18 research outputs found

    Satellite Communications

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    This study is motivated by the need to give the reader a broad view of the developments, key concepts, and technologies related to information society evolution, with a focus on the wireless communications and geoinformation technologies and their role in the environment. Giving perspective, it aims at assisting people active in the industry, the public sector, and Earth science fields as well, by providing a base for their continued work and thinking

    Telemedicine

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    Telemedicine is a rapidly evolving field as new technologies are implemented for example for the development of wireless sensors, quality data transmission. Using the Internet applications such as counseling, clinical consultation support and home care monitoring and management are more and more realized, which improves access to high level medical care in underserved areas. The 23 chapters of this book present manifold examples of telemedicine treating both theoretical and practical foundations and application scenarios

    Quality of service differentiation for multimedia delivery in wireless LANs

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    Delivering multimedia content to heterogeneous devices over a variable networking environment while maintaining high quality levels involves many technical challenges. The research reported in this thesis presents a solution for Quality of Service (QoS)-based service differentiation when delivering multimedia content over the wireless LANs. This thesis has three major contributions outlined below: 1. A Model-based Bandwidth Estimation algorithm (MBE), which estimates the available bandwidth based on novel TCP and UDP throughput models over IEEE 802.11 WLANs. MBE has been modelled, implemented, and tested through simulations and real life testing. In comparison with other bandwidth estimation techniques, MBE shows better performance in terms of error rate, overhead, and loss. 2. An intelligent Prioritized Adaptive Scheme (iPAS), which provides QoS service differentiation for multimedia delivery in wireless networks. iPAS assigns dynamic priorities to various streams and determines their bandwidth share by employing a probabilistic approach-which makes use of stereotypes. The total bandwidth to be allocated is estimated using MBE. The priority level of individual stream is variable and dependent on stream-related characteristics and delivery QoS parameters. iPAS can be deployed seamlessly over the original IEEE 802.11 protocols and can be included in the IEEE 802.21 framework in order to optimize the control signal communication. iPAS has been modelled, implemented, and evaluated via simulations. The results demonstrate that iPAS achieves better performance than the equal channel access mechanism over IEEE 802.11 DCF and a service differentiation scheme on top of IEEE 802.11e EDCA, in terms of fairness, throughput, delay, loss, and estimated PSNR. Additionally, both objective and subjective video quality assessment have been performed using a prototype system. 3. A QoS-based Downlink/Uplink Fairness Scheme, which uses the stereotypes-based structure to balance the QoS parameters (i.e. throughput, delay, and loss) between downlink and uplink VoIP traffic. The proposed scheme has been modelled and tested through simulations. The results show that, in comparison with other downlink/uplink fairness-oriented solutions, the proposed scheme performs better in terms of VoIP capacity and fairness level between downlink and uplink traffic

    Reliable, Context-Aware and Energy-Efficient Architecture for Wireless Body Area Networks in Sports Applications

