Method of making call-wait and call-alternation in electronic private branch exchange (EPBX)
Patent 4975944 Issued on December 4, 1990. Estimated Expiration Date: 
August 31, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
August 31, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesEnhanced calling number delivery service system Patent #: 4873719 InventorAssigneeApplicationNo. 400948 filed on 08/31/1989US Classes:379/209.01, Repetitive call attempts (e.g., camp-on-busy, retry)379/215.01Call WaitingExaminersPrimary: Dwyer, James L.Attorney, Agent or FirmInternational ClassesH04M 003/48H04M 003/54 Foreign Application Priority Data1988-08-31 KRAbstractThere is disclosed a method of making a call in an electronic private branch exchange system (EPBX), calling a subscriber pre-engaged in a call and thereby performing call-wait and call-alternation. The improvement performs a call-wait state so that a calling subscriber of an EPBX can be automatically linked up with a target subscriber of the EPBX, later on, if the target subscriber is already engaed in other call when the calling subscriber makes a call to the target subscriber. The invention also provides a subscriber of an EPBX with a method capable of switching a call central office from a line to another subscriber of the EPBX engaged in the other call. | |
