Automatic call distribution system

• US 4,048,452 A
• Filed: 05/28/1976
• Issued: 09/13/1977
• Est. Priority Date: 05/28/1976
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Rossomando, Philip Joseph, Oehring, Hans
• Primary Examiner(s): Cooper, William C.
• Application Number:
  US05/690,995
• Time in Patent Office: 473 Days
• Field of Search: 179/27 D, 179/27 DB
• US Class Current: 379/111
• CPC Class Codes: H04M 3/523 with call distribution or queueing
• CPC Class Codes: H04M 3/5237 Interconnection arrangements between ACD systems

Abstract

A telephone switching arrangement is disclosed incorporating means for automatically distributing calls among a plurality of groups of call answering consoles. In the disclosed arrangement, which may be part of a telephone central office or may be located in a remote location such as a customer'"'"'s premises, a directory number and a queuing register are assigned to each group of call answering consoles. Incoming calls for a particular directory number are queued in the associated queuing register and when a console of the assigned group of consoles is available, a connection is established to the available console from the line or trunk associated with a call in the queuing register. The time in queue for each call is measured and compared against upper and lower time thresholds. When the measured time in queue of a call exceeds the upper threshold, that call will be directed to an answering console associated with another directory number provided that the measured time in queue for the oldest call in the queuing register assigned to that directory number is less than the lower time threshold.

Claims

1. Telephone call handling apparatus for use in combination with a plurality of telephone lines and a plurality of groups of call answering stations, and comprising:

detection means for detecting from said lines dialing signals defining a called number identifying one of said groups of call answering stations;

clock means for generating time signals defining present time;

means for recording the identity of a line from which dialing signals defining a called number are detected by said detection means and for recording time signals generated by said clock means and representing time of request for said called number;

circuit means for comparing said recorded time signal with current time signals generated by said clock means, and for generating difference signals defining a time difference between said recorded time signals and said current time signals;

means for generating time trigger signals defining numerical constants representing first and second time triggers;

means for comparing said difference signals and said time trigger signals for generating a first output signal when the numerical value represented by said difference signals exceeds the numerical value of said first time trigger and for generating a second output signal when the numerical value represented by said difference signals is less than the numerical value of said second time trigger;

means responsive to said first output signal generated with respect to time of request for a first called number and said second output signal generated with respect to time of request for a second called number to connect a line from which dialing signals defining said first called number are detected to a call answering station of the group of call answering stations identified by said second called number.

2. A telephone call processing arrangement comprising:

first and second groups of telephone call answering stations;

a plurality of incoming lines;

means for detecting requests for connections to said stations from said incoming lines;

clock means for generating signals representative of present time;

interconnect means for selectively establishing talking path connections between said lines and said call answering stations in response to control signals;

register means for storing signals representative of the time of initiation of requests from said incoming lines;

means for generating signals defining numerical values representing an upper time trigger;

means responsive to said clock signals and said initiation time signals for generating elapsed time signals representing the time elapsed since initiation of request from a specified one of said lines;

comparing means for comparing said elapsed time signals and said signal representing said time trigger and for generating a first output signal when the elapsed time for a line requesting connection to a station of said first group exceeds said upper time trigger; and

a controller responsive to said first output signal for generating control signals for controlling said interconnect means to connect a line requesting connection to a station of said first group to a station of said second group.

3. A telephone call processing arrangement in accordance with claim 2, and further comprising means for generating signals defining numerical values representing a lower time trigger, and wherein said comparing means generates a second output signal when the elapsed time for a line requesting connection to a station of said second group is less than said second time trigger, and said controller is responsive to said first and second output signals to generate control signals to control said interconnect means to connect a line requesting connection to a station of said first group to a station of said second group.

