发明名称 |
Switching system having tone trunk |
摘要 |
A switching system having a tone trunk which stores, in the digital memory thereof, a predetermined digital tone signal in the form of digital codes for supplying the corresponding analog tone signal to telephone sets of subscribers. The digital codes have been coded in such a way that the analog tone signal is accompanied by a quantizing noise having a characteristic of white noise.
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申请公布号 |
US4680758(A) |
申请公布日期 |
1987.07.14 |
申请号 |
US19860845587 |
申请日期 |
1986.03.28 |
申请人 |
FUJITSU LIMITED |
发明人 |
KUMAZAKI, MASAYUKI;SHIMOE, TOSHIO;MURAKAMI, KOSO |
分类号 |
H04M19/02;H03M1/08;H03M1/12;H04B14/04;H04Q1/448;(IPC1-7):H04J3/12 |
主分类号 |
H04M19/02 |
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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