发明名称 |
Busy/no-answer call completion equipment |
摘要 |
Apparatus for recognizing a telephone call supervision signal by comparing its frequency and cadence to the frequency and cadence of a previously learned call supervision signal is provided as part of call completion equipment (10). Call progress tone detector (50) receives a call supervision signal and responds by outputting frequency parametric signals which indicate whether predetermined standard frequencies are present in the received signal. Microprocessor (74) determines the cadence of the received call supervision signal and outputs a corresonding cadence parametric signal. If it is beneficial to learn the received call supervision signal, the frequency and cadence parameters are stored in memory (78). Recognition circuits can then recognize a subsequent telephone call supervision signal by comparing its frequency and cadence parameters to the frequency and cadence parameters stored in memory (78) for at least one learned signal.
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申请公布号 |
US4935958(A) |
申请公布日期 |
1990.06.19 |
申请号 |
US19880286273 |
申请日期 |
1988.12.19 |
申请人 |
DYTEL CORPORATION |
发明人 |
MORGANSTEIN, SANFORD J.;MEHTA, BAKULESH A.;KRAKAU, HERBERT B.;MILSTED, NEIL F. N.;KLECKA, MARK D. |
分类号 |
H04M3/436;H04M3/51;H04M3/527;H04M3/533;H04M3/537;H04M3/54;H04Q3/62 |
主分类号 |
H04M3/436 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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