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    RÉSUMÉ Un RĂ©seau Corporel Sans Fil (RCSF, Wireless Body Area Network en anglais ou WBAN) permet de collecter de l'information Ă  partir de capteurs corporels. Cette information est envoyĂ©e Ă  un hub qui la transforme et qui peut aussi effectuer d'autres fonctions comme gĂ©rer des Ă©vĂ©nements corporels, fusionner les donnĂ©es Ă  partir des capteurs, percevoir d’autres paramĂštres, exĂ©cuter les fonctions d’une interface d’utilisateur, et faire un lien vers des infrastructures de plus haut niveau et d’autres parties prenantes. La rĂ©duction de la consommation d'Ă©nergie d’un RCSF est un des aspects les plus importants qui doit ĂȘtre amĂ©liorĂ© lors de sa conception. Cet aspect peut impliquer le dĂ©veloppement de protocoles de ContrĂŽles d'AccĂšs au Support (CAS, Media Access Control en anglais ou MAC), protocoles de transport et de routage plus efficients. Le contrĂŽle de la congestion est un autre des facteurs les plus importants dans la conception d’un RCSF, parce que la congestion influe directement sur la QualitĂ© De Service (QDS, Quality of Service en anglais ou QoS) et l’efficience en Ă©nergie du rĂ©seau. La congestion dans un RCSF peut produire une grande perte de paquets et une haute consommation d’énergie. La QDS est directement impactĂ©e par la perte de paquets. L’implĂ©mentation de mesures additionnelles est nĂ©cessaire pour attĂ©nuer l’impact sur la communication des RCSF. Les protocoles de CAS pour RCSF devraient permettre aux capteurs corporels d’accĂ©der rapidement au canal de communication et d’envoyer les donnĂ©es au hub, surtout pour les Ă©vĂ©nements urgents tout en rĂ©duisant la consommation d’énergie. Les protocoles de transport pour RCSF doivent fournir de la fiabilitĂ© bout-Ă -bout et de la QDS pour tout le rĂ©seau. Cette tĂąche peut ĂȘtre accomplie par la rĂ©duction du ratio de perte de paquets (Packet Loss Ratio en anglais ou PLR) et de la latence tout en gardant l'Ă©quitĂ© et la faible consommation d'Ă©nergie entre les noeuds. Le standard IEEE 802.15.6 suggĂšre un protocole de CAS qui est destinĂ© Ă  ĂȘtre applicable Ă  tous les types de RCSF; toutefois, ce protocole peut ĂȘtre amĂ©liorĂ© pour les RCSF utilisĂ©s dans le domaine du sport, oĂč la gestion du trafic pourrait ĂȘtre diffĂ©rente d’autres rĂ©seaux. Le standard IEEE 802.15.6 comprend la QDS, mais cela ne suggĂšre aucun protocole de transport ou systĂšme de contrĂŽle du dĂ©bit. Le but principal de ce projet de recherche est de concevoir une architecture pour RCSF en trois phases : (i) Conception d’un mĂ©canisme sensible au contexte et efficient en Ă©nergie pour fournir une QDS aux RCSF; (ii) Conception d’un mĂ©canisme fiable et efficient en Ă©nergie pour fournir une rĂ©cupĂ©ration des paquets perdus et de l’équitĂ© dans les RCSF; et (iii) Conception d’un systĂšme de contrĂŽle du dĂ©bit sensible au contexte pour fournir un contrĂŽle de congestion aux RCSF. Finalement, ce projet de recherche propose une architecture fiable, sensible au contexte et efficiente en Ă©nergie pour RCSF utilisĂ©s dans le domaine du sport. Cette architecture fait face Ă  quatre dĂ©fis : l'efficacitĂ© de l'Ă©nergie, la sensibilitĂ© au contexte, la qualitĂ© de service et la fiabilitĂ©. La mise en place de cette solution aidera Ă  l’amĂ©lioration des compĂ©tences, de la performance, de l’endurance et des protocoles d’entraĂźnement des athlĂštes, ainsi qu’à la dĂ©tection des points faibles. Cette solution pourrait ĂȘtre prolongĂ©e Ă  l’amĂ©lioration de la qualitĂ© de vie des enfants, des personnes malades ou ĂągĂ©es, ou encore aux domaines militaires, de la sĂ©curitĂ© et du divertissement. L’évaluation des protocoles et schĂ©mas proposĂ©s a Ă©tĂ© faite par simulations programmĂ©es avec le simulateur OMNeT++ et le systĂšme Castalia. PremiĂšrement, le protocole de CAS proposĂ© a Ă©tĂ© comparĂ© avec les protocoles de CAS suivants : IEEE 802.15.6, IEEE 802.15.4 et T-MAC (Timeout MAC). DeuxiĂšmement, le protocole de CAS proposĂ© a Ă©tĂ© comparĂ© avec le standard IEEE 802.15.6 avec et sans l’utilisation du protocole de transport proposĂ©. Finalement, le protocole de CAS proposĂ© et le standard IEEE 802.15.6 ont Ă©tĂ© comparĂ©s avec et sans l’utilisation du systĂšme de contrĂŽle du dĂ©bit proposĂ©. Le protocole de CAS proposĂ© surpasse les protocoles de CAS IEEE 802.15.6, IEEE 802.15.4 et T-MAC dans le pourcentage de pertes de paquets d’urgence et normaux, l’efficacitĂ© en Ă©nergie, et la latence du trafic d’urgence et du trafic normal. Le protocole de CAS proposĂ© utilisĂ© avec le protocole du transport proposĂ© surpasse la performance du standard IEEE 802.15.6 dans le pourcentage de perte de paquets avec ou sans trafic d’urgence, l’efficacitĂ© en Ă©nergie, et la latence du trafic normal. Le systĂšme de contrĂŽle du dĂ©bit proposĂ© a amĂ©liorĂ© la performance du protocole de CAS proposĂ© et du standard IEEE 802.15.6 dans le pourcentage de perte de paquets avec ou sans trafic d’urgence, l’efficacitĂ© en Ă©nergie, et la latence du trafic d’urgence.