Abstract: A method of transmitting data packets over a transmission channel shared by transmitters on the basis of a first unit of transmission of fixed length subdivided into second units of transmission of fixed length, includes: associating, at a first transmitter, for each packet to be transmitted at least two packet replicas with respective second units within a current first unit; generating, at the first transmitter, the replicas, in each of which signaling information is included, the signaling information indicating relative positions of the other replicas of the same packet within the current first unit with respect to the given replica; setting, at the first transmitter, a start timing for beginning transmission of the current first unit independently of the other transmitters of the transmitters sharing the transmission channel; and transmitting the replicas at respective timings in accordance with their association with the respective second units within the current first unit.

Abstract: A method of transmitting data packets over a transmission channel shared by transmitters on the basis of a first unit of transmission of fixed length subdivided into second units of transmission of fixed length, includes: associating, at a first transmitter, for each packet to be transmitted at least two packet replicas with respective second units within a current first unit; generating, at the first transmitter, the replicas, in each of which signaling information is included, the signaling information indicating relative positions of the other replicas of the same packet within the current first unit with respect to the given replica; setting, at the first transmitter, a start timing for beginning transmission of the current first unit independently of the other transmitters of the transmitters sharing the transmission channel; and transmitting the replicas at respective timings in accordance with their association with the respective second units within the current first unit.

Abstract: A first aspect of the invention is a method of transmitting data packets over a transmission channel shared by a plurality of users, based on the time and/or frequency diversity slotted Aloha technique, in which at least two replicas of each packet to be transmitted are sent over said transmission channel, wherein each replica transports signaling information enabling the other replica(s) of the same packet to be located in the time and/or frequency domain. A second aspect of the invention is a method of recovering packets in the receiver, the method exploiting said signaling information to execute an interference cancellation algorithm for recovering packets corrupted by collisions caused by access conflicts. Other aspects of the invention are a transmitter equipment and a receiver packet recovery equipment adapted to use said methods.

Abstract: A method of receiving data packets asynchronously transmitted by a plurality of user terminals using a spread-spectrum medium access protocol, comprises a step of cancelling interferences between colliding packets according to an innovative “sliding window” processing algorithm. A gateway receiver is adapted for carrying out interference cancellation using this algorithm. Asynchronous packet transmission from a user terminal is controlled by estimating a parameter indicative of the quality of information transmission through a communication channel; and inhibiting or allowing data transmission depending on a comparison between said estimated parameter and an adaptively varying threshold. A user terminal comprises transmission control means adapted for carrying out such a method.

Abstract: A method of receiving data packets asynchronously transmitted by a plurality of user terminals using a spread-spectrum medium access protocol, comprises a step of cancelling interferences between colliding packets according to an innovative “sliding window” processing algorithm. A gateway receiver is adapted for carrying out interference cancellation using this algorithm. Asynchronous packet transmission from a user terminal is controlled by estimating a parameter indicative of the quality of information transmission through a communication channel; and inhibiting or allowing data transmission depending on a comparison between said estimated parameter and an adaptively varying threshold. A user terminal comprises transmission control means adapted for carrying out such a method.

Abstract: A routing method for a multiplex system implements the following operations: For the data, multiplexing N input channels each having M multiplexed packets to generate an aggregate multiplex signal comprising all data packets representing the N input multiplexes. For each of N? outputs, providing the inputs of M+L parallel selection chains with access to the aggregate multiplexed signal. For input headers, performing demodulation and decoding. For output headers, performing encoding and modulation on the basis of the demodulated and decoded input headers. For the headers and the data, selecting from n of M+L selection chains corresponding to the kth output on the basis of the input headers corresponding to n packets that are to be routed to the kth of the N? outputs, the corresponding n data packets in the aggregate multiplexed signal and multiplexing these n data packets with an output header to generate the kth output multiplex.

Abstract: The invention provides a routing method for a multiplex system having N inputs each designed to receive one of N input multiplexes each having M input channels, each of the channels serving to transport an input packet, and N′ outputs each serving to generate one of the N′ output multiplexes each made up of output channels each serving to transport an output packet, each of the M channels in use in the input multiplex comprising a data packet associated with an input header serving firstly to identify the packet and secondly to specify at least one output to which it is to be routed, wherein each of the N′ output multiplexes has M+L channels where L≧0, and wherein the method implements the following operations: