An emitting method, by an emitting device to at least one receiving station, of UWB messages, the emitting device including a simplex communication module for the emitting of UWB messages, a module for receiving wireless electrical energy suitable for receiving emitted electrical energy and for storing the electrical energy received in an electric accumulator, the method including a charging of the electric accumulator by the module for receiving wireless electrical energy, an evaluation of a criterion of sufficient electrical energy for the emitting of a UWB message, when the criterion of sufficient electrical energy for the emitting of a UWB message is satisfied, a selecting of a random emission delay and an emitting of the UWB message, by the simplex communication module, after the expiration of the random emission delay selected.