A novel middleware for the mobility management over the Internet

The features of mobility, which enormously impact on how communication is evolving into the future, represent a particular challenge in today’s wireless networking research. After an identification and evaluation of the gap between the discontinuities of the communication service inherent to the physical layer of mobile networks and the continuity requirements issue from the stream centric multimedia applications, we propose a novel middleware 3MOI (Middleware for the Mobility Management Over the Internet) which can perform efficient and context-aware mobility management and satisfy new mobility requirements such as dynamical location management, fast handover, and continuous connection support

Properties of Channel Interference for Wi-Fi Location Fingerprinting

Localization systems for indoor areas have recently been suggested that make use of existing wireless local area network (WLAN) infrastructure and location fingerprinting approach. However, most existing research work ignores channel interference between wireless infrastructures and this could affect accurate and precise positioning. A better understanding of the properties of channel interference could assist in improving the positioning accuracy while saving significant amounts of resources in the location-aware infrastructure. This paper investigates to what extent the positioning accuracy is affected by channel interference between access points. Two sets of experiments compare how the positioning accuracy is affected in three different channel assignment schemes: ad-hoc, sequential, and orthogonal data is analyzed to understand what features of channel interference affect positioning accuracy. The results show that choosing an appropriate channel assignment scheme could make localization 10% more accurate and reduces the number of access points that are required by 15%. The experimental analysis also indicates that the channel interference usually obeys a right-skewed distribution and positioning accuracy is heavily dependent on channel interference between access points (APs)

Using a Cell-based WLAN Infrastructure Design for Resource-effective and Accurate Positioning

A large scale WLAN infrastructure requires the placement of many thousands of access points (APs). The current approach is to deploy these in an empirical and ad-hoc manner. However, this deployment results in poor resource utilization and inaccurate positioning due to signal overlap and black spots. In this paper, we propose three structured approaches to WLAN infrastructure deployment that would allow better positioning accuracy and optimal coverage. These three approaches make use of triangular, square, and hexagonal configurations. Our results show that all three are more effective in both 2-D and 3-D space than any of the current ad-hoc or empirical approaches to AP deployment. Overall, the hexagonal approach is the most cost effective and accurate. It allows better positioning with fewer APs than are normally used. As a further contribution, 3-D rendering of buildings and wireless signal coverage could give engineers a concrete visualization that helps them to foresee where the blind spots are in advance and how signal varied across multi-story buildings, such that engineers could estimate the optimal number of APs and where they should be placed

Serious Game with Augmented Reality - Programming on Indoor/Outdoor systems: A case study on Galeria da Biodiversidade da Universidade do Porto

