Method for controlling long distance calling using a multi-frequency receiver

A method for controlling long distance calling in an analog key telephone system having a multi-frequency receiver, said method comprising the steps of:

• determining whether a telephone connected within said system is in an off-hook state;
• determining whether said multi-frequency receiver is available for use, when said telephone is in said off-hook state;
• connecting said multi-frequency receiver to said telephone, when said multi-frequency receiver is available for use;
• determining whether numerical digit inputs corresponding to a complete telephone number are provided from said telephone through said multi-frequency receiver;
• determining whether said telephone is provided with a class of service that restricts long distance calling, when said numerical digit inputs corresponding to said complete telephone number are provided;
• determining whether said complete telephone number represents a long distance telephone number, when said telephone is provided with said class of service that restricts long distance calling;
• connecting a call initiated from said telephone, when said telephone is not provided with said class of service that restricts long distance calling, or when said complete telephone number does not represent said long distance telephone number;
• determining whether a predetermined time period for which said multi-frequency receiver is to be connected to said telephone between said numerical digit inputs has elapsed, when said numerical digit inputs corresponding to said complete telephone number are not provided from said telephone through said multi-frequency receiver;
• determining whether a numerical digit key of said telephone is in a depressed state, when said predetermined time period has elapsed;
• repeating said step of determining whether said numerical digit inputs corresponding to said complete telephone number are provided from said telephone through said multi-frequency receiver, when said numerical digit key of said telephone is in said depressed state;
• and
• disconnecting said multi-frequency receiver from said telephone when said numerical digit key of said telephone is not in said depressed state.

An apparatus for controlling long distance calling in an analog key telephone system, said apparatus comprising:

• a network circuit connected to a plurality of telephones within said system;
• a multi-frequency receiver connectable to each one of said telephones through said network circuit for receiving numerical digit inputs;
• and
• a controller for controlling operation of said apparatus by connecting said multi-frequency receiver to a first one of said telephones in response to an off-hook state of said first telephone, determining whether said numerical digit inputs provided from said first telephone through said multi-frequency receiver correspond to a complete telephone number, determining whether a predetermined time period for which said multi-frequency receiver is to be connected to said first telephone between said numerical digit inputs has elapsed when said numerical digit inputs provided from said first telephone through said multi-frequency receiver do not correspond to said complete telephone number, determining whether a numerical digit key of said first telephone is in a depressed state when said predetermined time period has elapsed, continuing to determine whether said numerical digit inputs provided from said first telephone through said multi-frequency receiver correspond to said complete telephone number when said numerical digit key of said first telephone is in said depressed state, and disconnecting said multi-frequency receiver from said first telephone when said numerical digit key of said first telephone is not in said depressed state.

A method for controlling long distance calling in an analog key telephone system having a multi-frequency receiver, said method comprising the steps of:

• connecting said multi-frequency receiver to a first telephone connected within said system in response to an off-hook state of said first telephone;
• determining whether numerical digit inputs provided from said first telephone through said multi-frequency receiver correspond to a complete telephone number;
• determining whether a predetermined time period for which said multi-frequency receiver is to be connected to said first telephone between said numerical digit inputs has elapsed when said numerical digit inputs provided from said first telephone through said multi-frequency receiver do not correspond to said complete telephone number;
• determining whether a numerical digit key of said first telephone is in a depressed state when said predetermined time period has elapsed;
• continuing to determine whether said numerical digit inputs provided from said first telephone through said multi-frequency receiver correspond to said complete telephone number when said numerical digit key of said first telephone is in said depressed state;
• and
• disconnecting said multi-frequency receiver from said first telephone when said numerical digit key of said first telephone is not in said depressed state.