4. Telephone call answering apparatus comprising:

first and second call answering stations;

a plurality of incoming telephone lines;

an interconnecting circuit responsive to control signals for selectively interconnecting said lines and said stations;

detection means for detecting signals from said lines defining a request for connections to said stations;

a clock counter and means for periodically incrementing said clock counter;

first and second register means associated with said first and second stations respectively for storing the state of said clock counter when a request for connection to the associated station is detected by said detection means for storing the identity of the incoming line from which the request was detected;

means for computing the difference value between the numerical value of the current state of said counter and the states of said counter stored in said register means;

means for defining an upper numerical value and a lower numerical value for said difference value;

comparator means for comparing said difference value with said upper and lower numerical values and for generating an output signal when the difference value computed on the basis of a clock state stored in said first register exceeds said upper numerical value and the difference computed on the basis of a clock state stored in said second register is less than said lower numerical value;

controller means responsive to said output signal for generating control signals to control said interconnect means to connect an incoming line requesting connection to said first station to said second station.

5. Telephone call answering system comprising:

a switching network;

a plurality of telephone lines and a plurality of groups of call answering stations, each group having associated therewith a queuing register;

a clock counter and means for periodically incrementing said counter;

means for detecting requests for connection to said groups of stations from said lines and for storing in the queuing register associated with the group of stations to connection is requested, the identity of the requesting line and the state of said clock counter at the time that the request was detected;

logic circuit means for comparing the state of said clock counter stored in a queuing register and the actual state of the clock counter and for generating a data word representing the difference values between the actual state of said counter and the states of said counter recorded in said queuing registers;

register means for storing data words defining an upper and lower value for said difference value;

comparator means for comparing said data word defining said difference value with said data words defining said upper and lower values and for generating and recording a first output signal when the difference value exceeds said upper value and for generating a second output signal when said difference value is less than said lower value;

controller means responsive to said second output signal and said recorded first output signal to connect a line identified in a first queuing register to a call answering station of a group of stations associated with another queuing register.

6. An automatic call distribution system comprising:

a plurality of incoming lines;

a plurality of storage registers each being associated with a unique directory number;

a call answering station individually associated with each of said registers;

a clock counter for defining present time and means for periodically incrementing said counter;

means for detecting from said incoming lines signaling information defining called directory numbers and for storing in the one of said storage registers associated with the detected number the identity of the line from which the signaling information is detected, and the state of said clock counter at time of detection;

logic circuit means for comparing the current state of said counter with a prior state of said counter stored in one of said registers and for generating difference signals representing a value of elapsed time;

means for generating first and second trigger signals defining first and second predetermined values of elapsed time, respectively;

logic circuit means for comparing said difference signals generated with respect to a line identified in a specified one of said registers with said trigger signals and for generating a first output signal when the value represented by said difference signals is greater than the value represented by said first trigger signal and for generating a second output signal when the value represented by said difference signals is less than the value represented by said second trigger signal;

storage means for storing said first output signal generated with respect to a line identified in a first one of said registers;

means responsive to said second output signal generated with respect to a line identified in a second one of said registers and the state of said first output signal stored in said storage means to establish a telephone connection from a line identified in said first one of said registers to the call answering station associated with said second one of said registers.

7. The method of distributing telephone calls among call answering stations in an automatic call distribution system wherein calls directed to a first directory number are normally served by a first group of call answering stations and calls directed to a second directory number are normally served by a second group of call answering stations and wherein a plurality of storage registers and logic circuit means are provided, comprising the steps of:

storing in a first one of said registers the identity of calling lines from which signaling information defining said first directory number is detected and an indication of the time of such detection;

storing in a second one of said registers the identity of calling lines from which signaling information defining said second directory number is detected and an indication of the time of such detection;

generating signals of defining numerical constants representing first and second time triggers;

comparing said indications of time of detection for at least one line identified in said first register and for at least one line identified in said second register with signals representing current time and generating difference signals representing elapsed time since detection; and

comparing said difference signals with said time triggers and establishing a telephone connection from a line identified in said first register to a call answering station normally serving the calls directed to said second directory number when the difference signal representing elapsed time for said one line identified in said first register exceeds said first time trigger and the difference signal representing elapsed time for said one line identified in said second register is less than said second time trigger.

