Method for transmitting and receiving downlink messages with implicit identification of recipients

A method for transmitting a downlink message on a downlink between an access network and a plurality of terminals, the downlink message formed from traffic data to be transmitted to an addressee terminal, the method comprising steps of:

• generating error detection data from the traffic data;
• modifying at least one of the traffic data and the error detection data on a basis of an identifier of the addressee terminal, by a predefined reversible modification function, said modification is made at a constant spectral width and at a constant duration in relation to at least one of the traffic data and the error detection data;
• transmitting, by a base station of the access network, the downlink message comprising the traffic data and the error detection data obtained after the modification;
• and
• wherein the downlink message is transmitted in response to an uplink message previously received from the addressee terminal, the identifier of the addressee terminal is a temporary identifier determined from control data included in the uplink message.