwise congested. Another part of the service which leads to a potential problem is making CB messages available in different languages. Investigating these problems is the objective of this thesis and the studies it includes. During the first part of the thesis, we measured the battery consumption of MSs in different modes of operation in order to analyse how CB affects the amount of current drained. The tests showed that battery consumption increased only slightly when CB messages were being received at the MS. Although some of the results can be, and are, discussed, we believe that CB would have a small effect on the power consumption of an MS, particularly in a context where it would be used for emergency warning messages only. This mentioned, it would however be wishful to confirm the conclusions further through the realisation of long-term testing. The second part of the thesis deals with the investigation of the MSs’ support for CB messages with different coding schemes. Based on the investigation’s result, we have come to the conclusion that in the long term the usage of different coding schemes on the same channel is preferred. However, the usage of one, global, emergency channel is hard to realise since that requires a standardisation between all countries. In our opinion this may be achieved first in the long run and until then, the usage of separate channels seems to be necessary.

Thesis (MEngineering)--University of South Australia, 2001

Thesis (Ph. D.)--University of Sydney, 2009. / Title from title screen (viewed February 20, 2009). Includes graphs and tables. Includes list of publications co-authored with others. Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Information Technologies, Faculty of Engineering and Information Technologies. Degree awarded 2009; thesis submitted 2008. Includes bibliographical references. Also available in print form.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2008. / Includes bibliographical references.

Thesis (M. Sc.)(Electronic Engineering)--University of Pretoria, 2004. / Summaries in English and Afrikaans. Includes bibliographical references (125-128).