Configurable parameter DTMF detector
Patent 5163050 Issued on November 10, 1992. Estimated Expiration Date: 
January 23, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 23, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesRemote supervisory monitoring and control system Method and apparatus for facilitating moves and changes in a communication system Failing resource manager in a multiplex communication system Remote supervisory monitoring and control apparatus connected to monitored equipment Distributed control and storage for a large capacity messaging system Patent #: 5029199 InventorAssigneeApplicationNo. 644934 filed on 01/23/1991US Classes:370/526, Digital tone detection379/88.07, Digital signal processing (DSP)379/88.26, Recording voice message from non subscriber caller379/339, With signal conversion (e.g., dial to DTMF, analog to PCM)379/351Signalling integrity protection (e.g., voice signal immunity)ExaminersPrimary: Olms, Douglas W.Assistant: Samuel, T. Attorney, Agent or FirmInternational ClassH04J 003/12AbstractIn a digital messaging system (10), an apparatus (37) and method for determining whether a DTMF (Dual Tone Multi Frequency) digit is present on an input signal (11,12). A heuristics engine (37) performs a series of tests on the input signal (11,12) using a set of parameters that are stored in a RAM (38). There is one parameter for each of a set of input signal (11,12) characteristics and for each of a set of operating modes of the digital messaging system (10). All of the parameters are configurable. The configurability allows for the use of non-standard telephone equipment (13,14) and minimizes deleterious effects such as talkoff. The tests are from the set of sets comprising an absolute magnitude test, a frequency deviation test, a twist test, an echo test, a consistency test, and a temporal test. | |
