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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

How to measure the true end-user impact of Energy Performance features in a mobile network

Rezaie, Diba January 2023 (has links)
The Information and Communication Technology (ICT) industry is one of the most energy consuming industries in the world. With the increase of the number of global mobile traffic users which is growing rapidly for each year, it is more important than ever for all industries to implement energy efficient methods to decrease the greenhouse gas emissions. This thesis looks into Ericsson, one of the largest companies within ICT, and how their energy efficient methods in LTE impact the end-users. The experiment was conducted in an Ericsson laboratory in Lund and the results showed that some quality of service metrics (latency,throughput, etc.) were impacted by the different energy efficient features enabled. However, performing a mean opinion score showed that the end-users were not as affected while browsing through different sites and streaming videos in 720p. While the experiment was performed on a smaller scale (4 User Equipments and 3 end-users) the result was promising enough for it to be conducted on a larger scale in the future. With enough data Ericsson and other ICT companies can be able to convince mobile operators to enable more energy efficient features (without it having any impact on the end-users) while fighting the climate change.
42

Radio access and core functionalities in self-deployable mobile networks / Accès radio et fonctionnalités de base dans les réseaux mobiles auto-déployables

Oueis, Jad 27 November 2018 (has links)
Les réseaux mobiles auto-déployables sont des réseaux qui peuvent être rapidement déployés, facilement installés, sur demande, n’importe où, et n’importe quand. Ils visent divers cas d’utilisation pour fournir des services aux utilisateurs lorsque le réseau classique ne peut pas être utilisé, ou n’existe pas : lors d’événements publics, lors des situations critiques, ou dans les zones isolées. Ces réseaux font évoluer l’architecture d’un réseau classique, en éliminant la séparation physique qui existe entre le réseau d’accès et le cœur de réseau. Cette séparation est désormais uniquement fonctionnelle, vu qu’une station de base est colocalisée avec les fonctionnalités du réseau de cœur, telles que la gestion de session et le routage, en plus des serveurs d’applications. Une station de base, toute seule, sans connexion à un réseau externe, fournit des services aux utilisateurs dans sa zone de couverture. Lorsque plusieurs stations de base sont interconnectées, les liens entre elles forment un réseau d’interconnexion, qui risque d’avoir une capacité limitée. Dans ce travail, nous nous appuyons sur les propriétés distinguant les réseaux auto-déployables pour revisiter des problèmes classiques du réseau d’accès dans ce nouvel contexte, mais aussi pour aborder de nouveaux défis créés par l’architecture du réseau. Tout d’abord, nous proposons un algorithme qui retourne un schéma d’allocation de fréquences et de puissances pour les stations de base. Celui-ci augmente considérablement les débits des utilisateurs par rapport aux schémas classiques de réutilisation de fréquences. Ensuite, nous traitons le problème de placement des fonctionnalités du cœur du réseau. Pour le placement centralisé, nous proposons une nouvelle métrique de centralité qui permet de placer les fonctions de façon à maximiser le trafic pouvant être échangé dans le réseau. Pour le placement distribué, nous évaluons le nombre de fonctions nécessaires et leur placement optimal, en tenant compte de l’impact sur la capacité du réseau d’interconnexion. Nous démontrons aussi les avantages du placement distribué par rapport au centralisé en terme de consommation de ressources sur le réseau d’interconnexion. Dans le même contexte, nous abordons le problème d’attachement des utilisateurs, lorsque les fonctionnalités du cœur de réseau sont distribuées, pour déterminer par laquelle de ces fonctionnalités un utilisateur est-il servi. Enfin, avec le réseau d’accès configuré et le cœur de réseau organisé, les utilisateurs commencent à arriver. Alors, nous abordons le problème de l’association des utilisateurs. Nous proposons une nouvelle politique d’association adaptée aux propriétés des réseaux auto-déployables. Cette politique réduit la probabilité de blocage par rapport aux politiques classiques basées uniquement sur la qualité de la voie descendante, en tenant compte à la fois des ressources du réseau d’accès, des ressources sur le réseau d’interconnexion, et des demandes des utilisateurs. / Self-deployable mobile networks are a novel family of cellular networks, that can be rapidly deployed, easily installed, and operated on demand, anywhere, anytime. They target diverse use cases and provide network services when the classical network fails, is not suitable, or simply does not exist: when the network saturates during crowded events, when first responders need private broadband communication in disaster-relief and mission-critical situations, or when there is no infrastructure in areas with low population density. These networks are challenging a long-standing vision of cellular networks by eliminating the physical separation between the radio access network (RAN) and the core network (CN). In addition to providing RAN functionalities, such as radio signal processing and radio resource management, a base station can also provide those of the CN, such as session management and routing, in addition to housing application servers. As a result, a base station with no backhaul connection to a traditional CN can provide local services to users in its vicinity. To cover larger areas, several base stations must interconnect. With the CN functions co-located with the RAN, the links interconnecting the BSs form the backhaul network. Being setup by the BSs, potentially in an ad hoc manner, the latter may have a limited bandwidth. In this thesis, we build on the properties distinguishing self-deployable networks to revisit classical RAN problems but in the self-deployable context, and address the novel challenges created by the core network architecture. Starting with the RAN configuration, we propose an algorithm that sets a frequency and power allocation scheme. The latter outperforms conventional frequency reuse schemes in terms of the achieved user throughput and is robust facing variations in the number of users and their distribution in the network. Once the RAN is configured, we move to the CN organization, and address both centralized and distributed CN functions placements. For the centralized placement, building on the shortages of state of the art metrics, we propose a novel centrality metric that places the functions in a way that maximizes the traffic that can be exchanged in the network. For the distributed placement, we evaluate the number of needed instances of the CN functions and their optimal placement, considering the impact on the backhaul bandwidth. We further highlight the advantages of distributing CN functions, from a backhaul point of view. Accordingly, we tackle the user attachment problem to determine the CN instances serving each user when the former are distributed. Finally, with the network ready to operate, and users starting to arrive, we tackle the user association problem. We propose a novel network-aware association policy adapted to self-deployable networks, that outperforms a traditional RAN-based policy. It jointly accounts for the downlink, the uplink, the backhaul and the user throughput request.
43

