Abstract: A terminal receives a digital content which is transmitted in the form of a data stream in a network. This digital content is received by the terminal with a reception throughput, a nominal rendering time being associated with the digital content. Activation of a trick mode corresponding to a modification of the nominal rendering time according to a modification factor associated with the trick mode is detected on the terminal. Data to be requested are then determined according to the modification factor and according to a value representative of reception throughput. The data are then requested from the network and the requested data are received.

Abstract: A method is provided for receiving a realtime data stream transmitted at a given speed in the form of packets between a transmitter and a receiver in a telecommunication network. The receiver has a buffer memory for storing the received packets. The method includes the following steps after detection of a loss of packets: requesting retransmission of the lost packets at a speed that is higher than the given speed; receiving retransmitted packets and realtime packets, the retransmitted packets having been transmitted with priority in relation to the realtime packets; and storing the retransmitted packets in the buffer memory.

Abstract: A method is provided for filtering a scalable video stream, organized in the form of data unit blocks, each of which comprises a base data unit and a set of data units distributed according to two types of enhancement data, corresponding respectively to time and/or space and/or quality characteristics and making it possible to define several quality levels. The method defines at least two distinct filtering profiles, or paths of each block data units, wherein each path defines a row of successive foldover positions and each foldover position uses at least by one less data units than a previous position, and selects one of the paths according to a predetermined criterion, taking into account the type of content of the stream and/or at least one information item representing the capacities of a terminal receiving the stream.

Abstract: A method is provided for receiving a realtime data stream transmitted at a given speed in the form of packets between a transmitter and a receiver in a telecommunication network. The receiver has a buffer memory for storing the received packets. The method includes the following steps after detection of a loss of packets: requesting retransmission of the lost packets at a speed that is higher than the given speed; receiving retransmitted packets and realtime packets, the retransmitted packets having been transmitted with priority in relation to the realtime packets; and storing the retransmitted packets in the buffer memory.

Abstract: A system for improving the reliability of transmission of multibroadcast data between a source of data and a plurality of customer receivers of the data via a telecommunications network. The system includes a supervision server adapted to provide each customer receiver with a list of at least one other receiver, said customer receiver being adapted to receive missing data from said the other customer receiver via a reliable peer-to-peer connection.

Abstract: The invention relates to a method of adapting a scalable data stream organized in blocks of data units, each comprising at least one basic data unit and at least one enhancement data unit, making it possible to define a plurality of quality and bit rate levels (N1 to N3) depending on the number and the type of data units used, each data unit being initially classified in an initial level selected from said plurality of levels. According to the invention, the method implements a regulation mechanism (8) such that, if a data unit is reclassified in a reclassification level of lower priority than the initial level of said data unit, all the data units that depend on the decoding of said reclassified data unit are also reclassified in reclassification levels where all the data units essential to their decoding are accessible.

Abstract: A terminal receives a digital content which is transmitted in the form of a data stream in a network. This digital content is received by the terminal with a reception throughput, a nominal rendering time being associated with the digital content. Activation of a trick mode corresponding to a modification of the nominal rendering time according to a modification factor associated with the trick mode is detected on the terminal. Data to be requested are then determined according to the modification factor and according to a value representative of reception throughput. The data are then requested from the network and the requested data are received.

Abstract: The invention relates to a method of adapting a scalable data stream organized in blocks of data units, each comprising at least one basic data unit and at least one enhancement data unit, making it possible to define a plurality of quality and bit rate levels (N1 to N3) depending on the number and the type of data units used, each data unit being initially classified in an initial level selected from said plurality of levels. According to the invention, the method implements a regulation mechanism (8) such that, if a data unit is reclassified in a reclassification level of lower priority than the initial level of said data unit, all the data units that depend on the decoding of said reclassified data unit are also reclassified in reclassification levels where all the data units essential to their decoding are accessible.

Abstract: The invention relates to a method of controlling data packet traffic at the input of a network, whereby the traffic comprises N streams and/or substreams which are each associated with a priority level, N=2, and each of the aforementioned packets is marked with the priority level associated with the stream or substream to which said packet belongs. The inventive method comprises a step employing a token bucket mechanism with N operating levels and N token buffers each containing a number of available tokens, the tokens of each of the N token buffers being used to process one of the N priority levels. Moreover, each of the packets is accepted or refused according to whether or not it is possible for same to be attributed tokens depending on the tokens available at least in the token buffer which is used to process the priority level of each packet.

Abstract: A system for improving the reliability of transmission of multibroadcast data between a source (10) of data and a plurality of customer receivers (201, 202, . . . , 20N) of said data via a telecommunications network (1), characterized in that said system includes a supervision server (30) adapted to provide each customer receiver with a list of at least one other receiver, said customer receiver being adapted to receive missing data from said other customer receiver via a reliable peer-to-peer connection. Application to the transmission of data in multicast mode.

Abstract: A method is provided for filtering a scalable video stream, organized in the form of data unit blocks, each of which comprises a base data unit and a set of data units distributed according to two types of enhancement data, corresponding respectively to time and/or space and/or quality characteristics and making it possible to define several quality levels. The method defines at least two distinct filtering profiles, or paths of each block data units, wherein each path defines a row of successive foldover positions and each foldover position uses at least by one less data units than a previous position, and selects one of the paths according to a predetermined criterion, taking into account the type of content of the stream and/or at least one information item representing the capacities of a terminal receiving the stream.

Abstract: The invention relates to a method of controlling data packet traffic at the input of a network, whereby the traffic comprises N streams and/or substreams which are each associated with a priority level, N =2, and each of the aforementioned packets is marked with the priority level associated with the stream or substream to which said packet belongs. The inventive method comprises a step employing a token bucket mechanism with N operating levels and N token buffers each containing a number of available tokens, the tokens of each of the N token buffers being used to process one of the N priority levels. Moreover, each of the packets is accepted or refused according to whether or not it is possible for same to be attributed tokens depending on the tokens available at least in the token buffer which is used to process the priority level of each packet.

Abstract: To increase the bit rate of transfer of information from an audiovisual base to numerous requesting parties, it is proposed, when a request has been made by a requesting party, not to meet this party's request immediately but to make him wait for a given period. During this period, those other requesting parties who are asking for the same sequence are detected. At the end of a waiting period, the same sequence is sent to all these requesting parties. It is shown that, by delaying the transmission slightly, the real bit rate of transmission from the data base is increased by very substantial proportions without the need, moreover, to modify the technology of extraction of data elements from this base.

Abstract: A television system with access control comprises a transmitter and receis. The transmitter comprises a video signal and sound signal formation circuit, means for transmitting these signals and a jamming circuit using a service key. Each receiver comprises means for receiving the transmitted signals, means for the display of the picture and for restoring the sound and an unjamming circuit connected to the reception means and working with the service key.It also comprises a subscription management center and in the transmitter a digital signal generator, a circuit for the formation of digital messages and a data broadcasting system and in the receiver a subscription card, an extraction circuit for the data, and a circuit for restoring the service key. There is also at least one subscription card loading station connected to the subscription management center.