Patent ID: 8804700

Claim:
A method for detecting one or more predetermined tones transmitted over a communication network, each predetermined tone having a predetermined frequency, comprising: receiving a signal transmitted over the communication network; dividing the received signal into at least two frequency sub bands so as to provide at least two components of the received signal in different frequency sub bands, the different frequency sub bands being selected based on the predetermined frequencies of the one or more predetermined tones; adjusting the power of the at least two components of the received signal to a predetermined level so as to provide at least two adjusted components having a predetermined power level, wherein in adjusting the power, power level information is provided; determining a power level of each of the at least two components of the received signal using the power level information; and determining a frequency of each tone in the at least two components and providing an indication that a predetermined tone has been detected when the determined frequency of a tone in a component corresponds to the predetermined frequency of one of the one or more predetermined tones.