发明名称 |
SYSTEM AND METHOD FOR DETECTING TELEPHONE LINE EVENTS |
摘要 |
A device connectable to a telephone line including detection circuitry for detecting telephone line events, such as telephone line-in-use, extension pick-up, and remote hang-up. The telephone line events are detected by monitoring the line voltage and loop current transmitted through the telephone line from a central office. A voltage sensor is connected to the telephone line to detect changes in the line voltage appearing in the telephone line. The changes detected in the line voltage are used in a line-in-use detection circuit to determine if the telephone line is already being used by another extension, while changes in loop current are used in a remote hang-up detection circuit to determine when a remote party ends their connection with the telephone line. An extension pick-up circuit is further provided for sensing changes in the telephone loop current in order to determine if a telephone extension has been picked up. If any of the circuits sense that one of these telephone conditions has occurred, the device may then change its mode of operation.
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申请公布号 |
WO9965220(A1) |
申请公布日期 |
1999.12.16 |
申请号 |
WO1999US13331 |
申请日期 |
1999.06.11 |
申请人 |
CONEXANT SYSTEMS, INC. |
发明人 |
GIZARA, ANDREW, R.;FRANKLAND, ROBERT, W. |
分类号 |
H04M11/06;(IPC1-7):H04M11/06 |
主分类号 |
H04M11/06 |
代理机构 |
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主权项 |
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地址 |
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