Patent · US Expired

Method for avoiding call blocking

US5070525A · kind A · utility

50Cited by
2References
62Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 12, 1990
Grant dateDec 3, 1991
Priority date
Expiry dateFeb 12, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M3/5158
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

Methods for avoiding a call blocking feature. In a first method a list is kept for the trunks previously used to call a particular telephone number. Each time that particular telephone number is called a different trunk, not on that list, is used to place the call. The list is cleared and restarted whenever all the trunks have been used. In a second method a list is kept for trunks for which a call blocking message has been received when an attempt was made to call that telephone number. Each time that particular telephone number is called a trunk which is not on that list is used to place the call. Only non-blocked trunks are used to call a telephone number.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.