Search results for "Télécommunications"
showing 4 items of 4 documents
An improvement of NFC-SEC with signed exchanges for an e-prescription-based application
2013
International audience; In the context of an aging population, drug intake can be a potential source of errors leading to death in some cases. Almost all of these errors are unintentional and come from incorrect prescriptions, unsuitable dosages for the patient or incompatibility with other treatments. To limit these risks which are especially important in the elderly or pre-dependency, we propose a secure system for drug treatment through the NFC (Near Field Communication) contact-less communication technology. The proposed system provides security mechanisms such as integrity, authentication, encryption and non-repudiation. To ensure this security, an extension of the international standa…
ultra-short pulse propagation at 160-Gb/s in dispersion managed optical fiber lines
2004
This thesis presents a study on ultra-short pulse propagation at 160-Gb/s in dispersion managed optical fiber lines. In a first part, we describe the experimental design of a SHG-FROG setup able to characterize high repetition rate pulse trains. Secondly, we demonstrate the efficiency of multiple four wave mixing phenomenon for the generation of a 160-GHz pulse train through the compression of a sinusoidal beat-signal. Then, in order to compare the experimental and theoretical results, we present the development of an optical fiber characterization benchtop based on modulational instability. In the last part of this thesis, we built and compare several recirculating loop setups. On the one …
Exploiter une plateforme de recherche en télécommunications optiques pour souligner la dualité temps/fréquence
2015
National audience; L’analyse de Fourier [1] tient une place majeure dans l’analyse et la compréhension de nombreux phénomènes de la physique et de l’ingénierie contemporaines. Pourtant les étudiants, qui ont souvent découvert cette notion à travers des travaux numériques ou en cours de mathématiques, ne cernent pas forcément toute la richesse qui peut être tirée de l’analyse conjointe dans les domaines temporels et spectraux, notamment dans le domaine de l’optique [2, 3]. De plus, si une grande attention est souvent accordée aux profils temporels ou spectraux en intensité, la notion de phase est souvent balayée beaucoup rapidement.Nous avons mis en place dans le cadre de la seconde année du…