Koninklijke Philips Corporation N.V.

Frank Van Dam

Franciscus J M Thus

Evert M Bosma

In known telephone subscriber end stations a caller_ID IC detects a tone alerting signal TAS alerting that successive caller_ID information can be received for displaying on a display of the phone. The known station applies narrow frequency band filters to detect tones indicating the end of TAS. Such a detection is not flexible as it can only be used for a specific caller_ID signal protocol. A flexible detector is proposed which can easily be adapted to widely varying protocols and which can also be used for other purposes such as the detection of power drops in an FSK signal. The detector comprises means for determining a time-domain signal representing the signal energy of a signal on the subscriber line in a predetermined time interval.

Growing community of inventors

Adliswil, Switzerland

Frank Van Dam