Abstract: The invention relates to improve use of resource units in MU transmissions of an 802.1 1ax network. An un-associated station may receive data frames over a downlink resource unit, RU, assigned to an AID, e.g. 2045, reserved for stations not associated with the AP, The AP may use a downlink RU sharing an allocation scheme feature of an uplink RU previously used by the un-associated station. The AP may also aggregated data frames addressed to several stations within the same downlink RU, for instance to acknowledge frames previously received from the stations. The aggregated data frames may signal which respective response RUs the addressee stations should use for a next multi-user uplink transmission to respond to the AP. These approaches particularly applies to the exchange of management frames for instance to speed up the association procedure of un-associated stations.

Abstract: Embodiments relate to a method for controlling a video-surveillance system processing a plurality of video streams. A set of video streams is processed based on a first configuration. Upon reception of a request for processing a new video stream with requested characteristics, the available resources (network and/or processing resources) are determined. For a requested new video stream that cannot be processed with the available resources, temporary characteristics are determined based on the available resources, the temporary characteristics making it possible to process the new video stream with the available resources. A second configuration for processing the set of video streams including the requested new video stream with the requested characteristics is then determined, and the set of video streams and the new video stream with are processed with the second configuration. Embodiments also relate to a videos surveillance system comprising a processing module configured to process such a method.

Abstract: At least one embodiment of a method of configuring a video source comprising an embedded encoder for generating a stream, in a video-surveillance system comprising virtual encoders generating virtual streams, the method comprising: transcoding a reference stream generated by the video source to generate virtual streams according to distinct encoding configurations of the virtual encoders; for each of the generated virtual streams, computing a similarity distance between the corresponding virtual stream and a reference stream generated by the video source; obtaining a quality indicator relative to a task to be carried out on a stream generated by the video source; selecting an encoding configuration of a virtual encoder based on the computed similarity distances and the obtained quality indicator; and determining at least one configuration parameter value of the encoder of the video source as a function of the selected encoding configuration of the virtual encoder and of a look-up table.

Abstract: The present invention relates to determining a trajectory of a target from two streams of images obtained from two sources of images, a sub-image of each of the images of the two streams of images representing an overlapping area of a real scene. After having obtained a target path for each of a plurality of targets, from images of the sources of images, for each of the two streams of images, each target path being obtained from a target tracker associated with a source of image, each of the obtained target paths is split into a plurality of target path portions as a function of each potential target switch along the obtained target path. Then, the trajectory is generated as a function of a plurality of the target path portions.

Abstract: There is provided methods for node discovery in a network comprising the following steps: performing a first discovery process for discovering at least one first node of said network, using at least one first wireless communication parameter, adapting said at least one first wireless communication parameter, thereby obtaining at least one second wireless communication parameter coordinated with wireless communication parameters of nodes of at least one group of nodes discovered during the first discovery process, and performing a second discovery process for discovering at least one second node of said network, using said at least one second wireless communication parameter. Embodiments of the invention provide better coordination during node discovery thereby making the node discovery is thus made faster and reducing interferences between the nodes.

Abstract: The present invention provides according to one of its aspects a method of queueing a data frame in one of a plurality of traffic queues at a communication station for transmission over a communication channel in a communication network comprising a plurality stations and an access point (AP). The method comprising selecting a traffic queue based on at least one of 1) a transmission mode, direct link or uplink, of the data frame, and 2) a transmission mode of the traffic queue; and queueing the data frame in the selected traffic queue. The transmission mode of the traffic queue may be a Multi-User (MU) uplink (UL) mode if a data frame previously stored in the traffic queue has been transmitted, since a predetermined period of time, in a resource unit (RU) provided by the AP within a transmission opportunity granted to the AP on the communication channel. The transmission mode may also be a Single-User (SU) mode.