Os museus são instituições culturais dedicadas a preservar e interpretar as provas tangíveis primárias da humanidade e do ambiente, como o Museu de História Natural de Londres. Como um dos objetivos principais dos museus é educar a população, envolver os visitantes é fundamental e por isso têm surgido novas formas de captar a atenção dos visitantes. Além disso, os jogos pervasivos oferecem uma forma de melhorar a experiência de um utilizador em qualquer contexto. Ao estender a experiência de jogo para o mundo real, tal como durante um visita num museu, o utilizador torna-se mais do que um observador, tornando-se num jogador que interage com o espaço à sua volta. No entanto, atualmente os museus ainda adotam métodos tradicionais de exibição das suas exposições, que não captam a atenção dos visitantes, especialmente para o público. No caso da Galeria da Biodiversidade, as vitrines com folhas não permitem nenhum tipo de interação, o que não atrai muitos visitantes. Para além disso, a ligação entre as folhas em exposição e as árvores plantadas no exterior, no Jardim Botânico, também passa despercebida, se os visitantes não estiverem numa visita guiada. O objetivo deste projeto é explorar soluções tecnológicas de Realidade Aumentada que estabelecem uma ligação entre espaços interiores e exteriores, que requerem diferentes acessos a Realidade Aumentada (RA) para a localização, tais como GPS e beacons Bluetooth, aplicando também elementos de design de jogos e princípios de desenvolvimento de jogos. Este projeto permite a ludificação da experiência do museu, e simultaneamente estabelecer a ligação entre as folhas em exposição na Galeria da Biodiversidade e as suas respetivas árvores plantadas no exterior, no Jardim Botânico, melhorando tanto a atratividade da exposição como o conhecimento adquirido pelos visitantes. Os resultados irão provavelmente aumentar o envolvimento dos visitantes com a exposição, tornando-a mais memorável. A abordagem proposta será testada na área expositiva das vitrines das folhas na Galeria da Biodiversidade e no exterior na área do Jardim Botânico do Porto.Museums are cultural institutions dedicated to preserving and interpreting the primary tangible evidence of humankind and the environment, such as the Natural History Museum in London. Since one of the main goals for museums is to educate the population, engaging visitors is paramount and so ways to grab the attention of visitors are being invented. Furthermore, pervasive gaming offers a way to enhance the experience of a user in any context. By extending the gaming experience to the real world, such as a museum visit, the visitors become more than observers, they become players who interact with the scene around them. However, museums still adopt traditional methods of displaying exhibits, which fail to catch the attention of some visitors, especially when it comes to younger people. In the case of Galeria da Biodiversidade, the showcases displaying leaves do not allow any kind of interaction, failing to attract many visitors. As a consequence, they are less likely to fully experience the museum. Additionally, the connection between the leaves in display and the trees planted outside, on Jardim Botânico, also goes unnoticed, if visitors are not on a guided tour. The aim of this project is to explore methods that connect indoor and outdoor environments, which require different accesses for localization, such as GPS and Bluetooth beacons, while applying game-design elements and game principles. This project explores the gamification of the museum experience, while also drawing a connection between the leaves in the exhibition and their respective trees planted outside of the Galeria da Biodiversidade, on Jardim Botânico, improving both the attractiveness of the exhibit and the knowledge acquired by the visitors. Results will likely increase the engagement with the exhibit, making it a more memorable visit. The proposed approach will be tested in the exposition area of the leaves vitrines in Galeria da Biodiversidade and on the exterior garden of Jardim Botânico da Universidade do Porto

An Experimental Study on the Effect of Pattern Recognition Parameters on the Accuracy of Wireless-Based Task Time Estimation

Task time estimation is a core industrial engineering discipline. However, the process to collect the required data is manually intensive and tedious, thus making it expensive to keep the data current. Radio frequency signals have been used to automate the required data collection in some applications. However, such radio frequency data is subject to systemic and random noise, leading to a reduction in the accuracy of the task time estimation. This research investigates the use of a pattern recognition method, the k-nearest-neighbor algorithm, to improve the accuracy of task time estimation in a simulated assembly work area. The results indicate that the parameters of the kNN algorithm can be experimentally tuned to improve the accuracy and to dramatically reduce the necessary computational time and the costs of performing real-time task time estimation.Keywords: work measurement, task time estimation, radio frequency, pattern recognition, wireless sensor networks, data mining, k-nearest-neighborKeywords: work measurement, task time estimation, radio frequency, pattern recognition, wireless sensor networks, data mining, k-nearest-neighbo

IEEE 802.11 i Security and Vulnerabilities

Despite using a variety of comprehensive preventive security measures, the Robust Secure Networks (RSNs) remain vulnerable to a number of attacks. Failure of preventive measures to address all RSN vulnerabilities dictates the need for enhancing the performance of Wireless Intrusion Detection Systems (WIDSs) to detect all attacks on RSNs with less false positive and false negative rates

