专利名称：Method and apparatus for sending a data
message to a selected station during a silentinterval between ringing
发明人：Carolyn A. Doughty申请号：US06/512955申请日：19830712公开号：US04551581A公开日：19851105
摘要：For use with a telephone switching system serving a plurality of stations andhaving a central processor for generating data messages and a ringing circuit forgenerating ringing signals to a selected station, method and apparatus are disclosed forsending a data message to a selected station during a silent interval between ringingsignals. The apparatus includes a detector and a sender. Responsive to a first ringingsignal, the detector generates a status signal representative of the silent intervalbetween ringing signals. During the silent interval, the sender sends to the selectedstation a frequency shift keyed signal representative of the data message.
申请人：AT&T BELL LABORATORIES
代理人：Richard J. Godlewski
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