8. The method of distributing telephone calls among call answering stations in accordance with claim 7 wherein said steps of storing include identifying the entry in each register which has been stored longer than any other entry therein;

and

wherein said step of comparing said indications of time of detection of said one line identified in said first register and said one line identified in said second register with said signals representing current time comprises performing said comparison with respect to the one line identified in said entry in each of said registers which has been stored longer than any other entry.

9. The method of effecting equalization of work among attendants of call answering stations in an automatic call distribution system wherein calls directed to a first directory number are normally served by a first group of call answering stations and calls directed to a second directory number are normally served by a second group of call answering stations and wherein a plurality of storage registers and logic circuit means are provided, comprising the steps of:

recording in said storage registers the identity of calling lines from which signaling information defining one of said directory numbers is detected and an indication of time of such detection;

generating signals defining numerical values representing upper and lower time triggers;

comparing said indications of time of detection for at least one line from which signaling information defining said first directory number was detected with signals representing current time and comparing said indications of time of detection for at least one line from which signaling information defining said second directory number was detected with signals representing current time and generating difference signals defining numerical values for the differences between said compared signals; and

establishing a telephone connection from a line from which signaling information defining said first directory number was received to a call answering station normally assigned to serve lines from which signaling information defining said second directory number is received when said signal defining the difference between said current time signals and said indications of time of detection for said one line from which information identifying said first directory number was received exceeds said first time trigger and said signal defining the difference between current time signal and said indications of time of detection for said one line from which information defining said second directory number was received is less than said second time trigger.

10. In a telephone call processing arrangement having a switching network, a plurality of incoming lines and a plurality of groups of call answering stations connectable to said network, and a controller for detecting signaling information from said lines and said stations and for controlling said network to selectively interconnect said lines and said stations and comprising storage register means and logic circuit means including:

a first register associated with a first group of call answering stations for storing the identity of certain of said lines from which call signaling information has been received and signals representing time of receipt;

a second register associated with a second group of call answering stations for storing the identity of others of said lines from which call signaling information has been received and signals representing the time of receipt;

logic circuit means for generating signals defining current time;

logic circuit means for generating trigger signals defining first and second time triggers; and

logic circuit means for subtracting the value of said signals representing time of receipt from the value of said signals defining current time and for comparing the result of said subtraction with said trigger signals to generate a first output signal when said result exceeds said first time trigger and generating a second output signal when said result is less than said second time trigger;

said controller being responsive to said first output signal generated with respect to a line identified in said first register and said second output signal generated with respect to a line identified in said second register to control said network to interconnect a line identified in said first register and a station of said second group of call answering stations.

11. In a program controlled call processing system having a switching network, a plurality of incoming lines and a plurality of groups of call answering stations connectable to said switching network, each of said groups of stations being associated with one of said groups of lines, and control means for detecting signaling information from said lines and said stations and for controlling said switching network to interconnect said lines and said call answering stations and comprising:

clock means for generating time signals defining present time;

register means for recording the identity of incoming lines from which call signaling information has been received and for recording therein signals representing time of receipt of call signaling information from an identified line;

means for generating signals defining numerical values representing upper and lower time triggers;

means for comparing said signals representing time of receipt of information and said signals defining present time to generate difference signals representing elapsed time since receipt of information, and for comparing said difference signals and said trigger signals to generate a first control signal when said difference signals for a line define a value greater than an upper time trigger and to generate a second control signal when said difference signals for a line define a value less than a lower time trigger;

circuit means responsive to said first control signal generated with respect to a line of a first group of lines and said second control signal generated with respect to a line of a second group of lines to control said network to interconnect a line of said first group of lines to a station associated with said second group of lines.