118documents trouvés
An investigation of self-organization in ad-hoc networks
A.AKL, T.GAYRAUD, P.BERTHOU
OLC
Manifestation avec acte : International Conference on Networking Sensing and Control (ICNSC 2011), Delft (Pays Bas), 11-13 Avril 2011, pp.237-242 , N° 11048
Lien : http://hal.archives-ouvertes.fr/hal-00661017
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Abstract
Wireless Sensor Network (WSN) is an emerging special type of ad-hoc wireless networks technology. It is usually designed for special purpose applications. WSN has its own special characteristics that differentiate it from other types of wireless networks. These differences raise new challenges to be overcome; one of them is self-organization. As in any rising domain, it is essential to specifically define the meaning of new terminologies. The terms self-organizing and self-configuring are an example of such terms that may have overlapping meaning. In this investigation, we tried to make a definition for both terms to specifically determine their role in the ad-hoc domain, and stress on the differences between them. Consequently, we tried to show the importance of self-organization in enhancing sensor network's performance, and efficient usage of its resources. Thus, we tried to highlight the role of different networking layers in affecting self-organization to be a guideline during WSN design phase. We also introduced a new self-organizing protocol that utilizes directional antenna in an In-Flight entertainment system. Finally, we highlighted some of the future needs in the WSN domain, and their need for research attention.
Controlled stochastic petri net model for end-to-end network QoS provisioning in middleware-based multimedia and real-time systems
A.HAKIRI, P.BERTHOU, T.GAYRAUD
OLC
Manifestation avec acte : Spring Simulation Multi Conférences. Annual Simulation Symposium (ANSS11), Boston (USA), 4-9 Avril 2011, pp.118-125 , N° 11076
Lien : http://hal.archives-ouvertes.fr/hal-00594898/fr/
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Abstract
End-to-end quality of service (QoS) is central to the objectives of the today's networks requirements of middleware based distributed real-time and embedded (DRE) systems. Any middleware based QoS system should be totally oriented to this goal, and in the scope of this purpose several mechanisms, components and approaches were, are being and will be developed in order to achieve it. In this paper, we show how controlled behavior of such QoS-aware systems can be developed based on stochastic Petri Nets. Afterwards, We show how to obtain, using such an interpreted formal model, powerful numerical analysis for the management of the network QoS.
Protocole de synchronisation hybride et directif pour réseaux de capteurs sans fil
E.ALBU, P.BERTHOU, T.GAYRAUD, Y.LABIT
OLC
Rapport LAAS N°11092, Mars 2011, 12p.
Diffusable
124084Energy-efficient directional antenna model for wireless sensor networks
E.ALBU, T.GAYRAUD, Y.LABIT, P.BERTHOU
OLC
Rapport LAAS N°11093, Mars 2011, 8p.
Diffusable
124085Design of a multiple-interfaces synchronized energy-efficient architecture for wireless sensor networks
E.ALBU, T.GAYRAUD, P.BERTHOU, Y.LABIT
OLC
Rapport LAAS N°11091, Mars 2011, 7p.
Diffusable
124083A new wireless architecture for IFE systems inside aircraft cabin
A.AKL, T.GAYRAUD, P.BERTHOU
OLC
Revue Scientifique : International Journal on Advances in Networks and Services, Vol.4, N°1-2, pp.159-175, Janvier 2011 , N° 11077
Lien : http://hal.archives-ouvertes.fr/hal-00661029
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Abstract
A primary difficulty when investigating communication requirements rises when a very specific field as an aircraft cabin is considered. The diverse needs of passengers are often incompatible to the strict constraints inside the cabin. Nowadays In-Flight Entertainment (IFE) systems, for instance, are widely spread in modern flights. An IFE system usually consists of a Seat Electronic Box, the passengers terminal hardware, plus a Passengers Control Unit, the remote control to select the service, and a Visual Display Unit, the screen. Using the wireless technology in these systems can increase the satisfaction level of both the passengers and the avionics companies. However, the inside of the cabin is not a flexible environment; reliability and safety are two mandatory requirements, so different constrains are imposed. This means that off-shelf technologies (hardware including antennas, network topology, network protocols and services) are usually not suitable for such environment. Consequently, a new architecture has to be designed and implemented. This paper aims at integrating heterogeneous available communication technologies, showing their pros and cons, within this context, while considering the imposed communication restrictions inside the aircrafts cabin. From that, a new wireless heterogeneous architecture is proposed. In addition, to be able to use such architecture, we propose a new protocol, which utilizes the smart antennas technology to allow Passenger Control Units to be recognized and configured autonomously without any external intervention.