A Location-Based Incentive Mechanism for Participatory Sensing Systems with Budget Constraints

Jaimes, Luis Gabriel 01 January 2012 (has links)
Participatory Sensing (PS) systems rely on the willingness of mobile users to participate in the collection and reporting of data using a variety of sensors either embedded or integrated in their cellular phones. Users agree to use their cellular phone resources to sense and transmit the data of interest because these data will be used to address a collective problem that otherwise would be very difficult to assess and solve. However, this new data collection paradigm has not been very successful yet mainly because of the lack of incentives for participation and privacy concerns. Without adequate incentive and privacy guaranteeing mechanisms most users will not be willing to participate. This thesis concentrates on incentive mechanisms for user participation in PS system. Although several schemes have been proposed thus far, none has used location information and imposed budget and coverage constraints, which will make the scheme more realistic and efficient. A recurrent reverse auction incentive mechanism with a greedy algorithm that selects a representative subset of the users according to their location given a fixed budget is proposed. Compared to existing mechanisms, GIA (i.e., Greedy Incentive Algorithm) improves the area covered by more than 60 percent acquiring a more representative set of samples after every round, i.e., reduces the collection of unnecessary (redundant) data, while maintaining the same number of active users in the system and spending the same budget.
44

Por que as tarifas de interconexão são tão altas? Um modelo de competição entre telefonia fixa e móvel

