Patent · US Expired

Multiparty telephone ringing

US4048448A · kind A · utility

9Cited by
8References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 19, 1976
Grant dateSep 13, 1977
Priority date—
Expiry dateFeb 19, 1996

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04Q5/02
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A subscriber loop carrier system using digital multiplex techniques is disclosed in which remote subscriber loops include multiparty lines. Four party fully selective ringing signals are detected at the central office terminal of the system and converted to cyclic codes which are detected at the remote terminal with simple asynchronous circuits. The code generation and detection circuits are implemented with multiple output inverter circuits which provide simple logic structures for integrated circuit realization. Standard polarized ringing signals are applied to either conductor at the remote terminal of the system to ring the proper party.

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