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.

Triangular active mesh for motion estimation

Abstract: This paper introduces a motion estimation tool based on triangular active mesh. This tool can be used to model the deformation of various kinds of objects, especially frames and arbitrarily shaped regions known as video object planes (VOPs) in the MPEG-4 context. In the latter case, a polygon approximation of the region is performed in order to define border nodes and to triangulate the whole considered domain. Object motion is represented by a piecewise affine transformation whose coefficients are estimated by means of motion estimation of triangle vertices. Within the context of very low bit-rate coding, this tool appears to be useful for image prediction, temporal interpolation and may achieve the optimal sharing between motion and error information encoding. Simulations show that the proposed motion estimation tool provides higher PSNR than the classical block matching algorithm.

Adaptive Vertical Mobility Decision in Heterogeneous Networks

Abstract: This paper focuses on mobility management between heterogeneous Radio Access Networks (RANs). A fuzzy multi-criteria vertical handover algorithm that enhances the system performances is proposed. This algorithm is based on fuzzy logic control. The Fuzzy Logic Controller (FLC) takes into account multiple relevant criteria and a set of rules defined from prior knowledge. Neural network adapts automatically the FLC parameters to the environment fluctuations and the traffic variations. The performances of our handover algorithm are evaluated and compared to a conventional vertical handover algorithm by means of simulations. The proposed handover algorithm improves the user- perceived performances.

40 Gbit/s OTDM soliton transmission over transoceanic distances

Abstract: 40 Gbit/s soliton transmission is achieved in a recirculating loop over 10000 km, for the first time to the authors' knowledge. With a single carrier wavelength. Propagation has been tested with and without polarisation multiplexing thanks to low polarisation dependency electroabsorption modulators for in-line control and for the time demultiplexing receiver.

1.55-μm polarization-insensitive optical amplifier with strain-balanced superlattice active layer

Abstract: A polarization insensitive (sensitivity < 1 dB) semi- conductor optical amplifier has been realized at 1.55 pm. The active layer consists of a strain-balanced superlattice structure. Gain polarization insensitivity on a large bandwidth (60 nm) together with a 22.5-dB signal gain and a 11-dBm polarization- insensitive saturation output power are obtained. EMICONDUCTOR optical amplifiers (SOA's) are a key S element for optical communication systems. Their main advantages compared to fiber optical amplifiers (FOA's) are the continuous choice of wavelength (from 1.3 to 1.55 pm), the low driving power, and its integrability in photonic integrated circuits. However, a disadvantage of standard SOA-based on bulk active layer is the polarization sensitivity of the gain due to difference of the TE and TM mode confinement factors, favoring the TE mode gain (l?TE/l?TM M 3 dB). A first solution to reduce this polarization sensitivity is to use a nearly square section active waveguide geometry (l). In addition to technological difficulties to fabricate waveguide with cross sections as small as 0.3 pm x 0.5 pm, this solution leads to strong coupling losses (which requires the use of tapers to reduce these losses) and difficulties in photonic integration with other components. Another solution is to keep the usual waveguide geometry (hence reducing the coupling losses), and to use tensile-strained materials in the active layer so as to favor the TM mode gain and to compensate the confinement factor difference. Three types of heterostructures have been proposed so far: low tensile-strained multiquantum well (MQW) (2), MQW comprising tensile and compressively strained wells (3) and strained-layer superlattices (SL's) al- temating tensile-strained and lattice-matched thin layers (4). We focused on this last approach to be able to simultaneously control the material bandgap and the Tm gain ratio, in contrast to the compressive/tensile MQW approach. We report here the results for a SOA based on a strain- balanced superlattice alternating tensile-strained GaInAs (-0.5%) and compressive-strained GaInAsP (1%). The zero net strain allows to avoid plastic relaxation problems. Therefore the thickness of the active layer can be varied without limitation, which is not the case with the strained-layer SL active layer (4). A low polarization sensitivity (51 dB) as well as a high signal gain (22 dB) and high saturation

Process for obtaining a transistor having a silicon-germanium gate

Abstract: The process includes the deposition of a stack of Si/Si 1-x Ge x /Si layers (2, 3, 4) on a gate oxide layer (1) in a single-wafer reactor and then the etching of the gate (GR) using an inorganic mask (5). Next, the gate (GR) is encapsulated in a material (7) which is non-oxidizing with respect to germanium before the isolating spacers (8) are formed.