Lima, Lucas Ferreira Matos 24 February 2014 (has links)
Submitted by Lucas Ferreira Matos Lima (lucas.lima@gvmail.br) on 2014-03-19T23:24:33Z No. of bitstreams: 1 Lucas.Dissertação.pdf: 1006691 bytes, checksum: 0cdbda535e7d2b8e4027523c167ae00f (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2014-03-20T16:34:02Z (GMT) No. of bitstreams: 1 Lucas.Dissertação.pdf: 1006691 bytes, checksum: 0cdbda535e7d2b8e4027523c167ae00f (MD5) / Made available in DSpace on 2014-03-20T17:53:56Z (GMT). No. of bitstreams: 1 Lucas.Dissertação.pdf: 1006691 bytes, checksum: 0cdbda535e7d2b8e4027523c167ae00f (MD5) Previous issue date: 2014-02-24 / There is a puzzle between the literature of competition of telecommunication networks and the reality. The first one has as the main result that the mobile termination rates will be set bellow the marginal cost to end a call. But the reality shows that the mobile termination rates are too high and the regulators faces a lot of constrains when they try to bring down the level of those rates, because the mobile networks oppose to those policies. This work develops a model based on Hoernig (2010) that presents more realistic results. It will use a new assumption: the mobile networks will compete at the same market with a fixed network and this last one will have its prices regulated. This is a plausible assumption considering the actual development of the mobile networks. The model has two frameworks: at the first there is any kind of shared control between one of the mobile and fixed telephony, but at the second that shared control exists. Because of the assumption that the mobile and fixed networks will compete, this work has as general result that the mobile networks will set the mobile termination rates above the marginal cost of terminating a call. / Existe uma dissonância entre a teoria dominante de competição entre telefonias e evidências empíricas. Aquela tem como resultado que as redes de telefonia móvel irão definir a tarifa de interconexão abaixo do custo marginal de término da ligação. Já evidências empíricas diversas mostram que as tarifas de interconexão das telefonias móveis são mais elevadas e que as agências reguladoras encontram resistência destas ao aplicarem políticas de redução das tarifas de interconexão. Este trabalho desenvolve um modelo, baseado em Hoernig (2010), que provê resultados mais aderentes às evidências de existência de incentivos para precificação de tarifas de interconexão acima do custo marginal. O modelo aqui proposto inova em relação a Hoernig (2010) ao assumir que as redes de telefonia móvel concorrem com a telefonia fixa, a qual é sujeita à regulação da tarifa de interconexão. Esta é uma representação bastante plausível frente ao desenvolvimento da telefonia móvel. O modelo também considera o efeito de uma das empresas de telefonia móvel ter o seu controle compartilhado com a de telefonia fixa. Devido ao pressuposto de competição em um mesmo mercado entre telefonia fixa e móvel, é encontrado como resultado geral que as redes de telefonia móvel irão definir a tarifa de interconexão acima do custo marginal de término da ligação.
45

Analysis and exploitation of mobile traffic datasets / Analyse et exploitation de données de trafic mobile

