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.

Method for establishing a multimedia session between a caller device and a receiver device of a multimedia sub-domain type network and a communications system implementing said method

Abstract: A method for establishing a multimedia session between a calling telecommunications equipment and a called equipment that is a mobile equipment of a network of the multimedia sub-domain type, wherein: an invitation (Invite) is sent from the first user equipment (UE 1 ) to establish a multimedia session, which comprises as he destination address a public identity of the second equipment, said invitation being transmitted: by the first equipment (UE 1 ) to a first proxy server (P-CSCF 1 ), then, from this first proxy server, to a first session control server (S-CSCF 1 ) of the network in which the first equipment (UE 1 ) is registered, and from this first session server (S-CSCF 1 ) to a point of entry server (I-CSCF 2 ) of the network corresponding to the destination address of the second equipment (UE 2 ); this point of entry server (I-CSCF 2 ) interrogates a database (HSS 2 ) of the network of the second equipment (UE 2 ) in order to obtain the address of a session control server (S-CSF 2 ) responsible for said second equipment (UE 2 ); when said second equipment (UE 2 ) is registered in said database: said point of entry server (I-CSCF 2 ) transmits the invitation message to the selected session server (S-CSCF 2 ), and said session server (S-CSCF 2 ) transmits the invitation message to a proxy server (P-CSCF 2 ) corresponding to the second equipment, wherein the proxy server (P-CSCF 2 ) transmits this invitation message by encapsulating it in an IP packet to the second equipment via an appropriate transit node (GGSN).

On the properties of a time-varying quasi-harmonic model of speech.

Abstract: In this paper we present the properties of a parametric speech model based on a deterministic plus noise representation of speech initially suggested by Laroche et al. [1]. Aiming at a high resolution analysis of speech signals for voice quality control (transformation) and assessment, we focus on the deterministic representation and we reveal the properties of the model showing that such a representation is equivalent to a time-varying quasi-harmonic representation of speech. Results show that the model is appropriate in estimating accurately linear amplitude modulations and modeling the inharmonicity of speech.

Sketch-Based Images Database Retrieval

Abstract: This paper describes an application allowing content-based retrieval that can thus be considered as an MPEG-7 example application. The application may be called "sketch-based database retrieval" since the user interacts with the database by means of sketches. The user draws its request with a pencil: the request image is then a binary image that comprises a contour on a uniform bottom.

Transmit Correlation-aided Scheduling in Multiuser MIMO Networks

Abstract: The problem of joint scheduling and beamforming for a multiuser multiple-input multiple-output (MIMO) network with partial channel state information at the transmitter (CSIT) is addressed here. Unlike most previous work that rely on full instantaneous CSIT and require inacceptable overhead feedback to the transmitter, we point out here that useful information relevant to the scheduler lies untapped in the long term statistical information of the user's channels. We show how statistical CSIT can be efficiently combined with partial instantaneous CSIT to derive a scheduling rule for the downlink of multiuser MIMO systems.

Impact of Clear Channel Assessment Mode on the Performance of ZigBee Operating in a WiFi Environment

Abstract: ZigBee is a standard optimised for radio networks used in applications such as interconnecting sensors, monitoring and automating home, medical, industrial, and agricultural systems where low levels of data throughput and low-power consumption are needed. The Physical (PHY) and Medium Access Control (MAC) layers of ZigBee are defined by the IEEE 802.15.4 standard. One of the operational frequency bands of ZigBee is the unlicensed 2.4 GHz Industrial, Scientific and Medical (ISM) band which is also used by WiFi. Several ZigBee and WiFi devices may operate in the same environment, which may result in the two systems performance degradation. Before transmitting, WiFi and ZigBee devices perform the Clear Channel Assessment (CCA) according to three different modes defined in the standards. In this paper, ZigBee throughput is obtained for the different CCA modes used by both ZigBee and WiFi systems operating in the same environment. Simulation results show that, ZigBee performance can be optimised by choosing the suitable CCA mode with respect to the interference level at the receiver.