发明名称 |
Method and apparatus for detecting a telephone CPE alerting signal |
摘要 |
A method and apparatus for verifying that a CAS (Customer Premises Equipment Alerting Signal) detect signal, which indicates the presence of a CAS on a transmission channel, is a valid detect signal, includes structure and process steps for suppressing a signal originating at a local telephone in response to the CAS detect signal. A determination is made whether the CAS detect signal remains in a predetermined condition at a predetermined time after the local telephone signal is suppressed. A validity signal is output when the CAS detect signal remains in the predetermined condition at the predetermined time. False detections are thereby minimized by ignoring detections caused by a signal originating at the local telephone.
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申请公布号 |
US6122353(A) |
申请公布日期 |
2000.09.19 |
申请号 |
US19970892102 |
申请日期 |
1997.07.14 |
申请人 |
CIDCO INCORPORATED |
发明人 |
BRADY, ROBERT H.;ZIELSKI, DAVID;NUTTER, WILLIAM L.;MARRA, ALEXANDER J. |
分类号 |
H04M1/57;H04M3/428;H04M19/04;(IPC1-7):H04M1/56 |
主分类号 |
H04M1/57 |
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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