----------ABSTRACT Information collected from body sensors in a Wireless Body Area Network (WBAN) is sent to a hub or coordinator which processes the information and can also perform other functions such as managing body events, merging data from sensors, sensing other parameters, performing the functions of a user interface and bridging the WBAN to higher-level infrastructure and other stakeholders. The reduction of the power consumption of a WBAN is one of the most important aspects to be improved when designing a WBAN. This challenge might imply the development of more efficient Medium Access Control (MAC), transport and routing protocols. Congestion control is another of the most important factors when a WBAN is designed, due to its direct impact in the Quality of Service (QoS) and the energy efficiency of the network. The presence of congestion in a WBAN can produce a big packet loss and high energy consumption. The QoS is also impacted directly by the packet loss. The implementation of additional measures is necessary to mitigate the impact on WBAN communications. The MAC protocols for WBANs should allow body sensors to get quick access to the channel and send data to the hub, especially in emergency events while reducing the power consumption. The transport protocols for WBANs must provide end-to-end reliability and QoS for the whole network. This task can be accomplished through the reduction of both the Packet Loss Ratio (PLR) and the latency while keeping fairness and low power consumption between nodes. The IEEE 802.15.6 standard suggests a MAC protocol which is intended to be applicable for all kinds of WBANs. Nonetheless, it could be improved for sports WBANs where the traffic-types handling could be different from other networks. The IEEE 802.15.6 standard supports QoS, but it does not suggest any transport protocol or rate control scheme. The main objective of this research project is to design an architecture for WBANs in three phases: (i) Designing a context-aware and energy-efficient mechanism for providing QoS in WBANs; (ii) Designing a reliable and energy-efficient mechanism to provide packet loss recovery and fairness in WBANs; and (iii) Designing a context-aware rate control scheme to provide congestion control in WBANs. Finally, this research project proposes a reliable, context-aware and energy-efficient architecture for WBANs used in sports applications, facing four challenges: energy efficiency, context awareness, quality of service and reliability. The benefits of this solution will help to improve skills, performance, endurance and training protocols of athletes, and deficiency detection. Also, it could be extended to enhance the quality of life of children, ill and elderly people, and to security, military and entertainment fields. The evaluation of the proposed protocols and schemes was made through simulations programed in the OMNeT++ simulator and the Castalia framework. First, the proposed MAC protocol was compared against the IEEE 802.15.6 MAC protocol, the IEEE 802.15.4 MAC protocol and the T-MAC (Timeout MAC) protocol. Second, the proposed MAC protocol was compared with the IEEE 802.15.6 standard with and without the use of the proposed transport protocol. Finally, both the proposed MAC protocol and the IEEE 802.15.6 standard were compared with and without the use of the proposed rate control scheme. The proposed MAC protocol outperforms the IEEE 802.15.6 MAC protocol, the IEEE 802.15.4 MAC protocol and the T-MAC protocol in the percentage of emergency and normal packet loss, the energy effectiveness, and the latency of emergency and normal traffic. The proposed MAC protocol working along with the proposed transport protocol outperforms the IEEE 802.15.6 standard in the percentage of the packet loss with or without emergency traffic, the energy effectiveness, and the latency of normal traffic. The proposed rate control scheme improved the performance of both the proposed MAC protocol and the IEEE 802.15.6 standard in the percentage of the packet loss with or without emergency traffic, the energy effectiveness and the latency of emergency traffic

