发明公开

  • 专利标题: Compression of a PCM facsimile signal for transmission in a packet switching network
  • 专利标题(中): FaksimilekomprimierungfürÜbertragung。
  • 申请号: EP90311489.0
    申请日: 1990-10-19
  • 公开(公告)号: EP0426336A2
    公开(公告)日: 1991-05-08
  • 发明人: Anderton, David O.Daggett, Ronald L.
  • 申请人: AT&T Corp.
  • 申请人地址: 32 Avenue of the Americas New York, NY 10013-2412 US
  • 专利权人: AT&T Corp.
  • 当前专利权人: AT&T Corp.
  • 当前专利权人地址: 32 Avenue of the Americas New York, NY 10013-2412 US
  • 代理机构: Buckley, Christopher Simon Thirsk
  • 优先权: US428560 19891030
  • 主分类号: H04N1/32
  • IPC分类号: H04N1/32 H04N1/41
Compression of a PCM facsimile signal for transmission in a packet switching network
摘要:
A transmission arrangement is disclosed which facilitates compression of modem modulated facsimile signals for transmission on digital facilities. The presence of a facsimile call is detected and facsimile control messages are obtained by demodulating and interpreting the facsimile call control protocol (111). A controller (114) is responsive to the obtained control messages for controlling a voiceband encoder (110) to encode the control portion of the facsimile call and for controlling a so-called facsimile page demodulator (112) to demodulate any facsimile page portions of the facsimile call to obtain a baseband digital bit stream. The encoded control portion of the facsimile call and the baseband digital bit stream representative of the demodulated, i.e. compressed, facsimile page portion of the facsimile call are transmitted along with control information (as side information) to a receiver (103). At the receiver, a replica of the original modem modulated facsimile signal is reconstructed in response to the control information and by decoding the control portion of the facsimile call and by remodulating the digital bit stream representative of the facsimile page portion of the facsimile call.
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