A wireless sensor network approach for estimating individual task time

Most existing methods for generating individual task time estimates in production systems where jobs move through various manually operated workstations remain tedious and time consuming. For existing systems, average task times may vary considerably from prior estimates causing system inefficiencies, poor scheduling and poor planning decisions. Accurate and up-to-date estimates are also extremely valuable when planning and designing future assembly lines. In this study, a wireless sensor network (WSN) based indoor positioning system (IPS) is proposed as a potential alternative for estimating individual task times. Several network design factors were varied in the experiments conducted to assess the ability of the WSN-based IPS to determine an operator’s position within the workstation so that the total production time can be allocated to the appropriate tasks. The main response variable utilized to determine the location of the operator within the workstation was the link quality indicator (LQI). Accurately measuring LQI levels is not a straightforward process since radio frequency (RF) signals can change over time depending on many conditions, including physical obstructions and electromagnetic interference (EMI). The results show that a WSN-based IPS is a viable approach to estimating individual task times. Additionally, the analysis of the experimental data showed that certain WSN design factors need to be set carefully to ensure good quality in the estimation of individual task times

kotaiiki antena no saitekika sekkei oyobi tokusei hyoka ni kansuru kenkyu : waseda daigaku shinsa gakui ronbun hakushi

制度:新 ; 報告番号:甲3277号 ; 学位の種類:博士(工学) ; 授与年月日:2011/2/21 ; 早大学位記番号:新558

Étude d'un réseau de capteur UWB pour la localisation et la communication dans un environnement minier

Le jour n'est peut-être pas très loin où une mine pourra compter sur un système de communication sans fil pour échanger des données, transmettre des informations ou localiser des travailleurs dans le cas d'une activité normale ou en cas d'urgence. Au point de vue de la sécurité, un système de communications sans fil aurait l'avantage de localiser en temps réel un travailleur ou un engin. Les travailleurs se déplacent sans cesse dans une mine. Avec une technologie sans fil permanente, on pourrait localiser les personnes de manière relativement précise. Même en cas d'éboulement, avec une technologie adaptée, il serait possible de savoir où se trouve la personne en détresse. Notre travail de recherche s'inscrit dans la perspective du développement d'un réseau de capteurs ultra large bande (UWB) pour deux applications : l'aide à la radiolocalisation et l'extension du réseau de capteurs sans fil dans la mine. Cette étude est focalisée sur trois aspects. La première partie de notre étude consiste à étudier tous les problèmes reliés à la radiolocalisation dans la mine. Vue l'importance de cette application, nous avons mis en oeuvre un réseau de capteurs en tenant compte d'un futur déploiement dans la mine. La technologie utilisée repose sur la technologie ultra large bande. Comme il n'existe pas de travaux qui traitent ce genre de problèmes, nous avons commencé notre étude par une caractérisation du canal UWB dans les mines souterraines. Pour atteindre ces objectifs, plusieurs campagnes de mesure sur site (mine expérimentale) ont été menées. Nous sommes parvenus à une modélisation du canal de propagation et à avancer des recommandations pour aider au dimensionnement d'un réseau de capteurs dans ce type d'environnement. Dans la première partie, le but est d'étudier le problème de radiolocalisation avec les réseaux de capteurs. Notre scénario proposé serait de placer des capteurs sur chaque agent (mineur, engin). On suppose que chaque noeud (agent) qui circule à travers un réseau d'ancre maillé (déjà déployé), va extraire des informations de distance (en utilisant le critère de temps d'arrivée), ensuite il va utiliser un algorithme de positionnement distribué afin de déterminer sa propre position. Lors de cette partie nous avons aussi étudié quelques estimateurs cohérents et non-cohérents du temps d'arrivée. La caractérisation de l'erreur de mesure utilisant le temps d'arrivée dans un environnement minier a été aussi évaluée. Enfin, dans la dernière partie, nous avons analysé par simulations un déploiement d'un réseau de capteurs UWB ad hoc dans la mine. Nous avons choisi d'adopter une approche théorique afin d'évaluer les performances de cette configuration. Une conception intercouche pour un routage optimal a été étudiée. Nous avons utilisé la couche physique/réseau afin de minimiser l'énergie consommée lors de l'acheminement du données