Naboulsi, Diala 24 September 2015 (has links)
Les équipements mobiles deviennent une partie intégrale de notre vie numérique. Ces équipements interagissent avec l'infrastructure des réseaux cellulaires et leur activité est enregistrée pour des buts de facturation et monitoring sous forme de données de trafic mobile. Les travaux menés dans cette thèse se focalisent sur le potentiel que portent ces données pour l'amélioration des réseaux cellulaires futurs. D'une part, on montre que les données mobiles permettent de construire des profils spatio-temporels typiques de l'utilisation des réseaux cellulaires en environnement urbain. Cette analyse permet aussi la détection des comportements atypiques dans le réseau qui sont liés à des événements spéciaux. D'autre part, on montre que les données mobiles constituent un élément méthodologique important pour l'évaluation des solutions réseaux. Dans ce sens, on propose un mécanisme pour réduire la consommation énergétique des infrastructures cellulaires, en contrôlant la puissance sur le réseau d'accès à différents moments de la journée, tout en assurant la couverture géographique du réseau. On exploite aussi ces données pour évaluer les gains apportés par une nouvelle architecture de réseau d'accès, basée sur la virtualisation d'une partie du réseau et sa centralisation dans un cloud. Nos résultats montrent que cette architecture est bénéfique du point de vue des messages de signalisation, notamment pour les utilisateurs mobiles. / Mobile devices are becoming an integral part of our everyday digitalized life. In 2014, the number of mobile devices, connected to the internet and consuming traffic, has even exceeded the number of human beings on earth. These devices constantly interact with the network infrastructure and their activity is recorded by network operators, for monitoring and billing purposes. The resulting logs, collected as mobile traffic datasets, convey important information concerning spatio-temporal traffic dynamics, relating to large populations with millions of individuals. The thesis sheds light on the potential carried by mobile traffic datasets for future cellular networks. On one hand, we target the analysis of these datasets. We propose a usage patterns characterization framework, capable of defining meaningful categories of mobile traffic profiles and classifying network usages accordingly. On the other hand, we exploit mobile traffic datasets to evaluate two dynamic networking solutions. First, we focus on the reduction of energy consumption over typical Radio Access Networks (RAN). We introduce a power control mechanism that adapts the RAN's power configuration to users demands, while maintaining a geographical coverage. We show that our scheme allows to significantly reduce power consumption over the network infrastructure. Second, we study the problem of topology management of future Cloud-RAN (C-RAN). We propose a mobility-driven dynamic association scheme of the C-RAN components, which takes into account users traffic demand. The introduced strategy is observed to lead to important savings in the network, in terms of handovers.
46

Marketingová strategie společnosti Telefónica O2 / Marketing Strategy of Telefónica O2

Bilavčík, Martin January 2010 (has links)
The goal of this diploma thesis is to prepare a marketing strategy for Telefónica O2 Czech Republic, a.s. The strategy is focused on target market and is based on questionnaire research made with respondents from target population. Strategy contains proposal of steps which could help to acquire new customers and keep recent customers. The diploma thesis also contains summary of information about the target population usable by Telefónica O2 for further analysis.
47

Směrovací protokol pro sítě MANET zohledňující požadavky na kvalitu služeb / MANET Routing Protocol with Quality of Service Support

Vajsar, Pavel January 2014 (has links)
The web and mobile web traffic is growing rapidly due to service accessibility in densely populated areas and massive usage of smart hand held devices (smartphones, pads and Internet dongles). This is a challenge for mobile operators and service providers, because it forces systematically increasing network throughput capacity and in parallel to keep this investment on profitable basis. On the other side, the user satisfaction with mobile broadband service should be considered as well, in order to balance the user expectations and mobile operator investments. Our work provides extensive QoE study for different conditions in sense of mobile web service, web content, network conditions and end user device. Finally, the obtained results create basis for more dimensional overview of mobile web QoE and allow to recognize quality and saturation thresholds based on network parameters. Further, obtained data provide base for design three prediction models for prediction of MOS (one for notebook, one for mobile device) and acceptability.
48

Emulátor Registru uživatelů mobilní sítě / Home Location Register Emulator

Juránek, Michal January 2014 (has links)
This thesis presents basic structure and entities of mobile network GSM. It presents principles of signalling with focus on core network via signalling systems SS7 and SIGTRAN. Chosen protocol layers and signalling message types are presented. The thesis is concluded by the design and implementation of the application emulating home location register of mobile users.
49

