Apparatus and method for identifying communications signal in preceding stage for communications modem

An apparatus for identifying a communication signal in a preceding stage for a communication modem, the apparatus comprising:

• a port for receiving the communication signal;
• and
• a communications signal identifying unit configured to receive the communication signal, deliver data included in the communication signal to the communication modem, and sample the communication signal which has passed through the port to detect a first pattern whose amplitude during a first length is greater than a predetermined amplitude and a second pattern whose amplitude during a second length longer than the first length is smaller than the predetermined amplitude,
• wherein, when a length from the first pattern to the second pattern is equal to or smaller than a reference length, the communications signal identifying unit delivers a data process stopping signal to the communication modem such that the communication modem stops a data reading operation.

A method for identifying a communication signal in a preceding stage for a communication modem, the method comprising:

• converting an analog communication signal into a digital communication signal;
• sampling the digital communication signal during every unit length to detect a unit length pattern corresponding to a start of communication;
• delivering the digital communication signal to the communication modem and counting a length of the digital communication signal after detecting the unit length pattern corresponding to the start of communication;
• sampling the digital communication signal at every unit length to detect a unit length pattern corresponding to an end of communication;
• and
• when a length from the start of communication to the end of communication is equal to or smaller than a reference length, initializing the communication modem.