Intercom telephone
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United States of America Patent
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-
Feb 26, 1991
Grant Date -
N/A
app pub date -
May 12, 1988
filing date -
May 12, 1988
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
An intercom system for use in combination with a multi-line telephone system wherein the intercom system utilizes the same wire pair for communications between intercom units that is used for normal telephone communications. The intercom system transmits voice signals on two or more frequency modulated channels over a wire pair of a local telephone network. Each intercom unit includes a microprocessor which controls communication activity and protocol in each unit and communicates with other intercom unit miroprocessors via a separate frequency modulated digital signal channel.
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