Nadine Adra - Academia.edu (original) (raw)
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Papers by Nadine Adra
2012 19th International Conference on Telecommunications (ICT), 2012
Nowadays, the current trend is to integrate mobile WiMAX with 3G networks to meet the growing dem... more Nowadays, the current trend is to integrate mobile WiMAX with 3G networks to meet the growing demand for high-speed connectivity and ubiquitous coverage. The design and implementation of seamless integration architecture for heterogeneous networks is a challenging task, as it requires comprehensive effort to provide mobile user with seamless experience while switching between access networks. In order to realize seamless
As wireless access technologies grow rapidly, the recent studies have focused on granting mobile ... more As wireless access technologies grow rapidly, the recent studies have focused on granting mobile users the ability of roaming across different wireless networks in a seamless manner thus offering seamless mobility. The different characteristics of each wireless technology with regard to Quality of Service (QoS) brought many challenges for provisioning the continuous services (audio/video streaming) in a seamless way. The paper proposes Context-Aware Management Scheme (CAMS) which facilitates service continuity in real-time application such as video and audio streaming. Unlike previous research efforts which focuses on session continuity only while handover and does not account for the characteristics differences between the networks, this work focuses on improving QoS and user experience by adapting the session parameters after Vertical Handover (VHO) according to the new environment and available resources. The new scheme would improve users experience and allow the network to admit more users at the same time compared to non-context aware solutions. In this paper, the architecture of the proposed scheme is presented. In addition, detailed signaling messages of the VHO and Context-Aware Management from WiFi to WiMax and vice versa are discussed.
Solar thermal systems are an ecological way of providing domestic hot water. They are experiencin... more Solar thermal systems are an ecological way of providing domestic hot water. They are experiencing a rapid growth since the beginning of the last decade. This study characterizes the environmental performances of such installations with a life-cycle approach. The methodology is based on the application of the international standards of Life Cycle Assessment. Two types of systems are presented. Firstly a temperate-climate system, with solar thermal collectors and a backup energy as heat sources. Secondly, a tropical system, with thermosiphonic solar thermal system and no backup energy. For temperate-climate systems, two alternatives are presented: the first one with gas backup energy, and the second one with electric backup energy. These two scenarios are compared to two conventional scenarios providing the same service, but without solar thermal systems. Life cycle inventories are based on manufacturer data combined with additional calculations and assumptions. The fabrication of the components for temperate-climate systems has a minor influence on overall impacts. The environmental impacts are mostly explained by the additional energy consumed and therefore depend on the type of energy backup that is used. The study shows that the energy pay-back time of solar systems is lower than 2 years considering gas or electric energy when compared to 100% gas or electric systems.
The international expansion of the PV industry can affect the range of indirect environmental imp... more The international expansion of the PV industry can affect the range of indirect environmental impacts, and mostly the CO 2 equivalent emissions, of the solar electricity produced in any country. We demonstrate a clear trend towards high variation in the global warming potential of solar electricity produced in France by PV installations which use modules produced with different electricity mix. The variation is somewhat less important when looking at the Energy Payback Time (EPBT) of the PV installation. In any studied case, the transportation between countries has a low effect compared to the choice made on the source of electricity used during the different steps involved in the fabrication of modules for any technology.
2012 19th International Conference on Telecommunications (ICT), 2012
Nowadays, the current trend is to integrate mobile WiMAX with 3G networks to meet the growing dem... more Nowadays, the current trend is to integrate mobile WiMAX with 3G networks to meet the growing demand for high-speed connectivity and ubiquitous coverage. The design and implementation of seamless integration architecture for heterogeneous networks is a challenging task, as it requires comprehensive effort to provide mobile user with seamless experience while switching between access networks. In order to realize seamless
As wireless access technologies grow rapidly, the recent studies have focused on granting mobile ... more As wireless access technologies grow rapidly, the recent studies have focused on granting mobile users the ability of roaming across different wireless networks in a seamless manner thus offering seamless mobility. The different characteristics of each wireless technology with regard to Quality of Service (QoS) brought many challenges for provisioning the continuous services (audio/video streaming) in a seamless way. The paper proposes Context-Aware Management Scheme (CAMS) which facilitates service continuity in real-time application such as video and audio streaming. Unlike previous research efforts which focuses on session continuity only while handover and does not account for the characteristics differences between the networks, this work focuses on improving QoS and user experience by adapting the session parameters after Vertical Handover (VHO) according to the new environment and available resources. The new scheme would improve users experience and allow the network to admit more users at the same time compared to non-context aware solutions. In this paper, the architecture of the proposed scheme is presented. In addition, detailed signaling messages of the VHO and Context-Aware Management from WiFi to WiMax and vice versa are discussed.
Solar thermal systems are an ecological way of providing domestic hot water. They are experiencin... more Solar thermal systems are an ecological way of providing domestic hot water. They are experiencing a rapid growth since the beginning of the last decade. This study characterizes the environmental performances of such installations with a life-cycle approach. The methodology is based on the application of the international standards of Life Cycle Assessment. Two types of systems are presented. Firstly a temperate-climate system, with solar thermal collectors and a backup energy as heat sources. Secondly, a tropical system, with thermosiphonic solar thermal system and no backup energy. For temperate-climate systems, two alternatives are presented: the first one with gas backup energy, and the second one with electric backup energy. These two scenarios are compared to two conventional scenarios providing the same service, but without solar thermal systems. Life cycle inventories are based on manufacturer data combined with additional calculations and assumptions. The fabrication of the components for temperate-climate systems has a minor influence on overall impacts. The environmental impacts are mostly explained by the additional energy consumed and therefore depend on the type of energy backup that is used. The study shows that the energy pay-back time of solar systems is lower than 2 years considering gas or electric energy when compared to 100% gas or electric systems.
The international expansion of the PV industry can affect the range of indirect environmental imp... more The international expansion of the PV industry can affect the range of indirect environmental impacts, and mostly the CO 2 equivalent emissions, of the solar electricity produced in any country. We demonstrate a clear trend towards high variation in the global warming potential of solar electricity produced in France by PV installations which use modules produced with different electricity mix. The variation is somewhat less important when looking at the Energy Payback Time (EPBT) of the PV installation. In any studied case, the transportation between countries has a low effect compared to the choice made on the source of electricity used during the different steps involved in the fabrication of modules for any technology.