1. A method of discriminating control signal information from non-control signal information, the control signal information for use by a communication system element, the control signal information and the non-control signal information included in one or more segments of a signal communicated over a communication system channel, the control signal information comprising signal components at one or more predetermined control signal frequencies, the non-control signal information comprising signal components at one or more information signal frequencies, the method comprising the steps of: applying a plurality of tapers to a segment of a communicated signal; performing a transform of a tapered segment; determining a similarity score based on a transform of a tapered segment and a model of a control signal, the similarity score reflecting a comparison of signal components of the communicated signal at the predetermined control signal frequencies with signal components of the communicated signal at other information signal frequencies; classifying one or more segments of the communicated signal as representing either control signal information or non-control signal information based on a similarity score; and providing an indicator signal representative of control signal information to the communication system element when the communicated signal has been classified as representing control signal information.