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.

Managing One’s Availability to Telephone Communication Through Mobile Phones: A French Case Study of the Development Dynamics of Mobile Phone Use

Abstract: This paper provides empirical results concerning the negotiation of access and joinability by mobile phone users. It shows how access is embedded in a gift-giving economy (giving one’s number for example). It also shows that the more users make themselves available on the mobile phone, the more their mobile phone traffic increases (both incoming and outgoing). This remarkable result is discussed in terms of the reciprocity involved in the management of mobile phone relationships.

Method for laying out the infrastructure of a cellular communications network

Abstract: A method for the laying out of the infrastructure of a cellular communications network, notably with mobile units, the network being of the type constituted by a plurality of broadcasting transmitters, each broadcasting on its own broadcasting cell, at least certain of the cells being adjacent and having common overlapping zones, a system of management of the network assigning a single broadcasting cell to a given mobile unit at a given time, according to a given broadcasting transmitter assigning method, the method for the laying out consisting in determining the geographical location and the technical characteristics of each of the transmitters of the network in taking account of the conditions of entry/exit and of movement of the mobile units in the overlapping zones. Thus, the coverage of the network is determined dynamically, such as it is seen by the mobile units.

Designing Specific Weighted Similarity Measures to Improve Collaborative Filtering Systems

Abstract: The aim of collaborative filteringis to help usersto find itemsthat they should appreciate from huge catalogues. In that field, we can distinguish user-basedfrom item-basedapproaches. The former is based on the notion of user neighbourhoods while the latter uses item neighbourhoods. The definition of similaritybetween users and items is a key problem in both approaches. While traditional similarity measures can be used, we will see in this paper that bespoke ones, that are tailored to type of data that is typically available (i.e. very sparse), tend to lead to better results. Extensive experiments are conducted on two publicly available datasets, called MovieLensand Netflix. Many similarity measures are compared. And we will show that using weighted similarity measures significantly improves the results of both user- and item-based approaches.

Device for the coherent demodulation of time-frequency interlaced digital data, with estimation of the frequency response of the transmission channel and threshold, and corresponding transmitter

Abstract: A coherent demodulation device, for the demodulation of a digital signal of the type constituted by digital elements distributed in the time-frequency space and transmitted in the form of symbols constituted by a multiplex of N orthogonal carrier frequencies modulated by a set of the digital elements and broadcast simultaneously, the digital signal comprising reference elements, having a value and a position, in the time-frequency space, that are known to the demodulation device, comprising means for the estimation, by Fourier transform, of the frequency response of the transmission channel at any instant, carrying out the transformation of the received samples, corresponding to reference elements, from the frequency domain to the temporal domain, the multiplication in the temporal domain of the transformed samples by a rectangular temporal window (f n) and the reverse transformation, after the multiplication, of the obtained samples from the temporal domain into the frequency domain, the estimation means comprising means for the thresholding of the samples in the temporal domain, providing for the systematic elimination of the samples below a certain threshold.

Adaptive Noise Mitigation in Impulsive Environment: Application to Power-Line Communications

Abstract: In this paper, we address the general issue of asynchronous impulsive noise mitigation and its application over coded power-line communications (PLC). As is well known, PLC channels usually suffer from significant degradation due to impulsive interference generated by electrical appliances. The use of a level limiter is a simple and intuitive technique, widely used to mitigate the noxious effect of impulsive noise in these channels. However, the determination of the clipping threshold remains, most of the time, empirical, and the impulse statistics are usually assumed to be known. In a previous study, we proposed an original threshold determination based on signal detection theory, using the well-known false alarm and good detection tradeoff. Here, we further investigate the proposed optimization method in closed form. We compare two tradeoff criteria by means of a receiver operating curves analysis. We clearly show that the resulting decision fits well with encountered bit-error rate performances. We also evaluate the influence of impulsive noise statistics estimation on the performance of the proposed approach. To do so, we assess the robustness of the classical method of moments on Gaussian mixture estimation. It clearly appears that the estimation method is reliable for reasonable values of the impulse occurrence. As one of the main results of this paper, we make a proposal for impulse statistics estimation under ?severe? conditions (i.e., for very rare impulse events, based on impulse detection over corrupted OFDM symbols). Subsequently, we propose a general scheme of automatic impulse mitigation, according to the disturbance ratio of the environment. Finally, the performance of the approach is evaluated over the Home-Plug AV (HPAV) physical layer.