Orange S.A.

About: Orange S.A. is a company organization based out in Paris, France. It is known for research contribution in the topics: Terminal (electronics) & Signal. The organization has 6735 authors who have published 9190 publications receiving 156440 citations. The organization is also known as: Orange SA & France Télécom.

Electronic signature method, program and server for implementing the method

Abstract: In order to apply an electronic signature from a client station having authentication resources at a server, the following steps are carried out: the client station is authenticated at the server, thus establishing an authenticated communication channel; a private key/public key pair is generated at the client station; a signature certificate request generated by means of at least the public key is transmitted from the client station to the server via the authenticated channel; a signature certificate obtained in response to the request is returned via the authenticated channel; this certificate is verified at the client station; an electronic signature is calculated at the client station by means of the private key, after which this private key is destroyed; and the calculated signature is formatted with the aid of the signature certificate received via the authenticated channel.

Simulation of typical Cox–Voronoi cells with a special regard to implementation tests

Abstract: We consider stationary Poisson line processes in the Euclidean plane and analyze properties of Voronoi tessellations induced by Poisson point processes on these lines. In particular, we describe and test an algorithm for the simulation of typical cells of this class of Cox–Voronoi tessellations. Using random testing, we validate our algorithm by comparing theoretical values of functionals of the zero cell to simulated values obtained by our algorithm. Finally, we analyze geometric properties of the typical Cox–Voronoi cell and compare them to properties of the typical cell of other well-known classes of tessellations, especially Poisson–Voronoi tessellations. Our results can be applied to stochastic–geometric modelling of networks in telecommunication and life sciences, for example. The lines can then represent roads in urban road systems, blood arteries or filament structures in biological tissues or cells, while the points can be locations of telecommunication equipment or vesicles, respectively.

Enhancing the Tracking of Partials for the Sinusoidal Modeling of Polyphonic Sounds

Abstract: This paper addresses the problem of tracking partials, i.e., determining the evolution over time of the parameters of a given number of sinusoids with respect to the analyzed audio stream. We first show that the minimal frequency difference heuristic generally used to identify continuities between local maxima of successive short-time spectra can be successfully generalized using the linear prediction formalism to handle modulated sounds such as musical tones with vibrato. The spectral properties of the evolutions in time of the parameters of the partials are next studied to ensure that the parameters of the partials effectively satisfy the slow time-varying constraint of the sinusoidal model. These two improvements are combined in a new algorithm designed for the sinusoidal modeling of polyphonic sounds. The comparative tests show that onsets/offsets of sinusoids as well as closely spaced sinusoids are better identified and stochastic components are better avoided.

P2P Network for very large virtual environment

Abstract: The ever increasing speed of Internet connections has led to a point where it is actually possible for every end user to seamlessly share data on Internet. Peer-To-Peer (P2P) networks are typical of this evolution. The goal of our paper is to show that server-less P2P networks with self-adaptive assignment techniques can efficiently deal with very large environments such as met in the geovisualization domain. Our method allows adaptative view-dependent visualization thanks to a hierarchical and progressive data structure that describes the environment. In order to assess the global efficiency of this P2P technique, we have implemented a dedicated real time simulator. Experimentation results are presented using a hierarchical LOD model of a very large urban environment.

Multimedia broadcast multicast service - technology overview and service aspects

Abstract: This paper provides an overview of potential services over MBMS, the broadcast /multicast service of the universal mobile telecommunication system (UMTS), and discusses related business models and service requirements. While MBMS is a suitable data service for some applications already envisaged for the introduction of UMTS (e.g. multimedia message service (MMS) push), MBMS can be an enabler for services that are not feasible over UMTS without major enhanced downlink capacity or broadcast/multicast capabilities. For both of these categories, potential services, their constraints and adequate business models are presented. The paper also analyses the main functional requirements that need to be taken into consideration when defining or dimensioning an MBMS service. Most of these requirements fall into the scope of standardisation. As a consequence, these requirements will have to be considered by relevant standardisation bodies (3GPP, OMA - open mobile alliance) as a way to guarantee that MBMS will meet these service requirements.