    A Participatory Action Research approach to telemedicine supported health care delivery in rural Nepal

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    Rural and geographically isolated, the majority of Nepalese communities have very low incomes, poor transportation, and scarce health care resources; these people provide the context for this study. The consequences of these deprivations include high maternal and infant mortality rates, high prevalence of infectious disease and poverty. There are therefore exceptional challenges and disparities in meeting health care needs. However the recent advent of modern information communication technology (ICT) or Telemedicine has unleashed a new wave of opportunities for supporting the delivery of health care services. Despite suggestions that telemedicine will offer hope in developing countries there is only limited published evidence to support this claim. Telemedicine is and must remain a process of the delivery of care rather than a technology. The system must connect patients and healthcare professionals in a chain of care, rather than follow the wide array of existing or new and advanced technology. The successful introduction of telemedicine with tangible outputs requires an in-depth understanding of the existing health care system of the country and its challenges; strongly expressed ‘genuine need’ for the service by all the stakeholders as interested partners (patients, practitioners, health care service providers and the public); the actual status of ICT infrastructure in the country and costs. This study used a Participatory Action Research (PAR) approach to explore the feasibility, acceptability and impact of a telemedicine system in partnership with Dhulikhel Hospital: Kathmandu University Hospital and with three of its 12 rural, remote outreach centres, and the populations they serve. Participatory, repeated data collection methods included surveys, interviewing, listening and being with staff and communities over a two year period. The researcher and researched engaged in a complex inter-locking journey from which the Unlocking, Unblocking and Validation concepts emerged. The findings of this study emphasise the pivotal role that the rural health care workers play. Telemedicine not only has a place in improving access to healthcare through enhanced communication but it also empowers health care workers. These people need continued support to develop their competencies and boost their confidence within the changing health care environment. In conclusion telemedicine is primarily about people rather than technology. Effective and holistic telemedicine development is built upon a combined, interactive model involving access, communication and empowerment

    A framework for secure mobile computing in healthcare

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    Mobile computing is rapidly becoming part of healthcare’s electronic landscape, helping to provide better quality of care and reduced cost. While the technology provides numerous advantages to the healthcare industry, it is not without risk. The size and portable nature of mobile computing devices present a highly vulnerable environment, which threaten the privacy and security of health information. Since these devices continually access possibly sensitive healthcare information, it is imperative that these devices are considered for security in order to meet regulatory compliance. In fact, the increase in government and industry regulation to ensure the privacy and security of health information, makes mobile security no longer just desirable, but mandatory. In addition, as healthcare becomes more aware of the need to reinforce patient confidence to gain competitive advantage, it makes mobile security desirable. Several guidelines regarding security best practices exist. Healthcare institutions are thus faced with matching the guidelines offered by best practices, with the legal and regulatory requirements. While this is a valuable question in general, this research focuses on the aspect of considering this question when considering the introduction of mobile computing into the healthcare environment. As a result, this research proposes a framework that will aid IT administrators in healthcare to ensure that privacy and security of health information is extended to mobile devices. The research uses a comparison between the best practices in ISO 17799:2005 and the regulatory requirements stipulated in HIPAA to provide a baseline for the mobile computing security model. The comparison ensures that the model meets healthcare specific industry requirement and international information security standard. In addition, the framework engages the Information Security Management System (ISMS) model based on the ISO 27000 standard. The framework, furthermore, points to existing technical security measurers associated with mobile computing. It is believed that the framework can assist in achieving mobile computing security that is compliant with the requirements in the healthcare industry
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