Call progress monitor circuitry and method for a communication system
First Claim
1. A communication system, comprising:
- phone line side circuitry that is capable of being coupled to phone lines;
powered side circuitry that is capable of being coupled to said phone line side circuitry through an isolation barrier; and
a call progress monitor circuit within said powered side circuitry coupled to oversampled digital transmit and receive data to provide a call progress signal.
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Accused Products
Abstract
A call progress monitor circuit is disclosed for a digital DAA in which digital information is transmitted across an isolation barrier from phone line side circuitry to powered side circuitry. In particular, the call progress monitor circuit of the present invention converts oversampled digital transmit and receive data into analog transmit and receive signals and then combines them to produce a call progress signal that is provided to be fed to a speaker driver circuit. In addition, the call progress signal in one embodiment is filtered with a low pass filter. The call progress monitor circuit in one embodiment includes oversampled digital-to-analog converters, a summing circuit, and a low pass filter. Corresponding methods for monitoring the progress of a call utilizing oversampled digital transmit and receive signals are also disclosed.
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Citations
18 Claims
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1. A communication system, comprising:
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phone line side circuitry that is capable of being coupled to phone lines;
powered side circuitry that is capable of being coupled to said phone line side circuitry through an isolation barrier; and
a call progress monitor circuit within said powered side circuitry coupled to oversampled digital transmit and receive data to provide a call progress signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for monitoring call progress in a communication system that is capable of being coupled to phone lines, comprising:
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coupling an isolation barrier between powered side circuitry and phone line side circuitry that is capable of being coupled to phone lines;
digitizing analog receive signals to produce oversampled digital receive data;
producing oversampled digital transmit data; and
monitoring said oversampled digital transmit and receive data to provide an analog call progress signal. - View Dependent Claims (10, 11, 12)
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13. A call progress monitor circuit within a communication system that is capable of being coupled to phone lines, comprising:
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digital-to-analog converters coupled to oversampled digital transmit and receive data to produce analog transmit and receive signals; and
a summing circuit coupled to combine said analog transmit and receive signals and having an analog call progress signal as an output. - View Dependent Claims (14, 15)
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16. A method for monitoring call progress in a communication system that is capable of being coupled to phone lines, comprising:
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converting oversampled digital transmit and receive data into analog transmit and receive signals; and
generating an analog call progress signal from said analog transmit and receive signals. - View Dependent Claims (17, 18)
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Specification