Embedded blade microsystem and events recorder for drone structural health monitoring
M.LASTAPIS, C.ESCRIBA, G.AURIOL, E.ALBU, P.BERTHOU, J.L.BOIZARD, J.M.DILHAC, J.Y.FOURNIOLS
N2IS, Labo. associé LATTIS, OLC, ISGE
Manifestation avec acte : Asia Pacific Workshop on Structural Health Monitoring (APWSHM 2010), Tokyo (Japon), 30 Novembre - 2 Décembre 2010, 9p. , N° 10651
Lien : http://hal.archives-ouvertes.fr/hal-00545117/fr/
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Abstract
Structural health monitoring is today growing challenge. A good health structure allows to assure in real-time a good performance level, to keep a high level of safety and to plan maintenance. Why drone applications? Drones are very expansive aircrafts, also referred to as UVA (unmanned air vehicle), exposed to a harsh environment due to their frequent military usage. In this context, propellers are among the key components worth health monitoring. The purpose of our research is to develop for the drone propeller an integrated electronics combining accelerometers and signal processing, able to record damaging events for the drone: shocks, vibrations or overspeeds whereas strain gauges could not analyze all these criteria. These parameters allow concluding whether the blade is damaged or not. This paper will present our embedded microsystem on drone propellers. Then we will show through real experiments how it is possible to monitor and detect events like stone shocks, propeller overspeeds or too strong vibrations. Specific algorithm for diagnosis will be discussed and evaluated in different environment tests conditions. Moreover the use of a wireless synchronization between several propellers will be studied too.
QoS-enabled ANFIS dead reckoning algorithm for distributed interactive simulation
A.HAKIRI, P.BERTHOU, T.GAYRAUD
OLC
Manifestation avec acte : IEEE/ACM International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2010), Faifax (USA), 17-20 Octobre 2010, pp.33-42 , N° 10522
Lien : http://hal.archives-ouvertes.fr/hal-00537501/fr/
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Abstract
Dead Reckoning mechanisms are usually used to estimate the position of simulated entity in virtual environment. However, this technique often ignores available contextual information that may be influential to the state of an entity, sacrificing remote predictive accuracy in favor of low computational complexity. A novel extension of Dead Reckoning is suggested in this paper to increase the network availability and fulfill the required Quality of Service in large scale distributed simulation application. The proposed algorithm is referred to as ANFIS Dead Reckoning, which stands for Adaptive Neuro-based Fuzzy Inference System Dead Reckoning is based on a fuzzy inference system which is trained by the learning algorithm derived from the neuronal networks and fuzzy inference theory. The proposed mechanism takes its based on the optimization approach to calculate the error threshold violation in networking games. Our model shows it primary benefits especially in the decision making of the behavior of simulated entities and preserving the consistence of the simulation.
An energy-efficient clock synchronization protocol for wireless sensor networks
E.ALBU, Y.LABIT, T.GAYRAUD, P.BERTHOU
OLC
Manifestation avec acte : IFIP Wireless Days 2010, Venise (Italie), 20-22 Octobre 2010, 5p. , N° 10659
Lien : http://hal.archives-ouvertes.fr/hal-00544972/fr/
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Abstract
The behavior of Wireless Sensor Networks (WSN) is nowadays widely analyzed. One of the most important issues is related to their energy consumption, as this has a major impact on the network lifetime. Another important application requirement is to ensure data sensing synchronization, which leads to additional energy consumption as a high number of messages is sent and received at each node. Our proposal consists in implementing a combined synchronization protocol based on the IEEE 1588 standard that was designed for wired networks and the PBS (Pairwise Broadcast Synchronization) protocol that was designed for sensor networks, as none of them is able to provide the needed synchronization accuracy for our application on its own. The main goals of our new synchronization protocol are: to ensure the accuracy of local clocks up to a tenth of a microsecond and to provide an important energy saving. Our results obtained using NS-2 (Network Simulator) show that the performance of our solution (IEEE 1588-PBS) matches our application requirements with regard to the synchronization, with a significant improvement in energy saving.
Dynamic QoS configuration of a DVB-RCS satellite terminal for SIPbased applications
B.JACQUEMIN , P.BERTHOU, T.GAYRAUD, C.BAUDOIN
OLC, Thalès Alenia Space
Manifestation avec acte : 16th Ka Band Conference, Milan (Italie), 20-22 Octobre 2010, 8p. , N° 10656
Lien : http://hal.archives-ouvertes.fr/hal-00529000/fr/
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Abstract
Satellite systems were long-dedicated mainly to broadcast services as television whereas Internet access was offered by terrestrial networks as DSL technologies. However, the democratization of DVB-S terminal, the standardization of a return channel via satellite (DVB-RCS) and the significant breakthroughs leading to DVB-S2 standard have allowed them to represent an interesting alternative to terrestrial networks in remote areas. But, to be competitive, DVB-S2/RCS systems have to offer an appropriate support to the variety of current and future multimedia applications (VoIP, videoconferencing) by providing QoS guarantees in spite of its specific characteristics: a long transmission delay and a limited bandwidth. In this context, this paper considers a DiffServ architecture, compliant with the SatLabs recommandations, in which three classes are considered at the IP layer to differentiate the traffic: EF, dedicated to real-time applications with strong time-constraints, AF used for non real-time applications and BE. Each Diffserv classe is mapped on a specific MAC queue to take benefit of the DAMA (Demand Assignment Multiple Access) mechanisms which allow the ST to dynamically request capacity to the NCC (Network Control Center). The goal of this work is to configure dynamically the DiffServ classes of service of the Linux-based ST for interactive applications, as VoIP, by using the session descriptors contained in SIP messages. For that, a complete QoS architecture based on the communication between an enhanced SIP proxy and a QoS Server and/or an ARC (Access Resource Controller) has been designed, developed and evaluated on a satellite network emulation testbed (PLATINE), implemented in the SatIP6 and SatSIX IST projects.