Abstract: The invention is directed to the optimization of an access to a medium in wireless networks which can be accessed by a plurality of nodes, each node of the plurality of nodes using a medium access mechanism of the Carrier Sense Multiple Access with Collision Avoidance type based on a computation of a backoff value. A specific value is associated with each node of a set of nodes of the plurality of nodes, the specific value of a node being known by the other nodes of the set of nodes. According to the invention, a backoff value is determined for each node of the set of nodes, in each node of the set of nodes, the backoff value associated with a node being determined as a function of the specific value associated with that node.

Abstract: At least one embodiment of a method of configuring a video source comprising an embedded encoder for generating a stream, in a video-surveillance system comprising virtual encoders generating virtual streams, the method comprising: transcoding a reference stream generated by the video source to generate virtual streams according to distinct encoding configurations of the virtual encoders; for each of the generated virtual streams, computing a similarity distance between the corresponding virtual stream and a reference stream generated by the video source; obtaining a quality indicator relative to a task to be carried out on a stream generated by the video source; selecting an encoding configuration of a virtual encoder based on the computed similarity distances and the obtained quality indicator; and determining at least one configuration parameter value of the encoder of the video source as a function of the selected encoding configuration of the virtual encoder and of a look-up table.

Abstract: The present disclosure relates to processing images representing a real scene, the images comprising at least two images obtained from at least two sources of images, a sub-image of each of the at least two images representing an overlapping area of the real scene. A role map comprising a plurality of parts, all the points of each part of the role map being associated with a single identifier of a source of images, is generated during a training phase. To process the images, parts of the role map are selected as a function of an identifier of a considered source of images, and sub-images of an image obtained from the considered source of images are processed, the processed sub-images corresponding to the selected parts of the role map.

Abstract: Embodiments relate to a method for controlling a video-surveillance system processing a plurality of video streams. A set of video streams is processed based on a first configuration. Upon reception of a request for processing a new video stream with requested characteristics, the available resources (network and/or processing resources) are determined. For a requested new video stream that cannot be processed with the available resources, temporary characteristics are determined based on the available resources, the temporary characteristics making it possible to process the new video stream with the available resources. A second configuration for processing the set of video streams including the requested new video stream with the requested characteristics is then determined, and the set of video streams and the new video stream with are processed with the second configuration. Embodiments also relate to a videos surveillance system comprising a processing module configured to process such a method.

Abstract: The present invention relates to determining a trajectory of a target from two streams of images obtained from two sources of images, a sub-image of each of the images of the two streams of images representing an overlapping area of a real scene. After having obtained a target path for each of a plurality of targets, from images of the sources of images, for each of the two streams of images, each target path being obtained from a target tracker associated with a source of image, each of the obtained target paths is split into a plurality of target path portions as a function of each potential target switch along the obtained target path. Then, the trajectory is generated as a function of a plurality of the target path portions.

Abstract: The present invention concerns a method and a device of transmitting uncompressed video streams. In particular, the method concerns the adaptation of a wireless transmission to bandwidth reduction and packet loss. There is provided a computer implemented method for sending uncompressed video data, wherein the video data comprises binary video components, the method comprising generating a plurality of SB packets from a group of video components, each SB packet being constituted by bits of the video components grouped according to their significance; determining available bandwidth for transmission and sending the most SB packets to fit the available bandwidth, beginning by the most significant ones, meaning containing the most significant bits of the video components. Accordingly, the best possible quality is obtained according to the available bandwidth.

Abstract: The present disclosure relates to processing images representing a real scene, the images comprising at least two images obtained from at least two sources of images, a sub-image of each of the at least two images representing an overlapping area of the real scene. A role map comprising a plurality of parts, all the points of each part of the role map being associated with a single identifier of a source of images, is generated during a training phase. To process the images, parts of the role map are selected as a function of an identifier of a considered source of images, and sub-images of an image obtained from the considered source of images are processed, the processed sub-images corresponding to the selected parts of the role map.