5G Sports – tragbare Technologiedemonstratoren im taktilen Internet

Lüneburg, Lisa-Marie, Papp, Emese, Krzywinski, Jens 03 January 2020 (has links)
Der fünfte Mobilfunkstandard 5G wird zukünftig die Übertragung großer Datenmengen auch über weite Strecken nahezu in Echtzeit ermöglichen. Diese neue, praktisch latenzfreie Kommunikationstechnologie erlaubt einen von zeit- und ortsunabhängigen Austausch von Fähigkeiten und Kompetenzen zwischen Menschen und Maschinen. Damit werden haptisches Feedback über weite Entfernungen (taktiles Internet) und als Anwendung dessen neue Formen des räumlich verteilten Kooperierens und Lernens (Internet der Fähigkeiten und Kompetenzen) möglich. Das Exzellenzcluster CeTI der TU Dresden setzt mit seiner Forschung genau an dieser Stelle an: Eine Vielzahl möglicher interaktiver Anwendungen im Konsumenten-, aber auch im professionellen Bereich ist denkbar. In einer interdisziplinären Vorstudie des Technisches Designs und des 5G Lab Germany wurden mögliche Einsatzfelder identifiziert und durch Demonstratoren erlebbar gemacht. Als ein Anwendungsbereich wurde der Leistungssport identifiziert. Da Disziplin, hohe körperliche Belastung und Perfektion im Bewegungsablauf von professionellen Sportlern über einen langen Zeitraum abverlangt wird, bringt der Bereich ein hohes Potenzial und Akzeptanz mit sich, um effizientere Trainingsmethoden mit Hilfe von cyber-physischen Systemen zu entwickeln. Eine wesentliche Fragestellung der Vorstudie war außerdem zu untersuchen, inwieweit Demonstratoren das Erleben verschiedener Ebenen einer abstrakten Technologie ermöglichen können. In einer Primärstudie, die als Beobachtungen während einer Messeveranstaltung des 5G Summit und weiteren öffentlichen Ausstellungen in Dresden 2018 durchgeführt wurden, konnten hierzu erste Erkenntnisse gewonnen werden.
50

Autonoma fordon – En jämförelse av tekniker för identifiering av utryckningsfordon

Berggren, Filip, Engström, Jakob January 2019 (has links)
Kraven på säkerhet och effektivitet ökar ständigt inom fordonsindustrin. För att uppfylla dessa strävar fordonstillverkare efter att uppnå en högre grad av autonomi, detta innebär dock att många problem måste lösas. Denna rapport behandlar ett av dessa, autonoma fordons möjlighet att identifiera utryckningsfordon. Målet är att presentera ett förslag på vilken teknik som anses mest lämpad för autonoma fordon att kommunicera med utryckningsfordon. Arbetet grundade sig i en förstudie där standarden ITS G5, IEEE 802.11g, ZigBee samt mobilnät analyserades utifrån deras tekniska specifikationer. Utifrån analysen presenterades tre situationer där de olika teknikernas användning ansågs begränsade, i tunnlar, i tät trafik samt på långa avstånd vid höga hastigheter. Dessa situationer ställde krav på teknikerna inom bland annat svarstid, räckvidd, överföringsförmåga samt möjlighet till direktkommunikation mellan fordonen. Utifrån dessa krav ställdes en jämförelsematris upp där de olika teknikernas prestanda jämfördes. Resultatet visar att ITS G5 och ZigBee har bäst prestanda på egen hand medan en kombination av mobilnät och ITS G5 uppnår högst prestanda. / The demand for safety and effectivity continuously increases within the automotive industry. One way to meet these demands is to achieve a higher level of autonomy, but to achieve the highest levels of autonomy there is a few problems to be solved along the way. This report treats one of these, an autonomous vehicle’s ability to identify emergency vehicles. The report, based on a pilot study, analyses the ITS G5 standard, IEEE 802.11g, Zigbee and mobile networks based on their technological specifications. From the analysis three situations are identified where the technologies are considered limited. These limitations are, but not limited to, reach, latency, data rates and ability to communicate vehicle to vehicle (V2V). The four technologies are then compared by these limitations in a matrix. The result shows that ITS G5 and ZigBee has the best performance by its own but the combination of mobile networks and ITS G5 shows the highest possible performance.

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