Portable one-way radio pager with an encoded sound signal transmitter and identification method using same

A portable one-way radio pager, comprising pager means (4, 5, 6) for receiving radio messages, a memory (8) for storing the messages, a screen (2), a keypad (3), a sound signal emitter (9), and an electronic CPU (7), the pager being designed to display on its screen at least some of the messages it receives, the sound signal emitter (9) being designed to emit sound signals in a plurality of frequencies, and the CPU (7) being designed:

• to recognize, in received messages, at least a specific message fraction referred to as a "primary code" for causing an encoded sound signal to be emitted by the sound signal emitter (9);
• to store in the memory (8) data representative of the received primary code;
• and
• as a function of commands received from a user by means of the keypad (3), to cause the sound signal emitter (9) to emit an encoded sound signal comprising a run of individual sound signals and defined by the CPU as a function at least of the primary code, said encoded sound signal varying as a function of the primary code;
• the pager being characterized in that the CPU (7) is also designed:
• to recognize at least one "certification" primary code and to display on the screen (2) a message requesting the user of said pager to enter a secondary code by means of the keypad (3);
• then to define the encoded sound signal as a function of the primary code, of an additional code accessible to the CPU, and of the secondary code entered with the keypad (3);
• and
• finally, as a function of commands received from the user by means of the keypad (3), to cause the encoded sound signal to be emitted by the sound signal emitter (9).