LOW FREQUENCY SIGNALS GENERATING DEVICE FOR RECOGNIZING TELEPHONE SETS AND METHOD THEREOF

摘要

PURPOSE: A low frequency signals generating device for recognizing telephone sets and a method thereof are provided to define and use a specific protocol only between two telephone sets, so as to eliminate the unpleasantness of a user due to the exchange of recognition signals when an apparatus setting a call through a PSTN(Public Switched Telephone Network) directly recognizes types of the telephone sets. CONSTITUTION: A low frequency signals generating device transmits corresponding DTMF(Dual Tone Multi Frequency) band signals to a receiving telephone set through a transmitting telephone set of a PSTN composed of the receiving and transmitting telephone sets and an exchange, to establish a call with the receiving telephone set and enable the recognition of telephone types with each other through a configured speech path network. In the device, an analog interface(130) transmits and receives low frequency signals connected to a line of the speech path network. A codec(140) converts the low frequency signals inputted to the analog interface(130) into digital signals, or converts digital signals into analog signals. And a control processor(150) recognizes the telephone sets through corresponding bands of low frequency attenuating signals stored in a memory(160), or calls low frequency attenuating signals corresponding to the telephone sets.