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Universal wireless radiotelephone system

  • US 5,574,775 A
  • Filed: 10/25/1994
  • Issued: 11/12/1996
  • Est. Priority Date: 08/04/1993
  • Status: Expired due to Fees
First Claim
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1. A method of selectively operating a mobile subscriber handset in a wide service area and in a local service area system:

  • comprising the steps of;

    initializing a mobile radiotelephone upon power turn on by;

    investigating if local service is enabled;

    investigating if cellular service is enabled if local service has not been enabled;

    determining which service is enabled and acquiring a valid channel for radiotelephone communications;

    checking for a valid system ID with the local/cellular service that is enabled;

    establish an active call state with the local/cellular service that is enabled; and

    when transiting from a local area to a wide area service area;

    transferring service from a local service area to a wide area service area by a handoff operation which includes the steps of;

    detecting an impairment in signal strength of a call in progress;

    providing notification to a handset user of a desirability of a hand-off;

    enabling the handset user to initiate and control an occurrence of the desired hand-off;

    retuning the handset in response to user enabling to acquire a cellular set up channel while continuing to communicate with the local service area station;

    detecting a page from a wide service area station and issuing a page response from the handset;

    assigning a voice channel in the wide area system and tuning the handset to that channel.

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