发明授权
- 专利标题: Far-end disconnect detector for telephony systems
- 专利标题(中): 用于电话系统的远端断开检测器
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申请号: US134497申请日: 1993-10-08
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公开(公告)号: US5479501A公开(公告)日: 1995-12-26
- 发明人: Daniel T. Lai
- 申请人: Daniel T. Lai
- 申请人地址: CA Santa Clara
- 专利权人: Rolm Systems
- 当前专利权人: Rolm Systems
- 当前专利权人地址: CA Santa Clara
- 主分类号: H04M3/533
- IPC分类号: H04M3/533 ; H04Q1/44 ; H04M1/00
摘要:
Method and apparatus for detecting a far-end disconnect signal for use by telephony applications such as voice messaging systems. In a preferred embodiment of the present invention, signal power of a telephone signal in particular frequency ranges is compared with the signal power in these frequency ranges for characteristic far-end disconnect signals used by telephone systems worldwide. Further, the cadence of the signal power of the telephone signal is examined to determine whether the cadence of the telephone signal is characteristic of far-end disconnect signals, including "busy signals" and "dial tones."
公开/授权文献
- US4854429A Variable rate shock absorber and system therefor 公开/授权日:1989-08-08
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