Abstract: The present invention relates to communication between collaborative nodes configured to collaboratively communicate in a radio network. A corresponding method comprises: sending, by each active node of the set of collaborative nodes, an RTS message for the same transmission slot; sending, by one of the active nodes, referred to as coordinator node, a CTS message to acknowledge reservation of said transmission slot on behalf of all the active nodes, upon receiving the RTSs; wherein the transmission slot is divided, based on the sent RTSs, into sub-slots for respective active nodes to transmit data packets. The invention provides an improved use of the reserved transmission slot, and a reduced waste of reserved time.

Abstract: The present invention a method of transmitting video information over a communication link made of several transmission paths between wireless transmitting and receiving stations. The method comprises, in the wireless transmitting station, obtaining an uncompressed video frame made of an array of pixel blocks, a pixel in the pixel blocks being represented by base pixel information and enhancement pixel information; generating at least one set of complementary pixel blocks from a given pixel block of the obtained uncompressed video frame, by applying different operations to said given pixel block for dropping different enhancement pixel information from that pixel block, so that the complementary pixel blocks comprise different enhancement pixel information and each comprises the base pixel information; and for each set, transmitting the complementary pixel blocks over respective different transmission paths to the wireless receiving station.

Abstract: There is provided methods for node discovery in a network comprising the following steps: performing a first discovery process for discovering at least one first node of said network, using at least one first wireless communication parameter, adapting said at least one first wireless communication parameter, thereby obtaining at least one second wireless communication parameter coordinated with wireless communication parameters of nodes of at least one group of nodes discovered during the first discovery process, and performing a second discovery process for discovering at least one second node of said network, using said at least one second wireless communication parameter. Embodiments of the invention provide better coordination during node discovery thereby making the node discovery is thus made faster and reducing interferences between the nodes.

Abstract: A data stream is transmitted from a transmitting device to a receiving device via a communication network. Data of the data stream is transmitted to the receiving device by using a transport protocol without data acknowledgement. In a transmission method, parity-encoding parameters for parity encoding a data set of the data stream is determined via the transmitting device. The transmitting device also generates parity data from the data set by using the determined parity-encoding parameters. The transmitting device further transmits the generated parity data to the receiving device via the communication network by using a transport protocol with data acknowledgement.

Abstract: The invention is directed to the optimization of an access to a medium in wireless networks which can be accessed by a plurality of nodes, each node of the plurality of nodes using a medium access mechanism of the Carrier Sense Multiple Access with Collision Avoidance type based on a computation of a backoff value. A specific value is associated with each node of a set of nodes of the plurality of nodes, the specific value of a node being known by the other nodes of the set of nodes. According to the invention, a backoff value is determined (505, 510) for each node of the set of nodes, in each node of the set of nodes, the backoff value associated with a node being determined as a function of the specific value associated with that node.

Abstract: The present invention concerns a method and a device of transmitting uncompressed video streams. In particular, the method concerns the adaptation of a wireless transmission to bandwidth reduction and packet loss. There is provided a computer implemented method for sending uncompressed video data, wherein the video data comprises binary video components, the method comprising generating a plurality of SB packets from a group of video components, each SB packet being constituted by bits of the video components grouped according to their significance; determining available bandwidth for transmission and sending the most SB packets to fit the available bandwidth, beginning by the most significant ones, meaning containing the most significant bits of the video components. Accordingly, the best possible quality is obtained according to the available bandwidth.

Abstract: A transmitting apparatus transmits a plurality of data packets to a receiver in a communication system, by transmitting one or more data packets from a list of data packets to be transmitted, and determining whether an acknowledgment is received for each transmitted data packet. When it is determined that an acknowledgement has not been received for at least one data packet, referred to as an unacknowledged data packet, the apparatus selects one or more additional data packets from the list of data packets to be transmitted, generates one or more parity packets by encoding a block of data containing a combination of the selected one or more additional data packets and at least one unacknowledged data packet using a forward error correction scheme, and transmits at least one of the generated parity packets.