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Portable telephone system using stratified exchange system

  • US 5,210,786 A
  • Filed: 05/10/1991
  • Issued: 05/11/1993
  • Est. Priority Date: 10/15/1986
  • Status: Expired due to Term
First Claim
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1. A channel setting system in a portable telephone system, in which a plurality of i-th class exchanges, which accommodate directly or through at least one (i-1)th exchange, at least one key service unit of a plurality of portable telephone sets present in each service area, and at least one (i+1)th class exchange, which accommodates the plurality of i-th class exchanges through junction lines, are stratified to form an exchange system so that i=2, 3, 4, 5 [1, 2, 3, . . . , ] and so that the (i+1)th class exchange covers all of the service areas through the i-th class exchanges, said number i being equal to a number of stratified steps minus one, said exchange system having a function whereby information which specifies a home area predetermined from the service areas for each of the portable telephone sets and the portable telephone sets in distinction from each other is registered in a memory in each of the i-th class exchanges and in a memory in the (i-1)th class and (i+1)th class exchange which administer the home area;

  • and in which a wide area communication i-th radio base station is provided for a plurality of portable telephone sets which are connected to one of the i-th class exchanges and are capable of being called and receiving a communication signal in the same area as the service area of said one of the i-th class exchanges;

    self-identification information of each of the plurality of portable telephone sets contains self-identification information corresponding to the i-th and (i+1)th class exchanges;

    in a case where any one of the portable telephone sets is called from a calling party of an incoming call in the service area of said one of the (i-1) class or i-th class exchanges and does not answer to an incoming call signal from the key service unit in which the position of the called one of the portable telephone sets has been registered, the i-th radio base station performs wide area calling; and

    when the called one of the portable telephone sets has sent back an answer signal to said one of the (i-1)th class or i-th class exchanges through the key service unit in the service area or through some other transmitting means during a fixed period time, communication channels are set up between said one of the i-th class exchanges or any one of the (i-1), (i-2), . . . exchanges and first class radio base stations and the called one of the portable telephone sets and between the key service unit and the called one of the portable telephone sets.

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