Key telephone system with virtual private lines

• US 5,214,691 A
• Filed: 09/26/1991
• Issued: 05/25/1993
• Est. Priority Date: 09/26/1991
• Status: Expired

• Current Assignee: IPC Information Systems, LLC
• Original Assignee: IPC Information Systems, Inc. (Silver Lake Management Co. LLC)
• Inventors: Olsen, Neil C., Cotton, John M.
• Primary Examiner(s): Schreyer, Stafford
• Application Number:
  US07/766,648
• Time in Patent Office: 607 Days
• Field of Search: 379/157, 379/156, 379/158, 379/165, 379/167, 379/171, 379/258, 379/268
• US Class Current: 379/157
• CPC Class Codes: H04M 1/57 Arrangements for indicating or recording the number of the calling subscriber at the called subscriber's set at the operator set in a manual exchange H04M5/20
• CPC Class Codes: H04M 7/009 in systems involving PBX or KTS networks
• CPC Class Codes: H04M 9/005 with subscriber controlled access to an exchange line
• CPC Class Codes: H04Q 11/0428 Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
• CPC Class Codes: H04Q 11/0471 Terminal access circuits

Abstract

A virtual private line key telephone system is provided. The system includes a console including a plurality of line keys each associated with a party that can be reached via a switched trunk line. A look-up table means associates the line keys with the telephone numbers of the associated parties. A communication path is established from the console to one of the trunk lines. Signals are sent to the central office via the selected trunk line corresponding to the telephone number in the look-up table means associated with a line key that is actuated to place a calls. The telephone number of incoming calls are determined and compared with telephone numbers in the look-up table. Thereafter the line keys which are associated with the incoming calls are determined. The incoming call is coupled to the console when a line key associated with the incoming caller is actuated.

Claims

1. A virtual private line key telephone system comprising:

a console including a plurality of line keys each associated with a party that can be reached via a switched trunk line;

a look-up table means associating said line keys with the telephone numbers of the associated parties;

means for establishing a communication path from said console to one of said trunk lines and sending signals to the central office via said selected trunk line corresponding to the telephone number in said look-up table means associated with a line key that is actuated to place a call;

means for determining the telephone number of incoming calls and comparing said incoming call telephone number with telephone numbers in said look-up table means to determine which line keys are associated with the incoming call; and

means coupling the incoming call to the console when a line key associated with the incoming caller is actuated.

2. The telephone system according to claim 1 wherein each of said line keys includes a status indication which emulates private line status indications.

3. The telephone system according to claim 1 wherein each of said line keys includes a status indication where the status of a call to a party is indicated at a fixed location associated with a particular line key regardless of which trunk line is used for he call.

4. The telephone system according to claim 1 wherein, said line keys are located at a plurality of consoles,

said trunk lines are each associated with a line card capable of detecting line status, and said look-up table means includes

a look-up tale at said console for associating line keys to virtual logic address codes, and

a look-up table at said line card for associating virtual logic address codes with said numbers of associated parties.

5. The telephone system according to claim 4 wherein the status of the calls to associated parties is displayed at said console for said line keys as though the lien key were associated with a private line.

6. A virtual private line key telephone system comprising:

at least one console including a plurality of assignable line keys;

a line key assignment look-up table for said console for associating specific line keys to parties that can be reached via a switched trunk line and a virtual logic address code;

at least one lie card for a switched trunk line which can connect to multiple parties via a central office switch and which provides calling party identification (cpi) on incoming call;

a cpi look-up table for associating calling party identification telephone numbers with virtual logic address codes;

means for placing an outgoing call on said switched lien by actuating a line key, looking up the virtual logic address code associated with the line key and party, and looking up the calling party identification telephone number corresponding to the virtual logic address code and automatically placing a call to said telephone number; and

mean for receiving incoming calls on said switched line by detecting the calling party identification (cpi), looking up the associated virtual logic address code, displaying status of the calling party as ringing, and connecting the trunk line to a console on which a line key corresponding to the calling party is actuated.

7. A method of making and receiving telephone calls on a multi-party key telephone system using switched lines including line keys at operator consoles and line cards at outside line terminations including the steps of:

maintaining in memory the association between line keys and telephone numbers of parties that can be called or from whom calls can be received;

receiving telephone calls by

determining the caller telephone number,

determining which line keys are associated with said caller telephone number and indicating the line status as "ringing",

connecting the line card for the incoming call to the console at which a line key associated with the calling party is actuated, and

making telephone calls by

determining the telephone number of the party to be called associated with an actuated line key

automatically dialing said telephone number associated with an actuated line key, and

connecting the line card used for said call to the console at which the line key was actuated.

8. A method of making and receiving telephone calls on a multi-party key telephone system using switched lines wherein said system includes line keys at consoles and trunk lines connected to line cards,

maintaining a look-up table associating line keys with address codes associated with parties that may be called,

maintaining a look-up table associating address codes and telephone numbers for parties that may be called,

placing outgoing calls by

actuating a key corresponding to the party to be called

looking up the address code and corresponding telephone number of the party corresponding to the actuated key and automatically placing a call to said corresponding telephone number;

and

receiving telephone calls

determining the caller telephone number,

looking up the address code associated with said caller telephone number,

indicating "ringing" by the caller,

connecting the incoming line to the console where a line key is actuated corresponding to said address code of said caller.