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Drop channel pre-alert for trunked radio communication system

  • US 5,086,507 A
  • Filed: 05/25/1989
  • Issued: 02/04/1992
  • Est. Priority Date: 05/25/1989
  • Status: Expired due to Term
First Claim
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1. In a trunked radio communications system, a method of operating plural radio frequency transceivers presently assigned for use of a radio frequency communications channel, said method comprising the following steps:

  • (a) monitoring said assigned channel for a period of non-use by said assigned transceivers and in response to the detection of said period of non-use;

    (b) transmitting a pre-alert signal on said assigned channel;

    (c) receiving said pre-alert signal present on said assigned radio frequency communications channel at each of said transceivers;

    (d) inhibiting further transmission of RF signals over said assigned communications channel by each of said transceivers but with each said transceiver continuing to monitor said assigned channel in response to receipt of said pre-alert signal;

    (e) subsequent to said receiving step (c), receiving a drop channel signal present on said assigned channel; and

    (f) each said transceiver ceasing to monitor said assigned channel in response to receipt of said drop channel signal.

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