Toll restrictor for a time division telecommunication system
AssigneeInternational Telephone and Telegraph Corporation
InventorAndrew Kontomerkos
Life of this patent
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Abstract
A toll restrictor is disclosed for use with a time division multiplex telephone switching system. The restrictor disclosed may serve an entire exchange, the restrictor having digit storage capability for each time slot used. The restrictor is capable of refusing or accepting a first digit and as many as six additional digits in the form of codes. Decisions by the restrictor are made on the basis of conditions programmed within the restrictor apparatus. Calls are completed or not depending on the decisions of the restrictor.
Claims9
A toll restrictor for use with a TDM switching system, adapted to receive digits representing calling information for generating restrictor initiating signals, and comprising:
- a decoder, said decoder responding to said restrictor initiating signals for generating and transmitting a first coded signal to enable intitiation of a restricting function and to maintain the restricting function during the receipt of digits from a calling station, first memory means, interface circuits coupled responsive to said first coded signal to transmit digits received from a calling station to said first memory means, second memory means containing data identifying restrictions applicable to all potential calling stations, comparison means coupled to said first memory means and to said second memory means, said comparison means providing additional signals to said system indicating whether a call from said calling station may be allowed or denied and said decoder responsive to said additional signals to clear said restricting function.
A call restrictor for a telephone system employing time division switching, said restrictor including a decoder responsive to call data representing called and calling station information for generating a restriction enabling signal, first memory means responsive to said signal for storing data of the calling station information, second memory means for storing restriction data, comparison means enabled responsive to the storage of data in said first memory means for comparing data from said first memory means against data from said second memory means to produce coded output signals, logic means responsive to said output signals to allow or deny the call represented by said call data or to continue operation of said comparison means for comparing further digits of said call data with data from said second memory means, said decoder responsive to output signals indicating allow or deny to terminate said restriction enabling signal.
Dependencies are inferred from the claim text.